Licentiate of Engineering Theses
No 17
INTERLEAVED PROCESSING OF NON-NUMERICAL
DATA STORED ON A CYCLIC MEMORY
Vojin
Plavsic
Abstract: The memory access delay, caused by
the ’emulation’ of the random access capabilities on a
sequential access memory type, is stated as a problem in
Non-Numerical Data Processing and the motivation for a problem
solution is provided. An adequate storage data representation and
the proper organization of processing algorithms are introduced, in
order to take advantage of the natural sequential access of a Cyclic
Memory. In support of this approach, two published works were
produced.
The first paper entitled "The Utilization of
Controllable Cyclic Memory Properties in Non-Numerical Data
Processing" defines the conditions for the sequential
evaluation of a given query. The second work "Sequential
Evaluation of Boolean Functions" was derived originally as a
supporting theory for the concepts presented in the first paper;
namely in order to enable the sequental (per Boolean function
argument) evaluation of a verification expression of a query, given
as a Boolean expression of predicates of attributes of given data
type. The last method however, has much broader application area
e.,g., time efficient real time decision making.
No 28
AN INTERACTIVE FLOWCHARTING TECHNIGUE
FOR COMMUNICATING AND REALIZING ALGORITHMS
Arne
Jönsson, Mikael Patel
Abstract: This thesis
describes the design, specification, implementation and experience
of the use of an interactive flowcharting technique for
communicating and realizing algorithms. Our goals are: 1) to help
novices to understand computers, by giving them a framework for
organizing algorithms, and 2) to support development of software
produced by groups of people over an extended period of time. Based
on the notions of Dimensional Flowcharts, a system called the
DIMsystem has been developed for handling structured flowcharts. The
DIMsystem consist of different modules for creating, manipulating
and communicating dimensional flowcharts. The current research
implementation is in Pascal and runs on a VAX/VMS computer
system.
No 29
RETARGETING OF AN INCREMENTAL CODE
GENERATOR
Johnny Eckerland
Abstract:
Incremental programming environments are becoming increasingly
popular. Earlier systems are mostly based on interpretation. DICE
is an incremental programming environment based on incremental
compilation only. In this thesis the retargeting of the code
generator from PDP-11 to DEC-20 is described.
DICE supports
separate host and target environments. The code and data
administration in the target is discussed and analyzed. A new
runtime environment in the target is created by providing an
interface to an existing one.
In DICE, the traditional compile,
link and load passes are integrated and interleaved. A
classification of linking programs is made from this point of
view.
No 48
ON THE USE OF TYPICAL CASES FOR
KNOWLEDGE-BASED CONSULTATION AND TEACHING.
Henrik
Nordin
Abstract: Knowledge-based approaches to software
development promise to result in important break-through both
regarding our ability to solve complex problems and in improved
software productivity in general. A key technique here is to
separate domain knowledge from control information needed for the
procedural execution of a program. However, general-purpose
inference mechanisms entail certain disadvantages with respect to
e.g. efficiency, focusing in problem-solving, and transparency in
knowledge representation. In this licentiate thesis we propose an
approach, where domain-dependent control is introduced in the form
of prototypes, based on typical cases from the application
domain. It is shown how this scheme results in a more effective
problem-solving behaviour as compared with a traditional approach,
relying entirely on rules for domain as well as control information.
Further we demonstrate how the knowledge base can be easily reused
for independent purposes, such as consultative problem solving and
teaching respectively. Our claims are supported by implementations,
both in a conventional knowledge system environment with the help of
the EMYCIN system, and in a system supporting reasoned control of
reasoning, namely the economic advice giving in a bank environment,
in particular advice on procedures for transfers of real
estates.
No 52
STEPS TOWARDS THE FORMALIZATION OF
DESIGNING VLSI SYSTEMS
Zebo Peng
Abstract:
This thesis describes an attempt to formalize the design process of
VLSI systems as a sequence of semantics-preserving mappings which
transforms a program-like behavioral description into a structural
description. The produced structural description may then be
partitioned into several potential asynchronous modules with
well-defined interfaces. The proposed strategy is based on a formal
computational model derived from timed Petri net and consisting of
separate, but related, models of control and data
parts. Partitioning of systems into submodules is provided both on
the data part and on the control part, which produces a set of pairs
of corresponding data subparts and control subparts and allows
potential asynchronous operation of the designed systems as well as
physical distribution of the modules. The use of such a formal
specification also leads to the effective use of CAD and automatic
tools in the synthesis process as well as providing for the
possibility of verifying some aspects of a design before it is
completed. CAMAD, an integrated design aid system, has been
partially developed based on these formalizations. The present
thesis attempts also to formulate the control/data path allocation
and module partitioning problem as an optimization problem. This
differs from previous approaches where ad hoc algorithms and
predefined implementation structures are explicitly or implicitly
used, and where a centralized control strategy is assumed.
No 60
SIMULATION AND EVALUATION OF AN
ARCHITECTURE BASED ON ASYNCHRONOUS PROCESSES
Johan
Fagerström
Abstract: Much research today is
devoted to finding new and improved computer architectures in which
parallel computations can be performed, the goal being an
exploitation of the natural parallelism inherent in many problem
descriptions. This thesis describes a register level simulator for
a family of architectures based on asynchronous processes. An
important aspect of this class of architectures is its
modularity. Within the architecture, we hope to avoid the problem of
dynamically binding every operation as in dataflow machines. A
silicon compiler can use the modularity of descriptions to perform
various optimizations on instances of the architecture. The
simulator is written in a language called Occam, in which parallel
execution at the statement level can be expressed. A short
description of the language is given and some of the issues of
designing, testing and maintaining concurrent programs are
discussed. The added complexity of parallelism especially makes the
debugging phase very difficult.
No 71
ICONSTRAINT, A DEPENDENCY DIRECTED
CONSTRAINT MAINTENANCE SYSTEM
Jalal Maleki
Abstract: Problem solving involves search. In AI we try to find ways
of avoiding or minimizing search. An effective approach is to
exploit knowledge of the problem domain. Such knowledge often takes
the form of a set of constraints. In general, a constraint
represents a required relationship among some variables. For this
reason we usually assume the existence of some machinery that can
enforce a given set of constraints and resolve the conflicts that
arise when these are violated.
Programming systems based on
constraints have been successfully applied to circuit analysis,
design and simulation, scene analysis, plan generation, hardware
diagnosis and qualitative reasoning.
This thesis presents
ICONStraint, a programming language based on the constraints
paradigm of computation and gives a characterization of consistency
conditions and the operations for ensuring consistency in constraint
networks designed in the language.
In ICONStraint we represent
constraint systems in dependency structures and use reason
maintenance, local propagation and dependency directed backtracking
for computation and consistency maintenance.
ICONStraint has
been implemented in Interlisp-D.
No 72
ON THE SPECIFICATION AND VERIFICATION OF
VLSI SYSTEMS
Tony Larsson
Abstract: System
designers now have the opportunity to place on the order of 105-106
transistors on a single chip allowing larger and more complicated
systems to be produced at reduced production costs. This opportunity
increases the demand for appropriate design automation including
tools for synthesis, analysis, and verification. However, human
designers still are and will be our main source of innovation. In
order to express and communicate new design ideas to a computer
aided engineering environment some form of specification language is
needed. Different tools and engineering situations put different
requirements on a specification language. Is is important that all
users of a language have a firm knowledge about how to interpret the
language. This thesis proposes a specification language (ASL), a
semantic model, and transformation rules related to the
language. The thesis focuses upon the specification of a systems
actional behaviour and the semantics provides a framework for the
verification of a systems structural implementation versus its
actional specification. A set of calculus, port and event reduction
rules, and rules for port binding and partial evaluation are
proposed as tools for verification.
No 73
A STRUCTURE EDITOR FOR DOCUMENTS AND
PROGRAMS
Ola Strömfors
Abstract: This
thesis presents a generalized approach to data editing in
interactive systems. The design and implementation of the ED3
editor, which is a powerful tool for text editing combining the
ability to handle hierarchical structures with screen-oriented text
editing facilities, is described as well as a number of ED3
applications.
A technique for efficient program editing for
large programs is also described. An editor for Pascal and Ada
programs has been created by integrating parsers and pretty-printers
and a Pascal to Ada syntax transaltor into ED3.
No 74
NEW RESULTS ABOUT THE APPROXIMATION
BEHAVIOR OF THE GREEDY TRIANGULATION
Christos
Levcopoulos
Abstract: In this paper it is shown that
there is some constant c, such that for any polygon, with or without
holes, with w concave vertices, the length of any greedy
triangulation of the polygon is not longer than c x (w + 1) times
the length of a minimum weight triangulation of the polygon (under
the assumption that no three vertices lie on the same line). A low
approximation constant is proved for interesting classes of
polygons. On the other hand, it is shown that for every integer n
greater than 3, there exists some set S of n points in the plane,
such that the greedy triangulation of S is
W(n1/2) times longer
than the minimum weight triangulation (this improves the previously
known W(n1/3) lower bound). Finally, a simple linear-time algorithm
is presented and analyzed for computing greedy triangulations of
polygons with the so called semi-circle property.
No 104
STATISTICAL EXPERT SYSTEMS - A SPECIAL
APPLICATION AREA FOR KNOWLEDGE-BASED COMPUTER METHODOLOGY
Shamsul I. Chowdhury
Abstract: The study
investigates the purposes, functions and requirements of statistical
expert systems and focuses attention on some unique characteristics
of this subcategory of knowledge-based systems. Statistical expert
systems have been considered in this thesis as one approach to
improve statistical software and extend their safe usability to a
broad category of users in different phases of a statistical
investigation. Some prototype applications in which the author has
been involved are presented and discussed. A special chapter is
devoted to the question whether this methodology might be a rare
example of an advanced technology that is suitable for application
in non-advanced environments, such as in developing countries.
No 108
INCREMENTAL SCANNING AND TOKEN-BASED
EDITING
Rober Bilos
Abstract: A primary
goal with this thesis work has been to investigate the consequences
of a token-based program representation. Among the results which are
presented here are an incremental scanning algorithm together with a
token-based syntax sensitive editing approach for program
editing.
The design and implementation of an incremental scanner
and a practically useful syntax-sensitive editor is described in
some detail. The language independent incremental scanner converts
textual edit operations to corresponding operations on the token
sequence. For example, user input is converted to tokens as it is
typed in. This editor design makes it possible to edit programs with
almost the same flexibility as with a conventional text editor and
also provides some features offered by a syntax-directed editor,
such as template instantiation, automatic indentation and
prettyprinting, lexical and syntactic error handling.
We have
found that a program represented as a token sequence can on the
average be represented in less than half the storage space required
for a program in text form. Also, interactive syntax checking is
speeded up since rescanning is not needed.
The current
implementation, called TOSSED - Token-based Syntax Sensitive Editor,
supports editing and development of programs written in Pascal. The
user is guaranteed a lexically and syntactically correct program on
exit from the editor, which avoids many unnecessary
compilations. The scanner, parser, prettyprinter, and syntactic
error recovery are table-driven and language independent template
specification is supported. Thus, editors supporting other languages
can be generated.
No 111
SPORT-SORT - SORTING ALGORITHMS AND
SPORT TOURNAMENTS
Hans Block
Abstract:
Arrange a really short, thrilling and fair tournament! Execute
parallel sorting in a machine of a new architecture! The author
shows how these problems are connected. He designs several new
tournament schemes, and analyses them both in theory and in
extensive simulations. He uses only elementary mathematical and
statistical methods. The results are much better than previous ones,
and close to the theoretical limit. Now personal computers can be
used to arrange tournaments which give the complete ranking list of
several thousands of participants within only 20 - 30 rounds.
No 113
NETWORK AND LATTICE BASED APPROACHES
TO THE REPRESENTATION OF KNOWLEDGE
Ralph
Rönnquist
Abstract: This report is a study of the
formal means for specifying properties of network structures as
provided by the theory of information management systems. Along
with axioms for some simple network structures we show examples of
the manner of which intuitive observations on the structures are
formulated and proved.
No 118
AFFECT-CHAINING IN PROGRAM FLOW
ANALYSIS APPLIED TO QUERIES OF PROGRAMS
Mariam Kamkar,
Nahid Shahmehri
Abstract: This thesis presents how
program flow analysis methods can be used to help the programmer
understand data flow and data dependencies in programs. The design
and implementation of an interactive query tool based on static
analysis methods is presented. These methods include basic analysis
and cross-reference analysis, intraprocedural data flow analysis,
interprocedural data flow analysis and affect-chaining analysis.
The novel concept of affect-chaining is introduced, which is the
process of analysing flow of data between variables in a program. We
present forward- and backward- affect-chaining, and also algorithms
to compute these quantities. Also, a theorem about affect-chaining
is proved.
We have found that data flow problems appropriate for
query applications often need to keep track of paths associated with
data flows. By contrast, flow analysis in conventional compiler
optimization
No 126
TRANSFER AND DISTRIBUTION OF
APPLICATION PROGRAMS
Dan Strömberg
Abstract: This work addresses two problems in development of
application software. One problem concerns the transfer of software
from environments optimized for development, to target environments
oriented towards efficient execution. The second problem is how to
express distribution of application software. This thesis contains
three papers. The first is about a programming language extension
for distribution of a program to a set of workstations. The second
reports on an experiment in downloading aiming at transfer of
programs from development to runtime environments, and the third
describes an application area where the need of these development
and distribution facilities are evident.
No 127
CASE STUDIES IN KNOWLEDGE ACQUISITION,
MIGRATION AND USER ACCEPTANCE OF EXPERT SYSTEMS
Kristian
Sandahl
Abstract: In recent years, expert systems
technology has become commercially mature, but widespread delivery
of systems in regular use is still slow. This thesis discusses three
main difficulties in the development and delivery of expert systems,
namely,
the knowledge acquisition bottleneck, i.e. the problem
of formalizing the expert knowledge into a computer-based
representation.
the migration problem, where we argue that the
different requirements on a development environment and a delivery
environment call for systematic methods to transfer knowledge bases
between the environments.
the user acceptance barrier, where we
believe that user interface issues and concerns for a smooth
integration into the end-user’s working environment play a
crucial role for the successful use of expert systems.
In this
thesis, each of these areas is surveyed and discussed in the light
of experience gained from a number of expert system projects
performed by us since 1983. Two of these projects, a spot-welding
robot configuration system and an antibody analysis advisor, are
presented in greater detail in the thesis.
No 139
REASONING ABOUT INTERDEPENDENT
ACTIONS
Christer Bäckström
Abstract: This thesis consists of two papers on different but
related topics.
The first paper is concerned with the use of
logic as a tool to model mechanical assembly processes. A restricted
2+-dimensional world is introduced and although this world is
considerably simpler than a 3-dimensional one, it is powerful enough
to capture most of the interesting geometrical problems arising in
assembly processes. The geometry of this 2+-dimensional world is
axiomatized in first order logic. A basic set of assembly operations
are identified and these operations are expressed in a variant of
dynamic logic which is modified to attack the frame problem.
The
second paper presents a formalism for reasoning about systems of
sequential and parallel actions that may interfere or interact with
each other. All synchronization of actions is implicit in the
definitions of the actions and no explicit dependency information
exists. The concept of action hierarchies is defined, and the
couplings between the different abstraction levels are implicit in
the action definitions. The hierarchies can be used both top-down
and bottom-up and thus support both planning and plan recognition in
a more general way than is usual.
No 140
ON CONTROL STRATEGIES AND
INCREMENTALITY IN UNIFICATION-BASED CHART PARSING
Mats
Wirén
Abstract: This thesis is a compilation of
three papers dealing with aspects of context-free- and
unification-based chart parsing of natural language. The first paper
contains a survey and an empirical comparison of rule-invocation
strategies in context-free chart parsing. The second paper describes
a chart parser for a unification-based formalism (PATR) which is
control-strategy-independent in the sense that rule invocation,
search, and parsing direction are parametrized. The third paper
describes a technique for incremental chart parsing (under PATR) and
outlines how this fits into continued work aimed at developing a
parsing system which is both interactive and incremental.
No 146
A SOFTWARE SYSTEM FOR DEFINING AND
CONTROLLING ACTIONS IN A MECHANICAL SYSTEM
Johan
Hultman
Abstract: This thesis deals with the subject of
technical systems where machinery, usually of mechanical character,
are controlled by a computer system. Sensors in the system provide
information about a machine’s current state, and are crucial
for the controlling computer. The thesis presents an architecture
for such a software system and then describes the actual
implementation along with some examples.
No 150
DIAGNOSING FAULTS USING KNOWLEDGE
ABOUT MALFUNCTIONING BEHAVIOR
Tim Hansen
Abstract: Second generation expert systems presume support for deep
reasoning, i.e. the modelling of causal relationships rather than
heuristics only. Such an approach benefits from more extensive
inference power, improved reusability of knowledge and a better
potential for explanations. This thesis presents a method for
diagnosis of faults in technical devices, which is based on the
representation of knowledge about the structure of the device an the
behavior of its components. Characteristic for our method is that
components are modelled in terms of states related to incoming and
outgoing signals, where both normal and abnormal states are
described. A bidirectional simulation method is used to derive
possible faults, single as well as multiple, which are compatible
with observed symptoms.
The work started from experiences with a
shallow expert system for diagnosis of separator systems, with a
main objective to find a representation of knowledge which promoted
reusability of component descriptions. The thesis describes our
modelling framework and the method for fault diagnosis.
Our
results so far indicate that reusability and maintainability is
improved, for instance since all knowledge is allocated to
components rather than to the structure of the device. Further more,
our approach seems to allow more reliable fault diagnosis than other
deep models, due to the explicit modelling of abnormal
states. Another advantage is that constraints do not have to be
stated separately, but are implicitly represented in simulation
rules.
No 165
SUPPORTING DESIGN AND MANAGEMENT OF
EXPERT SYSTEM USER INTERFACES
Jonas
Löwgren
Abstract: This thesis is concerned with
user interface aspects of expert systems, and in particular tools
for the design and management of such user interfaces. In User
Interface Management Systems (UIMSs) in general, the user interface
is seen as a separate structure. We investigate the possibilities of
treating an expert system user interface as separate from the
reasoning process of the system, and the consequences thereof.
We propose that an expert system user interface can be seen as a
combination of two different structures; the surface dialogue,
comprising mainly lexical and syntactical aspects, and the session
discourse which represents the interaction between user and system
on a discourse level. For the management of these two structures, a
tool consisting of two modules is outlined. The two modules are the
surface dialogue manager and the session discourse manager. Proposed
architectures for these two modules are presented and discussed. The
thesis also outlines further steps towards a validation of the
proposed approach.
No 166
ON ADAPTIVE SORTING IN SEQUENTIAL AND
PARALLEL MODELS
Ola Petersson
Abstract:
Sorting is probably the most well-studied problem in computer
science. In many applications the elements to be sorted are not
randomly distributed, but are already nearly ordered. Most existing
algorithms do not take advantage of this fact. In this thesis, the
problem of utilizing existing order among the input sequence,
yielding adaptive sorting algorithms, is explored. Different
measures for measuring existing order are proposed; all motivated by
geometric interpretations of the input. Furthermore, several
adaptive, sequential and parallel, sorting algorithms are
provided.
The thesis consists of three papers. The first paper
studies the local insertion sort algorithm of Mannila, and proposes
some significant improvements. The second provides an adaptive
variant of heapsort, which is space efficient and uses simple data
structures. In the third paper, a cost-optimal adaptive parallel
sorting algorithm is presented. The model of computation is the EREW
PRAM.
No 174
DYNAMIC CONFIGURATION IN A DISTRIBUTED
ENVIRONMENT
Yngve Larsson
Abstract: This
thesis describes an implementation of the PEPSy paradigm and
distinguishes between the different types of changes occurring in a
distributed system, and how the many complicating issues of
distribution affect our ability to perform these changes.
We
also compare our implementation with known systems from both the
distributed programming and software engineering communities.
The thesis includes a description of two tools for configuring and
reconfiguring distributed systems, a list of facilities and
constructs deemed necessary and desirable for reconfiguring
distributed systems, an enumeration of the different aspects of
change in distributed systems, and a short evaluation of the
programming language Conic used in the implementation.
No 177
DESIGN OF A MULTIPLE VIEW PRESENTATION
AND INTERACTION MANAGER
Peter Åberg
Abstract: This thesis describes the design model of a presentation
and interaction manager for an advanced information system, based on
concepts developed in the domain of User Interface Management
Systems - primarily, the separation of presentation and interaction
components from application semantics and data. We show our design
to be in many ways an extension of that common in UIMSs;
significantly, we apply presentation separation to data, as well as
programs; we allow presentation and interaction methods to be
selected dynamically at run-time, which gives rise to the concept of
multiple views on the same information, or application semantics;
and, we may adapt to the capabilities of different computer systems.
We present the components of the presentation manager, including the
methods used for specifying the user interface in terms of both
presentation and interaction; and the support provided for
application programs. We also present the LINCKS advanced
information system of which our presentation manager is a component,
and demonstrate how it affects our design.
No 181
A STUDY IN DOMAIN-ORIENTED TOOL
SUPPORT FOR KNOWLEDGE ACQUISITION
Henrik
Eriksson
Abstract: Knowledge acquisition is the process
of bridging the gap between human expertise and representations of
domain knowledge suited for storage as well as reasoning in a
computer. This gap is typically large, which makes the knowledge
acquisition process extensive and difficult.
In this thesis, an
iterative two-stage methodology for knowledge acquisition is
advocated. In the first stage, a domain-oriented framework with a
conceptual model of the domain is developed. In the second stage,
that framework together with supporting tools are actively used by
the domain expert for building the final knowledge base. The process
might be iterated when needed.
This approach has been tested for
explorative planning of protein purification. Initially, an expert
system was hand-crafted using conventional knowledge acquisition
methods. In a subsequent project, a compatible system was developed
directly by the domain expert using a customized tool. Experience
from these projects are reported in this thesis together with a
discussion of our methodological approach.
No 184
THE DEEP GENERATION OF TEXT IN EXPERT
CRITIQUING SYSTEMS
Ivan Rankin
Abstract: An
expert critiquing system differs from most first-generation systems
in that it allows the user to suggest his own solution to a problem
and then receive expert feedback (the critique) on his proposals. A
critique may be presented in different ways - textually,
graphically, in tabular form, or a combination of these. In this
report we discuss textual presentation. A generalized approach to
text generation is presented, in particular in producing the deep
structure of a critiquing text.
The generation of natural
language falls into two generally accepted phases: deep generation
and surface generation. Deep generation involves selecting the
content of the text and the level of detail to be included in the
text, ie. deciding what to say and how much information to
include. Surface generation involves choosing the words and phrases
to express the content determined by the deep generator. In this
report we discuss the deep generation of a critique.
We present
expert critiquing systems and the results of an implementation. Then
we review recent advances in text generation which suggest more
generalized approaches to the production of texts and we examine how
they can be applied to the construction of a critique.
Central
considerations in the deep generation of a text involve establishing
the goals the text is to achieve (eg. provide the user with the
necessary information on which to base a decision), determining a
level of detail of such information to be included in the text and
organizing the various parts of the text to form a cohesive unit. We
discuss the use of Speech Act Theory as means of expressing the
goals of the text, the user model to influence the level of detail
and the use of Rhetorical Structure Theory for the organization of
the text. Initial results from the text organization module are
presented.
No 187
CONTRIBUTIONS TO THE DECLARATIVE
APPROACH TO DEBUGGING PROLOG PROGRAMS
Simin
Nadjm-Tehrani
Abstract: Logic programs have the
characteristic that their intended semantics can be expressed
declaratively or operationally. Since the two semantics coincide,
programmers may find it easier to adopt the declarative view when
writing the program. But this causes a problem when the program is
to be debugged. The actual semantics of a logic program is dependent
on the specific implementation on which the program is run. Although
the actual semantics is of operational nature it is usually
different from the theoretical operational semantics. Hence
debugging may require a comparison of the actual (operational)
semantics of a program and its intended declarative semantics.
The idea of declarative debugging, first proposed by Shapiro under
the term algorithmic debugging, is a methodology which leads to
detecting errors in a logic program through knowledge about its
intended declarative semantics. Current Prolog systems do not employ
declarative diagnosis as an alternative to the basic tracer. This is
partly due to the fact that the Shapiro’s declarative
debugging system only dealt with pure Prolog programs, and partly
due to practical limitations of the suggested methods and
algorithms. This thesis consists of three papers. In these papers we
point out practical problems with the use of basic declarative
debugging systems, and present methods and algorithms which make the
framework applicable to a wider range of Prolog programs. We
introduce the concept of assertion that can ease communication
between the user and the debugging system by reducing the number of
necessary interactions, and introduce new debugging algorithms which
are adapted to this extended notion. Further, we extend the basic
debugging scheme to cover some built-in features of Prolog, and
report on practical experience with a prototype declarative
debugging system which incorporates the extensions.
No 189
TEMPORAL INFORMATION IN NATURAL
LANGUAGE
Magnus Merkel
Abstract: The
subject of this thesis is temporal information; how it is expressed
and conveyed in natural language. When faced with the task of
processing temporal information in natural language computationally,
a number of challenges has to be met. The linguistic units that
carry temporal information must be recognized and their semantic
functions decided upon. Certain temporal information is not
explicitly stated by grammatical means and must be deduced from
contextual knowledge and from discourse principles depending on the
type of discourse.
In this thesis, a grammatical and semantic
description of Swedish temporal expressions is given. The context
dependency of temporal expressions is examined and the necessity of
a conceptual distinction between phases and periods is argued for.
Furthermore, it is argued that the Reichenbachian notion of
reference time is unnecessary in the processing of temporal
processing of texts. Instead the general contextual parameters
speech time/utterance situation (ST/US) and discourse time/temporal
focus (DT/TF) are defended. An algorithm for deciding the temporal
structure of discourse is presented where events are treated as
primary individuals.
No 196
A SYSTEMATIC APPROACH TO ABSTRACT
INTERPRETATION OF LOGIC PROGRAMS
Ulf
Nilsson
Abstract: The notion of abstract interpretation
facilitates a formalized process of approximating meanings of
programs. Such approximations provide a basis for inferring
properties of programs. After having been used mainly in the area of
compiler optimization of traditional, imperative languages it has
recently also attracted people working with declarative
languages.
This thesis provides a systematic framework for
developing abstract interpretations of logic programs. The work
consists of three major parts which together provide a basis for
practical implementations of abstract interpretation techniques.
Our starting point is a new semantic description of logic programs
which extracts the set of all reachable internal states in a
possibly infinite collection of SLD-derivations. This semantics is
called the base interpretation. Computationally the base
interpretation is of little interest since it is not, in general,
effectively computable. The aim of the base interpretation is rather
to facilitate construction of abstract interpretations which
approximate it. The second part of this work provides systematic
methods for constructing such abstract interpretations from the base
interpretation. The last part of the thesis concerns efficient
computing of approximate meanings of programs. We provide some
simple but yet efficient algorithms for computing meanings of
programs.
The thesis also provides a survey of earlier work done
in the area of abstract interpretation of logic programs and
contains a comparison between that work and the proposed
solution.
No 197
HORN CLAUSE LOGIC WITH EXTERNAL
PROCEDURES: TOWARDS A THEORETICAL FRAMEWORK
Staffan
Bonnier
Abstract: Horn clause logic has certain
properties which limit its usefulness as a programming language. In
this thesis we concentrate on three such limitations: (1) Horn
clause logic is not intended for the implementation of algorithms.
Thus, if a problem has an efficient algorithmic solution it may be
difficult to express this within the Horn clause formalism. (2) To
work with a predefined structure like integer arithmetic, one has to
axiomatize it by a Horn clause program. Thus functions of the
structure are to be represented as predicates of the program. (3)
Instead of re-implement existing software modules, it is clearly
better to re-use them. To this end, a support for combining Horn
clause logic with other programming languages is needed.
When
extending the Horn clause formalism, there is always a trade-off
between general applicability and purity of the resulting
system. There have been many suggestions for solving some of
problems (1) to (3). Most of them use one of the following
strategies: (a) To allow new operational features, such as access to
low-level constructs of other languages. (b) To introduce new
language constructs, and to support them by a clean declarative
semantics and a complete operational semantics.
In this thesis a
solution to problems (1) to (3) is suggested. It combines the
strategies of (a) and (b) by limiting their generality: We allow
Horn clause programs to call procedures written in arbitrary
languages. It is assumed however that these procedures are either
functional or relational. The functional procedures yield a ground
term as output whenever given ground terms as input. Similarly, the
relational procedures either succeed or fail whenever applied to
ground terms. Under these assumptions the resulting language has a
clean declarative semantics.
For the operational semantics, an
extended but incomplete unification algorithm, called S-unify is
developed. By using properties of this algorithm we characterize
classes of goals for which our interpreter is complete. It is also
formally proved that (a slightly extended version of) S-unify is as
complete as possible under the adopted assumptions.
No 203
A PROTOTYPE SYSTEM FOR LOGICAL
REASONING ABOUT TIME AND ACTION
Christer
Hansson
Abstract: This thesis presents the experience
and results from the implementation of a prototype system for
reasoning about time and action. Sandewall has defined syntax,
semantics and preference relations on the interpretations of a
temporal logic. The preference relations are so defined that the
preferred interpretations will contain a minimal number of changes
not explained by actions occurring in the world and also a minimal
number of actions which do occur. An algorithm for a model-based
decision procedure is also defined by Sandewall. The algorithm is
given a partial description of a scenario and returns all the
preferred models of the given description. The preferred models are
calculated in two levels: the first searches the set of all sets of
actions; the second calculates all the preferred models of the given
description with respect to a given set of actions. In this work a
proposed implementation of the second level is described and
discussed. During the implementation of the system we discovered a
flaw in the temporal logic, which lead to a modification of the
logic. The implemented system is based on this modified logic.
A
discussion about the termination of the first level suggests that
the level only terminates under very strong conditions. However, if
the condition of returning all preferred models is relaxed, then the
first level will terminate for an arbitrary set of formulas under
the condition that there exists a preferred model with a finite set
of actions. The complexity of the proposed implementation of the
second level is of the order faculty over the number of actions in
the given plan.
Finally, the AI-planner TWEAK is reviewed and we
discuss the similarities in the problem-solving behavior of TWEAK
and the decision procedure.
No 212
AN APPROACH TO EXTRACTION OF PIPELINE
STRUCTURES FOR VLSI HIGH-LEVELSYNTHESIS
Björn
Fjellborg
Abstract: One of the concerns in high-level
synthesis is how to efficiently exploit the potential concurrency in
a design. Pipelining achieves a high degree of concurrency, and a
certain structural regularity through exploitation of locality in
communication. However, pipelining cannot be applied to all designs.
Pipeline extraction localizes parts of the design that can benefit
form pipelining. Such extraction is a first step in pipeline
synthesis. While current pipeline synthesis systems are restricted
to exploitation of loops, this thesis addresses the problem of
extracting pipeline structures from arbitrary designs without
apparent pipelining properties. Therefore, an approach that is based
on pipelining of individual computations is explored. Still, loops
constitute an important special case, and can be encompassed within
the approach in an efficient way. The general formulation of the
approach cannot be applied directly for extraction purposes, because
of a combinatorial explosion of the design space. An iterative
search strategy to handle this problem i presented. A specific
polynomial-time algorithm based on this strategy, using several
additional heuristics to reduce complexity, has been implemented in
the PiX system, which operates as a preprocessor to the CAMAD VLSI
design system. The input to PiX is an algorithmic description in a
Pascal-like language, which is translated into the Extended Timed
Petri Net (ETPN) representation. The extraction is realized as
analysis of and transformations on the ETPN. Preliminary results
from PiX show that the approach is feasible and useful for realistic
designs.
No 230
A THREE-VALUED APPROACH TO
NON-MONOTONIC REASONING
Patrick Doherty
Abstract: The subject of this thesis is the formalization of a type
of non-monotonic reasoning using a three-valued logic based on the
strong definitions of Kleene. Non-monotonic reasoning is the rule
rather than the exception when agents, human or machine, must act
where information about the environment is uncertain or
incomplete. Information about the environment is subject to change
due to external causes, or may simply become outdated. This implies
that inferences previously made may no longer hold and in turn must
be retracted along with the revision of other information dependent
on the retractions. This is the variety of reasoning we would like
to find formal models for.
We start by extending Kleene’s
three-valued logic with an "external negation" connective
where ~ a is true when a is false or unknown. In addition, a default
operator D is added where D a is interpreted as "a is true by
default. The addition of the default operator increases the
expressivity of the language, where statements such as "a is
not a default" are directly representable. The logic has an
intuitive model theoretic semantics without any appeal to the use of
a fixpoint semantics for the default operator. The semantics is
based on the notion of preferential entailment, where a set of
sentences G preferentially entails a sentence a, if and only if a
preferred set of the models of G are models of a. We also show that
one version of the logic belongs to the class of cumulative
non-monotonic formalisms which are a subject of current
interest.
A decision procedure for the propositional case, based
on the semantic tableaux proof method is described and serves as a
basis for a QA-system where it can be determined if a sentence a is
preferentially entailed by a set of premises G. The procedure is
implemented.
No 237
COACHING PARTIAL PLANS: AN APPROACH TO
KNOWLEDGE-BASED TUTORING
Tomas Sokolnicki
Abstract: The thesis describes a design for how a tutoring system
can enhance the educational capabilities of a conventional
knowledge-based system. Our approach to intelligent tutoring has
been conceived within the framework of the KNOWLEDGE-LINKER project,
which aims to develop tools and methods to support knowledge
management and expert advice-giving for generic
applications. Biochemistry, more specifically experiment planning,
is the current reference domain for the project. The selected
tutoring paradigm is a computer coach, based on the following
central concepts and structures: instructional prototypes, an
intervention strategy, teaching operators and instructional goals
controlling the instructional strategy; error descriptions to model
common faults; and stereotype user models to support the user
modelling process. The tutoring interaction is planned using the
instructional prototypes and constrained by an intervention strategy
which specifies when the user should be interrupted, for which
reason, and how the interruption should be handled. The set of
instructional prototypes and teaching operators can be used to
describe individual teaching styles within the coaching paradigm; we
propose one way to represent them using discourse plans based on a
logic of belief. The case data may be either generated by the coach
or specified by the user, thus making possible using the coach both
for instructional purposes as well as job assistance.
No 250
POSTMORTEM DEBUGGING OF DISTRIBUTED
SYSTEMS
Lars Strömberg
Abstract: This
thesis describes the design and implementation of a debugger for
parallel programs executing on a system of loosely coupled
processors. A primary goal has been to create a debugging
environment that structurally matches the design of the distributed
program. This means that the debugger supports hierarchical module
structure, and communication flow through explicitly declared
ports. The main advantages of our work over existing work in this
area are: overview of the inter-process communication structure, a
minimal amount of irrelevant information presented in the inspection
tools, and support for working at different levels of detail. The
debugging system consists of a trace collecting runtime component
linked into the debugged program, and two window based tools for
inspecting the traces. The debugger also includes animation of
traced events.
No 253
SLDFA-RESOLUTION - COMPUTING ANSWERS
FOR NEGATIVE QUERIES
Torbjörn
Näslund
Abstract: The notion of SLDNF-resolution
gives a theoretical foundation for implementation of logic
programming languages. However, a major drawback of SLDNF-resolution
is that for negative queries it can not produce answers other than
yes or no. Thus, only a limited class of negative queries can be
handled. This thesis defines an extension of SLDNF-resolution,
called SLDFA-resolution, that allows to produce the same kind of
answers for negative queries as for positive ones. The extension is
applicable for every normal program. A proof of its soundness with
respect to the completion semantics with the (weak) domain closure
axiom is given.
No 260
USING CONNECTIVITY GRAPHS TO SUPPORT
MAP-RELATED REASONING
Peter D. Holmes
This
thesis describes how connectivity graphs can be used to support
automated as well as human reasoning about certain map-related
problems. Here, the term "map" intends to denote the
representation of any two-dimensional, planar surface which can be
partitioned into regions of free vs. obstructed space. This thesis
presents two methods for solving shortest path problems within such
maps. One approach involves the use of heuristic rules of inference,
while the other is purely algorithmic. Both approaches employ A*
search over a connectivity graph -- a graph abstracted from the
map’s 2-D surface information. This work also describes how
the algorithmic framework has been extended in order to supply users
with graphical replies to two other map- related queries, namely
visibility and localization. The technique described to solve these
latter two queries is unusual in that the graphical responses
provided by this system are obtained through a process of synthetic
construction. This thesis finally offers outlines of proofs
regarding the computational complexity of all algorithmic methods
employed.
No 283
IMPROVING IMPLEMENTATION OF GRAPHICAL
USER INTERFACES FOR OBJECT-ORIENTED KNOWLEDGE-BASES
Olof
Johansson
Abstract: Second generation knowledge-based
systems have raised the focus of research from rule-based to
model-based systems. Model-based systems allow knowledge to be
separated into target domain model knowledge and problem solving
knowledge.
This work supports and builds on the hypothesis that
fully object-oriented knowledge-bases provide the best properties
for managing large amounts of target domain model knowledge. The
ease by which object-oriented representations can be mapped to
efficient graphical user interfaces is also beneficial for building
interactive graphical knowledge acquisition and maintenance
tools. These allow experts to incrementally enter and maintain
larger quantities of knowledge in knowledge-bases without support
from a knowledge engineer.
The thesis points to recent advances
in the conception of knowledge-based systems. It shows the need for
efficient user interfaces for management of large amounts of
heterogeneous knowledge components. It describes a user interface
software architecture for implementing interactive graphical
knowledge-base browsers and editors for such large
knowledge-bases. The architecture has been inspired by
object-oriented programming and data-bases, infological theory,
cognitive psychology and practical implementation work.
The goal
with the user interface software architecture has been to facilitate
the implementation of flexible interactive environments that support
creative work. Theoretical models of the entire user interaction
situation including the knowledge-base, the user interface and the
user are described. The models indicate how theoretical comparisons
of different user interface designs can be made by using certain
suggested measures.
The architecture was developed in the frame
of a cooperative project with the Department of Mechanical
Engineering on developing a knowledge-based intelligent front end
for a computer aided engineering system for damage tolerance design
on aircraft structures.
No 298
AKTIVITETSBASERAD KALKYRERING I ETT
NYTT EKONOMISYSTEM
Rolf G Larsson
Abstract:
Activity-Based Costing (ABC) for a New Management Accounting System
is a report on a matrix model. The model combines traditional
financial data from the accounting system with non-financial data
from production, administration and marketing. The financial
dimension is divided into cost centers at a foreman level. The two
dimensions are combined at the lowest organizational level by using
Cost drivers in an Activity-Based Costing technique. In doing so we
create “foreman centers” where each operation is matched
with a certain expenditure or income. These “foreman
centers” are later accumulated into divisions and
subsidiaries. The results from the matrix model can be used as
measurements for:
evaluation of ex ante - ex post variance in
production costs
productivity and efficiency at a foreman
level
capital usage and work-in-progress evaluations
production control and control of other operations
life cycle
cost-analysis
Gunnebo Fastening AB invited us to test the matrix
model in reality. Step by step the hypothetical model is
conceptualized into a system for management accounting. Gunnebo
Fastening AB produces about 6000 different types of nails per year.
The matrix model show that only about 50% of them are
profitable. The rest are non-profitable articles. Customers have a
vast range of discounts. This together with other special deals
turns many of them into non-profitable customers. As the model
points out which articles and customers are “in the
red”, Gunnebo have shown interest in adopting the matrix model
in a new system on a regular basis. The matrix model is compared
with other literature in the field of management
accounting. Important sources include the Harvard Business School
with Professors Kaplan, Cooper and Porter, who all contributed to
ABC and management accounting development in general. Another
valuable source is Professor Paulsson Frenckner. The literature
shows that both academics and practitioners seek ways to provide
more detailed and accurate calculations for product
profitability.
The report concludes with an analysis and
conclusions about the matrix model. It also indicates future
opportunities for the model in decision support systems (DSS).
No 318
STUDIES IN EXTENDED UNIFICATION-BASED
FORMALISM FOR LINGUISTIC DESCRIPTION: AN ALGORITHM FOR FEATURE
STRUCTURES WITH DISJUNCTION AND A PROPOSAL FOR FLEXIBLE SYSTEMS
Lena Strömbäck
Abstract:
Unification-based formalisms have been used in computational and
traditional linguistics for quite some while. In these formalisms
the feature structure is the basic structure for representing
linguistic information. However, these structures often do not
suffice for describing linguistic phenomena and various extensions
to the basic structures have been proposed. These extensions
constitute the subject of this thesis.
The thesis contains a
survey of the extensions proposed in the literature. The survey is
concluded by stating the properties that are most important if we
want to build a system that can handle as many of the extensions as
possible. These properties are expressiveness, flexibility,
efficiency and predictability. The thesis also evaluates four
existing formalisms with respect to these properties. On the basis
of the evaluation we also suggest how to design a system handling
multiple extensions where the main emphasis have been laid on
getting a flexible system.
As the main result the thesis
specifies an algorithm for unifying disjunctive feature
structures. Unlike previous algorithms, except Eisele &
Dörre (1990), this algorithm is as fast as an algorithm without
disjunction when disjunctions do not participate in the unification,
it is also as fast as an algorithm handling only local disjunctions
when there are only local disjunctions, and expensive only in the
case of unifying full disjunction. By this behaviour the algorithm
shows one way to avoid the problem that high expressiveness also
gives low efficiency. The description is given in the framework of
graph unification algorithms which makes it easy to implement as an
extension of such an algorithm
No 319
DML-A LANGUAGE AND SYSTEM FOR THE
GENERATION OF EFFICIENT COMPILERS FROM DENOTATIONAL
SPECIFICATION
Mikael Pettersson
Abstract:
Compiler-generation from formal specifications of programming
language semantics is an important field. Automatically-generated
compilers will have fewer errors, and be easier to construct and
modify. So far, few systems have succeeded in this area, primarily
due to a lack of flexibility and efficiency.
DML, the
Denotational Meta-Language, is an extension of Standard ML aimed at
providing a flexible and convenient implementation vehicle for
denotational semantics of programming languages. The main extension
is a facility for declaring and computing with first-class syntactic
objects. A prototype implementation of DML has been made, and
several denotational specifications have been implemented
successfully using it. Integrated in the system is a code generation
module able to compile denotational specifications of Algol-like
languages to efficient low-level code.
This thesis presents an
overview of the field, and based on it the DML language is
defined. The code generation method for Algol-like languages is
presented in detail. Finally, the implementation of the DML system
is described, with emphasis on the novel extensions for first-class
syntactic objects.
No 326
LOGIC PROGRAMMING WITH EXTERNAL
PROCEDURES: AN IMPLEMENTATION
Andreas
Kågedal
Abstract: This work aims at combining
logic programs with functions written in other languages, such that
the combination preserves the declarative semantics of the logic
program. S-Unification, as defined by S. Bonnier and J. Maluszynski,
provides a theoretical foundation for this.
- This thesis
presents a definition and an implementation of a logic programming
language, GAPLog, that uses S-unification to integrate Horn clauses
with external functional procedures. The implementation is described
as a scheme that translates GAPLog programs to Prolog. In
particular, a call to an external function is transformed to a piece
of Prolog code that will delay the call until all arguments are
ground. The scheme produces reasonably efficient code if Prolog
supports efficient coroutining. S-unification will cause no overhead
if there are no function calls in the program.
- If the
arguments are ground whenever a function call is reached in the
execution process, then the dynamic check for groundness is
unnecessary. To avoid the overhead caused by the groundness check a
restriction of GAPLog is described, called Ground GAPLog, where the
groundness of function calls is guaranteed. The restrictions are
derived from the language Ground Prolog defined by F. Kluzniak.
Many of the results for Ground Prolog also apply for Ground
GAPLog. They indicate that Ground GAPLog is suitable for compilation
to very efficient code.
No 328
ASPECTS OF VERSION MANAGEMENT OF
COMPOSITE OBJECTS
Patrick Lambrix
Abstract:
An important aspect of object oriented database systems is the
ability to build up composite objects from objects parts. This
allows modularity in the representation of objects and reuse of
parts where appropriate. It is also generally accepted that
object-oriented database systems should be able to handle temporal
data. However little theoretical work has been done on temporal
behaviour of composite objects, amd only relatively few systems
attempt to incorporate both historical information and composite
objects in a multi-user environment.
We argue that the support
for handling temporal information provided by other systems
addresses only one of two important kinds of historical information.
We describe the notions of temporal history and edit history.
In
this work we also make a first step in formalizing historical
information of composite objects. We identify different kinds of
compositions and give formal synchronization rules between a
composition and its components to induce the desired behavior of
these compositions in a database setting. We also discuss the
transitivity property for the part-of relation with respect to the
newly defined compositions.
Finally we address the problem of
maintaining consistent historical information of a composition using
the historical information of its components. This problem occurs as
a result of sharing objects between ceveral compositions. We propose
a solution and show an implementation in the LINCKS system.
No 333
TESTABILITY ANALYSIS AND IMPROVEMENT
IN HIGH-LEVEL SYNTHESIS SYSTEMS
Xinli Gu
Abstract: With the level of integration existing today in VLSI
technology, the cost of testing a digital circuit has become a very
significant part of a product. This cost mainly comes from the test
pattern generation (ATPG) for a design and the test execution for
each product. Therefore it is worthwhile to detect parts of a design
which are difficult for ATPG and test execution, and improve these
parts before using ATPG and testing.
There are existing methods
of improving the testability of a design, such as the scan path
technique. However, due to the high cost of introducing scan
registers for all registers in a design and the delay caused by long
scan paths, these approaches are not very efficient. In this thesis,
we propose a method which only selects parts of a design to be
transformed based on the testability analysis. For this purpose, we
1. define a testability measurement which is able to predict
the costs to be spent during the whole test procedure.
2. evaluate the result of the testability measurement, and based on
this evaluation develop some strategies to identify
difficult-to-test parts in a design.
3. create a class of
testability improvement transformations and apply them to the
difficult-to-test parts identified.
4. recalculate testability
for the design with part of it transformed.
These procedures
are repeated until design criteria are satisfied. The implementation
result conforms to our direct observation. For test examples
discussed in the thesis, we find the best improvement of testability
within the other design constraint.
No 335
ON THE ROLE OF EVALUATIONS IN
ITERATIVE DEVELOPMENT OF MANAGERIAL SUPPORT SYSTEMS
Torbjörn Näslund
Abstract: Iterative
development of information systems does not only mean iterative
construction of systems and prototypes. Even more important in
iterative development is the role of formative evaluations. The
connection between these activities is of crucial importance for
ensuring that the evaluations will be able to fulfil their formative
role. When this is achieved, the development process can be a
process of learning; acquiring missing information during the
development process.
For Managerial Support Systems, the fit
between the user, the organization, and the system is of vital
importance for the success of the system being developed. Iterative
development with an emphasis on evaluations is a suitable
development approach for this kind of system.
A framework for
iterative development of Managerial Support Systems is constructed
and discussed. The framework is assessed in real-world development
projects, and experiences from participant observation are
reported.
Among the findings from this explorative inquiry are
that it is easy to achieve very important information by the use of
evaluations. The applicability of the approach is however dependent
on explicitness of the support idea and an efficient flow of
information between developers and evaluators.
No 348
INDUSTRIAL SOFTWARE DEVELOPMENT - A
CASE STUDY
Ulf Cederling
Abstract: There
have been relatively few empirical studies of large-scale software
development in Sweden. To understand the development process and be
able to transfer knowledge from large-scale software development
projects to academic basic education as well as to other industrial
software projects, it is necessary to perform studies on-site where
those systems are built.
This thesis describes the development
process used at one particular Swedish company, NobelTech Systems
AB, where they are trying to develop reusable software. The
differences and similarities between their process and methodology
and the corresponding approaches described in the literature are
investigated.
The evolution of the software development process
over the course of a decade is also discussed. During the 80s the
company decided to make a technology shift in hardware as well as in
software. They changed from minicomputer - based systems to
integrated, distributed solutions, began to use Ada and the Rational
Environment in the building of large complex systems, and shifted
their design approach from structured to object-oriented
design. Furthemore, they decided to design a system family of
distributed solutions instead of specific systems to facilitare
future reuse.
No 352
PREDICTABLE CYCLIC COMPUTATIONS IN
AUTONOMOUS SYSTEMS: A COMPUTATIONAL MODEL AND IMPLEMENTATION
Magnus Morin
Cyclic computations under
real-time constraints naturally occur in systems which use periodic
sampling to approximate continuous signals for processing in a
computer. In complex control systems, often with a high degree of
autonomy, there is a need to combine this type of processing with
symbolic computations for supervision and coordination.
In this
thesis we present a computational model for cyclic time-driven
computations subjected to run-time modifications initiated from an
external system, and formulate conditions for predictable real-time
behaviour. We introduce the dual state vector for representing
periodically changing data. Computations are viewed as functions
from the state represented by the vector at time t to the state one
period later. Based on this model, we have implemented a software
tool, the Process Layer Executive, which maintains dual state
vectors and manages cyclic tasks that perform computations on
vectors.
We present the results of a theoretical and practical
evaluation of the real-time properties of the tool and give its
overhead as a function of application dependent parameters that are
automatically derivable from the application description in the
Process Layer Configuration Language.
No 371
EVALUATION OF STRATEGIC INVESTMENTS IN
INFORMATION TECHNOLOGY
Mehran Noghabai
This report tackles
the implications of the strategic role of information (IT) for
evaluation of investments in new technologies. The purpose is to
develop a strategic management perspective on IT-investments and
suggest appropriate methods for evaluation of flexible manufacturing
systems (FMS) and office information systems (OIS). Since
information systems are interdisciplinary in nature, our efforts
have been concentrated on integrating different perspectives on the
proliferation of new technology in organizations and theories about
planning, evaluation and development of strategic investments. Case
studies, surveys, statistics and empirical evidence from the
literature are used to support our findings and to expose some ideas
for further research.
The strategic and managerial perspective
on IT-investments is developed in the context of the role of
ledarship in a changing business, technological and organizational
environment. The strategic perspective is derived from integration
of different theories and perspectives on development of technology
and strategies in organizations, as well as planning and evaluation
in strategic investment decisions. In order to enhance our
understanding of the strategic roles of ITs, the rationale behind
introduction of IT-investments, their impact on firm’s
profitability and role as management support are discussed and the
pattern of technical change in organizations is
described. Particular attention is paid to the integrative role of
the FMS in the firms’s value chain and the OIS in supporting
administrators at different organization levels. Then we analyze the
crucial role of FMS- and OIS in the firm’s manufacturing
strategy and information system strategy and the implications for
measurement and evaluation of the effects of FMS- and
OIS-projects.
In order to extend the role of evaluation and
enable managers to handle strategic investment decisions, a model
for strategic investment planning has been developed. The model
integrates different development processes in the organization (such
as strategic management, organization and system development and
project control) and requires involvement of other members as
well. Furthermore, we suggest a mix of qualitative and quantitative
techniques and appraisal approaches for the analysis of the
strategic, tactical and operational implications of FMS- and
OIS-investments. Since the introduction of FMS and OIS is generally
a long-term and continuous process, our approach is regarded as an
attempt to create a flexible evaluation structure which can follow
changes in technologies and the organization’s development
strategies in a natural manner.
No 378
A TRANSFORMATIONAL APPROACH TO FORMAL
DIGITAL SYSTEM DESIGN
Mats Larsson
The
continuing development in electronic technology has made it possible
to fit more and more functionality on a single chip, thus allowing
digital systems to become increasingly complex. This has led to a
need for better synthesis and verification methods and tools to
manage this complexity.
Formal digital system design is one such
method. This is the integrated process of proof and design that
starting from a formal specification of a digital system, generates
a proof of correctness of its implementation as a by-product of the
design process. Thus, by using this method, the designer can
interactively transform the specification into a design that
implements the specification, and at the same time generate a proof
of its correctness.
In this thesis we present an approach to
formal digital system design that we call transformational. By this
we mean that we regard design as an iterative process that
progresses stepwise by applying design decisions that transforms the
design until a satisfactory design has been reached. To be able to
support both synthesis and verification we use a two-level design
representation where the first level is a design specification in
logic that is used for formal reasoning, and the second level is a
set of design annotations that are used to support design analysis
and design checking.
We have implemented an experimental design
tool based on the HOL (Higher Order Logic) proof system and the
window inference package. We demonstrate the usability of our
approach with a detailed account of two non trivial examples of
digital design derivations made using the implemented tool.
No 380
COMPILER GENERATION FOR PARALLEL
LANGUAGES FROM DENOTATIONAL SPECIFICATION
Johan
Ringström
There exist several systems for the
generation of compiler front-ends from formal semantics. Systems
that generate entire compilers have also started to appear. Many of
these use attribute grammars as the specification formalism, but
there also are systems based on operational semantics or
denotational semantics. However, there are very few systems based on
denotational semantics that generate compilers for parallel
languages.
The goal of this thesis is to show that it is
possible to automatically generate an efficient compiler for a
parallel language from a denotational specification. We propose a
two-level structure for the formal description. The high level uses
denotational semantics, whereas the low-level part consists of an
abstract machine including data-parallel operations.
This thesis
concentrates on the high-level denotational part. A prototype
compiler for a small Algol-like parallel language has been generated
using a modified version of the DML (Denotational Meta Language)
system back-end. A fixed operational semantics in the form of a
low-level language that includes data-parallel operations is used as
target during the generation.
No 381
PROPAGATION OF CHANGE IN AN
INTELLIGENT INFORMATION SYSTEMS
Michael
Jansson
This thesis pursues the issue of propagation of
change in an intelligent information system. Propagation of change
occurs when a data base manager executes transactions repeatedly,
though to different parts of a data base and possibly with some
small variations. A number of operations can be performed
automatically as propagation, such as: (1) merging variants of
information, (2) undoing a prior change to some information without
loosing recent changes, (3) fixing a set of (dissimilar) information
that contains the same bug, etc.
The emphasis is on the
potential problems that can arise when propagating changes, as well
as presenting a solution to the problems discussed. A secondary goal
is to describe the architecture and use of the surrounding system
where propagation of change can occur.
Three different aspects
of propagation of change are discussed in detail; determining the
change, performing the propagation, and issues regarding
implementing a propagation of change tool. This tool has been
implemented as an integrated part of LINCKS, an intelligent
information system designed and develop in Linköping.
No 383
AN ARCHITECTURE AND A KNOWLEDGE
REPRESENTATION MODEL FOR EXPERT CRITIQUING SYSTEMS
Jonni
Harrius
The aim of an expert critiquing system (ECS) is
to act as an assistant in a problem-solving situation. Once a user
has presented a tentative solution to a given problem, the ECS
reviews the proposed solution and then provides a critique —
an evaluation of the solution. In this thesis we provide an
architecture for an expert critiquing shell and present an
implementation of such a shell, the AREST system. Experience from
using this shell in two experimental implementations is
reported. Further we show how the critique generation process can be
supported by extending standard knowledge representation structures
by explicitly providing conceptual relationships between items in
the knowledge base in the form of a simple extension of a rule-based
schema. Current results in text generation have opened the way for
dynamically producing multi-paragraph text. Our work is based on a
theory for text organization, Rhetorical Structure Theory (RST). To
remedy certain shortcomings in RST we proposed improvements,
e.g. rhetorical aggregates for guiding content selection and
organization. In this thesis we discuss how the AREST system has
been used to construct two ECSs with text generation
capabilities.
No 386
SYMBOLIC MODELLING OF THE DYNAMIC
ENVIRONMENTS OF AUTONOMOUS AGENTS
Per
Österling
To interact with a dynamic environment
in a reliable and predictable manner, an autonomous agent must be
able to continuously sense and “understand” the
environment in which it is operating, while also meeting strict
temporal constraints.
In this thesis we present means to support
this activity within a unified framework aimed to facilitate
autonomous agent design and implementation. The central role in this
approach is played by models at different levels of abstraction.
Those models are continuously updated on the basis of available
information about the dynamic environment. We emphasize the
interface between the numeric and symbolic models, and present an
approach for recognizing discrete events in a dynamic environment
based on sequences of observations. Furthermore, we propose a logic
to specify these characterization procedures.
A prototype driver
support system is used as a means for testing our framework on a
real world application with considerable complexity. The
characterization procedures are specified in the logic, and an
implementation of the prototype is presented.
No 398
DEPENDENCY-BASED GROUNDNESS ANALYSIS
OF FUNCTIONAL LOGIC PROGRAMS
Johan Boye
The
object of study in this thesis is a class of functional logic
programs, where the functions are implemented in an external
functional or imperative language. The contributions are
twofold:
Firstly, an operational semantics is formally
defined. The key idea is that non-ground function calls selected for
unification are delayed and retained in form of constraints until
their arguments become ground. With this strategy two problems
arise: (1) Given a program P and an initial goal, will any delayed
unifications remain unresolved after computation? (2) For every
function call f(X) in P, find a safe evaluation point for f(X),
i.e. a point in P where X always will be bound to a ground term, and
thus f(X) can be evaluated.
Secondly, we present a static
groundness analysis technique which enables us to solve problems (1)
and (2) in a uniform way. The analysis method is dependency-based,
exploiting analogies between logic programs and attribute
grammars.
No 402
TABULATED RESOLUTION FOR WELL FOUNDED
SEMANTICS
Lars Degerstedt
This work is
motivated by the need for efficient question-answering methods for
Horn clause logic and its non-classical extensions - formalisms
which are of great importance for the purpose of knowledge
representation. The methods presented in this thesis are
particularly suited for the kind of ‘‘computable
specifications’’ that occur in areas such as logic
programming and deductive databases.
The subject of study is a
resolution-based technique, called tabulated resolution, which
provides a procedural counterpart to the so-called well-founded
semantics. Our study is carried out in two steps.
First we
consider only classical Horn theories. We introduce a framework
called the search forest which, in contrast to earlier
formalizations of tabulated resolution for Horn theories, strictly
separates between search space and search. We prove the soundness
and completeness of the search space and provide some basic
strategies for traversing the space. An important feature of the
search forest is that it clarifies the relationship between a
particular tabulation technique, OLDT-resolution, and the
transformational bottom-up method called ‘‘magic
templates’’.
Secondly, we generalize the notion of
a search forest to Horn theories extended with the non-monotonic
connective known as negation as failure. The tabulation approach
that we propose suggests a new procedural counterpart to the
well-founded semantics which, in contrast to the already existing
notion of SLS-resolution, deals with loops in an effective way. We
prove some essential results for the framework, including its
soundness and completeness.
No 406
SATELLITKONTOR - EN STUDIE AV
KOMMUNIKATIONSMÖNSTER VID ARBETE PÅ DISTANS
Anna Moberg
The purpose of this study is to
bring forward the relevant theories to describe and analyse the area
of remote work. Based upon these theories, the experiences of
satellite work centres is analysed. In this context, satellite work
centre means a part of a company department which has been
geographically separated from the rest of the department and where
normal departmental functions are carried out at a distance from the
company headquarters. The geographic separation requires that
communication between the different work places by and large must be
done with help of information technology. Three companies
participated in the study.
Satellite work centres can be studied
from several perspectives. A selection of theories from the area of
organisation is presented to illustrate organisational development
and to describe organisational structure. Furthermore, examples are
given of the interplay between technological development and changes
in the company’s business. Several different definitions of
remote work are presented. In literature which deals with working
remotely, no distinction is made amongst the experiences of
different organisational forms of remote work. Previous experiences
with remote work are used in this study as examples of satellite
work centres. The prerequisites for communication are central to the
ability to carry out remote work. The description of communication
patterns, both within and between the operational units in the
companies, is therefore given heavy treatment. Data have been
collected with help of a communication diary. The analysis builds
upon theories of communication and organisational communication,
which deal with information requirements, the function of
communication, communications patterns, choice of communication
medium, and so forth.
As part of the study’s results,
several factors are discussed which should be taken into
consideration by a company in order for remote work in satellite
work centres to function properly. These considerations are such
things as the content of the job, dissemination of information and
social contact. The results can also be found in a description of
the communications patterns in the study groups. The kinds of
information needed is by and large simple and can for the most part
be spread through computerised information systems, The most used
form of communication is the telephone, but telefax and electronic
mail also play a role. Three functions of communication are
studied. The command function, giving instructions about tasks to be
done, was responsible for a relatively small amount of the total
communication. the ambiquity management function, dissemination of
information to reduce insecurity, was responsible for a large
portion of the information flow, both between and within
organisational units. The relational function, maintaining social
contact, was also a significant portion of the
communication. Despite geographic distance, the prerequisites for
communication between those at the corporate headquarters and those
at the satellite work centres is much the same as for communication
within the corporate headquarters itself.
No 414
SEPARATION OF MANAGEMENT AND
FINANCING, CASE STUDIES OF MANAGEMENT BUY-OUTS IN AN AGENCY
THEORETICAL PERSPECTIVE
Peter Carlsson
The
interaction between owners, management team and lenders in companies
form a natural part of modern industry and commerce. The purpose of
this study is to investigate whether separation of management and
financing in companies causes costs. In the study financing relates
both to debt finance and equity finance provided by others than
members of the management team.
The study is based on an agency
theoretical perspective. According to agency theory, specific costs
arise in contractual relationships, namely agency costs. In order
to draw conclusions regarding the costs of separation between
management and financing, this study investigates the change in
agency costs in the contractual relationships between the owners and
the management team and the lenders and the owner/management group,
respectively, due to a management buy-out, MBO. A MBO is an
acquisition of a company or part of a company, where the
company’s management team constitutes or forms part of the
group of investors and where the acquisition normally is financed
with an above average proportion of debt finance in relation to
equity finance.
The results of the study indicate that the value
of a company is related to how the company is financed. In companies
where the management teams do not own the company, costs seem to
arise because the companies are not managed in a value-maximizing
way. Costs also seem to arise because of monitoring and bonding
activities in the relationship between the owners and the management
team. In companies where the owner/management group do not finance
the whole company but debt finance is used, costs seem to arise
primarily because of scarcity of capital and deteriorated conditions
in the relations with lenders and suppliers. Costs seem to arise
because of monitoring and bonding activities as well.
No 417
AUDITING AND LEGISLATION - AN HISTORIC
PERSPECTIVE
Camilla Sjöström
Laws
change due to changes in society’s norms. New laws in turn
alter conditions for business and society. Auditing is one of the
few professions in Sweden which is governed by comprehensive
legislation. Changes in the rules for auditing therefore mean
changes in the conditions of an auditor’s daily work.
It
was not until 1912 that individuals began to plan for a career in
auditing. It was then that the first auditors were certified by the
business community. Ever since then the profession has
changed. Auditing ceased to be only of concern to the business
community and became instead a concern for many interested parties,
such as creditors, the state, and tax authorities. Their needs have
been different and have therefore put different demands on
auditors. The state has as a consequence changed its regulation of
auditing in companies.
The purpose of this study is to describe
the changes in legislation which affect Swedish auditors’
work, as well as to illustrate the reasons and consequences which
were argued for by various interested parties in conjunction with
these changes. The areas which are covered are the changes with
regard to auditors’ education and competency, supervision and
certification of auditors, the auditor’s task, sphere of
activity, independence, and professional secrecy.
In this
debate, there is a gap between the expectations of what auditors
believe they should do and what the various interest groups, such as
clients and creditors, expect of them. This gap in expectations
might be due to dissatisfaction with the rules, a poor understanding
of what the rules are, or that the rules can be interpreted in
various ways. This gap in expectations could possibly be minimized
by making information about rules for auditing and their background
available for the various interested parties.
No 436
VOICES IN DESIGN: ARGUMENTATION IN
PARTICIPATORY DEVELOPMENT
Cecilia
Sjöberg
The focus in this thesis lies on methods
used to support the early phases in the information system design
process. The main perspective emanates from the
”Scandinavian” approach to systems development and
Participatory Design. This perspective can be characterised as being
based on a ”socio-cultural” understanding that a broad
participation is beneficial for social development
activities. Another perspective has its point of departure within
the Design Rationale field. A third perspective is derived from
Action Research. In detail, the goals have been to develop an
argumentation based method to support the design process; study how
this method relates to the process of participatory design in a work
life setting; and study how the method can come to support design
visualization and documentation in such a group process.
The
resulting Argumentative Design (aRD) method is derived from both
theoretical influences (Design theory, Design Rationale applications
and the Action Design method) and empirical evaluations and
revisions. The latter are performed in the form of a case study of
the interaction in a multi-disciplinary design group, analyzed by
using qualitative methods and application of activity theory. Three
”voices” in participatory development were here
identified to characterize the interaction in the design group: the
voice of participatory design, the voice of practice and the voice
of technology.
The conclusion is that the ideas of the second
generation of design methodologies fit well also in the Scandinavian
tradition of systems development. Both these perspectives converge
into the group process where the product is seen as secondary and
derived. aRD thus uses both types of theoretical arguments to push
the high-level design issues forward, while making different design
ideas and decisions explicit.
No 437
CONTRIBUTIONS TO A HIGH-LEVEL
PROGRAMMING ENVIRONMENT FOR SCIENTIFIC COMPUTING
Lars
Viklund
The usage of computers for solving real-world
scientific and engineering problems is becoming more and more
important. Nevertheless, the current development practice for
scientific software is rather primitive. One of the main reasons for
this is the lack of good high-level tools. Most scientific software
is still being developed the traditional way in Fortran, especially
in application areas such as machine element analysis, where complex
non-linear problems are the norm.
In this thesis we present a
new approach to the development of software for scientific computing
and a tool which supports this approach. A key idea is that
mathematical models should be expressed in a high-level modeling
language which allows the user to do this in a way which closely
resembles how mathematics is written with pen and paper. To
facilitate the structuring of complex mathematical models the
modeling language should also support object-oriented concepts.
We have designed and implemented such a language, called ObjectMath,
as well as a programming environment based on it. The system has
been evaluated by using it in an industrial environment. We believe
that the proposed approach, supported by appropriate tools, can
improve productivity and quality, thus enabling engineers and
scientists to solve problems which are too complex to handle with
traditional tools.
The thesis consists of five papers (four of
which have previously been published in the proceedings of
international conferences) dealing with various aspects of the
ObjectMath language and programming environment.
No 440
ERROR RECOVERY SUPPORT IN
MANUFACTURING CONTROL SYSTEMS
Peter Loborg
Instructing production equipment on a shop floor in mid 1990’s
is still done using concepts from the 1950’s, although the
electro-mechanical devices forming logical gates and memory cells
are nowadays replaced by computers. The gates and memory cells are
now presented in graphical editors, and there is support for
defining new building blocks (gates) handling complex data as well
as for advanced graphical monitoring of a production process. The
progress during the last 40 years concerns the implementation of the
control system, not the instruction of the control system. Although
this progress has increased the flexibility of the equipment, it has
not provided any support for error recovery. The contribution of
this thesis is twofold. Firstly, it presents Aramis - A Robot and
Manufacturing Instruction System - which extends the traditional
instruction taxonomy with notions developed in computer
science. Aramis uses a graphical task specification language which
operates on an abstract model of the plant, a world model. The
essence of the differences between Aramis and current practice is
the usage of abstraction layers to focus on different aspects of the
instruction task, and that Aramis retains much specification
knowledge about the controlled plant, knowledge which can be reused
for other purposes such as error recovery. Secondly, the problems
of error recovery is investigated, and a proposal for how to provide
recovery support in a system structured such as Aramis is presented.
The proposal includes the generation of a multitude of possible
restart points in a task program, and it uses a planning approach to
support the modification of the current state of the machinery to
the ”closest” restart point.
No 441
INFORMATION TECHNOLOGY AND INDUSTRIAL
LOCATION, EFFECT UPON PRODUCTIVITY AND REGINAL DEVELOPMENT
Lars Poignant
Companies within the service
sector have begun relocating units. Information technology
guarantees their ability to communicate from remote areas. In
addition companies have suffered from high costs in the Stockholm
area mainly during the 1980’s. This report aims to identify
the effects the relocations have had on the companies, the regions
and the process of finding a new site including the financial
support from regional funds. The study was based on 57 different
relocations.
The study has shown that 63% of the companies have
been more effective after relocation. The main reason for this has
been the use of the specific advantages the new site may offer such
as lower employee turnover and lower rents. Along with the local
advantages the most successful companies have used IT not only in
order to increase production, but also in order to change the
organisation. With technical support communication both within the
organisation and with the customers is improved, which decreases the
costs for transactions.
The communities to which the companies
have relocated the units have been within regional support areas,
which entitles the companies to governmental support. The relocated
units have had a very positive impact on the community. The reason
has been that the areas very often are dominated by a single
industry and have a low employment rate, leaving youth and women
without jobs and resulting in emigration. The new companies usually
hire people within these sectors, which means that the effect not
only increases the employment rate, but also within a desired
sector. It must however be remembered that there is a limited effect
on the rest of the community. Indirectly the settlements will cause
good will and a positive atmosphere, but they will not create a
large number of jobs, since the companies do not use suppliers or
transportation services.
Since 1983 representatives for the
government have actively encouraged companies to relocate
units. Besides the centrally financed funds there has been support
from both regional and local governments. Added together the total
support for each job guaranteed for five years averages 350.000 SEK,
which is far more than expected. The reason for the excess
contributions is the uncoordinated and overlapping contributions
from different actors at various stages of the relocating
process.
Besides the increased efficiency of the companies, IT
offers local communities in remote areas new possibilities for
development. Taken altogether and keeping in mind that the
improvements have been made within the expanding service sector, the
effects may lead to national growth.
No FHS 3/94
INFORMATIONSSYSTEM MED
VERKSAMHETSKVALITET - UTVÄRDERING BASERAT PÅ ETT
VERKSAMHETSINRIKTAT OCH SAMSKAPANDE PERSPEKTIV
Owen
Eriksson
Den övergripande forskningsuppgiften
för detta arbete är att diskutera och definiera begreppet
verksamhetskvalitet samt att utveckla en utvärderingsmetod
för att bedöma informationssystem med verksamhetskvalitet,
utvärderingsmetoden har även prövats empiriskt i
samband med två utvärderingstillfällen. Begreppet
verksamhetskvalitet och utvärderingsmetoden baserar sig
på ett verksamhetsinriktat och samskapande perspektiv på
informationssystem och kvalitet. Verksamhetskvalitet är det
centrala begreppet och utifrån detta begrepp definieras en
utvärderingsmetod för informationssystem med
verksamhetskvalitet. Begreppet verksamhetskvalitet blir
därför en syntes av den syn på kvalitet som finns i
de bägge grundläggande perspektiven. Begreppet
verksamhetskvalitet har utvecklats genom en kritisk analys av de
två perspektiven och utifrån denna analys har kriterier
medvetet valts ut som kännetecknar detta begrepp. I begreppet
verksamhetskvalitet finns det även med kriterier och
värderingar som man inte fokuserar på i de två
perspektiven, men som måste vara med för att man ska
få ett användbart kvalitetsbegrepp i samband med
utvärdering av informationssystem.
No FHS 4/94
INFORMATIONSSYSTEMSTRUKTURERING, ANSVARSFÖRDELNING OCH
ANVÄNDARINFLYTANDE - EN KOMPARATIV STUDIE MED
UTGÅNGSPUNKT I TVÅ INFORMATIONSSYSTEMSTRATEGIER
Karin Pettersson
I denna rapport identifieras
ett antal ansvarstyper avseende informationssystem och
informationssystemstrukturering. Sex stycken fallstudier har
genomförts i verksamheter där en datadriven eller
verksamhetsbaserad informationssystemstrategi tillämpas. Med
utgångs-punkt i dessa verksamheter presenteras erfarenheter
kring hur ansvar fördelas och realiseras. Detta görs genom
en jämförelse mellan strategiernas teoretiska principer
för ansvarsfördelning och de verkliga resultaten. Vidare
studeras vilka möjligheter till användarinflytande som
respektive strategi erbjuder samt hur detta i realiteten
utövas.
Rapporten består av en teoretisk del,
där en jämförelse på idealtypsnivå sker
mellan två informationssystemstrategier; Information Resource
Management (IRM) och VerksamhetsBaserad Systemstrukturering
(VBS). Därefter följer en genomgång av empiriskt
material från ovan nämnda fallstudier.
Resultatet av
studien visar att strategiernas idealbilder skiljer sig åt
på ett antal punkter, men att de trots detta leder till en rad
likartade konsekvenser vad gäller ansvarsfördelning och
användarinflytande. Det finns flera orsaker till att det
är svårt att få systemägare, ledning och
användare att ta sitt ansvar. Följden av detta blir att
dataavdelningen, eller en liknande funktion, får ta det
faktiska system- och strategiansvaret. Användarnas
möjlighet och vilja att ta ansvar har bl a visat sig vara
beroende av vilken grad av inflytande de haft vid
systemutvecklingen.
No 446
OBJECT VIEWA OF RELATIONAL DATA IN
MULTIDATABASE SYSTEMS
Gustav Fahl
In a
multidatabase system it is possible to access and update data
residing in multiple databases. The databases may be distributed,
heterogeneous, and autonomous. The first part of the thesis provides
an overview of different kinds of multidatabase system architectures
and discusses their relative merits. In particular, it presents the
AMOS multidatabase system architecture which we have designed with
the purpose of combining the advantages and minimizing the
disadvantages of the different kinds of proposed architectures.
A central problem in multidatabase systems is that of data model
heterogeneity: the fact that the participating databases may use
different conceptual data models. A common way of dealing with this
is to use a canonical data model (CDM). Object-oriented data
models, such as the AMOS data model, have all the essential
properties which make a data model suitable as the CDM. When a CDM
is used, the schemas of the participating databases are mapped to
equivalent schemas in the CDM. This means that the data model
heterogeneity problem in AMOS is equivalent to the problem of
defining an object-oriented view (or object view for short) over
each participating database.
We have developed such a view
mechanism for relational databases. This is the topic of the second
part of the thesis. We discuss the relationship between the
relational data model and the AMOS data model and show, in detail,
how queries to the object view are processed.
We discuss the key
issues when an object view of a relational database is created,
namely: how to provide the concept of object identity in the view;
how to represent relational database access in query plans; how to
handle the fact that the extension of types in the view depends on
the state of the relational database; and how to map relational
structures to subtype/supertype hierarchies in the view.
A
special focus is on query optimization.
No 450
A DECLARATIVE APPROACH TO DEBUGGING
FOR LAZY FUNCTIONAL LANGUAGES
Henrik
Nilsson
Debugging programs written in lazy functional
languages is difficult, and there are currently no realistic,
general purpose debugging tools available. The basic problem is that
computations in general do not take place in the order one might
expect. Furthermore, lazy functional languages to a large extent
free programmers from concerns regarding operational issues such as
evaluation order, i.e. they are ‘declarative’. Debugging
should therefore take place at the same, high level of
abstraction. Thus, we propose to use algorithmic debugging for lazy
functional languages, since this technique allows the user to focus
on the declarative semantics of a program.
However, algorithmic
debugging is based on tracing, and since the trace reflects the
operational behaviour of the traced program, the trace should be
transformed to abstract away these details if we wish to debug as
declaratively as possible. We call this transformation
strictification, because it makes the trace more like a trace from a
strict language.
In this thesis, we present a strictifying
algorithmic debugger for a small lazy functional language, and some
experience from using it. We also discuss its main shortcomings, and
outline a number of ideas for building a more realistic
debugger. The single most pressing problem is the size of a complete
trace. We propose to use a piecemeal tracing scheme to overcome
this, by which only a part of the trace is stored at any one time,
other parts being created on demand by re-executing the program.
No 451
CREDITOR - FIRM RELATIONS: AN
INTERDISCIPLINARY ANALYSIS
Jonas Lind
The
thesis gives a survey of theories relevant for understanding the
problems in relations between lending banks and borrowing business
firms.
First a survey of comparative financial systems is given:
The main types are bank-oriented (Germany, Japan, Sweden) and
market-oriented systems (USA, GB). In the bank-oriented systems the
risk exposure due to high-firm indebtedness is counteracted by trust
in dense informal bank-firm networks. Market-oriented systems are
characterized by arms-lenght bank-firm relations. Legal rules hinder
the banks from active long-term relations with borrowing
firms. Firms are financed on the anonymous markets.
Sociology
provides theory for analysis: social cohesion, norms, networks and
trust. Institutional arrangements provide norms for societal
cooperation that are enforced by culture. Traditional and modern
society are used to exemplify two different ways of upholding social
cohesion with emphasis on business relations.
Concepts from
neoclassical economic theory for analyzing these relations are:
agency, transaction costs, contract, and asymmetric information.
Game theory models strategic behaviour and conflict:; long-term
relations can be interpreted as a way of bonding partners in an
n-period Prisoners Dilemma game. A model is developed for analyzing
bank-firm interaction for a firm in insolvency in a bank-oriented
system.
The thesis concludes with a speculative integrative
model for the development of the business community. Three models
are identified and named: the Oligarchy, the War-Lords and the
Business(like) Rationality. The last model is an attempt to
construct a model on the advantages from both The Oligarchy
(inspired by the bank-oriented systems) and the War-Lords (inspired
by the market-oriented systems).
No 452
ACTIVE RULES BASED ON OBJECT
RELATIONAL QUERIES - EFFICIENT CHANGE MONITORING TECHNIQUES
Martin Sköld
The role of databases is
changing because of the many new applications that need database
support. Applications in technical and scientific areas have a great
need for data modelling and application-database cooperation. In an
active database this is accomplished by introducing active rules
that monitor changes in the database and that can interact with
applications. Rules can also be used in databases for managing
constraints over the data, support for management of long running
transactions, and database authorization control.
This thesis
presents work on tightly integrating active rules with a second
generation Object-Oriented(OO) database system having transactions
and a relationally complete OO query language. These systems have
been named Object Relational. The rules are defined as Codition
Action (CA) pairs that can be parameterized, overloaded, and
generic. The condition part of a rule is defined as a declarative OO
query and the action as procedural statements.
Rule condition
monitoring must be efficient with respect to processor time and
memory utilization. To meet these goals, a number of techniques have
been developed for compilation and evaluation of rule
conditions. The techniques permit efficient execution of deferred
rules, i.e. rules whose executions are deferred until a check phase
usually occurring when a transaction is committed.
A rule
compiler generates screener predicates and partially differentiated
relations. Screener predicates screen physical events as they are
detected in order to efficiently capture those events that influence
activated rules. Physical events that pass through screeners are
accumulated. In the check phase the accumulated changes are
incrementally propagated to the relations that they affect in order
to determine whether some rule condition has changed. Partial
Differentiation is defined formally as a way for the rule compiler
to automatically generate partially differentiated relations. The
techniques assume that the number of updates in a transaction is
small and therefore usually only some of the partially
differentiated relations need to be evaluated. The techniques do not
assume permanent materializations, but this can be added as an
optimization option. Cost based optimization techniques are
utilized for both screener predicates and partially differentiated
relations. The thesis introduces a calculus for incremental
evaluation based on partial differentiation. It also presents a
propagation algorithm based on the calculus and a performance study
that verifies the efficiency of the algorithm.
Nr 452
A COLLABORATIVE APPROACH TO USABILITY
ENGINEERING: TECHNICAL COMMUNICATORS AND SYSTEM DEVELOPERS IN
USABILITY-ORIENTED SYSTEMS DEVELOPMENT
Pär
Carlshamre
For the last 20 years, the human-computer
interaction research community has provided a multitude of methods
and techniques intended to support the development of usable
systems, but the impact on industrial software development has been
limited. One of the reasons for this limited success is argued to be
the gap between traditional academic theory generation and
industrial practice.
Furthermore, technical communicators (TCs)
have until recently played a subordinate role in software design,
even in usability-oriented methods. Considering their close relation
to the users of the developed systems, and to the usability issue
itself, they constitute a hidden resource, which potentially would
contribute to the benefit of more usable systems.
We formed the
Delta project as a joint effort between industry and academia. The
objectives of the project were to jointly develop usability-oriented
method extensions, adapted for a particular industrial setting, and
to account for the specialist competence of the TCs in the software
development process. This thesis is a qualitative study of the
development, introduction and evaluation of the Delta method
extension. The analysis provides evidence in favor of a closer
collaboration between system developers (SDs) and TCs. An additional
outcome of the in-depth study is a proposed redefinition of the
extended interface concept, taking into account the inseparability
of user documentation and user interface, while providing a natural
common ground for a closer collaboration between SDs and TCs.
No FHS 5/94
VARFÖR CASE-VERKTYG I
SYSTEMUTVECKLING? EN MOTIV- OCH KONSEKVENSSTUDIE AVSEENDE
ARBETSSÄTT OCH ARBETSFORMER
Stefan
Cronholm
För utveckling av datorbaserade
informationssystem existerar numera många olika typer av
datorstöd. På senare år har det skett en intensiv
utveckling av olika verktyg (programvaror) som skall vara
behjälpliga vid systemutveckling (SU). Verktyg för senare
faser (realisering/konstruktion) under SU-processen har funnits
sedan en lång tid tillbaka, men datorstödda
hjälpmedel har nu även konstruerats för de tidigare
faserna (analys, design).
Verktyg som skall ge stöd under
SU-processen benämns ofta för CASE-verktyg. CASE är
en förkortning av Computer Aided Systems/Software
Engineering. CASE-verktyg som stödjer tidiga faser brukar
kallas för upper-CASE och CASE-verktyg som stödjer senare
faser för lower-CASE. I denna rapport identifieras ett antal
motiv för att införa CASE-verktyg i
systemutvecklingsprocessens tidigare faser. I rapporten identifieras
också konsekvenser av användning av CASE-verktyg för
arbetssätt och arbetsformer. Slutligen studeras om de motiv som
föranlett en satsning på CASE-verktyg har infriats.
Sex fallstudier har genomförts i svenska företag som
utvecklar administrativa system. Utifrån dessa fallstudier
presenteras erfarenheter kring motiv och konsekvenser av
användning av CASE-verktyg. Rapporten består av en
inledande del där problemområde, forskningsmetod och
teoretiska förutsättningar redovisas. Därefter
redovisas empiriskt material från fallstudierna.
Resultatet av denna studie visar att de huvudsakliga motiven
för att införa CASE-verktyg är att man vill
uppnå konkurrensfördelar genom att erhålla kortare
projekttider och att få en bättre produktkvalitet. Det
finns inget i denna studie som tyder på att användning av
CASE-verktyg har medfört förändrade
arbetsformer. CASE-verktyg används huvudsakligen i enskilt
arbete.
Olika konsekvenser för arbetssätt har
identifierats. De CASE-verktyg som använts i fallstudierna kan
i första hand klassificeras som dokumentationsstödjande
och verktygen stödjer huvudsakligen framställning av
diagram. Användare av undersökta CASE-verktyg har ansett
sig fått ett godtagbart stöd för diagramutformning
och lagring av objekt. I flera av de studerade fallen anser man att
de motiv man haft för införande har infriats och att
verktygen innehåller en godtagbar funktionalitet. I andra fall
anser man att motiven ej infriats och att verktygens funktionalitet
är otillräcklig.
För att lyckas med ett
CASE-införande är det viktigt att en noggrann behovsanalys
genomförs och att man före införandet utsätter
CASE-verktygen för en omfattande prövning. Resultatet
från denna prövning skall ligga till grund för en
utvärdering och bedömning av verktygets
förmåga. Avsaknaden av dokumenterade utvärderingar
är påtaglig i de studerade fallen.
No 462
A STUDY OF TRACEABILITY IN
OBJECT-ORIENTED SYSTEMS DEVELOPMENT
Mikael
Lindvall
We regard a software system as consisting not
only of its source code, but also of its documented
models. Traceability is defined as the ability to trace the
dependent items within a model and the ability to trace the
correspondent items in other models. A common use of the term
traceability is requirements traceability which is the ability to
trace a requirement via the different models to its implementation
in the source code. Traceability is regarded as a quality factor
that facilitates maintenance of a software system.
The thesis is
the result from a case study performed on a large commercial
software system developed with an object-oriented methodology and
largely implemented in C++ and by using a relational database. A
number of concrete traceability examples collected from the project
are the result of a thorough investigation of the various models
that were produced during the project. The exemples are thoroughly
analyzed and discussed, forming the main contribution of this
research. Insight and knowledge as regards traceability and
object-oriented modeling is the result from the work with the
examples.
No 463
STRATEGI PCH EKONOMISK STYRNING - EN
STUDIE AV SANDVIKS FÖRVÄRV AV BAHCO VERKTYG
Fredrik Nilsson
Att företag köper
andra företag är ett vanligt inslag i svenskt och
internationellt näringsliv. Andelen misslyckade
förvärv är dock hög. Tidigt uppmärksammades
att många förvärv misslyckas pga bristande planering
och frånvaro av en strategisk analys. Senare forskning har
visat att även hanteringen av förändringsprocessen
efter ett förvärv påverkar
förvärvsutfallet. Ekonomiska styrsystem är en
förändringsmekanism som kan antas ha stor betydelse i
denna process. Syftet med denna undersökning är
därför att studera vilken roll ekonomiska styrsystem har i
den förändringsprocess som följer av ett
förvärv.
En undersökningsmodell har utvecklats
där en av de teoretiska utgångspunkterna är att
företagsförvärv skall vara ett resultat av en
strategisk analys. I de fall analysen leder till att
förvärvet genomförs kan det antas att någon
form av förändring i det förvärvade
företagets affärsstrategiska inriktning blir
följden. En modifierad affärsstrategi innebär nya
krav på information för planering, beslutsfattande och
kontroll. Det förvärvade företagets ekonomiska
styrsystem måste då utformas på ett sådant
sätt att de svarar upp mot dessa nya
informationskrav. Därigenom kan de ekonomiska styrsystemen
användas för att styra beteendet i enlighet med den
strategiska inriktningen. Detta är en förutsättning
för att synergier skall kunna realiseras och därmed leda
till resultatförbättringar i det förvärvade
företaget.
Undersökningsmodellen testades genom en
empirisk studie av Sandviks förvärv av Bahco
Verktyg-gruppen. Av verktygsgruppens affärsenheter valdes
Sandvik Bahco i Enköping som lämpligt
studieobjekt. Förändringsprocessen inom Sandvik Bahco
efter förvärvet kan karakteriseras som linjär och
sekventiell bestående av faserna strategiformulering och
implementering. Av den strategiska analysen drogs slutsatsen att
Sandvik Bahcos affärsstrategi inte var nödvändig att
förändra i någon större utsträckning. Inom
ramen för den befintliga affärsstrategin ansågs dock
förändringar vara nödvändiga inom områden
såsom exempelvis kvalitet, leveranssäkerhet,
produktivitet etc. Dessa förändringar implementerades
bland annat genom att förändra utformningen och
användningen av Sandvik Bahcos ekonomiska
styrsystem. Därigenom blev det möjligt att följa upp
förändringsarbetet löpande. Trots att de ekonomiska
styrsystemen i hög utsträckning anpassats till den
affärsstrategiska inriktningen har det inte varit möjligt
att belägga ett samband mellan styrsystemens utformning och
förvärvets utfall.
Förändringen av Sandvik
Bahcos ekonomiska styrsystem kan även hänföras till
koncerngemensamma instruktioner och rekommendationer. Denna typ av
centrala riktlinjer tar vanligtvis ej hänsyn till
affärsenhetens specifika verksamhet vilket kan medföra en
försämrad anpassning till enhetens affärsstrategiska
inriktning. En sådan försämrad anpassning har dock
ej kunnat påvisas när det gäller Sandvik Bahcos
styrsystem. Detta kan förklaras med att de informationsbehov
som uppstår pga av Sandvik-koncernens och Sandvik Bahcos
strategiska inriktning är likartade. Kraven på koncernens
och affärsenhetens styrsystem blir därför
snarlika.
No 464
COLLAGE INDUCTION: PROVING PROGRAM
PROPERTIES BY PROGRAM SYSNTHESIS
Hans
Olsén
The motivation behind this thesis is to
formally prove programs correct. The contributions are twofold:
Firstly, a new rule of mathematical induction called collage
induction, is introduced, which treats mathematical induction as a
natural generalization of the CUT-rule. Conceptually the rule can
be understood as follows: To prove an implication G ? D, an
inductively defined property p is constructed such that G ? p. The
implication p ? D is then proved by induction according to the
definition of p.
Secondly, a program synthesis method for
extracting programs from proofs in Extended Execution, is
generalized to allow the relations defining p to be synthesized from
the proof of an induction lemma.
No 469
SPECIFICATION AND SYNTHESIS OF PLANS
USING THE FEATURES AND FLUENTS FRAMEWORK
Lars
Karlsson
An autonomous agent operating in a dynamical
environment will face a number of different reasoning problems, one
of which is how to plan its actions in order to pursue its
goals. For this purpose, it is important that the agent represents
its knowledge about the world in a coherent, expressive and
well-understood way, in our case the temporal logics from Erik
Sandewall's ”Features and Fluents” framework.
However, most existing planning systems make no use of temporal
logics, but have specialised representations such as the STRIPS
formalism and hierarchical task networks. In order to benefit from
the techniques used by these planners, it is useful to analyse and
reconstruct them within the given framework. This includes making
explicit the ontological and epistemological assumptions underlying
the planners; representing plans as entities of the temporal logic;
and reconstructing the algorithms in terms of the new
representation.
In this thesis, a number of traditional planners
are analysed and reconstructed in this way. The total-order planner
STRIPS, the partial-order planner TWEAK, the causal-link planner
SNLP, and finally the decompositional planner NONLIN are all
examined. The results include reconstructions of the planners
mentioned, operating on a temporal logic representation, and truth
criteria for total-order and partial-order plans. There is also a
discussion regarding the limitations of traditional planners from
the perspective of ”Features and Fluents”, and how these
limitations can be overcome.
No 473
ON CONCEPTUAL MODELLING OF MODE
SWITCHING SYSTEMS
Ulf Söderman
This
thesis deals with fundamental issues underlying the systematic
construction of behaviour models of physical systems, especially man
made engineering systems. These issues are important for the design
and development of effective computer aided modelling systems
providing high-level support for the difficult task of modelling. In
particular, the thesis is about conceptual modelling of physical
systems, i.e. modelling characterized by the explicit use of well
defined abstract physical concepts. An extensive review of
conceptual modelling is presented, providing good insight into
modelling in its own and forming a useful reference for the
development of computer aided modelling systems.
An important
contribution of this work is the extension of the conceptual
modelling framework by an ideal switch concept. This novel concept
enables a uniform and systematic treatment of physical systems
involving continuous as well as discrete changes. In the discussion
of the switch concept, the bond graph approach to modelling is used
as a specific example of a conceptual modelling approach. In this
dicussion, the bond graph version of the switch is presented. This
switch element fully complies with the standard bond graph modelling
formalism.
The thesis consists of six papers. The first paper
contains an extensive review of (traditional) conceptual
modelling. The next three papers deals with the ideal switch concept
and the remaining two papers discuss an application. Four of these
papers have been published in proceedings of international
conferences.
No 475
REASONING ABOUT CONCURRENT ACTIONS IN
THE TRAJECTORY SEMANTICS
Choong-ho Yi
We
have introduced concurrency into the framework of Sandewall. The
resulting formalism is capable of reasoning about interdependent as
well as independent concurrent actions. Following Sandewall’s
systematical method, we have then applied the entailment criterion
PCM to selecting intended models of common sense theories where
concurrent actions are allowed, and proved that the criterion leads
to only intended models for a subset of such theories. Our work
implies that most of Sandewall’s results on the range of
applicability of logics for sequential actions can be reobtained
similarly for concurrent actions as well after necessary
generalizations.
No 476
SUCCESSIV RESULTATAVRÄKNING AV
PÅGÅENDE ARBETEN. FULLSTUDIER I TRE BYGGFÖRETAG
Bo Lagerström
I Swerige har sedan
längeden externa redovisningen av resultat i
pågående arbeten varit direkt anpassad till en
sträng tolkning av realisationsprincipen och en strikt
tillämpning av försiktighetsprincipen. Med anledning av
harmoniseringssträvanden och en internationell
regleringsaktivitet i riktning mot periodisering (matching) har det
uppfattats som angeläget att studera
förutsättningarna för ett principbyte i den externa
redovisningen även i Sverige.
Syftet med undersökning
har varit att kartlägga och beskriva potentiella problem som en
tillämpning av successivresultatavräkning kan
medföra. Undersökningen har genomförts med ett
överordnat systemperspektiv viklet innebär att bygg- och
anläggningsföretag betraktas som en speciell kategori av
företag med en egen karaktäristik. De teoretiska
utgångspunkterna har tagits i ett synsätt som
innebär att informationens beslutsanvändbarhet för
externa intressenter ställs i fokus. Följden av detta
är att redovisningsdatans relevans och tillförlitlighet
diskuterats ingående med avseende på realisations- och
försiktighetsprincipen. Resultatet av denna diskussion har
varit att ett starkt stöd för periodisering av resultat i
pågående arbeten har konstaterats.
En referensram
har därefter formulerats utifrån ett urval av
internationella rekommendationer och standards i vilka reglerna har
tagit ställning för successiv resultatavräkning av
entreprenadprojekt. Syftet med detta har varit att analysera valda
rekommendationer och standards för att identifiera och belysa
väsentliga problemområden vid tillämpning av
successiv resultatavräkning. Genomgången har resulterat i
en arbetsmodell där detaljerade bestämningar formulerats
om problemens struktur. Arbetsmodellen har sedan legat till grund
för en intervjuguide som tillämpats i de
fallstudier. Fallstudierna har genomförts för att
empiriskt belysa de identifierade problemområdena.
Urvalet
av fallföretag täcker en majoritet av de i Sverige
börsnoterade företagen som bedriver bygg- och
anläggningsentreprenader. Undersökninger har
därför karaktären av en
totalundersökning. På grund av att tre fallstudier har
genomförts har det uppfattats föreligga goda
möjligheter till generaliseringar. De tre fallen har varit PEAB
Öst AB, ett entreprenadbolag inom PEAB-koncernen, Siab och
Skanska.
Undersökningsresultaten har indikerat en stor
överensstämmelse mellan företagen i samtliga
problemområden. Slutsatser som resultaten givit är bland
annat att bygg- och anläggningsföretagen i
undersökningen har kapacitet, kunskap och erfarenhet av
tillämpning avsuccessiv resultatavräkning av sina
fastprisprojekt. Det har även konstaterats att företagen
har en väl utvecklad systemteknisk kapacitet för hantering
av sina projekt vad avser kalkylering, redovisning och
uppföljning. De problem som iakttagits har framförallt
varit hänförliga till prognosarbetet där eventuella
brister i framtida uppskattningar om kvarvarande kostnader
uppfattats ha stor inverkan på avräknade resultatandelars
riktighet. Även de inledande faserna där
produktionskalkyler formuleras och konton väljs har uppfattats
som kritiska för riktigheten i avräknade resultatandelar.
Till sist har även själva redoviningen av nedlagda
kostnader uppfattats utgöra en potentiell felkälla
på grund av att det akn vara svårt att hänföra
kostnader till rätt projekt och projektdel.
De
implikationer som resultaten givit upphov till har varit att det
bör finnas möjligheter till en tillämpning av
successiv resultatavräkning även i den externa
redovisningen för den undersökta kategorin av
företag. Undersökningen har dock inte mer än
kortfattat tagit upp skattemässiga konsekvenser som ett
principbyte skulle kunna medföra varför dessa inte har
kunnat analyseras.
No FHS 7/95
ARBETSINTEGRERAD
SYSTEMUTVECKLING MED KALKYLPROGRAM
Anders
Avdic
Studieområdet för denna rapport kan
formuleras: ”Människor utvecklar med hjälp av
kalkylprogram, inom ramen för sina linjearbetsuppgifter,
tillämpningar för eget behov, som om de gjordes med
’traditionell’ systemutveckling, skulle innebära
betydligt större insatser av tid, personal och
specialistkompetens”. Denna aktivitet kan ses ur ett process-
produktperspektiv, där processen kallas arbetsintegrerad
systemutveckling med kalkylprogram (AIS-K) och produkten kallas
kalkylsystem. Människorna som utför aktiviterna kallas
användarutvecklare.
Syftet med rapporten är att
analysera AIS-K som fenomen. AIS-K har analyserats teoretiskt och
empiriskt. Den teoretiska analysen har bestått i att relatera
AIS-K till Livscykelmodellen och till Nurminens HIS-modell. Fyra
empiriska studier har gjorts, en genom rekonstruerad deltagande
observation och de övriga genom intervjuer och
enkäter.
Resultaten visar att arbetsintegrerad
systemutveckling är att uttryck för integration dels av
arbetsuppgifter och systemutveckling och dels av olika
systemutvecklingsaktiviteter. I relation till
”traditionell” systemutveckling fokuseras
arbetsuppgiften snarare än utvecklingsarbetet. AIS-K
präglas av stegvis förfining, sammanflätade
aktiviteter, deklarativt arbetssätt samt avsaknad av
standardiserat metodarbete. Kalkylsystem kan indelas efter krav
på användarutvecklares förkunskaper om
kalkylprogram. AIS-K innebär förändring av roller i
utvecklingsarbetet där användarutvecklaren kombinerar
utvecklarrollen med någon traditionell
användarroll. Syftena med kalkylsystem kan vara
rationaliserande, beslutsstödjande eller strategiska.
No 478
COMPLEXITY OF STATE-VARIABLE PLANNING
UNDER STRUCTURAL RESTRICTIONS
Peter Jonsson
Computationally tractable planning problems reported in the
literature have almost exclusively been defined by syntactical
restrictions. To better exploit the inherent structure in problems,
it is probably necessary to study also structural restrictions on
the underlying state-transition graph. Such restrictions are
typically hard to test since this graph is of exponential size. We
propose an intermediate approach, using a state variable model for
planning and defining restrictions on the state-transition graph for
each state variable in isolation. We identify such restrictions
which are tractable to test and we present a planning algorithm
which is correct and runs in polynomial time under these
restrictions.
Moreover, we present an exhaustive map over the
complexity results for planning under all combinations of four
previously studied syntactical restrictions and our five new
structural restrictions. This complexity map considers both the
bounded and unbounded plan generation problem. Finally, we extend a
provably correct, polynomial-time planner to plan for a miniature
assembly line, which assembles toy cars. Although somewhat limited,
this process has many similarities with real industrial
processes.
No 482
TOWARDS STUDENT MODELLING THROUGH
COLLABORATIVE DIALOGUE WITH A LEARNING COMPANION
Eva L
Ragnemalm
Understanding a student's knowledge is an
important part of adapting the instruction to that individual
student. In the area of Intelligent Tutoring Systems this is called
Student Modelling.
A specific student modelling problem is
studied in the situation where a simulator-based learning
environment is used to train process operators in diagnosis. An
experiment shows that the information necessary for building a
student model is revealed in the dialogue between two students
collaborating on diagnosing a fault.
As a side effect of this
investigation a framework for describing student modelling
emerged. In this framework student modelling is viewed as the
process of bridging the gap between observations of the student and
the system's conception of the knowledge to be taught.
This
thesis proposes the use of a Learning Companion as the collaboration
partner. The ensuing dialgoue can then be used for student
modelling. An analysis of the collaborative dialogue is presented
and several important characteristics identified. An architecture is
presented and a prototype that reproduces these characteristics is
described.
No 488
CONTRIBUTIONS TO PARALLEL
MULTUPARADIGM LANGUAGES: COMBINING OBJECT-ORIENTED AND RULE-BASED
PROGRAMMING
Eva Toller
Today,
object-oriented programming is widely used as a practical tool. For
some types of complex applications, the object-oriented style needs
to be complemented with other types of programming paradigms into a
multiparadigm language. One candidate for such a complement is the
rule-based programming paradigm. For this purpose, several
object-oriented languages have been extended with rule-based
features from production systems.
- We propose a loosely coupled
parallel multiparadigm language based on object-orientation,
features from production systems, and ideas from the joint action
concept. The latter is a model for writing executable
specifications, but basically it is a rule-oriented technique. It
has a loose coupling between objects and actions, which is essential
to extend an object-oriented language in an evolutionary way.
-
Production systems have a natural potential for massively parallel
execution, and have a general execution model. However, they have
traditionally been limited to applications within the area of
artificial intelligence. If the restrictions imposed by the
traditional problems are eliminated, rule-based programming can
become practical for a wider spectrum of applications, and they can
also utilize parallelism to a higher degree.
- The main
contribution of this thesis is to investigate the possibilities of
cross-fertilization between some research areas that can contribute
to a language of the proposed type. These areas are
object-orientation, production systems, parallel computing, and to
some extent formal specification languages and database management
systems.
- A prototype, intended to verify some of our ideas,
has been built with the Erlang functional language and is
implemented on a parallel machine.
No 489
A PETRI NET BASE UNIFIED
REPRESENTATION FOR HARDWARE/SOFTWARE CO-DESIGN
Erik
Stoy
This thesis describes and defines a design
representation model for hardware/software co-design. To illustrate
its usefulness we show how designs captured in the representation
can be repartitioned by moving functionality between hardware and
software. We also describe a co-simulator which has been implemented
using the representation and can be used to validate systems
consisting of hardware and software components.
The term
co-design implies the use of design methodologies for heterogeneous
systems which emphasize the importance of keeping a system-wide
perspective throughout the design process and letting design
activities in different domains influence each other. In the case of
hardware/software systems this means that the design of hardware and
software subsystems should not be carried out in isolation from each
other.
We are developing a design environment for
hardware/software co-design and the objective of the work presented
in this thesis has been to define the internal representation that
will be used in this environment to capture designs as they
evolve. The environment should support transformation-based design
methods and in particular it should be possible to introduce
transformations that move functionality from hardware to software
and vice versa, thus allowing repartitioning of designs to be
performed as a part of the normal optimization process.
Our
co-design representation captures systems consisting of hardware
circuits cooperating with software processes run on pre-defined
processors. Its structure and semantics are formally defined, and
hardware and software are represented in very similar manners, as
regards both structure and semantics. Designs are represented as
subsystems linked by communication channels. Each subsystem has a
local controller which is represented by a Petri net. Data
manipulation representation is based on datapaths in hardware and
syntax trees in software. The representation is executable. It
captures both abstract and concrete aspects of designs and supports
transformation-based design methods. Implementation of the co-design
representation has demonstrated that it can be used for several
important tasks of the hardware/software co-design process.
No 497
ENVIRONMENT SUPPORT FOR BUILDING
STRUCTURED MATHEMATICAL MODELS
Johan Herber
This thesis is about two topics. It describes a high-level
programming environment for scientific computing, called ObjectMath,
and several contributions to this environment. It also analyses the
concept of software development environment architecture, in
particular with respect to the ObjectMath environment. The
ObjectMath programming environment is designed to partly automate
many aspects of the program development cycle in scientific
computing by providing support for high-level object-oriented
mathematical modelling and generation of efficient numerical
implementations from such high-level models. There is a definite
need for such tools, since much scientific software is still written
in Fortran or C the traditional way, manually translating
mathematical models into procedural code and spending much time on
debugging and fixing convergence problems. The automatic code
generation facilities in the ObjectMath environment eliminate many
of the problems and errors caused by this manual translation. The
ObjectMath language is a hybrid language, combining computer algebra
facilities from Mathematica with object-oriented constructs for
single and multiple inheritance and composition. Experience from
using the environment shows that such structuring concepts increase
re-use and readability of mathematical models. Large object-oriented
mathematical models are only a third of the size of corresponding
models that are not object-oriented. The system also provides some
support for visualization, both for models and for numerical
results.
The topic of engineering a software development
environment is very important in itself, and has been dealt with
primarily from an architectural point of view. Integration of
different tools and support facilities in an environment is
important in order to make it powerful and to make it easy to
use. On the other hand, developing whole environments completely
from scratch is very costly and timeconsuming. In the ObjectMath
project, we have followed an approach of building an integrated
environment using mostly pre-existing tools, which turned out very
well. In this thesis the integration aspects of ObjectMath is
analysed with respect to three dimensions: control, data and user
interface, according to a general model described by
Schefström. The conclusion is that ObjectMath fits this model
rather well, and that this approach should be successful in the
design of future environments, if the integration issues are dealt
with in a systematic way. In addition, the analysis provides some
guidance regarding integration issues that could be enhanced in
future versions of ObjectMath.
No 498
STRUCTURE DRIVEN DERIVATION OF
INTER-LINGUAL-ARGUMENT TREES FOR MULTI LINGUAL GENERATION
Stefan Svenberg
We show how an inter-lingual
representation o messages can be exploited for natural language
generation of technical documentation into Swedish and English in a
system called Genie. Genie has a conceptual knowledge base of the
facts considered as true in the domain. A user queries the knowledge
base for the facts she wants the document to include. The responses
constitute the messages which are multi-lingually generated into
Swedish and English texts.
The particular kind of conceptual
representation of messages that is chosen, allows for two
assumptions aboutinter-linguality; (i) Syntactic compositionality,
viz. the linguistic expression for a message is a function from the
expressions obtained from the parts of the message. (ii) A message
has in itself an adequate expression, which gives a restriction in
size of the input to generation. These assumptions underlie a
grammar that maps individual messages to linguistic categories in
three steps. The first step constructs a functor-argument tree over
the target language syntax using a non-directed unification
categorial grammar. The tree is an inter-mediate representation that
includes the message and the assumptions. It lies closer to the
target languages but is still language neutral. The second step
instantiates the tree with linguistic material according to target
language. The final step uses the categorial grammar application
rule on each node of the tree to obtain the resulting basic
category. It contains an immediate representation for the linguistic
expression of the message, and is trivially converted into a string
of words. Some example texts in the genre have been studied. Their
sublanguage traits clearly enable generation by the proposed
method.
The results indicate that Genie, and possibly other
comparable systems that have a conceptual message representation,
benefits in efficiency and ease of maintenance of the linguistic
resources by making use of the knowledge-intensive multi-lingual
generation method described here.
No 503
PREDICTION AND POSTDICTION UNDER
UNCERTAINTY
Hee-Cheol Kim
An intelligent
agency requires the capability to predict what the world looks like
as a consequence of its actions. It also needs to explain present
observations in order to infer previous states. This thesis proposes
an approach to realize both capabilities, that is prediction and
postdiction based on temporal information. In particular, there is
always some uncertainty in the knowledge about the world which the
autonomous agent inhabits. Therefore we handle uncertainty using
probability theory. None of the previous works dealing with
quantitative (or numerical) approaches addressed on the postdiction
problem in designing an intelligent agent. Our thesis presents a
method to resolve this postdiction problem under uncertainty.
No FHS 8/95
METODER I ANVÄNDNING -
MOT FÖRBÄTTRING AV SYSTEMUTVECKLING GENOM SITUATIONELL
METODKUNSKAP OCH METODANALYS
Dan Fristedt
För utveckling av datorbaserade system har det under flera
decennier funnits många olika metoder och
modeller. Utvecklingen av metoder har skett ända från
slutet av 60-talet och fram till nu. Under senare år har
medvetenheten för metoder ökat och de används som
hjälpmedel för att utveckla verksamheter och
datasystem. Det finns många olika faktorer som påverkar
metodanvändningen, vilka kan benämnes som situationella
omgivningsfaktorer. Dessa faktorer är viktiga att ta
hänsyn till då man använder metoder. Till metoder
finns det olika typer av datorstöd för att stödja
användningen. Verktyg för de senare faserna av
systemutvecklingsprocessen har existerat under en lång tid,
medan verktyg för de tidigare faserna har blivit allt vanligare
under de senare åren.
Verktyg som ger stöd för
metodanvändningen kallas för CASE-verktyg. CASE är
en förkortning av Computer Aided Systems/Software Engineering.
CASE-verktyg som stödjer de tidiga faser kallas för
UpperCASE och verktyg som stödjer senare faser kallas för
LowerCASE. En viktig del i ett CASE-verktyg är dess
metodstöd, eftersom detta påverkar
metodanvändningen.
Avhandlingen behandlar hur metoder
används i systemutveckling och vad som påverkar
användningen samt hur metoden påverkar
systemutvecklingsarbetet. Det redovisas också en teoretisk
kunskapsgenomgång av metodanalys och hur detta kan utnyttjas
för att förbättra metodanvändningen. Resultatet
från undersökningen visar på att det finns olika
aspekter som påverkar metodanvändningen som t ex
utvecklingsmiljö, förankring av metoden och olika
situationella omgivningsfaktorer. Dessa omgivningsfaktorer är
mer eller mindre generella och dessa är situationella av sin
karaktär. Det innebär att de uppkommer i olika situationer
och de är faktorer som bör beaktas då man
situationsanpassar sin metod. Metodanalys kan användas på
ett antal områden för att förbättra
metodanvändningen. I rapporten identifieras följande
områden: drivkraft i organisationen, aktiv metodutveckling -
precisering av metoden, kompetensutveckling kring metoder,
metamodeller för integration av CASE-verktyg och
jämförelseinstrument av metoder.
No FHS 9/95
SYSTEMFÖRVALTNING I
PRAKTIKEN - EN KVALITATIV STUDIE AVSEENDE CENTRALA BEGREPP,
AKTIVITETER OCH ANSVARSROLLER
Malin
Bergvall
Intresset för systemförvaltning har
ökat under senare år, inte minst mot bakgrund av att
stora resurser av de totala ADB-kostnaderna anses åtgå
till förvaltning av befintliga system. Syftet med den här
studien är att undersöka vad systemförvaltning
egentligen innebär. Den här studien kan sägas
utgöra en grundläggande verksamhetsanalys av
systemförvaltningsarbetet med inriktning på
ändringshantering och dess problembild. Sju fallstudier har
genomförts i svenska organisationer som bedriver
systemförvaltning. Utifrån dessa fallstudier har begrepp
och kategorier genererats med hjälp av ”grounded
theory” - ansats. Rapporten består av en inledande del
där frågeställningar, forskningsmetod och teoretiska
förutsättningar redovisas. Därefter redovisas det
empiriska materialet från fallstudierna. Resultatet av
studien visar att systemförvaltning idag bedrivs främst
ADB-inriktat. De verksamhetsinriktade aspekterna tillgodoses inte
tillräckligt. I rapporten presenteras därför en
är- och en bör-definition av
systemförvaltning. Är-definitionen uttrycker hur
systemförvaltning bedrivs idag (på ADB-inriktat
sätt). Bör-definitionen uttrycker vad
systemförvaltning borde vara utifrån en
verksamhetsinriktad syn. Systemförvaltningens aktiviteter har
identifierats och presenteras i rapporten. Avgränsning mot
närliggande aktiviteter görs genom att en ny
livscykelmodell för informationssystemarbete presenteras. Ett
antal ansvarsroller som är nödvändiga i samband med
systemförvaltning har identifierats och presenteras i
rapporten.
No 513
TOWARDS A STRATEGY FOR SOFTWARE
REQUIREMENTS SELECTION
Joachim Karlsson
The
importance of identifying clearly the requirements for a software
system is now widely recognized in the software engineering
community. From the emerging field of requirements engineering, this
thesis identifies a number of key areas. In particular, it shows
that, to achieve customer satisfaction, it is essential to select a
subset of all candidate requirements for actual implementation.
This selection process must take into account both the value and the
estimated cost of including any candidate requirements in the set to
be implemented. At the moment this entire process is usually carried
out in an informal manner so there is a pressing need for techniques
and a strategy to support it.
With the explicit aim of clearly
identifying requirements, the use of quality function deployment
(QFD) in an industrial project at Ericsson Radio Systems AB was
studied and evaluated. It was found that QFD helps developers to
focus more clearly on the customer’s needs and in managing
non-functional requirements.
To trade off maximization of value
and minimization of cost when selecting requirements for
implementation a method was developed, the contribution-based
method, which is based on the analytic hierarchy process (AHP). The
contribution-based method was applied in two industrial projects and
the results evaluated. Both studies indicate that both the value and
cost of candidate requirements can vary by orders of
magnitude. Thus, deciding which requirements to be selected for
implementation is of paramount importance, and also a primary
determinant of customer satisfaction. The contribution-based method
forms the basis of a selection strategy that will maximize customer
satisfaction.
No 517
SCHEDULABILITY-DRIVEN PARTITIONING OF
HETEROGENEOUS REAL-TIME SYSTEMS
Jakob
Axelsson
During the development of a real-time system,
the main goal is to find an implementation that satisfies the
system's specified worst-case timing constraints. Often, the most
cost-effective solution is a heterogeneous implementation, where
some parts of the functionality are implemented in software, and the
rest in hardware, using application-specific
circuits. Hardware/software codesign allows the designer to describe
the complete system homogeneously, and thereafter divide it into
separate hardware and software parts. This thesis is a contribution
to hardware/software partitioning of real-time systems. It proposes
an automatic partitioning of a set of real-time tasks in order to
meet their deadlines. A key issue when verifying timing constraints
is the analysis of the task scheduler. Therefore, an extension of
fixed-priority scheduling theory is proposed, which is suitable for
heterogeneous implementations. It includes an optimal task priority
assignment algorithm. The analysis uses information about the
execution time of the tasks in different implementations, and a
method for estimating these data is also proposed. The analysis
results are used to guide the partitioning process, which is based
on a branch-and-bound algorithm.
No 518
TOWARD COOPERATIVE ADVICE-GIVING
SYSTEMS: THE EXPERT SYSTEMS EXPERIENCE
Göran
Forslund
Expert systems have during the last fifteen
years successfully been applied to a number of difficult problems in
a variety of different application domains. Still, the impact on
the commercial market has been less than expected, and the predicted
boom just failed to occur. This thesis seeks to explain these
failures in terms of a discrepancy between the tasks expert systems
have been intended for and the kind of situations where they
typically have been used. Our studies indicate that the established
expert systems technology primarily focuses on providing
expert-level solutions to comparatively well-defined problems, while
most real-life applications confront a decision maker with much more
ill-defined situations where the form of the argumentation rather
than the explicit decision proposal is crucial. Based on several
commercial case-studies performed over a 10-year period together
with a review of relevant current research in decision making
theory, this thesis discusses the differences between different use
situations with respect to the degree of how well-defined the
decision task is and what kind of support the users require. Based
on this analysis, we show the need for a shift in research focus
from autonomous problem solvers to cooperative advice-giving systems
intended to support joint human-computer decision making. The
requirements on techniques suitable to support this trend toward
cooperative systems are discussed and a tentative system
architecture and knowledge representation for such systems is
proposed. The thesis concludes with a research agenda for examining
the cost and benefits of the suggested approach as a tool for
cooperative advice-giving systems, and to determine the
appropriateness of such systems for real-world application
problems.
No 522
BILDER AV SMÅFÖRETAGARES
EKONOMISTYRNING
Jörgen Andersson
Utvecklingen av ekonomisk styrning och även den aktuella
debatten inom området är till stora delar koncentrerad
till stora företag. Under en seminarieserie om risker i
samband med nyföretagande anordnad av Närings- och
teknikutvecklingsverket (NUTEK) aktualiserades frågan om
ekonomisk styrning i små och nystartade företag.
Inför denna studie blev det därför naturligt att
ställa sig frågan om hur de teorier och metoder som idag
finns till förfogande för ekonomistyrning fungerar i
små företag. Syftet med denna studie är att öka
insikterna om hur ekonomisk styrning bedrivs i små
företag. Detta sker genom att beskriva och analysera den
ekonomiska styrningen i ett antal små företag.
Undersökningen omfattar intervjuer med nio
småföretagsledare. Centrala forskningsfrågor
är vilka mål företagsledaren har, vilka ekonomiska
verktyg som används, hur beslutsfattande sker samt hur
samarbetet med externa aktörer i form av banker, revisorer och
konsulter fungerar.
Studien visar att långsiktiga
mål ofta anges i kvalitativa termer. Mer sällan är
de monetära målen konkret formulerade. Företagandet
bygger ofta på ett praktiskt kunnande hos
företags-ledaren. Affärsidén kan antingen vara
explicit formulerad eller mer outtalad. Vidare visas hur komplext
beslutsfattande kan vara i den typ av verksamhet som har
studerats. I vissa fall kan en sekventiell och rationell
beslutsmodell spåras. I andra fall kan irrationella
beslutsmodeller beskriva beslutsprocessen. Tydligt är dock att
både formella beslutsunderlag och intuition och erfarenhet
spelar en viktig roll vid beslutsfattande. Studien visar dessutom
att många av de metoder och verktyg som anges inom
ekonomistyrningslitteratur också används i de studerade
företagen. Vilka verktyg som upplevs som mest betydelsefulla
varierar mellan de olika företagsledarna. I studien tolkas
användningen av formella ekonomistyrningsmetoder som ett utslag
för en avvägning mellan nytta och kostnader i en situation
där resurserna är mycket begränsade. Dessutom
framkommer att företagsledare har förhållandevis
få externa kontakter med vilka affärsverksamheten
diskuteras. Av dessa upplevs samarbetet med revisor i många
fall som det viktigaste.
Slutligen argumenteras för att nya
metoder för styrning av verksamheter mot ekonomiska mål
behöver utvecklas. Traditionella metoder för
ekonomistyrning kan behöva kompletteras med andra metoder
där verksamhetens centrala resultatskapande faktorer
identifieras och utnyttjas för styrning, vilket kan
innebära att icke-monetära mått får en
ökad betydelse.
No 538
EFFICIENT MANAGEMENT OF
OBJECT-ORIENTED QUERIES WITH LATE BINDING
Staffan
Flodin
To support new application areas for database
systems such as mechanical engineering applications or office
automation applications a powerful data model is required that
supports the modelling of complex data, e.g. the object-oriented
model.
The object-oriented model supports subtyping,
inheritance, operator overloading and overriding. These are features
to assist the programmer in managing the complexity of the data
being modelled.
Another desirable feature of a powerful data
model is the ability to use inverted functions in the query
language, i.e. for an arbitrary function call fn(x)=y, retrieve the
arguments x for a given result y.
Optimization of database
queries is important in a large database system since query
optimization can reduce the execution cost dramatically. The
optimization considered here is a cost-based global optimization
where all operations are assigned a cost and a way of a priori
estimating the number of objects in the result. To utilize available
indexes the optimizer has full access to all operations used by the
query, i.e. its implementation.
The object-oriented data
modelling features lead to the requirement of having late bound
functions in queries which require special query processing
strategies to achieve good performance. This is so because late
bound functions obstruct global optimization since the
implementation of a late bound function cannot be accessed by the
optimizer and available indexes remain hidden within the function
body.
In this thesis the area of query processing is described
and an approach to the management of late bound functions is
presented which allows optimization of invertible late bound
functions where available indexes are utilized even though the
function is late bound. This ability provides a system with support
for the modelling of complex relations and efficient execution of
queries over such complex relations.
No 545
AN APPROACH TO AUTOMATIC CONSTRUCTION
OF GRAPHICAL USER INTERFACES FOR APPLICATIONS IN SCIENTIFIC
COMPUTING
Vadim Engelson
Applications in
scientific computing perform input and output of large amounts of
data of complex structure. Since it is difficult to interpret these
data in textual form, a graphical user interface (GUI) for data
editing, browsing and visualization is required. The availability of
a convenient graphical user interface plays a critical role in the
use of scientific computation systems.
Most approaches to
generating user interfaces provide some interactive layout facility
together with a specialized language for describing user
interaction. Realistic automated generation approaches are largely
lacking, especially for applications in the area of scientific
computing.
This thesis presents two approaches to automatically
generating user interfaces from specifications. The first is a
semi-automatic approach, that uses information from object-oriented
mathematical models, together with a set of predefined elementary
types and manually supplied layout and grouping information. This
system is currently in industrial use for generating user interfaces
that include forms, pull-down menus and pop-up windows. The current
primary application is bearing simulation, which typically accepts
several thousand input parameters and produces gigabytes of output
data. A serious disadvantage is that some manual changes need to be
made after each update of the high-level model.
The second
approach avoids most of the limitations of the first generation
graphical user interface generating system. We have designed a tool,
PDGen (Persistence and Display Generator) that automatically creates
a graphical user interface from the declarations of data structures
used in the application (e.g., C++ class declarations). This largely
eliminates the manual update problem. Structuring and grouping
information is automatically extracted from the inheritance and
part-of relations in the object-oriented model and transferred to
PDGen which creates the user interface. The attributes of the
generated graphical user interface can be altered in various ways if
necessary.
This is one of very few existing practical systems
for automatically generating user interfaces from type declarations
and related object-oriented structure information.
No 546
MULTIDATABASE INTEGRATION USING
POLYMORPHIC QUERIES AND VIEWS
Magnus Werner
Modern organizations need tools that support coordinated access to
data stored in distributed, heterogeneous, autonomous data
repositories.
Database systems have proven highly successful in
managing information. In the area of information integration
multidatabase systems have been proposed as a solution to the
integration problem.
A multidatabase system is a system that
allows users to access several different autonomous information
sources. These sources may be of a very varying nature. They can
use different data models or query languages. A multidatabase system
should hide these differences and provide a homogeneous interface to
its users by means of multidatabase views.
Multidatabase views
require the query language to be extended with multidatabase
queries, i.e. queries spanning multiple information sources allowing
information from the different sources to be combined and
automatically processed by the system.
In this thesis we present
the integration problem and study it in an object-oriented
setting. Related work in the area of multidatabase systems and
object views is reviewed. We show how multidatabase queries and
object views can be used to attack the integration problem. An
implementation strategy is described, presenting the main
difficulties encountered during our work. A presentation of a
multidatabase system architecture is also given.
No FiF-a 1/96
AFFÄRSPROCESSINRIKTAD
FÖRÄNDRINGSANALYS - UTVECKLING OCH TILLÄMPNING AV
SYNSÄTT OCH METOD
Mikael Lind
Affärsprocesstänkande är ett idag mycket
populärt synsätt då verksamheter utvärderas och
utvecklas. Definitionen av begreppet affärsprocess varierar
bland olika författare och osäkerhet råder om hur
det skall tolkas. I studien som ligger till grund för denna
rapport används begreppet affärsprocess för den
samling av aktiviteter som utförs i samband med affärer, d
v s det sätt på vilket verksamheten gör
affärer. Det affärsprocessinriktade perspektivet
innebär en fokusering på kunden och en tydlig koppling
till verksamhetens affärsidé. Det är
därför viktigt att detta perspektiv anläggs då
verksamhetsutveckling bedrivs. En förändringsanalys
innebär att förutsättningar för
verksamhetsutveckling skapas, där utveckling av
informationssystem är en väsentlig aspekt. Att
genomföra en förändringsanalys innebär att
verksamheten analyseras i syfte att generera ett antal
förändringsbehov till vilka sedan olika
förändringsåtgärder föreslås och
värderas. De föreslagna
förändringsåtgärderna skall utgöra ett
beslutsunderlag för fortsatt verksamhetsutveckling. I studien
har förändringsanalys enligt SIMMetoden (FA/SIMM)
vidareutvecklats till affärsprocessinriktad
förändringsanalys (AFA) genom att ta hänsyn till de
konsekvenser som affärsprocesstänkande innebär.
Processen att (vidare)utveckla en metod innebär att metoden
grundas såväl internt som i teori och empiri. I denna
rapport presenteras resultatet av ett aktionsforskningsprojekt
där AFA både har generats och prövats empiriskt,
varvid metoden har tillämpats i en omfattande
förändringsanalys på ett medelstort
stålföretag. Metoden utgör en kongruent helhet och
dess kategorier har relaterats till andra teorier och
begrepp. Metodutvecklingen har särskilt fokuserats på
verksamhetsanalys och processmodellering. Resultatet av studien
är ett metodkoncept som är vidareutvecklat med FA/SIMM som
basmetod vad gäller såväl synsätt,
arbetssätt, begrepp som notation.
No 549
HIGH-LEVEL SYNTHESIS UNDER LOCAL
TIMING CONSTRAINTS
Jonas Hallberg
High-level synthesis deals with the problem of transforming a
behavioral description of a design into a register transfer level
implementation. This enables the specification of designs at a high
level of abstraction. However, designs with timing requirements can
not be implemented in this way, unless there is a way to include the
timing requirements in the behavioral specification. Local timing
constraints (LTCs) enable the designer to specify the time between
the execution of operations and more closely model the external
behavior of a design. This thesis deals with the modelling of LTCs
and the process of high-level synthesis under LTCs.
Since
high-level synthesis starts from behavioral specifications an
approach to transfer LTCs from behavioral VHDL to an intermediate
design representation has been adopted. In the intermediate design
representation the LTCs are modelled in such a way that they can be
easily analyzed and interpreted. Before the high-level synthesis
process is started a consistency check is carried out to discover
contradictions between the specified LTCs.
If the LTCs are
consistent a preliminary scheduling of the operations can be
performed and the clock period decided. For that purpose two
different approaches, based on unicycle and multicycle scheduling,
have been developed. The unicycle scheduling approach assumes that
the longest delay between two registers equals the clock
period. Design transformations are used to change the number of
serialized operations between the registers and, thus, change the
clock period to satisfy the LTCs. The multicycle scheduling approach
allows the longest delay between two registers to be several clock
periods long. Thus, the goal is to find a reasonable clock period
and a preliminary schedule that satisfy the LTCs. Furthermore, the
multicycle scheduling approach does trade-offs between speed and
cost (silicon area) when deciding on which modules to be used to
implement the operations. Both Genetic algorithms and Tabu search
are used to solve the combinatorial optimization problem that arises
during the multicycle scheduling.
If the preliminary schedule
fulfills all the LTCs then module allocation and binding is
performed. The goal is to perform all the operations while using as
few functional modules as possible. This is achieved by module
sharing. Experimental results show that the high-level synthesis
performed by the proposed methods produces efficient designs.
No 550
FÖRUTSÄTTNINGAR OCH
BEGRÄNSNINGAR FÖR ARBETE PÅ DISTANS - ERFARENHETER
FRÅN FYRA SVENSKA FÖRETAG
Kristina
Larsen
Att arbeta på distans är inget nytt
fenomen, men dagens informationsteknik har gjort arbetsformen
tillgänglig för fler yrkeskategorier än tidigare och
intresset för distansarbete är idag stort. Denna
undersökning avser arbete på distans i företag
där ett flertal personer i samma grupp distansarbetar. I dessa
grupper arbetar de anställda både på distans
från arbetsgivaren och från varandra. Syftet har varit
att utifrån de studerade fallen identifiera möjliga
förutsättningar och begränsningar för
arbetsformen. Särskilt har arbetsuppgifter och koordination
varit i fokus.
Undersökningens empiriska del utgörs av
studier i fyra företag där distansarbete tillämpas. I
de studerade fallen är förutsättningarna något
olika. I två fall sker distansarbetet på heltid och i
två fall på deltid. Arbetsuppgifterna och de övriga
förutsättningarna varierar. Datainsamlingen har skett i
form av kvalitativa intervjuer med distansarbetare och deras
chefer. Det empiriska materialet relateras till teorier om
koordination och kommunikation och till resultat från ett
antal andra undersökningar om distansarbete. I
undersökningen görs också en jämförelse
mellan de studerade fallen.
I undersökningen konstateras
att behovet av koordination och kommunikation vid distansarbete i
första hand styrs av de arbetsuppgifter som utförs.
Många av de resultat som presenteras hänför sig
därför till den typ av arbetsuppgifter som
utförs. Arbetsuppgifter som är speciellt lämpliga
för distansarbete är självständiga uppgifter,
uppgifter som innehåller många externa kontakter och
uppgifter där behovet av koncentration är
stort. Koordinationen av distansarbete underlättas av en stark
företagskultur och tydliga resultatvariabler. Det krävs
också rutiner för att befrämja erfarenhetsutbyte
mellan kollegor. Undersökningens resultat pekar på att
behovet av formaliserade rutiner och styrprocesser kan öka vid
distansarbete. Vidare konstateras att motivationen hos
anställda och chefer är fundamental för att
distansarbete ska fungera bra. Undersökningen visar att
informationsteknik på flera sätt kan vara ett stöd
för distansarbete, men att sårbarheten inom
organisationen ökar. En intressant fråga som
undersökningen ger upphov till är vilka konsekvenser
distansarbete får på sikt.
No 557
QUALITY FUNCTIONS FOR REQUIREMENTS
ENGINEERING METHODS
Mikael Johansson
The
objectives for this thesis is to establish what aspects of
Requirements Engineering (RE) methods are considered important by
the users. The thesis is to study an alternative RE method (Action
Design), present evaluation results and establish general quality
characteristics for RE methods. It is also an attempt to invoke the
need to reflect over quality aspects of use and development of
ethods within the field of RE.
The research is based on a
grounded theory perspective where the studies together form the
final results. The data collection was performed by intreviews and
focus groups. The analysis of data was done by using (1) Action
Design (AD) methodology as an instrument to evaluate AD itself, (2)
Quality Function Deployment to structure and rank quality
characteristics, and (3) by phenomenological analyses.
The
results show the importance of considering social and organizational
issues, user participation, project management and method
customizing in the process of RE.
Further, the results suggest
that support which integrate different methods, or parts of methods
to achieve a suitable collection of instruments tailored for a
specific project is needed. It is also found that RE is to be
considered, not only in the early parts of the software development
cycle, but as an integrated part of the whole software development
cycle.
The conclusion is that RE methods beside the integation,
need to be approached diffrently in the future. The integrated view
of RE (as a part of the entire development process) could also be a
way to solve some of the current problems that are discussed in
relation to requirements in software development.
No 558
THE SIMULATION OF ROLLING BEARING
DYNAMICS ON PARALLEL COMPUTERS
Patrik
Nordling
In this thesis we consider the simulation of
rolling bearing dynamics on parallel computers. Highly accurate
rolling bearing models currently require unacceptably long
computation times, in many cases several weeks, using sequential
computers.
We present two novel methods on how to utilize
parallel computers for the simulation of rolling bearing
dynamics. Both approaches give a major improvement in elapsed
computation time.
We also show that, if knowledge about the
application domain is used, the solution of stiff ordinary
differential equations can successfully be performed on parallel
computers. Potential problems with scalability of the Newton
iteration method in the numerical solver are addressed and
solved.
This thesis consists of five papers. One paper deals
with more general approaches on how to solve ordinary differential
equations on parallel computers. The other four papers are more
focused on specific solution methods including applications to
rolling bearing.
No 561
EXPLORATION OF POLYGONAL
ENVIRONMENTS
Anders Ekman
Several robotic
problems involve the systematic traversal of environments, commonly
called exploration. This thesis presents a strategy for exploration
of finite polygonal environments, assuming a point robot that has 1)
no positional uncertainty and 2) an ideal range sensor that measures
range in N uniformly distributed directions in the plane. The range
data vector, obtained from the range sensor, corresponds to a
sampled version of the visibility polygon. Edges of the visibility
polygon that do not correspond to environmental edges are called
jump edges and the exploration strategy is based on the fact that
jump edges indicate directions of possibly unexplored regions.
This thesis describes a) the conditions under which it is possible
to detect environmental edges in the range data, b) how the
exploration strategy can be used in an exploration algorithm, and c)
the conditions under which the exploration algorithm is guaranteed
to terminate within a finite number of measurements.
No 563
COMPILATION OF MATHEMATICAL MODELS TO
PARALLEL CODE
Niclas Andersson
Generating
parallel code from high-level mathematical models is in its general
form an intractable problem. Rather than trying to solve this
problem, a more realistic approach is to solve specific problem
instances for limited domains.
In this thesis, we focus our
efforts on problems where the main computation is to solve ordinary
differential equation systems. When solving such a system of
equations, the major part of the computing time is spent in
application specific code, rather than in the serial solver
kernel. By applying domain specific knowledge, we can generate
efficient parallel code for numerical solution.
We investigate
automatic parallelisation of the computation of ordinary
differential equation systems at three different levels of
granularity: equation system level, equation level, and clustered
task level. At the clustered task level we employ existing
scheduling and clustering algorithms to partition and distribute the
computation.
Moreover, an interface is provided to express
explicit parallelism through annotations in the the mathematical
model.
This work is performed in the context of ObjectMath, a
programming environment and modelling language that supports classes
of equation objects, inheritance of equations, and solving systems
of equations. The environment is designed to handle realistic
problems.
No 567
SIMULATION AND DATA COLLECTION IN
BATTLE TRAINING
Johan Jenvald
To achieve
realism in force-on-force battle training, it is important that the
major factors of the battlefield are simulated in a realistic
way. We describe an architecture for battle training and evaluation
which provides a framework for integrating multiple sensors,
simulators and registration equipment together with tools for
analysis and presentation. This architecture is the basis for the
MIND system, which is used in realistic battle training and for
advanced after-action review. MIND stores the information recorded
in a database which is the basis for subsequent analysis of training
methods and improvement of tactics and military equipment. Data
collected during battle training can support both modelling of
Distributed Interactive Simulation (DIS) objects and the presented
Time- delayed DIS (TDIS) approach. TDIS facilitates the training of
staffs and commanders on high levels under realistic circumstances
without the need of trainees and trainers on the lower unit
levels. Systematic evaluation and assessment of the MIND system and
its influence on realistic battle training can provide information
about how to maximise the effect of the conducted battle training
and how to best support other applications that use information from
the system.
No 575
SOFTWARE QUALITY ENGINEERING BY EARLY
IDENTIFICATION OF FAULT-PRONE MODULES
Niclas
Ohlsson
Quality improvement in terms of lower costs,
shorter development times and increased reliability are not only
important to most organisations, but also demanded by the
customers. To enable management to early identify problems, and
subsequently to support planning and scheduling of development
processes, methods for identifying fault–prone modules are
desirable. This thesis demonstrates how software metrics can form
the basis for reducing development costs by early identification, at
the completion of design, of the most fault–prone software
modules. Based on empirical data, i.e. design metrics and fault
data, that have been collected from two successive releases of
switching systems developed at Ericsson Telecom AB, models for
predicting the most fault–prone modules were successfully
developed. Apart from reporting the successful analysis, this thesis
outlines a quality framework for evaluation of quality efforts,
provides a guide for quantitative studies, introduces a new approach
to evaluating the accuracy of prediction models, Alberg diagrams,
suggests a strategy for how variables can be combined, and evaluates
and improves strategies by replicating analyses suggested by
others.
No 576
COMMENTING SYSTEMS AS DESIGN
SUPPORT—A WIZARD-OF-OZ STUDY
Mikael
Ericsson
User-interface design is an activity with high
knowledge requirements, as evidenced by scientific studies,
professional practice, and the amounts of textbooks and courses on
the subject. A concrete example of the professional need for design
knowledge is the increasing tendency of customers in industrial
systems development to require style-guide compliance. The use of
knowledge-based tools, capable of generating comments on an evolving
design, is seen as a promising approach to providing user-interface
designers with some of the knowledge they need in their
work. However, there is a lack of empirical explorations of the
idea.
We have conducted a Wizard-of-Oz study in which the
usefulness of a commenting tool integrated in a design environment
was investigated. The usefulness measure was based on the user's
perception of the tool. In addition, the appropriateness of
different commenting strategies was studied: presentation form
(declarative or imperative) and delivery timing (active or
passive).
The results show that a commenting tool is seen as
disturbing but useful. Comparisons of different strategies show that
comments from an active tool risk being overlooked, and that
comments pointing out ways of overcoming identified design problems
are the easiest to understand. The results and conclusions are used
to provide guidance for future research as well as tool
development.
No 587
CHEFERS ANVÄNDNING AV
KOMMUNIKATIONSTEKNIK
Jörgen
Lindström
Under senare år har
affärsmiljön för de flesta företag
förändrats i snabb takt samtidigt som informations- och
kommunikationstekniken genomgått en snabb utveckling. Den
förändrade affärsmiljön kan tänkas
förändra arbetssituationen för exempelvis chefer.
Eftersom tidigare studier visat att ett mycket väsentligt
inslag i chefers arbete är kommunikation skulle den nya
tekniken kunna användas för att möta denna
förändring i arbetssituation. Syftet med den här
studien är mot denna bakgrund att skapa en
förståelse för chefers inställning till och
användning av kommunikationsteknik.
Studien har
huvudsakligen genomförts genom intervjuer med chefer i
två företag. Totalt har sexton chefer och sju medarbetare
till dessa chefer intervjuats. De i studien intervjuade cheferna
upplever en arbetssituation som är mycket tidspressad, med
fragmenterade arbetsdagar, ett högt kommunikationstryck och ont
om tid till ostört arbete. Vidare uttrycker respondenterna av
en mängd olika skäl en stark preferens för
kommunikation ansikte mot ansikte. Denna preferens är delvis en
följd av att arbetsuppgifterna ibland är så komplexa
att de kräver ett personligt möte för att kunna
hanteras effektivt. En annan mycket viktig aspekt är de
symboliska faktorerna, att chefen genom att närvara personligen
signalerar att en viss fråga, en viss enhet, en viss kund
etc. är viktig för organisationen.
Vad gäller
användandet av kommunikationsteknik så förefaller
det av studien att döma som om modern teknik i ganska liten
utsträckning används för att minska resande och
lätta på arbetsbördan för den studerade
kategorin människor. Detta tycks bero på att man av
sociala, symboliska och andra skäl vill och behöver
träffas personligen. Dessa krav och önskemål
på kontakter ansikte mot ansikte tycks vara så starka
att inte ens mycket sofistikerad teknik kan ersätta den typen
av kontakter. Det tycks i stället närmast vara så
att teknikutvecklingen ökat mängden kommunikation genom
att kommunikation via exempelvis mobiltelefon eller elektronisk post
till viss del adderats till den tidigare kommunikationen.
No 589
DATA MANAGEMENT IN CONTROL
APPLICATIONS - A PROPOSAL BASED ON ACTIVE DATABASE SYSTEMS
Esa Falkenroth
Active database management
systems can provide general solutions to data management problems in
control applications. This thesis describes how traditional control
algorithms and high-level operations in a control system can be
combined by using an embedded active object-relational database
management system as middleware. The embedded database stores
information about the controlled environment and machinery. The
control algorithms execute on a separate real-time server. Active
rules in the database are used to interface the model of the
environment, as stored in the database, and the control
algorithms. To improve information access, the control system is
tightly integrated with the database query processor.
A
control-application language specifies high-level manufacturing
operations which are compiled into queries and active rules in the
database. The thesis describes how the generated active rules can be
organized to solve problems with rule interaction, rule cycles, and
cascading rule triggering. Efficiency issues are addressed. The
thesis also presents practical experience of building the integrated
control system and the requirements such systems put on an embedded
adbms.
No 591
A DEFAULT EXTENSION TO DESCRIPTION
LOGICS AND ITS APPLICATIONS
Niclas
Wahllöf
This thesis discusses how to extend a
family of knowledge representation formalisms known as description
logics with default rules. Description logics are tailored to
express knowledge in problem domains of a hierarchical or
taxonomical nature, that is domains where the knowledge is easily
expressed in terms of concepts, objects and relations. The proposed
extension makes it possible to express "rules of thumb" in
a restricted form of Reiter's default rules. We suggest that
defaults of this form improve both the representational and
inferential power of description logics. The default rules are used
to compute the preferential instance relation which formally
expresses when it is plausible that an object is an instance of a
concept. We demonstrate the usefulness of the extension by
describing two applications. The first solves a configuration
problem where the goal is to find a suitable wine for a given meal
where defaults are used as recommendations of wines. The second is a
document retrieval application where default rules are used to
enhance the search of WWW documents. The applications are based on
an extended version of the knowledge-based system CLASSIC.
No 595
EKONOMISK STYRNING OCH ORGANISATORISK
PASSION - ETT INTERAKTIVT PERSPEKTIV
Annika Larsson
Denna
fallstudie handlar om ekonomisk styrning inom
sjukvårdsverksamhet, där verksamheten utgörs av en
vårdavdelning och dess personal. Studien fokuserar
interaktionen mellan budgeten och de aktiviteter och personer som
arbetar på lokal nivå i organisationen. Budgeten kan
betraktas som den mekanism vilken dominerar den ekonomiska
styrningen på vårdavdelningen.
I denna studie ses
ekonomisk styrning ur ett interaktivt perspektiv. Med detta menar
jag att styrningen måste förstås i ett praktiskt
och konkret sammanhag där tekniska och sociala aspekter
integreras. Detta görs genom att fyra begrepp lyfter fram
specifika kontextuella faktorer vilka är av väsentlig
betydelse för förståelsen av den ekonomiska
styrningen på vårdavdelningen. Begreppen är
professionalism, språk, mätbarhet och etik.
Avhandlingen bygger upp en teoretisk referensram kring begreppen
styrning och budgetering. Genom att beskriva teorier ur olika
perspektiv kan den mångfald som finns i begreppen lyftas
fram. Samtidigt är den praktiska verkligheten på
vårdavdelningen av stort intresse. Syftet är
framförallt att visa den komplexitet som är
förknippad med det praktiska användandet av teoretiska
modeller, under specifika kontextuella förhållanden. Med
detta menar jag bland annt att studien genomförs i en
organisation där passionen och ansvarskänslan för
arbetsuppgiften, det vill säga omhändertagandet av
patienten, i de flesta fall prioriteras framför ekonomiska och
administrativa kriterier.
För att beskriva det enskilda
fallet har tre olika datainsamlingsmetoder använts. Insamling
av dokument, deltagande observation och intervju. Genom de olika
metoderna beskrivs budgetens roll på avdelningen utifrån
det formella perspektivet, observatörens perspektiv samt de
intervjuades perspektiv. Genom metodvalet har ett försök
till ett holistiskt synsätt gjorts.
Studiens slutsatser
presenteras i en modell där de organisatoriska krafterna
systematisera i kategorierna administrativ, social och
individbaserad styrning. Modellen betonar vidare att
förståelse för styrning i en organisation
uppnås genom förståelse för respektive
kategori samt kopplingarna mellan dessa.
No 597
A VALUE-BASED INDEXING TECHNIQUE FOR
TIME SEQUENCES
Ling Lin
A time sequence is
a discrete sequence of values, e.g. temperature measure ments,
varying over time. Conventional indexes for time sequences are built
on the time domain and cannot deal with inverse queries on time
sequences under some interpolation assumptions (i.e. computing the
times when the values satisfy some conditions). To process an
inverse query the entire time sequence has to be scanned.
This
thesis presents a dynamic indexing technique, termed the IP-index
(Interpolation-index), on the value domain for large time
sequences. This index can be implemented using regular ordered
indexing techniques such as B-trees.
Performance measurements
show that this index dramatically improves the query processing time
of inverse queries compared to linear scanning. For periodic time
sequences that have a limited range and precision on their value
domain (most time sequences have this property), the IP-index has an
upper bound for insertion time and search time.
The IP-index is
useful in various applications such as scientific data analysis or
medical symptom analysis. In this thesis we show how this index can
be applied in the aeroplane navigation problem and dramatically
improve the real-time performance.
No 598
C3 FIRE - A MICROWORLD SUPPORTING
EMERGENCY MANAGEMENT TRAINING
Rego Granlund
The objective of this work has been to study how to support
emergency management training using computer simulations. The work
has focused on team decision making and the training of situation
assessment in a tactical reasoning process. The underlying
assumption is that computer simulations in decision-making training
systems should contain pedagogical strategies. Our investigations
started with empirical studies of an existing system for training
infantry battalion staffs. In order to promote controlled studies
in the area, we developed a microworld simulation system, C3Fire. By
using a microworld, we can model important characteristics of the
real world and create a small and well-controlled simulation system
that retains these characteristics. With a microworld training
system, we can create similar cognitive tasks to those people
normally encounter in real-life systems. Our experimental use of
C3Fire focuses on the problem of generating an information flow that
will support training in situation assessment. Generated messages
should contain information about the simulated world that will build
up the trainees' mental pictures of the encountered situations. The
behaviour of the C3Fire microworld was examined in an experimental
study with 15 groups of subjects. The aim of the system evaluation
of C3Fire was mainly to study the information flow from the computer
simulation through the training organisation, involving role-playing
training assistants, to the trained staff. The training domain,
which is the co-ordination of forest fire fighting units, has been
chosen to demonstrate principles rather than for its own sake.
No 599
A ROBUST TEXT PROCESSING TECHNIQUE
APPLIED TO LEXICAL ERROR RECOVERY
Peter
Ingels
This thesis addresses automatic lexical error
recovery and tokenization of corrupt text input. We propose a
technique that can automatically correct misspellings, segmentation
errors and real-word errors in a unified framework that uses both a
model of language production and a model of the typing behavior, and
which makes tokenization part of the recovery process.
The
typing process is modeled as a noisy channel where Hidden Markov
Models are used to model the channel characteristics. Weak
statistical language models are used to predict what sentences are
likely to be transmitted through the channel. These components are
held together in the Token Passing framework which provides the
desired tight coupling between orthographic pattern matching and
linguistic expectation.
The system, CTR (Connected Text
Recognition), has been tested on two corpora derived from two
different applications, a natural language dialogue system and a
transcription typing scenario. Experiments show that CTR can
automatically correct a considerable portion of the errors in the
test sets without introducing too much noise. The segmentation error
correction rate is virtually faultless.
No 607
TOWARD A GROUNDED THEORY FOR SUPPORT
OF COMMAND AND CONTROL IN MILITARY COALITIONS
Per-Arne
Persson
Command and control in military operations
constitute a complex web of interrelated cognitive activities and
information processes. Today, the practice of command and control is
affected by simultaneous social and technological
changes. Intensified research is justified in order to conceive the
nature of the practice, the changes, and develop relevant theories
for future evolution.
The purpose of the study is to generate
theories, providing new insights in the traditional practices as the
basis for continued research. In particular, we have studied
coalition command and control during the UN operation in former
Yugoslavia from the perspective of participating Swedish forces. We
conduct a qualitative analysis of interview data, and apply a
grounded theory approach within the paradigm of information systems
research.
We have found that constraint management, for instance
physical, communicative, and social constraints, dominates the
command and control activities. We describe the intense
communication and personal interaction and clarify the interaction
between informal procedures and the traditional formal structures
and rules when constraints appear. The evolving grounded theory is a
recognition of the non-orderly components within command and
control.
Based on the results of this study we suggest that
support for constraint management, within information systems
research, becomes the common framework for continued research on
support for military command and control. This perspective affects
the design of information systems, modelling efforts, and ultimately
the doctrines for command and control. Hopefully our result will
encourage cooperation between military practitioners, systems
designers and researchers, and the development of adequate tools and
techniques for the management of constraints and change in the
military and elsewhere.
No 609
A SCALABLE DATA STRUCTURE FOR A
PARALLEL DATA SERVER
Jonas S Karlsson
Modern and future applications, such as in the telecommunication
industry and real-time systems, store and manage very large amounts
of information. This information needs to be accessed and searched
with high performance, and it must have high availability. Databases
are traditionally used for managing high volumes of data. Currently,
mostly administrative systems use database technology. However,
newer applications need the facilities of database support. But just
applying traditional database technology to these applications is
not enough. The high-performance demands and the required ability
to scale to larger data sets are generally not met by current
database systems.
Data Servers are dedicated computers which
manage the internal data in a database system (DBMS). Modern
powerful workstations and parallel computers are used for this
purpose. The idea is that an Application Server handles user input
and data display, parses the queries, and sends the parsed query to
the data server that executes it. A data server, using a dedicated
machine, can be better tuned in memory management than a general
purpose computer.
Network multi-computers, such as clusters of
workstations or parallel computers, provide a solution that is not
limited to the capacity of one single computer. This provides the
means for building a data server of potentially any size. This
gives rise to the interesting idea of enabling the system to grow
over time by adding more components to meet the increased storage
and processing demands. This exhibits the need for scalable
solutions that allow for data to be reorganized smoothly, unnoticed
by the clients, the applications servers, accessing the data
server.
In this thesis we identify the importance of appropriate
data structures for parallel data servers. We focus on Scalable
Distributed Data Structures (SDDSs) for this purpose. In particular
LH*, and our new data structure LH*LH. An overview is given of
related work, and systems that have traditionally implicated the
need of such data structures. We begin by discussing
high-performance databases, and this leads us to database machines
and parallel data servers. We sketch an architecture for an
LH*LH-based file storage that we will use for a parallel data
server. We also show performance measures for the LH*LH and present
its algorithm in detail. The testbed, the Parsytec switched
multi-computer, is described along with experience acquired during
the implementation process.
FiF-a 4/97
VIDEOMÖTESTEKNIK I OLIKA
AFFÄRSSITUATIONER - MÖJLIGHETER OCH HINDER
Carita Åbom
Användning av
informationsteknik (IT) kan skapa ett geografiskt och
tidsmässigt oberoende. Det är inte längre
nödvändigt att man befinner sig på en viss plats
för att arbeta tillsammans med andra människor.
Datorstöd i form av groupware och videomötessystem
gör att man kan befinna sig var som helst och ändå
stå i nära kontakt med dem man arbetar tillsammans med. I
denna rapport studeras videomötesteknik i olika
affärssituationer. Syftet har varit att identifiera
möjligheter och hinder för införande och
användande.
Sju fallstudier har genomförts i
företag i Jönköpings län. Dessa företag
har under perioden introducerat
videomötesteknik. Företagen har valts bland mindre och
medelstora företag, vilka främst har använt
videomötestekniken för produktutveckling, d v s
videoutrustningen har använts som ett arbetsredskap för
samarbete i lokalmässigt skilda grupper. Datainsamlingen har
skett med hjälp av kvalitativa intervjuer med sådana
personer i de sju företagen som har erfarenhet av tekniken.
Det empiriska materialet har sedan ananlyserats med hjälp av en
modifierad form av ”grounded theory”.
I
undersökningen konstateras att intresset för att
använda videomöten som komplement till möten
”ansikte mot ansikte” är mycket stort. Motiven
är kortare ledtider samt ökad kundtillfredställelse
genom den högre kvalitet på kundkontakter man vinner
genom möjligheter till tätare kontakt. Däremot kan
inte videomöten ersätta möten ”ansikte mot
ansikte”. Tre mötestyper har identifierats:
1. Personlig kontakt (uppbyggnad av sociala relationer)
2. Informationsöverföring
3. Fysisk kontakt (man
måste vrida och vända och känna på
produkten)
Vid typ 1 och 3 är det inte lämpligt med
videomöte.
Undersökningen visar också att det
är svårighter förknippat med införande av
videomötesteknik. Det krävs mycket energi och motivation
för att komma igång. Antalet sålda system har
ännu inte nått ”kritisk massa”. Det är
fortfarande, trots ett omfattande standardiseringsarbete, inte
självklart att kunna kommunicera mellan system av olika
märken, och tekniken upplevs i somliga fall som
instabil. Tekniken är ännu så pass ny för dessa
företag att man provar sig fram. Det har inte kunnat
identifieras några fall av planerad förändring av
arbetsprocesser, utan de förändringar som skett har varit
ad hoc. Har man emellertid skaffat utrustning, kommer det fram
många bra idéer om tillämpningar som skulle kunna
användas, om det fanns flera motparter att kommunicera
med. Videomöten är ingen tvingande teknik. Vid stress
faller man lätt tillbaka i gammalt beteende, d v s
använder telefon eller fax.
FiF-a 6/97
ATT SKAPA EN
FÖRETAGSANPASSAD SYSTEMUTVECKLINGSMODELL - GENOM
REKONTSTRUKTION, VÄRDERING OCH VIDAREUTVECKLING I T50-BOLAG
INOM ABB
Tommy Wedlund
En systemutvecklare
arbetar med olika hjälpmedel vid verksamhetsutveckling och
systemutveckling. Inom ABB används ofta T50-programmet för
att utveckla verksamheten till ett s k T50-bolag. I några av
dessa T50-bolag har systemutvecklare använt Pegasus-modellen
vid systemutveckling. Pegasus-modellen utvecklades inom
Pegasus-projektet, vilket är ett av de största
systemutvecklingsprojekten som har genomförts inom ABB. Denna
studie handlar om hur man kan skapa en företagsanpassad
systemutvecklingsmodell. Med företagsanpassad avses att den
utgår ifrån T50-programmet och Pegasus-modellen. Studien
handlar om både skapandet av en systemutvecklingsmodell och
själva systemutvecklingsmodellen d v s både process och
produkt. I processen ingår arbetsmomenten rekonstruktion med
modellering, värdering och vidareutveckling. Resultatet av
processen är en produkt. Produkten i studien utgörs av den
skapade företagsanpassade systemutvecklingsmodellen. Denna
systemutvecklingsmodell skall stödja utveckling av både
verksamheten och ett informationssystem i ett T50-bolag.
I
denna rapport presenteras resultatet av ett forsknings- och
utvecklingsprojekt tillsammans med ABB Infosystems. Studien har
genomförts hos två T50-bolag inom ABB. De två
T50-bolagen är ABB Control och ABB Infosystems i
Västerås.
No 615
A DECISION-MECHANISM FOR REACTIVE AND
COORDINATED AGENTS
Silvia Coradeschi
In
this thesis we present preliminary results in the development of
LIBRA (LInköping Behavior Representation for Agents). LIBRA is
a rule-based system for specifying the behavior of automated agents
that combine reactivity to an uncertain and rapidly changing
envi-ronment and coordination. A central requirement is that the
behavior specification should be made by users who are not computer
and AI specialists. Two application domains are considered:
air-combat simulation and a simulated soccer domain from the
perspective of the RoboCup competition. The behavior of an agent is
specified in terms of prioritized production rules organized in a
decision tree. Coordinated behaviors are encoded in the decision
trees of the individual agents. The agents initiate tactics
depending on the situation and recognize the tactics that the other
team members have initiated in order to take their part in it.What
links individual behavior descriptions together are explicit
communication and common means to describe the situation the agents
find themselves in.
No FiF-a 34
NÄTVERKSINRIKTAD FÖRÄNDRINGSANALYS - PERSPEKTIV OCH METODER SOM STÖD FÖR FÖRSTÅELSE OCH UTVECKLING AV AFFÄRSRELATIONER OCH INFORMATIONSSYSTEM
Göran Hultgren
Att förstå och att utveckla affärsverksamheter som bedrivs i samverkan mellan ett flertal företag inbegriper problemställningar som inte är lika aktuella vid analyser inom en organisation. Vid inter-organisatorisk verksamhetsutveckling, t.ex. vid utveckling av inter-organisatoriska informationssystem, är de förväntade effekterna inte lika möjliga att förutse som i samband med intern verksamhetsutveckling.
Vid analys av samverkande affärsverksamheter, såsom vid all analys, styrs utredaren av både perspektiv och de metoder som används. Med denna utgångspunkt fokuserar avhandlingen på hur perspektiv- och metoddriven analys kan utföras inom samverkande affärsverksamheter för att styra utredarens uppmärksamhet också till relationer och nätverksdynamiska aspekter.
Den teoretiska grunden utgörs av ett handlings- och affärsaktsperspektiv med utgångspunkt från Förändringsanalys enligt SIMMetoden, samt ett nätverksperspektiv med utgångspunkt från den så kallade Uppsalaskolan. Genom denna deduktiva ansats och med empiriskt stöd från två genomförda studier inom turismnäringen, har metodvarianten Nätverksinriktad Förändringsanalys enligt SIMMetoden utvecklats, vilken baserar sig på en perspektivväxlande strategi. De empiriska studierna bidrar dessutom till ökad förståelse för kommunikation och utveckling inom samverkande affärsverksamheter.
No 640
CAFE: TOWARDS A CONCEPTUAL MODEL FOR INFORMATION MANAGEMENT IN ELECTRONIC MAIL
Juha Takkinen
Managing information in the form of text is the main concern of this thesis. In particular,we investigate text that is daily made available through the increasing use of e-mail. Wedescribe the design and implementation of a conceptual model,CAFE (CategorizationAssistant For E-mail). We also present the results of a case study and a survey that moti-vate the model.
The case study studies the effect of the computer screen on people’s structural build-up ofcategories for e-mail messages. Three different representations of categories are used:desktop, tree, and mind map. Cognitive science theories have served as an inspiration andmotivation for the study. The survey presents a selection of currently available e-mail cli-ents and the state-of-the-art and trends in e-mail management.
Our conceptual model provides support for organization, searching, and retrieval of infor-mation in e-mail. Three working modes are available for satisfying the user’s variousneeds in different situations: the Busy mode for intermittent usage at times of high stress,the Cool mode for continuous usage at the computer, and the Curious mode for sporadicusage when exploring and (re-)organizing messages when more time is at hand.
A prototype implementation has been developed. Each mode required using a different in-formation retrieval and filtering technique. Busy uses the text-based Naive Bayesian ma-chine learning algorithm, Cool uses common e-mail filtering rules, and Curious uses acombination of clustering techniques known asSCATTER/GATHER. Preliminary tests of theprototype have proved to be promising.
No 754
BANKENS VILLKOR I LÅNEAVTAL VID KREDITGIVNING TILL HÖGT BELÅNADE FÖRETAGSFÖRVÄRV
Magnus Lindahl
No 775
UNIQUE KERNEL DIAGNOSIS
Anders Henriksson
The idea of using logic in computer programs to perform systematic diagnosis was
introduced early in computation history. There are several systems using punch-cards and
rulers described as early as the mid 1950’s. Within the area of applied artificial intelligence
the problem of diagnosis made its definite appearance in the form of expert systems during
the 1970’s. This research eventually introduced model based diagnosis in the field of
artificial intelligence during the mid 1980’s. Two main approaches to model based
diagnosis evolved: consistency based diagnosis and abductive diagnosis. Later kernel
diagnosis complemented these two approaches. Unique kernel diagnosis is my contribution
to model based diagnosis within artificial intelligence.
Unique kernel diagnosis addresses the problem of ambiguous diagnoses, situations where
several possible diagnoses exist with no possibility to determine which one describes the
actual state of the device that is diagnosed. A unique kernel diagnosis can per definition
never be ambiguous. A unique kernel diagnosis can be computed using the binary decision
diagram (BDD) data structure by methods presented in this thesis. This computational
method seems promising in many practical situations even if the BDD data structure is
known to be exponential in size with respect to the number of state variabels in the worst
case. Model based diagnosis in the form of consistency based-, abductive and kerneldiagnosis
is known to be an NP-complete problem. A formal analysis of the computational
complexity of the problem of finding a unique kernel diagnosis reveals that it is in PNP.
No 788
INFORMATIONSTEKNIK OCH DRIVKRAFT I GRANSKNINGSPROCESSEN - EN STUDIE AV FYRA REVISIONSBYRÅER
Håkan Nilsson
Utvecklingen i slutet av 1900-talet inom området informationsteknik har förändrat förutsättningarna för revision, vilket har inneburit att revisionsbyråerna har förändrat sina granskningsprocesser. Granskningsmoment som tidigare inte har varit praktiskt möjliga att genomföra kan numera utföras tack vare att kapaciteten att lagra, sortera och överföra information har ökat dramatiskt. Informationstekniken har fått en framträdande roll i arbetet med att öka effektiviteten utan att försämra kvaliteten. Granskningsarbetet har dock inte automatiskt blivit effektivare enbart genom att användningen av informationsteknik har ökat. En frågeställning i detta arbete är hur revisionsbyråerna har hanterat de nya förutsättningarna som informationstekniken har skapat. Syftet med studien är att öka förståelsen för hur och varför globala revisionsbyråer idag använder informationsteknik i granskningsprocessen. För att uppfylla studiens syfte har fyra praktikfall genomförts. De fyra praktikföretagen är de fyra största revisionsbyråerna i Sverige. Arbetet har utgått från ett systemsynsätt med en kvalitativ ansats.
Revisionsbyråernas drivkrafter att använda informationsteknik i granskningsprocessen är främst att minska kostnaderna via kvalitetsförbättringar och produktivitetsökningar.
Informationstekniken stärker möjligheterna till att verifiera och granska en affärshändelse i efterhand. Trenden är att granska allt mindre affärshändelser allt längre ifrån primärkällorna. Två av de undersökta revisionsbyråerna använder främst informationsteknikens möjligheter till att automatisera befintliga rutiner och arbetssätt, medan de två andra byråerna försöker att arbeta utifrån nya koncept. De byråer, som har valt att främst satsa på att automatisera befintliga rutiner och arbetsmoment, behöver på längre sikt också förändra sina revisionsprocesser. Byråer, som har valt att satsa på ett förändrat revisionssynsätt och infört informationsteknik utifrån dessa tankar, behöver troligen på kort sikt automatisera delar av den befintliga revisionsprocessen. Dessa två olika utvecklingsvägar kommer förmodligen att mer eller mindre mötas i framtiden.
No 844
VAD KOSTAR HUNDEN? MODELLER FÖR FÖR INTERN REDOVISNING
Mikael Cäker
Allt fler industriella företag erbjuder kundanpassade produkter. Produkterna utvecklas inom ramen för långvariga relationer med kunder. Detta har betydelse för hur de ekonomiska informationssystemen bör utformas. I uppsatsen föreslås modeller för den interna redovisningen som stödjer fokusering av både kunder och produkter. Därtill studeras hur kunder påverkar företagets kostnader. Litteraturen om redovisning och kalkylering, som har utvecklats för att i första hand fördela kostnader på produkter, analyseras utifrån att både produkter och kunder är väsentliga för uppföljningen. De föreslagna modellerna illustreras via en analys av kostnadsdata från Paroc AB. Dessutom diskuteras hur de föreslagna modellerna kan stödja kalkylering inför olika kundrelaterade handlingssituationer.
Både kund och produkt bör användas som kostnadsbärare i redovisningen för industriella företag som arbetar med en hög grad av kundanpassning. Detta ökar möjligheterna att analysera kostnaderna, jämfört med att enbart produkter fokuseras. Vidare kan kategorisering av kostnader efter hur resurser som förbrukas har anskaffats ge värdefull information, som inte är beroende av analysobjekt. I uppsatsen skiljs mellan prestationsberoende, kapacitetsberoende och nedlagda kostnader. Att använda kund och produkt som kostnadsbärare i redovisningssystem komplicerar dock att etablera nivåer av kostnadsställen i redovisningen som föreslagits i ABC-litteraturen. Det är bättre att använda den traditionella nivåindelningen av kostnadsbärare enligt stegkalkylsmetoden.
Kundrelaterade aktiviteter är ofta avsedda att skapa värden i senare tidsperioder. Framåtriktade aktiviteter kan redovisas som ’goda kostnader’, om de inte anses vara investeringar i formell bemärkelse. Detta medför att kostnaderna kan analyseras i senare tidsperioder utan att värdering av investeringar eller avskrivningar av tillgångar behöver göras. Investeringar i kunder skapar ofta immateriella tillgångar. För att värdera immateriella tillgångar är det väsentligt att studera möjligheterna till alternativ användning. I uppsatsen föreslås en kategorisering av tillgångar i specifika, begränsade och icke begränsade tillgångar.
No FiF-a 32
KUNSKAPSANVÄNDLING OCH KUNSKAPSUTVECKLING HOS VERKSAMHETSKONSULTER - ERFARENHETER FRÅN ETT FOU-SAMARBETE
Karin Hedström
Att förstå hur kunskap kan användas och utvecklas är viktigt för alla som arbetar med kunskapsutveckling. Detta gäller inte minst forskare som ofta hoppas och tror att deras forskningsresultat på något sätt kommer att bidraga till samhällets utveckling. Mitt arbete har fokuserat hur verksamhetskonsulter kan utveckla och anpassa yrkesinriktad praktisk kunskap genom att samarbeta med forskare och verksamhetskonsult från andra discipliner.
Mycket av den kunskap som forskare inom informationssystemutveckling utvecklar är tänkt att i slutändan användas av praktiker som dagligen arbetar med de frågor vi behandlar i våra forskningsprojekt. Därför känns det både viktigt och naturligt att utveckla kunskap som gör att vi bättre kan förstå hur systemutvecklare och andra verksamhetskonsulter arbetar. Vi behöver utveckla kunskap om den praktik som verksamhetskonsulter tillhör – dvs vad systemutvecklare och andra verksamhetsutvecklare gör, hur de använder och anpassar olika typer av kunskap som stöd för sitt agerande. Vi måste förstå hur systemutvecklare arbetar och resonerar.
Ett sätt att få bättre kunskap om den rationalitet som styr verksamhetskonsulters praktik är genom att arbeta med aktiva verksamhetsutvecklare som använder både forskningsbaserad och praktikbaserad kunskap som stöd i sin yrkesutövning. Under tre år har jag observerat och arbetat tillsammans med två verksamhetskonsulter, och har på så sätt utvecklat en ökad förståelse för hur kunskap kan översättas, utvecklas och användas av konsulter som på olika sätt arbetar med verksamhetsutveckling.
Studiens resultat beskriver och relaterar omständigheter, handlingar och konsekvenser kring verksamhetskonsulters kunskapsutveckling. Kunskap i användning översätts och anpassas till den specifika situationen samt kunskapsanvändarens förförståelse och referensram, vilket också innebär att kunskapen utvecklas och förändras.
No FiF-a 37
ORGANISATIONERS KUNSKAPSVERKSAMHETER - EN KRITISK STUDIE AV "KNOWLEDGE MANAGEMENT"
Ewa Braf
Att utveckla, tillvarata och återanvända kunskap är centrala företeelser för organisationers framåtskridande och utveckling. Härmed har kunskapsmanagement (KM) en viktig roll för och i organisationer. Med KM eftersträvas bl a att medvetandegöra medarbetarnas kunskaper i syfte att hantera, utveckla och sprida dem på ett för organisationen fruktbart sätt. Genom en framgångsrik KM finns potential att öka organisationers handlingsförmåga, följaktligen även verksamheters värdeskapande och konkurrenskraft. Icke desto mindre är kunskap en abstrakt och svårhanterlig organisatorisk tillgång. Därtill, trots att det finns en hel del skrivet kring KM, kan det vara svårt för organisationer att förstå hur de praktiskt ska arbeta med detta verksamhetsområde, samt vad det innebär.
I syfte att öka förståelsen för KM har jag studerat och kritiskt analyserat en del existerande litteratur kring området. Med analysen som utgångspunkt har ett antal forskningsfrågor preciserats. För att överbrygga en del av de oklarheter som identifierats i samband med litteraturgenomgången, samt för att svara på avhandlingens forskningsfrågor, har stöd sökts i andra teorier, bl a kunskapsteori och teori om hur vi kan se på verksamheter. Därtill har hanteringen av och synen på kunskap studerats genom en fallstudie genomförd på ett konsultbolag inom IT-branschen. Utifrån litteraturanalysen, grundning i annan teori, samt avhandlingens empiriska data har jag presenterat min syn på organisationers kunskapsverksamheter (min benämning på kunskapsmanagement).
Resultatet av avhandlingsarbetet är bl a en utvecklad och preciserad begreppsapparat för organisatorisk kunskapsverksamhet (KM). Detta innefattar bl a en klassificering av begreppet organisatorisk kunskap och dess relation till organisatorisk handling. I avhandlingen klassificeras även ett antal vanliga situationer för kunskapande (lärande), vilka i sin tur relateras till organisationers kärnverksamhet respektive kunskapsverksamhet. Ett av huvudbidragen är en modell över organisatoriskt kunskapsverksamhet. Modellen inkluderar kunskapsverksamhetens centrala förutsättningar, handlingar, resultat, samt dess relation till kärnverksamheten. Genom denna avhandling vill jag bidra med en ökad förståelse för vad kunskapsverksamheter handlar om och vad som behöver beaktas för att utveckla en framgångsrik kunskapsverksamhet.
No FiF-a 40
WEBBASERADE AFFÄRSPROCESSER - MÖJLIGHETER OCH BEGRÄNSNINGAR
Henrik Lindberg
Dagens litteratur kring området webbaserade affärsprocesser är ofta möjlighetsinriktad och framtidsorienterad. Det finns således en risk för att litteraturen ger en alltför ensidig bild av forskningsområdet. För att söka erhålla en mer nyanserad bild av området ställer jag mig den övergripande forskningsfrågan: Vilka möjligheter och begränsningar medför webbaserade affärsprocesser?
För att besvara denna fråga används en triangulerande ansats och förutsättningslösa empiriska studier, för att undvika blockerande förförståelse. Jag genomför två fallstudier på företag vilka båda bedriver handel mot konsumentledet uteslutande via Internet. Fallstudieföretagen är NetShop och BuyOnet, där NetShop är anonymiserad. Dessa fallstudieföretag har valts så att de skiljer sig på ett flertal punkter för att erhålla ett komparativt analysmaterial. Den kanske främsta skillnaden är att NetShop säljer en fysisk produkt och BuyOnet en digital produkt. Metodologisk inspirationskälla är grounded theory, men datainsamling och dataanalys utförs med stöd av generiska teorier. Som stöd för dataanalysen har jag även utvecklat ett informationssystem. Inledningsvis analyseras producenten med avseende på dess förutsättningar och hur den webbaserade affärsprocessen genomförs. Därefter kartläggs det webbaserade affärsgörandets effekter genom att kunders förfrågningar och producentens svar analyseras. För respektive fallstudie analyseras också vilka möjligheter och begränsningar som det webbaserade affärsgörandet medför. Resultaten från fallstudierna jämförs därefter med avseende på framkomna aspekter. För att söka erhålla ett mer generellt resultat med avseende på webbaserade affärsprocessers möjligheter och begränsningar förs avslutningsvis en resultatdiskussion med utgångspunkt tagen i teori.
Resultatet karakteriseras som empiri- och teorigrundade tendenser. Bland resultaten utmärker sig den webbaserade affärsmodellen, verksamhetskarakteriserande kategorier och olika webbaserade aspekters möjliggörande och begränsande relationer till varandra.
No 863
TOWARDS BEHAVIORAL MODEL FAULT ISOLATION FOR OBJECT ORIENTED CONTROL SYTEMS
Dan Lawesson
We use a system model expressed in a subset of the Unified Modeling Language to perform fault isolation in large object oriented control systems. Due to the severity of the failures considered and the safety critical nature of the system we cannot perform fault isolation online. Thus, we perform post mortem fault isolation which has implications in terms of the information available; the temporal order in the error log can not be trusted. In our previous work we have used a structural model for fault isolation. In this thesis we provide a formal framework and a prototype implementation of an approach taking benefit of a behavioral model. This gives opportunities to perform more sophisticated reasoning at the cost of a more detailed system model. We use a model-checker to reason about causal dependencies among the events of the modeled system. The model-checker performs reasoning about temporal dependencies among the events in the system model and the scenario at hand, allowing for conclusions about the causal relation between the events of the scenario. This knowledge can then be transferred to the corresponding fault in the system, allowing us to pinpoint the cause of a system failure among a set of potential causes.
No 882
XML-BASED FRAMEWORKS FOR INTERNET COMMERCE AND AN IMPLEMENTATION OF B2B E-PROCUREMENT
Yuxiao Zhao
It is not easy to apply XML in e-commerce development for achieving interoperability in heterogeneous environments. One of the reasons is a multitude of XML-based Frameworks for Internet Commerce (XFIC), or industrial standards. This thesis surveys 15 frameworks, i.e., ebXML, eCo Framework, UDDI, SOAP, BizTalk, cXML, ICE, Open Applications Group, RosettaNet, Wf-XML, OFX, VoiceXML, RDF, WSDL and xCBL.
This thesis provides three models to systematically understand how the 15 frameworks meet the requirements of e-commerce. A hierarchical model is presented to show the purpose and focus of various XFIC initiatives. A relationship model is given to show the cooperative and competitive relationships between XFIC. A chronological model is provided to look at the development of XFIC. In addition, the thesis offers guidelines for how to apply XFIC in an e-commerce development.
We have also implemented a B2B e-procurement system. That not only demonstrates the feasibility of opensource or freeware, but also validates the complementary roles of XML and Java: XML is for describing contents and Java is for automating XML documents (session handling). Auction-based dynamic pricing is also realized as a feature of interest. Moreover, the implementation shows the suitability of e-procurement for educational purposes in e-commerce development.
No FiF-a 47
WEBBASERADE IMAGINÄRA
ORGANISATIONERS SAMVERKANSFORMER: INFORMATIONSSYSTEMARKITEKTUR OCH
AKTÖRSSAMVERKAN SOM FÖRUTSÄTTNINGAR FÖR
AFFÄRSPROCESSEN
Per-Arne Segerkvist
De Internetbutiker som skapades under senare delen av
1990-talet, präglades av snabb etablering och deras
övergripande mål var att ta så stora
marknadsandelar som möjligt. Detta högt prioriterade
krav på snabbhet var en av anledningarna till att dessa
företag ofta tog hjälp av partners för att
sköta delar av verksamheten. På detta sätt skapas
imaginära organisationer, som via webben erbjuder varor och
tjänster till sina kunder. Dessa företag fokuserar
på sin kärnkompetens och låter denna kompletteras
med andra externa aktörers kompetenser. För att lyckas
måste man erbjuda sina kunder minst samma priser, kvalitet
och service som en traditionell butik, vilket kräver en
verksamhet med hög processeffektivitet och -kvalitet. Denna
avhandling fokuserar på vilka faktorer som är
avgörande för att dessa önskvärda effekter ska
kunna uppnås, vilket också innebär att brister
och problem kommer att beröras.
I två fallstudier
har studerats hur dessa imaginära organisationers olika
informationssystem, och den informationssystemarkitektur de
bildar, stödjer affärsprocessen i syfte att nå
önskvärda effekter. Organisationernas aktörer, och
den aktörsstruktur de bildar, har också studerats
för att klargöra stöd till affärsprocessen.
Studiens resultat visar att samverkan mellan den imaginära
organisationens informationssystem och aktörer är av
central betydelse för att nå dessa effekter. Den visar
också på problem som finns i detta
sammanhang. För att uppnå denna goda samverkan mellan
informationssystem krävs en hög kvalitet i densamma,
något som också är av stor vikt för att
uppnå förtroende och tillit i den samverkan som sker
mellan aktörer inom den imaginära
organisationen. För att nå en hög
förändringsbarhet och följsamhet i den
imaginära organisationens processer, är det
nödvändigt att fokusera på systemstrukturering,
både intern och extern. Studien pekar också på
de rationaliseringseffekter som kan uppnås genom ett
högt utnyttjande av modern informationsteknik.
No 890
DOMAIN KNOWLEDGE MANAGEMENT IN
INFORMATION-PROVING DIALOGUE SYSTEMS
Annika
Flycht-Eriksson
In this thesis a new concept called
domain knowledge management for informationproviding dialogue
systems is introduced. Domain knowledge management includes issues
related to representation and use of domain knowledge as well as
access of background information sources, issues that previously
have been incorporated in dialogue management.
The work on
domain knowledge management reported in this thesis can be divided
in two parts. On a general theoretical level, knowledge sources and
models used for dialogue management, including domain knowledge
management, are studied and related to the capabilities they
support. On a more practical level, domain knowledge management is
examined in the contexts of a dialogue system framework and a
specific instance of this framework, the ÖTRAF system. In this
system domain knowledge management is implemented in a separate
module, a Domain Knowledge Manager.
The use of a specialised
Domain Knowledge Manager has a number of advantages. The first is
that dialogue management becomes more focused as it only has to
consider dialogue phenomena, while domain-specific reasoning is
handled by the Domain Knowledge Manager. Secondly, porting of a
system to new domains is facilitated since domain-related issues are
separated out in specialised domain knowledge sources. The third
advantage with a separate module for domain knowledge management is
that domain knowledge sources can be easily modified, exchanged, and
reused.
No 894
STYRNING AV INVESTERINGAR I
DIVISIONALISERADE FÖRETAG - ETT KONCERNPERSPEKTIV
Stefan Svarén
Avhandlingen beskriver
hur större divisionaliserade företag, ur ett
koncernperspektiv, styr investeringar av strategisk
betydelse. Bakgrunden till forskningsarbetet är bland annat att
flera forskare har visat den traditionella investeringsforskningens
brist på helhetssyn. Skälet till att
investeringsforskningen ansetts sakna helhetssynen är att den i
hög utsträckning inriktats på investeringsbeslutet
och då främst investeringskalkylen, även om det
är otvivelaktigt att investeringsbeslutet inte är
någon skild företeelse från företaget i
övrigt. Ett annat faktum som förbisetts av många
forskare är att företagsledningen inte styr
investeringarna i olika divisioner genom att rangordna och
välja enskilda investeringar, utan genom att påverka
spelreglerna för investeringsprocessen.
Det
övergripande syftet med forskningsarbetet är att ur ett
koncernperspektiv förklara hur divisionaliserade företag
styr investeringar av strategisk betydelse. Avhandlingen tar sin
utgångspunkt i att koncernstrategin kan förväntas
påverka hur investeringsstyrningen utformas och används.
Studien kan indelas i fyra delar; teoretisk referensram,
föreställningsram, empirisk studie i fyra koncerner samt
analys och slutsatser. Den teoretiska referensramen utgör
grunden för föreställningsramen, som redogör
för hur investeringsstyrningen kan förväntas vara
utformad och användas i koncerner med olika koncernstrategisk
inriktning. Den empiriska studien har genomförts genom
intervjuer med ansvariga för investeringsstyrning på
koncernnivå i fyra koncerner; Investment AB Bure, Finnveden
AB, Munksjö AB och Svedala Industri AB.
Avhandlingens
slutsatser sammanfattas i en typologi för investeringsstyrning.
Det finns, enligt avhandlingens typologi, fyra olika alternativa
sätt att utforma och använda investeringsstyrningen.
Huvudvariablerna i typologin är ”Koncernstrategi”
och ”Dominerande investeringstyp”. Båda är
variabler vars betydelse för investeringsstyrningen
påvisas genom hela avhandlingen.
No 906
SECURE AND SCALABLE E-SERVICE
SOFTWARE DELIVERY
Lin Han
Due to the
complexity of software and end-user operating environments, software
management in general is not an easy task for end-users. In the
context of e-service, what end-users buy is the service
package. Generally speaking, they should not have to be concerned
with how to get the required software and how to make it work
properly on their own sites. On the other hand, service providers
would not like to have their service-related software managed in a
non-professional way, which might cause problems when providing
services.
E-service software delivery is the starting point in
e-service software management. It is the functional foundation for
performing further software management tasks, e.g., installation,
configuration, activation, and so on.
This thesis concentrates
on how to deliver e-service software to a large number of
geographically distributed end-users. Special emphasis is placed on
the issues of efficiency (in terms of total transmission time and
consumed resources), scalability (in terms of the number of
end-users), and security (in terms of confidentiality and
integrity). In the thesis, we propose an agent-based architectural
model for e-service software delivery, aiming at automating involved
tasks, such as registration, key management, and recipient status
report collection. Based on the model, we develop a multicast
software delivery system, which provides a secure and scalable
solution to distributing software over publicly accessible
networks. By supplying end-users with site information examination,
the system builds a bridge towards further software management
tasks. We also present a novel strategy for scalable multicast
session key management in the context of software delivery, which
can efficiently handle a dynamic reduction in group membership of up
to 50% of the total. An evaluation is provided from the perspective
of resource consumption due to security management activities.
No 915
REDOVISNING I SKUGGAN AV EN BANKKRIS -
VÄRDERING AV FASTIGHETER
Niklas
Sandell
Den grundläggande
frågeställningen för denna avhandling är
huruvida extern redovisningsinformation kan medföra
snedvridande ekonomiska konsekvenser, genom dess påverkan
på ekonomiska aktörers agerande. En utgångspunkt
härvid är att frågeställningarna kring
redovisningens ekonomiska konsekvenser ställs på sin
spets under finansiella kriser. I denna avhandling studeras
redovisning vid tidpunkten för 1990-talets svenska
bankkris.
Till följd av bankkundernas bristande
betalningsförmåga blev bankernas fordringar
avhängiga av värdet av ställda
säkerheter. Säkerheterna bestod i stor utsträckning
av fastigheter, varför frågan kring värdering av
fastigheter i redovisningen kom att bli betydelsefull.
I
avhandlingen beskrivs och analyseras Finansinspektionens regelverk
avseende värdering av fastigheter som övertagits för
skyddande av fordran respektive fastigheter som utgör
säkerhet för osäker fordran. Studien avser
regelverket, dess utveckling och tillämpning med
koncentration
på krisåren 1990-1993.
Regelverket
kom under krisen att utvecklas successivt och kompletteras för
då rådande behov. Att regelverket, såsom i vissa
sammanhang antytts, skulle ha medfört en undervärdering av
bankernas fastighetsbestånd ifrågasätts i
avhandlingen. Regelverket var dock vagt formulerat, vilket under
hela perioden medförde tolknings- och tillämpningsproblem.
Finansinspektionens arbete med regelverket måste dock anses ha
bidragit till att frågorna om fastighetsvärdering kom att
fokuseras i samband med bankernas årsbokslut under
krisåren.
No 917
OPTIONSPROGRAM FÖR
ANSTÄLLDA: EN STUDIE AV SVENSKA BÖRSFÖRETAG
Emma Hansson
An important strategic question
for companies today is how to recruit, motivate and retain
employees. It is becoming more important to consider the incentive
programs in the valuation process of companies. Recent studies show
that employee stock option plans are more commonly used in Swedish
companies than earlier. However, there are few studies about how
employee stock options influence company performance and affect
employees.
The purpose of this thesis is to increase the
awareness of what the introduction of an employee stock option plan
means, both from a management perspective and from the
employees’ perspective. There are many different kinds of
stock option plans and the plans can vary in terms of type of
options, time to expiry, exercise price and tax consequences. This
study started with a pre-study of which types of employee stock
option plans that are used in Swedish companies. A closer study was
then carried out in four companies in different industries with
different stock option plans.
The motives for introducing
employee stock option plans can be divided into five categories:
personnel motives, incentive motives, salary motives, accounting
motives and tax motives. The case studies show how motives for
option plans can be dependent on different circumstances within the
companies. Further, the study also shows that the consequences of
the stock option plans varies according to factors such as motives,
design of the stock option plan, share price performance and other
context factors. Context factors that could have an effect are the
company’s business, organisational structure, corporate
culture and experiences from employee stock options in the industry,
employees’ education and tax rules. The consequences for the
company are also dependent on how the employees react to the
options.
To be able to estimate what an employee stock option
plan means for the company, all these factors must be taken under
consideration. Further one must take into account the costs for the
stock options such as dilution effects, hedging costs, personnel
costs and costs for designing the program.
No FiF-a 51
INFORMATIONSSÄKERHET I
VERKSAMHETER: BEGREPP OCH MODELLER SOM STÖD FÖR
FÖRSTÅELSE AV INFORMATIONSSÄKERTHET OCH DESS
HANTERING I VERKSAMHETER
Per Oscarson
Verksamheters säkerhetsproblem i samband med informationssystem
och informationsteknik (IS/IT) är ett område som
uppmärksammats kraftigt de senaste åren. Denna
avhandling syftar till att ge en ökad förståelse av
informationssäkerhet; begreppet i sig, dess hantering i
verksamheter samt dess betydelse för verksamheter. För
att nå en ökad förståelse för
informationssäkerhet och dess hantering består
avhandlingen till stora delar av konceptuella
resonemang. Avhandlingens huvudsakliga kunskapsbidrag är:
-
En kritisk granskning och en revidering av den begreppsapparat som
dominerar i Sverige inom området informationssäkerhet och
dess hantering.
- En generisk modell (ISV-modellen) avseende
verksamheters hantering av informationssäkerhet.
ISV-modellen beskriver vilka grundläggande
förutsättningar, aktiviteter, resultat och konsekvenser
som kan kopplas till hantering av informationssäkerhet i
verksamheter. Informationssäkerhetsområdet betraktas
utifrån ett perspektiv som har sin grund i Skandinavisk
informationssystemforskning. Ett viktigt kännetecken hos detta
perspektiv är att IS/IT betraktas i en verksamhetskontext
där bl a människors roller och aktiviteter utgör en
viktig del.
Studien bygger på både teoretiska och
empiriska studier som har skett parallellt och genom
växelverkan. De teoretiska studierna har främst
bestått av litteraturstudier och konceptuellt modellerande som
har konfronterats med empiriskt material vilket huvudsakligen har
hämtats genom en fallstudie på en kommun i
Bergslagen.
No 919
A PETRI NET BASED MODELING AV
VERIFICATION TECHNIQUE FOR REAL-TIME EMBEDDED SYSTEMS
Luis Alejandro Cortes
Embedded systems are used
in a wide spectrum of applications ranging from home appliances and
mobile devices to medical equipment and vehicle controllers. They
are typically characterized by their real-time behavior and many of
them must fulfill strict requirements on reliability and
correctness.
In this thesis, we concentrate on aspects related
to modeling and formal verification of realtime embedded
systems.
First, we define a formal model of computation for
real-time embedded systems based on Petri nets. Our model can
capture important features of such systems and allows their
representations at different levels of granularity. Our modeling
formalism has a welldefined semantics so that it supports a precise
representation of the system, the use of formal methods to verify
its correctness, and the automation of different tasks along the
design process.
Second, we propose an approach to the problem of
formal verification of real-time embedded systems represented in our
modeling formalism. We make use of model checking to prove whether
certain properties, expressed as temporal logic formulas, hold with
respect to the system model. We introduce a systematic procedure to
translate our model into timed automata so that it is possible to
use available model checking ools. Various examples, including a
realistic industrial case, demonstrate the feasibility of our
approach on practical applications.
No 931
ETT DYNAMISKT PERSPEKTIV PÅ
INDIVIDUELLA SKILLNADER AV HEURISTISK KOMPETENS, INTELLIGENS,
MENTALA MODELLER, MÅL OCH KONFIDENS I KONTROLL AV
MIKROVÄRLDEN MORO
Fredrik Elg
Theories
predicting performance of human control of complex dynamic systems
must assess how decision makers capture and utilise knowledge for
achieving and maintaining control. Traditional problem solving
theories and corresponding measures such as Ravens matrices have
been applied to predict performance in complex dynamic
systems. While they assume stable properties of decision makers to
predict control performance in decision-making tasks these tests
have shown to provide only a limited degree of prediction in human
control of complex dynamic systems. This paper reviews theoretical
developments from recent empirical studies and tests the theoretical
predictions of a model of dynamic decision-making using a complex
dynamic microworld – Moro. The requirements for control of
the microworld is analysed in study one. Theoretical predictions
from the reviewed theory and results from study one are tested in
study two. In study three additional hypotheses are derived by
including meta cognitive dynamics to explain anomalies found in
study two. A total of 21 Hypotheses are tested. Results indicate
that for predicting human control of complex dynamic opaque systems
a number of meta cognitive processes play an important role in
determining outcome. Specifically, results show that we cannot
expect a lower risk of failure in complex dynamic opaque systems
from people with high problem solving capabilities when these also
express higher goals. Further research should seek to explore the
relative contribution of task characteristics to determine
conditions under which these meta cognitive processes of decision
makers take a dominant role over problem-solving capabilities
– enabling improved decision-maker selection and support.
No 933
AUTOMATIC PARALLELIZATION OF
SIMULATION CODE FROM EQUATION BASED SIMULATION LANGUAGES
Peter Aronsson
Modern state-of-the-art equation
based object oriented modeling languages such as Modelica have
enabled easy modeling of large and complex physical systems. When
such complex models are to be simulated, simulation tools typically
perform a number of optimizations on the underlying set of equations
in the modeled system, with the goal of gaining better simulation
performance by decreasing the equation system size and
complexity. The tools then typically generate efficient code to
obtain fast execution of the simulations. However, with increasing
complexity of modeled systems the number of equations and variables
are increasing. Therefore, to be able to simulate these large
complex systems in an efficient way parallel computing can be
exploited.
This thesis presents the work of building an
automatic parallelization tool that produces an efficient parallel
version of the simulation code by building a data dependency graph
(task graph) from the simulation code and applying efficient
scheduling and clustering algorithms on the task graph. Various
scheduling and clustering algorithms, adapted for the requirements
from this type of simulation code, have been implemented and
evaluated. The scheduling and clustering algorithms presented and
evaluated can also be used for functional dataflow languages in
general, since the algorithms work on a task graph with dataflow
edges between nodes.
Results are given in form of speedup
measurements and task graph statistics produced by the tool. The
conclusion drawn is that some of the algorithms investigated and
adapted in this work give reasonable measured speedup results for
some specific Modelica models, e.g. a model of a thermofluid pipe
gave a speedup of about 2.5 on 8 processors in a PC-cluster.
However, future work lies in finding a good algorithm that works
well in general.
No 938
Bourhane Kadmiry
FUZZY CONTROL FOR AN UNMANNED HELICOPTER
The overall
objective of the Wallenberg Laboratory for Information
Technology and Autonomous Systems (WITAS) at Linköping
University is the development of an intelligent command and
control system, containing vision sensors, which supports the
operation of a unmanned air vehicle (UAV) in both semi- and
full-autonomy modes. One of the UAV platforms of choice is the
APID-MK3 unmanned helicopter, by Scandicraft Systems AB. The
intended operational environment is over widely varying
geographical terrain with traffic networks and vehicle
interaction of variable complexity, speed, and density.
The present version of APID-MK3 is capable of autonomous
take-off, landing, and hovering as well as of autonomously
executing pre-defined, point-to-point flight where the latter is
executed at low-speed. This is enough for performing missions
like site mapping and surveillance, and communications, but for
the above mentioned operational environment higher speeds are
desired. In this context, the goal of this thesis is to explore
the possibilities for achieving stable
‘‘aggressive’’ manoeuvrability at
high-speeds, and test a variety of control solutions in the
APID-MK3 simulation environment.
The objective of
achieving ‘‘aggressive’’ manoeuvrability
concerns the design of attitude/velocity/position controllers
which act on much larger ranges of the body attitude angles, by
utilizing the full range of the rotor attitude angles. In this
context, a flight controller should achieve tracking of
curvilinear trajectories at relatively high speeds in a robust,
w.r.t. external disturbances, manner. Take-off and landing are
not considered here since APIDMK3 has already have dedicated
control modules that realize these flight modes.
With this
goal in mind, we present the design of two different types of
flight controllers: a fuzzy controller and a gradient descent
method based controller. Common to both are model based design,
the use of nonlinear control approaches, and an inner- and
outer-loop control scheme. The performance of these controllers
is tested in simulation using the nonlinear model of
APID-MK3.
No 942
PREDICTION AS A KNOWLEDGE
REPRESENTATION PROBLEM: A CASE STUDY IN MODEL DESIGN
Patrik Haslum
The WITAS project aims to
develop technologies to enable an Unmanned Airial Vehicle (UAV) to
operate autonomously and intelligently, in applications such as
traffic surveillance and remote photogrammetry. Many of the
necessary control and reasoning tasks, e.g. state estimation,
reidentification, planning and diagnosis, involve prediction as an
important component. Prediction relies on models, and such models
can take a variety of forms. Model design involves many choices with
many alternatives for each choice, and each alternative carries
advantages and disadvantages that may be far from obvious. In spite
of this, and of the important role of prediction in so many areas,
the problem of predictive model design is rarely studied on its
own.
In this thesis, we examine a range of applications
involving prediction and try to extract a set of choices and
alternatives for model design. As a case study, we then develop,
evaluate and compare two different model designs for a specific
prediction problem encountered in the WITAS UAV project. The problem
is to predict the movements of a vehicle travelling in a traffic
network. The main difficulty is that uncertainty in predictions is
very high, du to two factors: predictions have to be made on a
relatively large time scale, and we have very little information
about the specific vehicle in question. To counter uncertainty, as
much use as possible must be made of knowledge about traffic in
general, which puts emphasis on the knowledge representation aspect
of the predictive model design.
The two mode design we develop
differ mainly in how they represent uncertainty: the first uses
coarse, schema-based representation of likelihood, while the second,
a Markov model, uses probability. Preliminary experiments indicate
that the second design has better computational properties, but also
some drawbacks: model construction is data intensive and the
resulting models are somewhat opaque.
No 956
ON THE INSTRUMENTS OF GOVERNANCE - A
LAW & ECONOMICS STUDY OF CAPITAL INSTRUMENTS IN LIMITED
LIABILITY COMPANIES
Robert Sevenius
The foundation of this thesis is the connection between corporate
finance and corporate governance. Corporate finance has
predominantly been analysed by financial economics models and
thereby not recognised significant intrinsic features of the capital
instrument design. In this paper, the principles of corporate
governance are utilised to remedy these shortcomings, elaborating
the control contents of capital instrument design.
The
methodology of this thesis is derived from law &
economics. Traditionally, the methodology encompass an economic
ordering of legal subject matter but according to an integrated
version of the methodology, legal and economic analytical models may
be used on equal standing. Certain residual discrepancies between
legal and economics reasoning are noted in the paper.
The
capital instrument design is explored in an analysis of rationale
and composition. The rationale of capital instruments is derived
from the preferred state of the company technique, as it is
understood in company law and agency theory. The composition is
analysed in three levels - mechanistic, contractual and structural -
based on a conjecture that governance rights counterbalance control
risks.
The conclusions include that capital instruments are
designed to establish flexibility and balance in the company
technique. The governance rights are similar in both equity and debt
instruments, which enable a condensed description of capital
instrument design. The holders are empowered by the capital
instruments and may use their governance rights to allocate and
reduce their risks, adapting the company into a balanced structure
of finance and governance.
No FiF-a 58
LOKALA ELEKTRONISKA
MARKNADSPLATSER: INFORMATIONSSYSTEM FÖR PLATSBUNDNA
AFFÄRER
Johan Petersson
Intresset
för olika yttringar av elektroniska affärer fokuseras inte
sällan på globala och nationella ansträngningar. Detta
gäller inte minst sedan uppmärksamheten under senare
år kommit att riktas mot Internetbaserade tillämpningar och
implikationer av dessa. Uppmärksamheten har också
innefattat förutsägelser där förändrade
förutsättningar hotar traditionella mellanhänders
existens. Föreliggande avhandling berör också denna
typ av tillämpning men fokuserar en situation där just
traditionella mellanhänder i form av små och medelstora
detaljhandelsföretag valt att även möta sina lokala
kunder via Internet. Det är en arena för dessa möten
som står i avhandlingens fokus – den lokala elektroniska
marknadsplatsen. En sådan marknadsplats erbjuder förutom
möjligheter till detaljhandel även tjänster, medium
för diskussion och spridning av information som inte
nödvändigtvis är affärsinriktad.
Arbetet har
genomförts i en pilotstudie och två efterföljande
fallstudier där aktiviteterna på två svenska
webbplatser med den beskrivna inriktningen stod i
centrum. Avhandlingen förmedlar kunskap om sammansättningen
av aktörer på en lokal elektronisk marknadsplats, deras
aktiviteter och samspelet dem emellan. Fokus är riktat mot hur
informationssystem (IS) kan stödja aktörernas olika
ändamål. Avhandlingens resultat rör därmed
utformningen och funktionalitet hos ett möjliggörande
marknadsplats-IS. Denna kunskap är ämnad för
applicering i en beskriven situation av platsbundna elektroniska
affärer.
No 958
MANAGEMENT CONTROL AND STRATEGY - A
CASE STUDY OF PHARMACEUTICAL DRUG DEVELOPMENT
Fredrika
Berglund
How are formal management controls designed
and used in research & development (R&D)? The purpose of
this study is to explain how such systems are designed and used in
formulating and implementing strategies in a pharmaceutical product
development organisation. The study uses a contingency approach to
investigate how the control system is adjusted to the business
strategy of the firm. A case study was conducted in AstraZeneca
R&D where strategic planning, budgeting, project management,
goals and objective systems and the reward systems were studied.
Managers, external investors and researchers increasingly
recognize the strategic importance of R&D activities. This has
inspired researchers and practitioners to develop formal systems and
methods for controlling R&D activities. There is, however,
previous research in which a resistance towards using formal control
systems to manage R&D was observed. This contrasts the general
perception of management control systems as important in
implementing and formulating strategies.
The results of this
study show that formal management control have an important role in
managing R&D. It also explains how the system is adjusted to the
business strategy of the studied firm. Different control systems
(e.g. budget, project management) were found to be designed and used
in different ways. This implies that it is not meaningful to discuss
whether the entire control system of a firm is tight or loose and/or
used interactively or diagnostically. Rather, the systems may
demonstrate combinations of these characteristics. The control
systems of the studied firm were found to be used differently in the
project and the functional dimensions. The control systems were also
designed and used in different ways at different organisational
levels. Comprehensive and rather detailed studies of control systems
are called for in order to understand how they are designed and used
in organisations. Such studies may explain some contradictory
results in previous studies on how control systems are adjusted to
business strategy.
No 964
DEBUGGING AND STRUCTURAL ANALYSIS OF
DECLARATIVE EQUATION-BASED LANGUAGES
Peter
Bunus
A significant part of the software development
effort is spent on detecting deviations between software
implementations and specifications, and subsequently locating the
sources of such errors. This thesis illustrates that is possible to
identify a significant number of errors during static analysis of
declarative object-oriented equation-based modeling languages that
are typically used for system modeling and simulation. Detecting
anomalies in the source code without actually solving the underlying
system of equations provides a significant advantage: a modeling
error can be corrected before trying to get the model compiled or
embarking on a computationally expensive symbolic or numerical
solution process. The overall objective of this work is to
demonstrate that debugging based on static analysis techniques can
considerably improve the error location and error correcting process
when modeling with equation-based languages.
A new method is
proposed for debugging of over- and under-constrained systems of
equations. The improved approach described in this thesis is to
perform the debugging process on the flattened intermediate form of
the source code and to use filtering criteria generated from program
annotations and from the translation rules. Each time when an error
is detected in the intermediate code and the error fixing solution
is elaborated, the debugger queries for the original source code
before presenting any information to the user. In this way, the user
is exposed to the original language source code and not burdened
with additional information from the translation process or required
to inspect the intermediate code.
We present the design and
implementation of debugging kernel prototypes, tightly integrated
with the core of the optimizer module of a Modelica compiler,
including details of the novel framework required for automatic
debugging of equation-based languages.
This thesis establishes
that structural static analysis performed on the underlying system
of equations from object-oriented mathematical models can
effectively be used to statically debug real Modelica programs. Most
of our conclusions developed in this thesis are also valid for other
equation-based modeling languages.
No 973
HIGH-LEVEL TEST GENERATION AND
BUILT-IN SELF-TEST TECHNIQUES FOR DIGITAL SYSTEMS
Gert
Jervan
The technological development is enabling
production of increasingly complex electronic systems. All those
systems must be verified and tested to guarantee correct behavior. As
the complexity grows, testing is becoming one of the most significant
factors that contribute to the final product cost. The established
low-level methods for hardware testing are not any more sufficient and
more work has to be done at abstraction levels higher than the
classical gate and register-transfer levels. This thesis reports on
one such work that deals in particular with high-level test generation
and design for testability techniques.
The contribution of this
thesis is twofold. First, we investigate the possibilities of
generating test vectors at the early stages of the design cycle,
starting directly from the behavioral description and with limited
knowledge about the final implementation architecture. We have
developed for this purpose a novel hierarchical test generation
algorithm and demonstrated the usefulness of the generated tests not
only for manufacturing test but also for testability analysis.
The second part of the thesis concentrates on design for
testability. As testing of modern complex electronic systems is a very
expensive procedure, special structures for simplifying this process
can be inserted into the system during the design phase. We have
proposed for this purpose a novel hybrid built-in self-test
architecture, which makes use of both pseudorandom and deterministic
test patterns, and is appropriate for modern system-on-chip
designs. We have also developed methods for optimizing hybrid built-in
self-test solutions and demonstrated the feasibility and efficiency of
the proposed technique.
No FiF-a 61
META - METHOD FOR METHOD
CONFIGURATION: A RATIONAL UNIFIED PROCESS CASE
Fredrik Karlsson
The world of systems
engineering methods is changing as rigorous
‘off-the-shelf’ systems engineering methods become more
popular. One example of such a systems engineering method is
Rational Unified Process. In order to cover all phases in a software
development process, and a wide range of project-types, such methods
need to be of an impressive size. Thus, the need for configuring
such methods in a structured way is increasing accordingly. In this
thesis, method configuration is considered as a particular kind of
method engineering that focuses on tailoring a standard systems
engineering method. We propose a meta-method for method
configuration based on two fundamental values: standard systems
engineering method’s rationality and reuse. A conceptual
framework is designed, introducing the concepts Configuration
Package and Configuration Template. A Configuration Package is a
pre-made ideal method configuration suitable for a delimited
characteristic of a (type of) software artifact, or a (type of)
software development project, or a combination
thereof. Configuration Templates with different characteristics are
built combining a selection of Configuration Packages and used as a
base for a situational method. The aim of the proposed meta-method
is to ease the burden of configuring the standard systems
engineering method in order to reach an appropriate situational
method.
No 982
PERFORMANCE AND AVAILABILITY
TRADE-OFFS IN FAULT-TOLERANT MIDDLEWARE
Diana
Szentiványi
Distributing functionality of an
application is in common use. Systems that are built with this
feature in mind also have to provide high levels of dependability.
One way of assuring availability of services is to tolerate faults
in the system, thereby avoiding failures. Building distributed
applications is not an easy task. To provide fault tolerance is even
harder.
Using middlewares as mediators between hardware and
operating systems on one hand and high-level applications on the
other hand is a solution to the above difficult problems. It can
help application writers by providing automatic generation of code
supporting e.g. fault tolerance mechanisms, and by offering
interoperability and language independence.
For over twenty
years, the research community is producing results in the area of
. However, experimental studies of different platforms are performed
mostly by using made-up simple applications. Also, especially in
case of CORBA, there is no fault-tolerant middleware totally
conforming to the standard, and well studied in terms of
trade-offs.
This thesis presents a fault-tolerant CORBA
middleware built and evaluated using a realistic application running
on top of it. Also, it contains results obtained after experiments
with an alternative infrastructure implementing a robust
fault-tolerant algorithm using basic CORBA. In the first
infrastructure a problem is the existence of single points of
failure. On the other hand, overheads and recovery times fall in
acceptable ranges. When using the robust algorithm, the problem of
single points of failure disappears. The problem here is the memory
usage, and overhead values as well as recovery times that can become
quite long.
No 985
SCHEDULABILITY ANALYSIS OF REAL-TIME
SYSTEMS WITH STOCHASTIC TASK EXECUTION TIMES
Sorin
Manolache
Systems controlled by embedded computers
become indispensable in our lives and can be found in avionics,
automotive industry, home appliances, medicine, telecommunication
industry, mecatronics, space industry, etc. Fast, accurate and
flexible performance estimation tools giving feedback to the
designer in every design phase are a vital part of a design process
capable to produce high quality designs of such embedded systems.
In the past decade, the limitations of models considering fixed
task execution times have been acknowledged for large application
classes within soft real-time systems. A more realistic model
considers the tasks having varying execution times with given
probability distributions. No restriction has been imposed in this
thesis on the particular type of these functions. Considering such a
model, with specified task execution time probability distribution
functions, an important performance indicator of the system is the
expected deadline miss ratio of tasks or task graphs.
This
thesis proposes two approaches for obtaining this indicator in an
analytic way. The first is an exact one while the second approach
provides an approximate solution trading accuracy for analysis
speed. While the first approach can efficiently be applied to
monoprocessor systems, it can handle only very small multi-processor
applications because of complexity reasons. The second approach,
however, can successfully handle realistic multiprocessor
applications. Experiments show the efficiency of the proposed
techniques.
No 988
GOOD TO USE!: USE QUALITY OF
MULTI-USER APPLICATIONS IN THE HOME
Mattias
Arvola
Traditional models of usability are not
sufficient for software in the home, since they are built with
office software in mind. Previous research suggest that social
issues among other things, separate software in homes from software
in offices. In order to explore that further, the use qualities to
design for, in software for use in face-to-face meetings at home
were contrasted to such systems at offices. They were studied using
a pluralistic model of use quality with roots in
socio-cultural theory, cognitive systems engineering, and
architecture. The research approach was interpretative design
cases. Observations, situated interviews, and workshops were
conducted at a Swedish bank, and three interactive television
appliances were designed and studied in simulated home
environments. It is concluded that the use qualities to design for
in infotainment services on interactive television are laidback
interaction, togetherness among users, and
entertainment. This is quite different from bank office
software that usually is characterised by not only traditional
usability criteria such as learnability, flexibility, effectiveness,
efficiency, and satisfaction, but also professional face
management and ante-use. Ante-use is the events and
activities that precedes the actual use that will set the ground for
whether the software will have quality in use or not. Furthermore,
practices for how to work with use quality values, use quality
objectives, and use quality criteria in the
interaction design process are suggested. Finally, future research
in design of software for several co-present users is proposed.
No 989
MODELING AND SIMULATION OF
CONTACTING FLEXIBLE BODIES IN MULTIBODY SYSTEMS
Iakov
Nakhimovski
This thesis summarizes the equations,
algorithms and design decisions necessary for dynamic simulation of
flexible bodies with moving contacts. The assumed general shape
function approach is also presented. The approach is expected to be
computationally less expensive than FEM approaches and easier to use
than other reduction techniques. Additionally, the described
technique enables studies of the residual stress release during
grinding of flexible bodies.
The overall software system
design for a flexible multi-body simulation system BEAST is
presented and the specifics of the flexible modeling is specially
addressed. An industrial application example is also described in
the thesis. The application presents some results from a case where
the developed system is used for simulation of flexible ring
grinding with material removal.
No 990
PDEMODELICA - TOWARDS A HIGH-LEVEL
LANGUAGE FOR MODELING WITH PARTIAL DIFFERENTIAL EQUATIONS
Levon Saldamli
This thesis describes initial
language extensions to the Modelica language to define a more
general language called PDEModelica, with built-in support for
modeling with partial differential equations (PDEs). Modelica®
is a standardized modeling language for objectoriented,
equation-based modeling. It also supports component-based modeling
where existing components with modified parameters can be combined
into new models. The aim of the language presented in this thesis is
to maintain the advantages of Modelica and also add partial
differential equation support.
Partial differential equations
can be defined using a coefficient-based approach, where a
predefined PDE is modified by changing its coefficient values.
Language operators to directly express PDEs in the language are also
discussed. Furthermore, domain geometry description is handled and
language extensions to describe geometries are presented. Boundary
conditions, required for a complete PDE problem definition, are also
handled.
A prototype implementation is described as well. The
prototype includes a translator written in the relational
meta-language, RML, and interfaces to external software such as mesh
generators and PDE solvers, which are needed to solve PDE
problems. Finally, a few examples modeled with PDEModelica and
solved using the prototype are presented.
No 991
SECURE EXECUTION ENVIRONMENT FOR
JAVA ELECTRONIC SERVICES
Almut Herzog
Private homes are becoming increasingly connected to the Internet in
fast and reliable ways. These connections pave the way for networked
services, i.e. services that gain their value through their
connectivity. Examples of such electronic services (e-services) are
services for remote control of household appliances, home health
care or infotainment.
Residential gateways connect the
private home with the Internet and are the home access point and one
execution platform for e-services. Potentially, a residential
gateway runs e-services from multiple providers. The software
environment of such a residential gateway is a Java execution
environment where e-services execute as Java threads within the Java
virtual machine. The isolation of these Java e-services from each
other and from their execution environment is the topic of this
thesis.
Although the results of this thesis can be applied
to most Java servers—e.g. Javaenabled web browsers, web
servers, JXTA, JINI—this work focuses on e-services for the
private home and their execution platform. Security for the private
home as a prerequisite for end user acceptance is the motivation for
this approach.
This thesis establishes requirements that
prevent e-services on the Java execution platform from harming other
e-services on the same or other network nodes and that prevent
e-services from harming their underlying execution environment. Some
of the requirements can be fulfilled by using the existing Java
sandbox for access control. Other requirements, concerned with
availability of e-services and network nodes, need a modified Java
environment that supports resource control and e-service-specific
access control. While some of the requirements result in
implementation guidelines for Java servers, and in particular for
the e-service environment, other requirements have been implemented
as a proof of concept.
No 999
CONTRIBUTIONS TO PROGRAM- AND
SPECIFICATION-BASED TEST DATA GENERATION
Jon
Edvardsson
Software testing is complex and time
consuming. One way to reduce testing effort is to automatically
generate test data. In the first part of this thesis we consider a
framework by Gupta et al. for generating tests from programs. In
short, their approach consists of a branch predicate collector,
which derives a system of linear inequalities representing an
approximation of the branch predicates for a given path in the
program. This system is solved using their constraint solver called
the Unified Numerical Approach (UNA). In this thesis we show that in
contrast to traditional optimization methods the UNA is not bounded
by the size of the solved system. Instead it depends on how input is
composed. That is, even for very simple systems consisting of one
variable we can easily get more than a thousand iterations. We will
also give a formal proof that UNA does not always find a mixed
integer solution when there is one. Finally, we suggest using some
traditional optimization method instead, like the simplex method in
combination with branch-andbound and/or a cutting-plane algorithm as
a constraint solver.
In the second part we study a
specification-based approach for generation of software tests
developed by Meudec. Briefly, tests are generated by an automatic
partitioning strategy based on partition rules. An important step in
the process is to reduce the number of generated subdomains and find
a minimal partition. However, we have found that Meudec’s
algorithm does not always produce a minimal partition. In this work
we present an alternative solution to the minimal partition problem
by formulating it as an integer programming problem. By doing so, we
can use well known optimization methods to solve this problem.
A more efficient way to derive a minimal partition would be using
Meudec’s conjectured two-step reduction approach: vertex
merging and minimal path coverage. Failing to find a general
solution to either of the steps, Meudec abandoned this approach.
However, in this work we present an algorithm based on partial
expansion of the partition graph for solving the first
step. Furthermore, our work in partial expansion has led to new
results: we have determined an upper bound on the size of a minimal
partition. In turn, this has led to a stronger definition of our
current minimal partition algorithm. In some special cases we can
also determine lower bounds.
No 1000
ADAPTIVE SEMI-STRUCTURED
INFORMATION EXTRACTION
Anders Arpteg
The number of domains and tasks where information extraction tools
can be used needs to be increased. One way to reach this goal is to
construct user-driven information extraction systems where novice
users are able to adapt them to new domains and tasks. To accomplish
this goal, the systems need to become more intelligent and able to
learn to extract information without need of expert skills or
time-consuming work from the user.
The type of information
extraction system that is in focus for this thesis is semistructural
information extraction. The term semi-structural refers to documents
that not only contain natural language text but also additional
structural information. The typical application is information
extraction from World Wide Web hypertext documents. By making
effective use of not only the link structure but also the structural
information within each such document, user-driven extraction
systems with high performance can be built.
The extraction
process contains several steps where different types of techniques
are used. Examples of such types of techniques are those that take
advantage of structural, pure syntactic, linguistic, and semantic
information. The first step that is in focus for this thesis is the
navigation step that takes advantage of the structural
information. It is only one part of a complete extraction system,
but it is an important part. The use of reinforcement learning
algorithms for the navigation step can make the adaptation of the
system to new tasks and domains more user-driven. The advantage of
using reinforcement learning techniques is that the extraction agent
can efficiently learn from its own experience without need for
intensive user interactions.
An agent-oriented system was
designed to evaluate the approach suggested in this thesis. Initial
experiments showed that the training of the navigation step and the
approach of the system was promising. However, additional components
need to be included in the system before it becomes a fully-fledged
user-driven system.
No 1001
A DYNAMIC PROGRAMMING APPROACH TO
OPTIMAL RETARGETABLE CODE GENERATION FOR IRREGULAR ARCHITECTURES
Andrzej Bednarski
In this thesis we
address the problem of optimal code generation for irregular
architectures such as Digital Signal Processors (DSPs). Code
generation consists mainly of three tasks: instruction selection,
instruction scheduling and register allocation. These tasks have
been discovered to be \NP-difficult for most of the architectures
and most situations.
A common approach to code generation
consists in solving each task separately, i.e. in a decoupled
manner, which is easier from an engineering point of view. Decoupled
phase based compilers produce good code quality for regular
architectures, but if applied to DSPs the resulting code is of
significantly lower performance due to strong interdependencies
between the different tasks.
We report on a novel method for
fully integrated code generation based on dynamic programming. It
handles the most important tasks of code generation in a single
optimization step and produces optimal code sequence. Our dynamic
programming algorithm is applicable to small, yet not trivial
problem instances with up to 50 instructions per basic block if data
locality is not an issue, and up to 20 instructions if we take data
locality on irregular processor architectures into account.
In
order to obtain a retargetable framework we developed a first
version of a structured hardware description language, ADML, which
is based on XML. We implemented a prototype framework of such a
retargetable system for optimal code generation.
As far as we
know from the literature, this is the first time that the main tasks
of code generation are solved optimally in a single and fully
integrated optimization step that additionally considers data
placement in registers.
No FiF-a 62
Utveckling av en
projektivitetsmodell: om organisationers förmåga att
tillämpa projektarbetsformen
Lennart
Ljung
I dagens affärsdrivande organisationer
genomförs projekt inte enbart för att skapa
förändringar av organisation, arbetssätt eller
infrastruktur. Marknadens rörlighet och kundspecifika krav
på komplexa produkter, medför att projekt även
genomförs inom den ordinarie operativa verksamheten för
att hantera temporära, komplexa engångsuppgifter i form
av både kundorder och produktutvecklingar. Projektarbetsformen
kan öka engagemanget och samarbetet över
organisationsgränserna, men det är vanligt att
organisationer även upplever problem med projekten. En stor del
av problemen kan antas bero på organisationens
förmåga att tillämpa projektarbetsformen –
organisationens projektivitet. Avhandlingens övergripande
forskningsfråga lyder: Hur kan en organisations projektivitet
beskrivas i en modell? Med utgångspunkt i Ericsson Infotechs
projektivitetsmodell har syftet med forskningsarbetet varit att
utveckla en ny projektivitetsmodell som skall kunna tillämpas
vid fortsatt utveckling av en metod för
projektivitetsanalys. En explorativ studie har genomförts i fem
etapper, där valideringen av modellversioner varit ett viktigt
inslag. Resultatet av arbetet är dels ett utvecklat
projektbegrepp med en klar åtskillnad mellan projektuppgift
och projektarbetsform, dels en multidimensionell
projektivitetsmodell (MDP-modellen) med fyra dimensioner:
projektfunktioner, triader, influerande faktorer samt
organisatoriskt lärande. Avhandlingens resultat är avsett
att ligga till grund för framtida forskning inom området,
exempelvis fortsatt utveckling av en projektivitetsanalys eller
organisatorisk lärande genom tillämpning av
projektmodeller
No 1003
USER EXPERIENCE OF SPOKEN FEEDBACK
IN MULTIMODAL INTERACTION
Pernilla
Qvarfordt
The area of multimodal interaction is fast
growing, and is showing promising results in making the interaction
more efficient and Robust. These results are mainly based on better
recognizers, and studies of how users interact with particular
multimodal systems. However, little research has been done on
users’ subjective experience of using multimodal interfaces,
which is an important aspect for acceptance of multimodal
interfaces. The work presented in this thesis focuses on how users
experience multimodal interaction, and what qualities are important
for the interaction. Traditional user interfaces and speech and
multimodal interfaces are often
described as having different
interaction character (handlingskaraktär).
Traditional user interfaces are often seen as tools, while
speech and multimodal interfaces are often described as dialogue
partners. Researchers have ascribed different qualities as
important for performance and satisfaction for these two interaction
characters. These statements are examined by studying how users
react to a multimodal timetable system. In this study spoken
feedback was used to make the interaction more human-like. A
Wizard-of-Oz method was used to simulate the recognition and
generation engines in the timetable system for public
transportation. The results from the study showed that users
experience the system having an interaction character, and that
spoken feedback
influences that experience. The more spoken
feedback the system gives, the more users will experience the system
as a dialogue partner. The evaluation of the qualities of
interaction showed that user preferred no spoken feedback, or
elaborated spoken feedback. Limited spoken feedback only distracted
the users.
No 1005
VISUALIZATION OF DYNAMIC MULTIBODY
SIMULATION - WITH SPECIAL REFERENCE TO CONTACTS
Alexander Siemers
This thesis describes the
requirements for creating a complete multibody visualization
system. The complete visualization process includes everything from
data storage to image rendering, and what is needed for a meaningful
user-to-data interaction. Other topics covered in this thesis are
2D data packing for parallel simulation and remote simulation
control.
System modeling is an important aspect in multibody
simulation and visualization. An object oriented approach is used
for the multibody model, its basic simulation data structures, and
for the visualization system. This gives well structured models and
supports both efficient computation and visualization without
additional transformations.
The large amount of data and time
steps require data compression. An compression algorithm specially
designed for numerical data of varying step size is used for all
time-varying data. All data is organized in blocks which allows fast
selective data access during animation. The demands on a multibody
simulation tool focusing on contact analysis represents a special
challenge in the field of scientific visualization. This is
especially true for multidimensional time-varying data, i.e. two
dimensional surface related data.
A surface data structure is
presented which is designed for efficient data storage, contact
calculation, and visualization. Its properties include an oriented
multibody modeling approach, memory allocation on demand, fast data
access, effective data compression, and support for interactive
visualization.
Contact stresses between two surfaces penetrate
the material underneath the surface. These stresses need to be
stored during simulation and visualized during animation. We
classify this stresses as sub-surface stresses, thus a thin layer
volume underneath the surface.
A sub-surface data structure
has been created. It has all the good properties of the surface data
structure and additional capabilities for visualization of
volumes.
In many application fields the simulation process is
computation intensive and fast remotely located computers,
e.g. parallel computers or workstation clusters, are needed to
obtain results in reasonable time. An application is presented which
addresses all the major problems related to the data transfers over
networks, unified access to different remote systems and
administration across different organizational domains.
No 1008
TOWARDS UNANTICIPATED RUNTIME
SOFTWARE EVOLUTION
Jens Gustavsson
For
some software systems with high availability requirements, it is not
acceptable to have the system shut down when a new version of it is to
be deployed. An alternative is to use unanticipated runtime software
evolution, which means making changes to the Software system while it
is executing. We propose a classification of unanticipated runtime
software changes. Our classification consists of a code change aspect,
a state change aspect, an activity aspect and a motivation aspect.
The purpose of the classification is to get a greater understanding of
the nature of such changes, and to facilitate an abstract view of
them. We also present a case study, where historical changes to an
existing software system have been categorized according to the
classification. The data from the case study gives an indication that
the Java Platform Debugger Architecture, a standard mechanism in Java
virtual machines, is a viable technical foundation for runtime
software evolution systems.
We also discuss taxonomies of
unanticipated runtime software evolution and propose an extension to
the concept of validity of runtime changes.
No 1010
ADAPTIVE QOS-AWARE RESOURCE
ALLOCATION FOR WIRELESS NETWORKS
Calin
Curescu
Wireless communication networks are facing a
paradigm shift. From providing only voice communication, new
generations of wireless networks are designed to provide different
types of multimedia communications together with different types of
data services and aim to seamlessly integrate in the big Internet
infrastructure.
Some of these applications and services have
strong resource requirements in order to function properly
(e.g. videoconferences), others are flexible enough to adapt to
whatever is available (e.g. FTP). Also, different services (or
different users), might have different importance levels, and should
be treated accordingly. Providing resource assurance and
differentiation is often referred to as quality of service
(QoS). Moreover, due to the constrained and fluctuating bandwidth of
the wireless link, and user mobility, wireless networks represent a
class of distributed systems with a higher degree of
unpredictability and dynamic change as compared to their wireline
counterparts.
In this thesis we study how novel resource
allocation algorithms can improve the behaviour (the offered QoS) of
dynamic unpredictable distributed systems, such as a wireless
network, during periods of overload. This work concerns both low
level enforcement mechanisms and high-level policy dependent
optimisation algorithms.
First, we propose and evaluate
adaptive admission control algorithms for controlling the load on a
processor in a radio network controller. We use feedback mechanisms
inspired by automatic control techniques to prevent CPU overload,
and policy-dependent deterministic algorithms to provide service
differentiation.
Second, we propose and evaluate a QoS-aware
bandwidth admission control and allocation algorithm for the radio
link in a network cell. The acceptable quality levels for a
connection are specified using bandwidth dependent utility
functions, and our scheme aims to maximise system-wide utility. The
novelty in our approach is that we take into account bandwidth
reallocation, which arise as a consequence of the dynamic
environment, and their effects on the accumulated utility of the
different connections.
No 1015
MANAGEMENT INFORMATION SYSTEMS IN
PROCESS-ORIENTED HEALTHCARE ORGANISATIONS
Anna
Andersson
The aim of this thesis work was to develop
a management information system model for process-oriented
healthcare organisations. The study explores two questions:
“What kinds of requirements do healthcare managers place on
information systems?” and “How can the work and
information systems of healthcare managers and care providers be
incorporated into process-oriented healthcare
organisations?”
The background to the study was the
process orientation of Swedish healthcare organisations. The study
was conducted at the paediatric clinic of a county hospital in
southern Sweden. Organisational process was defined as “a
sequence of work procedures that jointly constitute complete
healthcare services”, while a functional unit was the
organisational venue responsible for a certain set of work
activities.
A qualitative research method, based on a
developmental circle, was used. The data was collected from
archives, interviews, observations, diaries and focus groups. The
material was subsequently analysed in order to categorise, model and
develop small-scale theories about information systems.
The
study suggested that computer-based management information systems
in processoriented healthcare organisations should: (1) support
medical work; (2) integrate clinical and administrative tools; (3)
facilitate the ability of the organisation to measure inputs and
outcomes.
The research effort concluded that various
healthcare managers need the same type of primary data, though
presented in different ways. Professional developers and researchers
have paid little attention to the manner in which integrated
administrative, financial and clinical systems should be configured
in order to ensure optimal support for process-oriented healthcare
organisations. Thus, it is important to identify the multiple roles
that information plays in such an organisation.
No 1018
FEEDFORWARD CONTROL IN DYNAMIC
SITUATIONS
Björn Johansson
This
thesis proposal discusses control of dynamic systems and its
relation to time. Although much research has been done concerning
control of dynamic systems and decision making, little research
exists about the relationship between time and control. Control is
defined as the ability to keep a target system/process in a desired
state. In this study, properties of time such as fast, slow,
overlapping etc, should be viewed as a relation between the variety
of a controlling system and a target system. It is further concluded
that humans have great difficulties controlling target systems that
have slow responding processes or "dead" time between
action and response. This thesis proposal suggests two different
studies to adress the problem of human control over slow responding
systems and dead time in organisational control.
No 1022
SCHEDULING AND OPTIMISATION OF
HETEROGENEOUS TIME/EVENT-TRIGGERED DISTRIBUTED EMBEDDED SYSTEMS
Traian Pop
Day by day, we are witnessing a
considerable increase in number and range of applications which entail
the use of embedded computer systems. This increase is closely
followed by the growth in complexity of applications controlled by
embedded systems, often involving strict timing requirements, like in
the case of safety-critical applications. Efficient design of such
complex systems requires powerful and accurate tools that support the
designer from the early phases of the design process.
This
thesis focuses on the study of real-time distributed embedded systems
and, in particular, we concentrate on a certain aspect of their
real-time behavior and implementation: the time-triggered (TT) and
event-triggered (ET) nature of the applications and of the
communication protocols. Over the years, TT and ET systems have been
usually considered independently, assuming that an application was
entirely ET or TT. However, nowadays, the growing complexity of
current applications has generated the need for intermixing TT and ET
functionality. Such a development has led us to the identification of
several interesting problems that are approached in this
thesis. First, we focus on the elaboration of a holistic
schedulability analysis for heterogeneous TT/ET task sets which
interact according to a communication protocol based on both static
and dynamic messages. Second, we use the holistic schedulability
analysis in order to guide decisions during the design process. We
propose a design optimisation heuristic that partitions the task-set
and the messages into the TT and ET domains, maps and schedules the
partitioned functionality, and optimises the communication protocol
parameters. Experiments have been carried out in order to measure the
efficiency of the proposed techniques.
No FiF-a 65
KUNDKOMMUNIKATION PÅ
DISTANS - EN STUDIE OM KOMMUNIKAITONSMEDIETS BETYDELSE I
AFFÄRSTRANSAKTIONER
Britt-Marie
Johansson
Tidigare var det vanligaste, och ofta enda,
sättet att skaffa varor av olika slag, att besöka en butik
och där välja ut och betala de produkter vi
behövde. Sätten att införskaffa produkter har dock
förändrats. Under senare år har det blivit mer vanligt
att handla på distans. Det som började med postorder har i
allt högre grad kompletterats med handel via webben och
sätten att kommunicera mellan företag och kunder har blivit
fler.
Många företag erbjuder sina kunder flera olika
kommunikationsmedier såsom e-post, fax och
telefon. Utgångspunkten för studien har varit att
både kunder och företag väljer, medvetet eller
omedvetet, att använda sig av olika kommunikationsmedier vid
genomförandet av affärstransaktioner. Huvudsyftet med
avhandlingen är att bidra med kunskap som kan användas av
företag till att fatta mer genomtänkta beslut avseende vilka
kommunikationsmedier som bör inkluderas i deras strategier
för kundkommunikation. För att kunna värdera hur olika
kommunikationsmedier påverkar kund och företag måste
de betraktas ur både kundens och företagets
ögon. För att belysa detta har en fallstudie
genomförts, där dessa båda perspektiv på olika
kommunikationsmedier har undersökts.
Vad som klart
framgår av studien är att samtliga studerade
kommunikationsmedier har både för- och nackdelar. De
faktorer som huvudsakligen påverkade både kundens och
företagets val av kommunikationsmedium var vilken
kommunikationshandling (t ex beställning eller
förfrågan) som skulle utföras samt tidsfaktorn;
tidpunkten samt tidsåtgången för
genomförandet.
En slutsats som kan dras av denna studie
är att företag med en heterogen kundgrupp eller med en
kundgrupp som inte är väl segmenterad, bör erbjuda sina
kunder flera olika kommunikationsmedier för att inte
utestänga vissa kundkategorier från att interagera med
företaget på ett sätt som passar dem.
No 1024
TOWARDS ASPECTUAL COMPONENT-BASED
REAL-TIME SYSTEM DEVELOPMENT
Aleksandra
Tešanovic
Increasing complexity of real-time
systems and demands for enabling their configurability and
tailorability are strong motivations for applying new software
engineering principles such as aspectoriented and component-based
software development. The integration of these two techniques into
real-time systems development would enable: (i) efficient system
configuration from the components in the component library based on
the system requirements, (ii) easy tailoring of components and/or a
system for a specific application by changing the behavior (code) of
the component by aspect weaving, and (iii) enhanced flexibility of
the real-time and embedded software through the notion of system
configurability and components tailorability.
In this thesis
we focus on applying aspect-oriented and component-based software
development to real-time system development. We propose a novel
concept of aspectual component-based real-time system development
(ACCORD). ACCORD introduces the following into real-time system
development: (i) a design method that assumes the decomposition of
the real-time system into a set of components and a set of aspects,
(ii) a real-time component model denoted RTCOM that supports aspect
weaving while enforcing information hiding, (iii) a method and a
tool for performing worstcase execution time analysis of different
configurations of aspects and components, and (iv) a new approach to
modeling of real-time policies as aspects.
We present a case
study of the development of a configurable real-time database
system, called COMET, using ACCORD principles. In the COMET example
we show that applying ACCORD does have an impact on the real-time
system development in providing efficient configuration of the
realtime system. Thus, it could be a way for improved reusability
and flexibility of real-time software, and modularization of
crosscutting concerns.
In connection with development of
ACCORD, we identify criteria that a design method for
component-based real-time systems needs to address. The criteria
include a well-defined component model for real-time systems, aspect
separation, support for system configuration, and analysis of the
composed real-time system. Using the identified set of criteria we
provide an evaluation of ACCORD. In comparison with other
approaches, ACCORD provides a distinct classification of
crosscutting concerns in the real-time domain into different types
of aspects, and provides a real-time component model that supports
weaving of aspects into the code of a component, as well as a tool
for temporal analysis of the weaved system.
No 1033
SVENSKA BANKERS REDOVISNINGSVAL
VID RESERVERING FÖR BEFARADE KREDITFÖRLUSTER - EN STUDIE
VID INFÖRANDET AV NYA REDOVISNINGSREGLER
Peter
Nilsson
Den 1 januari 2002 infördes i Sverige
nya regler avseende redovisningsmässig reservering för
befarade kreditförluster i banker. Tidigare bankkriser hade
aktualiserat frågan om huruvida traditionella individuella
kreditreserveringsregler tenderade till att fördröja
redovisningen av osäkra fordringar och därmed verka
destabiliserande på det finansiella systemet. Den stora
förändringen i de nya reglerna är krav på
bedömning av behov av gruppvis reservering i det fall
någonting inträffat med negativ inverkan på
kreditkvalitén i en grupp av lånefordringar som skall
värderas individuellt men där den försämrade
kreditkvalitén ännu inte kan spåras i individuella
låntagares beteende. Reglerna syftar därmed till att
minska tiden från det att en händelse, med negativ effekt
på kreditkvalitén för en grupp av krediter
inträffar, till det att denna händelse leder till en
ökad reservering för befarade kreditförluster.
Föreliggande empiriska studie av de svenska
storbankskoncernernas redovisning under 2002 och intervjuer med
företrädare för dessa banker, visar att
införandet av de nya reglerna kring gruppvis reservering inte
medförde den ökning av de totala reserverna hos bankerna
som kunde förväntas. Istället skedde en
omfördelning från tidigare gjorda individuella och
generella reserver till gruppvis reserv. En stor oenighet i
tolkningen av reglerna avseende innebörden av begreppet
inträffad händelse, en skild syn på behovet av nya
regler och en osäkerhet bland bankerna, Finansinspektionen och
de externa revisorerna kring reglernas innebörd, fick till
följd att redovisningen hos de svenska bankerna vid
utgången av år 2002 väsentligen skiljer sig
åt. Studien visar vidare, i enlighet med i referensramen
presenterade studier, att aktiva redovisningsval görs vid
bedömning av reserv för befarade kreditförluster och
att dessa redovisningsval kan antas vara påverkade av ett
antal föreliggande incitament. Utifrån bankernas externa
redovisning är det som läsare svårt att
förstå hur bankerna fastställer den gruppvisa
reserven, vilket kan antas försvåra möjligheten att
”se igenom” redovisningen och öka risken för
att eventuell earnings management skall få negativa
konsekvenser på resursallokeringen.
No 1034
DESIGNING FOR USE IN A FUTURE
CONTEXT - FIVE CASE STUDIES IN RETROSPECT
Arja
Vainio-Larsson
This thesis presents a framework
– Use Oriented Service Design – for how design can be
shaped by people’s future communications needs and
behaviour. During the last ten years we have seen the telecom
industry go through several significant changes. It has been
re-regulated into much more of an open market and, as a result of
this, other actors and role-holders have entered the market place
and taken up the competition with traditionally monopolistic telecom
players. Systems and applications are opening up in order to support
interoperability. The convergence between the telecom and IT sector
with respect to technology, market and business models is
continuing. In this process, we have seen a continuous development
which involves a change of focus: from the user interface towards
the services and from users towards usage situations. The Use
Oriented Service Design approach (UOSD for short) addresses this
change.
In UOSD three different design views are explored and
analysed: the needs view, the behavioural view, and the technical R
& D view.
UOSD was developed with the specific aim of
helping companies to meet pro-actively the requirements a future use
context will place on their service offerings. Two gaps are defined
and bridged: the needs gap and the product gap. The needs gap,
defines a set of needs that is not met in a current context of
study. Three different needs categories are addressed: needs that
users easily can articulate, needs that users can articulate only by
indirect means and, finally, needs users can neither foresee nor
anticipate. The second gap is the product gap, it provides a
measure of the enabling power of a company’s technical
initiatives. Technology as it is applied, or as it readily can be
applied to meet a set of defined needs, together with planned R
& D initiatives will predict the company’s ability to meet
a future use context.
An Integrated Prototyping Environment
(IPE) was defined and partly developed to support four modes of
operation: collection, Analysis, design and evaluation. IPE consists
of a collection & analysis module, a sketching & modelling
module and a module for prototyping & simulation. It also
provides an access port that supports communication with an external
development environment.
The thesis reflects the evolution
from before the widespread introduction of the web to today’s
pervasive computing and is based on work done within both research
and industrial settings. In the first part of the thesis, the UOSD
framework is presented together with a background and a discussion
of some key concepts. Part two of the thesis includes five case
studies of which the two first Represent a more traditional human
factors work approach and its application in an industrial
context. The three remaining studies exemplify the industrial
application of UOSD as it is presented in this thesis.
No FiF-a 69
INFORMATION TECHNOLOGY FOR
LEARNING AND ACQUIRING OF WORK KNOWLEDGE AMONG PRODUCTION WORKERS
Fredrik Ericsson
This thesis is about
information technology for learning and acquiring of work knowledge
among production workers in a manufacturing company. Focus is on
production or factory workers in workplaces where the job workers do
have a routine character. The thesis builds upon a research project
aiming at developing an information system for learning and acquiring
of work knowledge among production workers. The system manages
manufacturing related operational disturbances and production workers
use the system to learn from operational disturbances in such a way
that workers do the job grounded on knowledge of prior
disturbances. The thesis covers intervention measures aiming at
integrating learning and work by developing an information system. The
thesis presents and elaborates on the process and outcome of such a
development. The empirical work in this thesis is based on an action
case study research approach.
The thesis proposes three
interrelated aspects concerning use of information technology for
learning and acquiring work knowledge among production workers. Such
aspects are the (a)work practice, (b)learning and acquiring of work
knowledge and (c)information systems.
These aspects must be
considered as a coherent whole to seek to integrate learning and work
(i.e. to create a learning environment). The work practice sets the
scope for workplace learning (to what extent learning takes place at
work). The scope for learning is related to for example, machinery and
equipment, management and the organizing principle of work. Learning
and acquiring of work knowledge is related to in what ways workers
learn about the job. Information systems must be in alignment with the
practice and the ways workers learn and acquire work knowledge.
No 1049
TOWARDS FINE-GRAINED BINARY
COMPOSITION THROUGH LINK TIME WEAVING
Marcus
Comstedt
This thesis presents ideas for a system
composing software components in binary form. Binary components are
important since most off-the-shelf components on a mature component
market can be expected to be delivered in binary form only. The
focus in this
work is to enable efficient composition and
bridging of architectural mismatch between such components.
The central result is a model for describing binary components and
their interactions. This model supports invasive composition, i.e.,
the code of the components themselves can be transformed for more
efficient adaptation. The model is also designed to be independent
of the source and binary language of the individual components. It
supports unforeseen composition, by finding interaction points
between software objects and making them available for
modification. Therefore, it can be used to insert variability in
places where it was not originally intended.
In addition to
the model, an architecture for a composition system is presented.
In this architecture, language dependent parts of the composition
process are separated into specific modules. Thus, the central parts
of the architecture become language independent,
allowing
complex composition operators to be defined and reused for a
multitude of languages.
No 1052
INCREASING THE AUTOMATION OF RADIO
NETWORK CONTROL
Åsa Hedenskog
The
efficient utilization of radio frequencies is becoming more
important with new technology, new telecom services and a rapidly
expanding market. Future systems for radio network management are
therefore expected to contain more automation than today’s
systems.
This thesis describes a case study performed at a
large European network operator. The first purpose of this study
was to identify and describe elements in the current environment of
telecommunication radio network management, in order to draw
conclusions about the impact of a higher degree of automation in
future software systems for radio network management.
The
second purpose was to identify specific issues for further analysis
and development.
Based on a case study comprising eight
full-day observations and eleven interviews with the primary user
category, and their colleagues on other teams, this thesis:
- Describes the
work environment by presenting findings regarding task performance and the
use of knowledge, qualities of current tools and the expected qualities of new technology. - Based on the empirical findings, it concludes that full automation is
not feasible at this time,
but that a supervisory control system including both a human operator and a machine is
therefore the best solution. - Describes the design considerations for such a supervisory control system for this domain.
- Based on the finding that users allocate function in order to learn
about a tool, it introduces
the concept of adaption through praxis, as a way of introducing a supervisory control system
which includes automation. - In conclusion, it discusses research issues for future studies in this area.
No 1054
SECURITY AND EFFICIENCY TRADEOFFS
IN MULTICAST GROUP KEY MANAGEMENT
Claudiu
Duma
An ever-increasing number of Internet
applications, such as content and software distribution, distance
learning, multimedia streaming, teleconferencing, and collaborative
workspaces, need efficient and secure multicast
communication. However, efficiency and security are competing
requirements and balancing them to meet the application needs is
still an open issue.
In this thesis we study the efficiency
versus security requirements tradeoffs in group key management for
multicast communication. The efficiency is in terms of minimizing
the group rekeying cost and the key storage cost, while security is
in terms of achieving backward secrecy, forward secrecy, and
resistance to collusion.
We propose two new group key
management schemes that balance the efficiency versus resistance to
collusion. The first scheme is a flexible category-based scheme, and
addresses applications where a user categorization can be done based
on the user accessibility to the multicast channel. As shown by the
evaluation, this scheme has a low rekeying cost and a low key
storage cost for the controller, but, in certain cases, it requires
a high key storage cost for the users. In an extension to the basic
scheme we alleviate this latter problem.
For applications
where the user categorization is not feasible, we devise a
cluster-based group key management. In this scheme the resistance to
collusion is measured by an integer parameter. The communication and
the storage requirements for the controller depend on this parameter
too, and they decrease as the resistance to collusion is relaxed.
The results of the analytical evaluation show that our scheme allows
a fine-tuning of security versus efficiency requirements at runtime,
which is not possible with the revious group key management
schemes.
No FiF-a 71
EFFEKTANALYS AV IT-SYSTEMS
HANDLINGSUTRYMME
Emma Eliason
Syftet
med design av IT-system är att förändra eller
stödja användares handlingar genom att göra vissa
handlingar möjliga att utföra och andra
omöjliga. Detta görs genom att systemet tilldelats vissa
egenskaper i utvecklingsprocessen som skall möjliggöra och
begränsa vissa typer av handlingar. Detta resulterar i ett
designat handlingsutrymme. Kontrollen som designers haft över
sin design tappas när applikationen börjar
användas. Det uppstår då effekter i
användarens användning av systemet som designers inte har
kontroll över. En effekt av användningen är
användarens upplevda handlingsutrymme och konsekvenserna av den
upplevelsen. En designer är därmed delvis ansvarig
över de möjligheter och begräsningar som har
implementerats i form av funktioner i systemet. IT-system kan ses
som en ställföreträdare som kommunicerar till
användarna vad designern förväntade, och
användarna kan endast kommunicera med designerns
ställföreträdare inte med designern. Därmed kan
effekter av IT-systemets design identifieras i användarens
upplevelse av IT-systemet. Men hur går man tillväga
för att studera effekter av ett IT-systems design? I denna
avhandling presenteras utvecklingen av ett
tillvägagångssätt (effektanalys) med
tillhörande analysmodeller (D.EU.PS. Modellen och
fenomenanalys) av IT-system användning, som kan användas
för att studera effekter av ett designat
handlingsutrymme. Detta görs genom att fokusera användares
upplevelser av IT-systemet. Detta arbete genomförs i en
pilotstudie och två efterföljande
fallstudier. D.EU.PS. Modellen används för att
klassificera IT-systems funktionalitet och erbjuder ett praktiskt
stöd för att värdera specifika egenskaper av ett
IT-system. Den bidrar även med en förståelse
för vad designers avser och vad användare
upplever. Begreppet handlingsutrymme konkretiseras genom att det
egenskapsbestäms i avhandlingen. Med egenskaper avser jag
sådant som påverkar användningen av IT-systemet i
dess handlingskontext och upplevelsen av IT-systemets
handlingsutrymme.
No 1055
EXPERIMENTS IN INDIRECT FAULT
INJECTION WITH OPEN SOURCE AND INDUSTRIAL SOFTWARE
Carl Cederberg
Software fault injection is a
technique in which faults are injected into a program and the
response of the program is observed. Fault injection can be used to
measure the robustness of the program as well as to find faults in
the program, and indirectly contributes to increased robustness. The
idea behind software fault injection is that the better the system
handles the faults, the more robust the system is. There are
different ways of injecting faults, for example, by changing a
variable value to a random value or by changing the source code to
mimic programmer errors. The thesis presents an overview of fault
injection in hardware and software. The thesis deals with a special
case of fault injection, i.e., indirect fault injection. This means
that the faults are injected into one module and the response is
observed in another module that communicates with the first one. The
thesis presents two experiments designed to measure the effect of
the fault model used when faults are injected using the indirect
fault injection method. The first experiment is conducted on open
source software. The result from the experiment was not entirely
conclusive, but there are indications that the fault model does
matter, but this needs to be further examined. Therefore, a second
experiment is designed and presented. The second experiment is
conducted on larger, industrial software. The goals of both
experiments are to find out whether or not the results of fault
injection are affected by how the injected faults are generated. The
second experiment shows the feasibility of using fault injection in
industrial strength software. The thesis concludes with the
proposal for a PhD thesis on a suite of different experiments.
No 1058
TOWARDS FORMAL VERIFICATON IN A
COMPONENT-BASED REUSE METHODOLOGY
Daniel
Karlsson
Embedded systems are becoming increasingly
common in our everyday lives. As techonology progresses, these
systems become more and more complex. Designers handle this
increasing complexity by reusing existing components (Intellectual
Property blocks). At the same time, the systems must still fulfill
strict requirements on reliability and correctness.
This
thesis proposes a formal verification methodology which smoothly
integrates with component-based system-level design using a divide
and conquer approach. The methodology assumes that the system
consists of several reusable components. Each of these components
are already formally verified by their designers and are considered
correct given that the environment satisfies certain properties
imposed by the component. What remains to be verified is the glue
logic inserted between the components. Each such glue logic is
verified one at a time using model checking techniques.
The
verification methodology as well as the underlying theoretical
framework and algorithms are presented in the thesis. Experimental
results have shown the efficiency of the proposed methodology and
demonstrated that it is feasible to apply it on real-life
examples
No FiF-a 73
ATT ETABLERA OCH
VIDMAKTHÅLLA FÖRBÄTTRINGSVERKSAMHET - BEHOVET AV
KOORDINATION OCH INTERAKTION VID FÖRÄNDRING AV
SYSTEMUTVECKLINGSVERKSAMHETER
Anders
Hjalmarsson
Det har sedan länge konstaterats att
det är komplicerat och problematiskt att utveckla
informationssystem. Det har exempelvis visat sig att de
informationssystem som utvecklats ibland inte
överensstämmer med de mål som den användande
organisationen har. Informationssystemen har därtill en tendens
av att inte bli färdiga i tid eller inom
budget. Informationssystemsutveckling kan således betecknas
som en komplex verksamhet vilken återkommande måste
förändras och utvecklas för att kunna fungera
framgångsrikt.
Att medvetet arbeta med att
förbättra systemutvecklingsverksamheten har sedan
länge varit ett fenomen som fokuserats i forskning. Resultatet
av forskningen har inneburit att metoder, modeller och strategier
för hur förbättringsarbete skall bedrivas har
utvecklats. Ett tillvägagångssätt för att
genomföra dessa förbättringsintentioner är att
organisera arbetet i en temporär
förbättringsverksamhet och därtill frigöra denna
verksamhet från den ordinarie systemutvecklingsverksamheten.
Härigenom skapas ett förbättringsprojekt som
genomförs på en separerad arena. Projektet har som syfte
att utarbeta förbättringar som sedan skall implementeras i
systemutvecklingsverksamheten. De problem som kan uppstå vid
denna organisering innebär att projektet kan hamna i ett
»vakuum« vilket innebär att
förbättringsintentionerna ej får utväxling i
form av en förbättrad systemutvecklingsverksamhet.
I
denna avhandling har jag studerat projektorganiserad
förbättringsverksamhet utifrån detta problem. Det
övergripande syftet med studien har varit att utveckla
råd för hur en framgångsrik projektorganiserad
förbättringsverksamhet etableras och
vidmakthålls. För att nå detta resultat har jag
skapat mig en förståelse för genomförandet av
projektorganiserad förbättringsverksamhet genom att under
tre år följa ett förbättringsprogram på
ett mindre IT-företag. Jag har här kunnat kartlägga
vilka problem och styrkor som uppstår under denna typ av
förbättringsarbete. Denna empiri har jag använt
för att pröva och vidareutveckla en praktikteoretiskt
grundad vision om hur framgångsrik projektbaserad
förbättringsverksamhet bör etableras och
vidmakthållas. Resultatet av forskningsarbetet har
primärt inneburit kunskapsbidrag i form av råd vilka
framhäver behovet av samt understödjer möjligheten
till interaktion vid och koordination av projektorganiserad
förbättringsverksamhet i systemutvecklingssammanhang.
No 1079
DESIGN AND DEVELOPMENT OF
RECOMMENDER DIALOGUE SYSTEMS
Pontus
Johansson
The work in this thesis addresses design
and development of multimodal dialogue recommender systems for the
home context-of-use. In the design part, two investigations on
multimodal recommendation dialogue interaction in the home context
are reported on. The first study gives implications for the design
of dialogue system interaction including personalization and a
three-entity multimodal interaction model accommodating dialogue
feedback in order to make the interaction more efficient and
successful. In the second study a dialogue corpus of movie
recommendation dialogues is collected and analyzed, providing a
characterization of such dialogues. We identify three initiative
types that need to be addressed in a recommender dialogue system
implementation: system-driven preference requests, user-driven
information requests, and preference volunteering. Through the
process of dialogue distilling, a dialogue control strategy covering
system-driven preference requests from the corpus is arrived at.
In the development part, an application-driven development
process is adopted where re-usable generic components evolve through
the iterative and incremental refinement of dialogue systems. The
Phase Graph Processor (PGP) design pattern is one such evolved
component suggesting a phase-based control of dialogue systems. PGP
is a generic and flexible micro architecture accommodating frequent
change of requirements inherent of agile, evolutionary system
development. As PGP has been used in a series of previous
information-providing dialogue system projects, a standard phase
graph has been established that covers the second initiative type;
user-driven information requests. The phase graph is incrementally
refined in order to provide user preference modeling, thus
addressing the third initiative type, and multimodality as indicated
by the user studies. In the iterative development of the multimodal
recommender dialogue system MADFILM the phase graph is coupled with
the dialogue control strategy in order to cater for the seamless
integration of the three initiative types.
No 1084
A STUDY OF CAUL CENTRE LOCATIONS
IN A SWEDISH RURAL REGION
Charlotte Stoltz
The business economy is undergoing structural changes as we are
moving towards more information based businesses. Most studies of
industrial location have however focused on manufacturing activities
and there is a lack in knowledge of the exact determinants for the
location of information based and geographically independent
activities. Traditional locational theories have to be complemented
with factors that consider these types of businesses. A focus on
information based and geographically independent organisations, such
as call centres, has a potential to fuel research into industrial
location.
The general aim of this thesis is, from a business
perspective, to explore and identify a number of factors that are of
importance for call centre locations in a specific region. More
specifically, the thesis deals with the fact that development and use
of information and communication technology, organisational
prerequisites in form of changed organisational structures and
management of organisations and also more individually related aspects
nowadays seem to play an important role for both how business are
organised and for where they are located. The thesis is mainly based
on a case study of a Swedish rural region that has been successful in
its efforts to attract and develop call centre activities.
First, it is shown that the call centre concept is full of nuance and
researchers as well as practitioners use the concept differently. In
order to enhance and balance discussions about call centres and also
facilitate the process of comparing research findings, ten
characteristics that are regarded as useful for discriminating among
call centre activities are presented. Second, the importance of
distinguishing location choices for information based business from
location choices for more traditional service business and
manufacturing businesses is an important finding and examples that
support this are given. A third finding is that even though call
centres are often regarded as geographically independent, the
proximity that can be offered with cluster formations seems to be of
importance also for this type of businesses. It is however more about
horizontal integration and not about vertical integration, which is
often present for manufacturing businesses. Finally, call centres seem
to offer opportunities for regions and localities that wish to create
work opportunities and achieve a positive regional development and
this applies especially to rural or peripheral areas. However, in
order to be successful there are many interacting factors that have to
be considered and dealt with and it is important to notice that it
often takes time to build up a positive climate for call centre
businesses in a region, i.e. different regional actors can and have to
do much more than just call for call centres.
No FiF-a 74
DECIDING ON USING
APPLICATON SERVICE PROVISION IN SMES
Björn
Johansson
The use of external providers for the
provision of information and communication technology (ICT) in small
and medium-sized enterprises (SMEs) is expected to increase. At the
end of the 1990s the concept of Application Service Provision (ASP)
and Application Service Providers (ASPs) was introduced. This is
described as one way for SMEs to provide themselves with software
applications. However, it can be stated that the concept has not
taken off. This study examines what reasons influence the
decision-making when deciding to use or not use ASP. The research
question is: How do SMEs decide on using an Application Service
Provider for the provision and maintenance of ICT? In order to
answer the question decision-making processes in SMEs have been
investigated in an interpretive case study. This study consisted of
mainly semi-structured interviews that were done with three
different ASPs and customers related to them. It also consisted of a
questionnaire to the customers of one of the service providers. The
analysis was then made as a withincase analysis, consisting of
detailed write-ups for each site. The interviews and a literature
survey of the ASP concept and theories that have been used to
explain the ASP decision-making process generated seven
constructs. From the presented and discussed theories, models and
proposed constructs seven propositions were formulated. These
propositions were used for the analysis and presentation of the
findings in the study. The main conclusion of the study is the
disparate view of what affects the adoption or non-adoption of the
ASP concept. The service providers express the decision as a wish
from the prospective customer to decrease costs and increase the
predictability of costs. The customers on the other hand express it
as a wish to increase accessibility; the cost perspective is found
to be secondary.
No 1094
LANGUAGE MODELLING AND ERROR
HANDLING IN SPOKEN DIALOGUE SYSTEMS
Genevieve
Gorrell
Language modelling for speech recognition is
an area of research currently divided between two main approaches:
stochastic and grammar-based approaches are each being differently
preferred for their respective strengths and weaknesses. At the same
time, dialogue systems researchers are becoming aware of the
potential value of handling recognition failures better to improve
the user experience. This work aims to bring together these two
areas of interest, in investigating how language modelling
approaches can be used to improve the way in which speech
recognition errors are handled.
Three practical ways of
combining approaches to language modelling in spoken dialogue
systems are presented. Firstly, it is demonstrated that a stochastic
language model-based recogniser can be used to detect
out-of-vocabulary material in a grammar-based system with high
precision. Ways in which the technique could be used are
discussed. Then, two approaches to providing users with recognition
failure assistance are described. In the first, poor recognition
results are re-recognised with a stochastic language model, and a
decision tree classifier is then used to select a context-specific
help message. The approach thereby improves on traditional
pproaches, where only general help is provided on recognition
failure. A user study shows that the approach is well-received. The
second differs from the first in its use of layered recognisers and
a modified dialogue, and uses Latent Semantic Analysis for the
classification part of the task. Decision-tree classification
outperforms Latent Semantic Analysis in the work presented here,
though it is suggested that there is the potential to improve LSA
performance such that it may ultimately prove superior.
No 1095
RULE EXTRACTION - THE KEY TO
ACCURATE AND COMPREHENSIBLE DATA MINING MODELS
Ulf
Johansson
The primary goal of predictive modeling is
to achieve high accuracy when the model is applied to novel
data. For certain problems this requires the use of complex
techniques, such as neural networks, resulting in opaque models that
are hard or impossible to interpret. For some domains this is
unacceptable, since the model needs to be comprehensible. To
achieve comprehensibility, accuracy is often sacrificed by using
simpler models; a tradeoff termed the accuracy
vs. comprehensibility tradeoff. In this thesis the tradeoff is
studied in the context of data mining and decision support. The
suggested solution is to transform high-accuracy opaque models into
comprehensible models by applying rule extraction. This approach is
contrasted with standard methods generating transparent models
directly from the data set. Using a number of case studies, it is
shown that the application of rule extraction generally results in
higher accuracy and comprehensibility.
Although several rule
extraction algorithms exist and there are well-established
evaluation criteria (i.e. accuracy, comprehensibility, fidelity,
scalability and generality), no existing algorithm meets all
criteria. To counter this, a novel algorithm for rule extraction,
named GREX (Genetic Rule EXtraction), is suggested. G-REX uses an
extraction strategy based on genetic programming, where the fitness
function directly measures the quality of the extracted model in
terms of accuracy, fidelity and comprehensibility; thus making it
possible to explicitly control the accuracy vs. comprehensibility
tradeoff. To evaluate G-REX, experience is drawn from several case
studies where G-REX has been used to extract rules from different
opaque representations; e.g. neural networks, ensembles and boosted
decision trees. The case
studies fall into two categories; a
data mining problem in the marketing domain which is extensively
studied and several well-known benchmark problems. The results show
that GREX, with its high flexibility regarding the choice of
representation language and inherent ability to handle the accuracy
vs. comprehensibility tradeoff, meets the proposed criteria
well.
No 1099
COMPUTATIONAL MODELS OF SOME
COMMUNICATIVE HEAD MOVEMENTS
Sonia
Sangari
Speech communication involves normally not
only speech but also face and head movements. In the present
investigation the visual correlates to focal accent in read speech
and to confirmation in Swedish are studied and a computational model
for the movements is hypothesized. Focal accent is signalling
“new” information in speech and is signalled by means of
the fundamental frequency manifestation and by prolonged segment
durations. The head movements are recorded by the Qualisys
MacReflex motion tracking system simultaneously with the speech
signal. The results show that head movements that co-occur with the
signalling of focal accent in the speech signal will have the
extreme values at the primary stressed syllable of the word carrying
focal accent independent of the word accent type in Swedish. To be
noted is that focal accent in Swedish will have the fundamental
frequency manifestation in words carrying the word accent II at the
secondary stressed vowel. The nodding that is signalling
confirmation is signalled by means of a damped oscillation of the
head. The head movements in both cases may be simulated by a second
order linear system and the different patterns are two of the three
possible solutions to the equations.
No 1110
INTRA-FAMILY INFORMATION FLOW AND
PROSPECTS FOR COMMUNICATION SYSTEMS
Hans
Nässla
Today, information and communication
technology is not only for professional use, but also for private
tasks. In this thesis, the use of such technology for managing
family information flow is investigated. Busy family life today,
with school, work and leisure activites, makes coordination and
synchronisation a burden. In what way cell-phones and Internet
provides a support for those tasks is investigated, together with
proposals for future technology.
The problem with coordination
and synchronisation were found to be managed by a bulletin board
placed at a central point at home. Besides the bulletin board, we
found that calendars, shopping lists, and to-do lists are
important. The families we investigated in field studies were all
intensive users of both Internet and cell-phones.
Since the
bulletin board played such an important role in the family life, we
equipped families with cameras to be able to track what happened at
those places with help of photo diaries. The field studies revealed
that each family had their own unconscious procedure to manage the
flow of notes on the bulletin board.
With technology, new
problem will emerge. We investigated how notes on typical family
bulletin boards may be visualised on a computer screen, and compared
click-expand, zoompan and bifocal interfaces. The click-expand
interface was substantially faster for browsing, and also easier to
use.
An advantage of information and communication technology
is that it may provide possibilities for multiple interfaces to
information, and not only different terminals but also from
different places. At home, a digital refrigerator door or a mobile
web tablet; at work or at school, a conventional computer; when on
the move, a cell-phone or a PDA. System architecture for these
possibilities is presented.
No 1116
ON THE VALUE OF CUSTOMER LOYALTY
PROGRAMS - A STUDY OF POINT PROGRAMS AND SWITCHING COSTS
Henrik Sällberg
The increased prevalence
of customer loyalty programs has been followed by an increased
academic interest in such schemes. This is partly because the
Internet has made competition ‘one click away’. It is
also because information technology has made it more economical for
firms to collect customer information by way of loyalty
programs. Point programs are a type of loyalty program where
firms’ reward customers for repeat purchases or sum spent in
order to induce switching costs on them. Researchers have paid
attention to how to measure the value of such schemes. Previous
research indicates disparity of what determines the value of point
programs.
The main aim of this thesis is to explore dimensions
of point programs and analyse these dimensions in regards to loyalty
program value. A particular aim is to discuss and define the
concepts customer loyalty and customer loyalty program. A better
understanding of these concepts are necessary in order to be able to
better understand what determines loyalty program value.
Six
dimensions of point programs are explored; value of choice, reward
valuation, alliances, consumer arbitrage, non-linearity and the
principal-agent relation. A theoretical model of loyalty program
value to the firm is developed. In the model, loyalty program value
is a function of the following parameters; the customer’s
subjective value of rewards, the customers subjective best
alternative forgone, the firm’s marginal cost of producing
rewards and the firm’s ability to exploit customer switching
costs induced.
The most interesting findings from analysing
the dimensions are: a) researchers seem to not have distinguished
between the non-linearity of point functions and the non-linearity
of the reward function of point programs. I suggest that the
non-linearity of the reward function does not necessarily have to
depend on the non-linearity of the point function; b) Previous
research points out that customers cash value of rewards depend on
the number of reward alternatives (value of choice). I also suggest
that how multidimensional and demand inelastic each reward is impact
on customer’s value of choice in point programs; c) I also
propose that principal-agent relations and consumer arbitrage may
impact on firm’s ability to utilize customer switching cost in
terms of raising price. Generally, raising price has been suggested
as the firm strategy to utilize customer switching cost. I propose
that firms may not want to charge higher prices from loyal customers
and that one important value of
customer-lock in might be
reduced uncertainty of future cash flows.
No FiF-a 77
DESIGNARBETE I DIALOG -
KARAKTÄRISERING AV INTERAKTIONEN MELLAN ANVÄNDARE OCH
UTVECKLARE I EN SYSTEMUTVECKLINGSPROCESS
Ulf
Larsson
Att utveckla IT-system handlar inte enbart
om en teknikinriktad utveckling utan innebär att transformera
och förändra verksamhetskommunikation för
aktörer inom en yrkesroll. Utveckling och införande av
IT-systemet i verksamheten innebär att verksamheten
förändras. Detta har föranlett modern
systemutveckling att på olika sätt inkludera ett aktivt
deltagande från framtida användare av systemet. Det har
även bedrivits forskning kring användares medverkan i
systemutveckling vilket gett upphov till bl.a. metodutveckling. Men
relativt lite forskningsfokus har lagts på studier av hur
användare och utvecklare interagerar under
systemutvecklingsarbetet.
Min avhandling är en induktiv
studie av dialogen mellan aktörerna i
systemutvecklingsprocessen, och mer specifikt söker jag i min
analys ta fram faktorer i interaktionen som har positiv
påverkan på designarbetet. Underlag för att
studera denna interaktion mellan systemutvecklare och användare
i IT-design, utgörs av ett antal videoinspelade möten
mellan aktörer i ett systemutvecklingsprojekt för journal-
och ärendehantering inom äldreomsorg. Projektet har
bedrivits på s k aktionsforskningsbasis där forskare
från Linköpings universitet har samverkat med en enhet
för äldreomsorg inom en mellansvensk kommun. I denna
IT-utveckling agerade forskare i rollen som
systemutvecklare. Deltagarna från den kommunala omsorgsenheten
representerade användarna av systemet, vårdbiträden
och föreståndare.
Resultatet av min analys av ett
antal samtalssekvenser ur dessa möten kallar jag
designbefrämjande karaktäristika på dialogen mellan
aktörerna. Några av dessa karaktäristika som
frilagts genom analysen är: utnyttjande och syntetiserande av
olika yrkeskunskaper; sökande efter problemlösning genom
att ställa frågor; användning av
verksamhetspraktikens språk; reflektion med
verksamhetserfarenhet som grund; utveckling av
samförstånd; och återfokusering på diskursens
tema. Resultatet har jag sedan relaterat till principer för
dialoger.
No 1126
CONTRIBUTIONS TO MANAGEMENT AND
VALIDATION OF NON-FUNCTIONAL REQUIREMENTS
Andreas Borg
Non-functional requirements (NFRs) are essential
when considering software quality in that they shall represent the
right quality of the intended software. It is generally hard to get
hold of NFRs and to specify them in measurable terms, and most
software development methods applied today focus on functional
requirements (FRs). Moreover, NFRs are relatively unexplored in the
literature and knowledge regarding real-world treatment of NFRs is
particularly rare.
A case study and a literature survey were
performed to provide this kind of knowledge, which also served as a
problem inventory to outline future research activities. An
interview series with practitioners at two large software
development organizations was carried out. As a major result, it was
established that too few NFRs are considered in development and that
they are stated in vague terms. Moreover, it was observed that
organizational power structures strongly influence the quality of
the forthcoming software, and that processes need to be well suited
for dealing with NFRs.
It was selected among several options
to explore how processes can be better suited to handle NFRs by
adding the information of actual feature use. A case study was
performed in which the feature use of an interactive product
management tool was measured indirectly from log files of an
industrial user, and the approach was also applied to the problem of
requirements selection. The results showed that the idea is feasible
and that quality aspects can be effectively addressed by considering
actual feature use.
An agenda for continued research
comprises: further studies in system usage data acquisition,
modelling of NFRs, and comparing means for predicting feasibility of
NFRs. One strong candidate is weaving high-level requirement models
with models of available components.
No 1127
LARGE VOCABULARY SHORTHAND WRITING
ON STYLUS KEYBOARD
Per-Ola Kristensson
We present a novel text entry method for pen-based computers. We
view the trace obtained by connecting the letter keys comprising a
word on a stylus keyboard as a pattern. This pattern can be matched
against a user’s pen trace, invariant of scale and
translation. Hence the patterns become an efficient form of
shorthand gestures, allowing users to use eyes-free openloop motor
actions to perform the gestures. This can result in higher text
entry speed than optimized stylus keyboards, the fastest known text
entry technique for pen-computers as of today. The approach supports
a gradual and seamless skill transition from novices tracing the
letter keys to experts articulating the shorthand gestures. Hence
the ratio between the learning effort and efficiency in using the
system can be said to be optimized at any given point in time
in the user’s experience with the technique. This thesis
describes the rationale, architecture and algorithms behind a stylus
keyboard augmented with a high-capacity gesture recognition
engine. We also report results from an Expanding Rehearsal Interval
(ERI) experiment which indicates that users can acquire about 15
shorthand gestures per 45 minute training session. Empirical expert
speed estimates of the technique indicate text entry speeds much
higher than any prior known pen-based text entry system for mobile
computers.
No 1130
SAFETY-ORIENTED COMMUNICATION IN
MOBILE NETWORKS FOR VEHICLES
Ioan Chisalita
Accident statistics indicate that every year a large number of
casualties and extensive property losses are recorded due to traffic
accidents. Consequently, efforts are directed towards developing
passive and active safety systems that help reducing the severity of
crashes or prevent vehicles to collide with each other. Within the
development of these systems, technologies such as sensor systems,
computer vision and vehicular communication are considered of
importance. Vehicular communication is defined as the exchange of data
between vehicles, and is considered a key technology for traffic
safety due to its ability to provide the vehicles with information
that cannot be acquired using other means (e.g. radar and video
systems). However, due to the current early stage in the development
of in-vehicle safety systems, the applicability of communication for
improving traffic safety is still an open issue. Furthermore, due to
the specificity of the environment in which
vehicles travel, the
design of communication systems that provide an efficient exchange of
safety-related data between vehicles poses a series of major technical
challenges.
In this thesis we focus on the development of a
communication system that provides support for in-vehicle active
safety systems such as collision warning and collision avoidance.
We begin by studying the applicability of communication for
supporting the development of effective active safety systems. Within
our study, we investigate different safety aspects of traffic
situations. For performing such investigations we develop ECAM, a
temporal reasoning system for modeling and analyzing accident
scenarios. This system gives us the possibility of analyzing
relations between events that occur in traffic and their possible
consequences. We use ECAM for analyzing the degree of accident
prevention that can be achieved by applying crash countermeasures
based on communication in specific traffic scenarios.
By
acknowledging the potential of communication for traffic safety, we
further focus in the thesis on the design of a safety-oriented
vehicular communication system. We propose a new solution for
vehicular communication in the form of a distributed communication
protocol that allows the vehicles to organize the network in an ad-hoc
decentralized manner. For disseminating information, we develop an
anonymous contextbased broadcast protocol that requires the receivers
to determine whether they are the intended destination of sent
messages based on knowledge about their momentary situation in
traffic. We further design a vehicular communication platform that
provides an implementation framework for the communication system, and
integrates it within a vehicle. Investigations of the communication
performances, which evaluate metrics such as transmission delay, send
errors, packet collisions and information filtering, indicate that the
proposed vehicular communication system is able to provide a reliable
and timely exchange of data between vehicles.
No 1132
INTERACTING WITH COMMAND AND
CONTROL SYSTEMS: TOOLS FOR OPERATORS AND DESIGNERS
Pär-Anders Albinsson
Command and control
is central in all distributed tactical operations such as rescue
operations and military operations. It takes place in a complex
system of humans and artefacts, striving to reach common goals. The
command and control complexity springs from several sources,
including dynamism, uncertainty, risk, time pressure, feedback
delays and interdependencies. Stemming from this complexity, the
thesis approaches two important and related problem areas in command
and control Research. On a general level, the thesis seeks to
approach the problems facing the command and control operators and
the problems facing the designers in the associated systems
development process.
We investigate the specific problem of
operators losing sight of the overall perspective when working with
large maps in geographical information systems with limited screen
area. To approach this problem, we propose high-precision input
techniques that reduce the need for zooming and panning in
touch-screen systems, and informative unit representations that make
better use of the screen area available. The results from an
experimental study show that the proposed input techniques are as
fast and accurate as state-of-the-art techniques without the need to
resort to zooming. Furthermore, results from a prototype design show
that the proposed unit representation reduces on-screen clutter and
makes use of off-screen units to better exploit the valuable screen
area.
Developing command and control systems is a complex task
with several pitfalls, including getting stuck in exhaustive
analyses and overrated reliance on rational Methods. In this thesis,
we employ a design-oriented research framework that acknowledges
creative and pragmatic ingredients to handle the pitfalls. Our
approach adopts the method of reconstruction and exploration of
mission histories from distributed tactical operations as a means
for command and control analysis. To support explorative analysis of
mission histories within our framework, we propose tools for
communication analysis and tools for managing metadata such as
reflections, questions, hypotheses and expert comments. By using
these tools together with real data from live tactical operations,
we show that they can manage large amounts of data, preserve
contextual data, support navigation within data, make original data
easily accessible, and strengthen the link between metadata and
supporting raw data. Furthermore, we show that by using these tools,
multiple analysts, experts, and researchers can exchange comments on
both data and metadata in a collaborative and explorative
investigation of a complex scenario.
No 1138
MAINTAINING DATA CONSISTENCY IN
EMBEDDED DATABASES FOR VEHICULAR SYSTEMS
Thomas
Gustafsson
The amount of data handled by real-time
and embedded applications is increasing. This calls for
data-centric approaches when designing embedded systems, where data
and its metainformation (e.g., temporal correctness requirements)
are stored centrally. The focus of this thesis is on efficient data
management, especially Maintaining data freshness and guaranteeing
correct age on data.
The contributions of our research are
updating algorithms and concurrency control algorithms using data
similarity. The updating algorithms keep data items up-to-date and
can adapt the number of updates of data items to state changes in
the external environment. Further, the updating algorithms can be
extended with a relevance check allowing for skipping of unnecessary
calculations. The adaptability and skipping of updates have positive
effects on the CPU utilization, and freed CPU resources can be
reallocated to, e.g., more extensive diagnosis of the system. The
proposed multiversion concurrency control algorithms guarantee
calculations reading data that is correlated in time.
Performance evaluations show that updating algorithms with a
relevance check give significantly better performance compared to
well-established updating approaches, i.e., the applications use
more fresh data and are able to complete more tasks in time. The
proposed multiversion concurrency control algorithms perform better
than HP2PL and OCC and can at the same time guarantee correct age on
data items, which HP2PL and OCC cannot guarantee. Thus, from the
perspective of the application, more precise data is used to achieve
a higher data quality overall, while the number of updates is
reduced.
No 1149
A STUDY IN INTEGRATING MULTIPLE
BIOLOGICAL DATA SOURCES
Vaida
Jakoniené
Life scientists often have to
retrieve data from multiple biological data sources to solve their
research problems. Although many data sources are available, they
vary in content, data format, and access methods, which often vastly
complicates the data retrieval process. The user must decide which
data sources to access and in which order, how to retrieve the data
and how to combine the results – in short, the task of
retrieving data requires a great deal of effort and expertise on the
part of the user.
Information integration systems aim to
alleviate these problems by providing a uniform (or even integrated)
interface to biological data sources. The information Integration
systems currently available for biological data sources use
traditional integration approaches. However, biological data and
data sources have unique properties which introduce new challenges,
requiring development of new solutions and approaches.
This
thesis is part of the BioTrifu project, which explores approaches to
integrating multiple biological data sources. First, the thesis
describes properties of biological data sources and existing systems
that enable integrated access to them. Based on the study,
requirements for systems integrating biological data sources are
formulated and the challenges involved in developing such systems
are discussed. Then, the thesis presents a query language and a
highlevel architecture for the BioTrifu system that meet these
requirements. An approach to generating a query plan in the presence
of alternative data sources and ways to integrate the data is then
developed. Finally, the design and implementation of a prototype for
the BioTrifu system are presented.
No 1156
HIGH-LEVEL TECHNIQUES FOR
BUILT-IN SELF-TEST RESOURCES OPTIMIZATION
Abdil Rashid
Mohamed
Design modifications to improve testability
usually introduce large area overhead and performance
egradation. One way to reduce the negative impact associated with
improved testability is to take testability as one of the
constraints during high-level design phases so that systems are not
only optimized for area and performance, but also from the
testability point of view. This thesis deals with the problem of
optimizing testing-hardware resources by taking into account
testability constraints at high-levels of abstraction during the
design process.
Firstly, we have provided an approach to solve
the problem of optimizing built-in selftest (BIST) resources at the
behavioral and register-transfer levels under testability and
testing time constraints. Testing problem identification and BIST
enhancement during the optimization process are assisted by symbolic
testability analysis. Further, concurrent test sessions are
generated, while signature analysis registers’ sharing
conflicts as well as controllability and observability constraints
are considered.
Secondly, we have introduced the problem of
BIST resources insertion and optimization while taking wiring area
into account. Testability improvement transformations have been
defined and deployed in a hardware overhead minimization technique
used during a BIST synthesis process. The technique is guided by the
results of symbolic testability analysis and inserts a minimal
amount of BIST resources into the design to make it fully
testable. It takes into consideration both BIST components cost and
wiring overhead. Two design space exploration approaches have been
proposed: a simulated annealing based algorithm and a greedy
heuristic. Experimental results show that considering wiring area
during BIST synthesis results in smaller final designs as compared
to the cases when the wiring impact is ignored. The greedy
heuristic uses our behavioral and register-transfer levels BIST
enhancement metrics to guide BIST synthesis in such a way that the
number of testability improvement transformations performed on the
design is reduced.
No 1162
CONTRIBUTION TO META-MODELING TOOLS
AND METHODS
Adrian Pop
Highly
integrated domain-specific environments are essential for the
efficient design of complex physical products. However, developing
such design environments is today a resource-consuming error-prone
process that is largely manual. Meta-modeling and meta-programming
are the key to the efficient development of such
environments.
The ultimate goal of our research is the
development of a meta-modeling approach and its associated
metaprogramming methods for the synthesis of model-driven product
design environments that support modeling and simulation. Such
environments include model-editors, compilers, debuggers and
simulators. This thesis presents
several contributions towards
this vision, in the context of the Modelica framework. Thus, we
have first designed a meta-model for the object-oriented declarative
modeling language Modelica, which facilitates the development of
tools for analysis, checking, querying, documentation,
transformation and management of Modelica models. We have used XML
Schema for the representation of the meta-model, namely,
ModelicaXML. Next, we have focused on the automatic composition,
refactoring and transformation of Modelica models. We have extended
the invasive composition environment COMPOST to handle Modelica
models described using ModelicaXML.
The Modelica language
semantics has already been specified in the Relational Meta-Language
(RML), which is an executable meta-programming system based on the
Natural Semantics formalism. Using such a metaprogramming approach
to manipulate ModelicaXML, it is possible to automatically
synthesize a Modelica compiler. However, such a task is difficult
without the support for debugging. To address this issue we have
developed a debugging framework for RML, based on abstract syntax
tree instrumentation in the RML compiler and support of efficient
tools for complex data structures and proof-trees visualization.
Our contributions have been implemented within OpenModelica,
an open-source Modelica framework. The evaluations performed using
several case studies show the efficiency of our meta-modeling tools
and methods.
No 1165
ON THE INFORMATION EXCHANGE
BETWEEN PHYSICIANS AND SOCIAL INSURANCE OFFICERS IN THE SICK LEAVE
PROCESS: AN ACTIVITY THEORETICAL PERSPECTIVE
Fidel
Vascós Palacios
In Sweden, there has been a
substantial increase in the number of people on long-term sick
leave. This phenomenon has awakened the interest of researchers for
understanding its causes. So far, no simple and unambiguous reason
explaining this phenomenon has been found. However, previous studies
indicate that it may be caused by a combination of different aspects
such as the state of the national economy, an ageing labour force in
Sweden, and inefficiencies in the information exchange and
cooperation among the participants in the sick leave process. This
thesis deals with the information exchange between two of these
participants, namely physicians from district health care centres
and insurance officers from the Social Insurance Office.
The
information exchange between these two parties constitutes a
critical aspect in the sick leave process and has been reported in
the scientific literature as having problems. Nevertheless, most of
earlier studies dealing with the interaction between physicians and
officers have been purely descriptive, of quantitative nature and
lack a common theoretical basis for analysing it.
In this
thesis, a philosophical theoretical framework, namely Activity
Theory (AT), is applied to gain understanding into the
interconnection between physicians and insurance officers and the
problems of their information exchange. Based on concepts from AT,
the elements that form the structure of these players’ work
actions are identified and used to provide a picture of the
interconnection between these parties and to uncover some reasons
for the failure in their information exchange. Additionally, an
activity theoretical perspective about how to see the participation
of these players in the sick leave process is provided.
The
analysis in this thesis shows that physicians and insurance officers
form a fragmented division of labour of a common collective
activity: the sick leave process. In this process physicians provide
the officers with a tool of their work: information for
decision-making. Physicians provide this information through the
sickness certificate, which sometimes does not carry the information
necessary for the officers to do their work. This failure is partly
a result of the complexity of the
No 1167
VIRTUAL LEARNING ENVIRONMENTS IN
HIGHER EDUCATION. A STUDY OF STUDENTS´ ACCEPTANCE OF
EDUCATIONAL TECHNOLOGY
Christina Keller
Virtual Learning Environments (VLEs) are fundamental tools for
flexible learning in higher education, used in distance education as
well as a complement to teaching on campus (blended learning). VLEs
imply changing roles for both teachers and students. The general
aim of this thesis is to explore and analyse students’
acceptance of VLEs in a blended learning environment. In the
explorative part of the study data were collected by means of a
questionnaire distributed to students at two schools at
Jönköping University College. Quantitative data were
processed in factor analysis and multiple regression analysis and
additional qualitative data in content analysis. The
conceptual-analytical part of the study aimed at identifying
perspectives that could describe critical and relevant aspects of
the process of implementation and acceptance. Literature from
Organisation Theory, Management and Information Systems Research was
analysed. A retrospective analysis of the explorative findings, by
means of the theoretical framework from the conceptual-analytical
part of the study, focused on explanation of the findings.
This thesis gives rise to three main conclusions. First,
organisational factors seem to have a stronger impact on
students’ acceptance of VLEs in a blended learning environment
than user factors. Second, Implementation models from Information
Systems Research and Organisation Theory contribute to our
understanding of students’ acceptance of VLEs by providing
concepts describing the implementation process on both individual
and organisational level. Third, the theoretical models of Unified
Theory of Acceptance and Use of Technology and Innovation Diffusion
Theory are able to explain differences in students’ acceptance
of VLEs. The Learning Process Perspective obtains concepts to study
the possibilities of learning about the VLE in a formal and informal
way. Finally, a research model for students’ acceptance of
VLEs in a blended learning environment is presented.
No 1168
INTEGRATION OF ORGANIZATIONAL
WORKFLOWS AND THE SEMANTIC WEB
Cécile
Åberg
The Internet and the Web provide an
environment to do business-to-business in a virtual world where
distance is less of an issue. Providers can advertise their products
globally and consumers from all over the world obtain access to
these products. However, the heterogeneous and continually changing
environment leads to several problems related to finding suitable
providers that can satisfy a consumer's needs. The Semantic Web aims
to alleviate these problems.
By allowing software agents to
communicate and understand the information published on the Web, the
Semantic Web enables new ways of doing business and consuming
services. Semantic Web technology will provide an environment where
the comparison of different business contracts will be made in a
matter of minutes, new contractors may be discovered continually and
the organizations' routines may be automatically updated to reflect
new forms of cooperation.
Organizations, however, do not
necessarily use the Semantic Web infrastructure to communicate
internally. Consequently, to be able to gain new advantages from
using Semantic Web technology, this new technology should be
integrated into existing routines.
In this thesis, we
propose a model for integrating the usage of the Semantic Web into
an organization's work routines. We provide a general view of the
model as well as an agentbased view. The central component of the
model is an sButler, a software agent that mediates between the
organization and the Semantic Web. We describe an architecture for
one of the important parts of the sButler, the process instance
generation, and focus on its service retrieval capability. Further,
we show the feasibility of our approach with a prototype
implementation, and discuss an experiment.
No FiF-a 85
STANDARDISERING SOM GRUND
FÖR INFORMATIONSSAMVERKAN OCH IT-TJÄNSTER - EN FALLSTUDIE
BASERAD PÅ TRAFIKINFORMATIONSTJÄNSTEN RDS-TMC
Anders Forsman
I dagens samhälle
ställs allt högre krav på samverkan och
informationsutbyte mellan olika personer, organisationer, och
informationssystem (IS). Detta betyder att utveckling och
användning av IS tenderar att bli allt mer
komplex. Standardisering kan i detta sammanhang spela en viktig roll
för att hantera den ökande komplexiteten, samt för
att underlätta utvecklingen av nya IS och
IT-tjänster. Standardisering i detta sammanhang skapar
förutsättningar för att på ett effektivt
sätt kunna kommunicera information mellan olika personer,
organisationer och IS. Den typ av standarder, som är i fokus i
avhandlingen, innehåller konceptuella beskrivningar av
funktionalitet, meddelandestrukturer och informationsmodeller. I
avhandlingen benämns dessa standarder som
”konceptuella” standarder.
Frågan är
dock om de standarder som utvecklas verkligen bidrar till en
effektivare informationssamverkan, och om utvecklade standarder
verkligen blir implementerade på ett riktigt
sätt. Avhandlingen syftar till att beskriva och skapa
förståelse för hur standarder används i samband
med IS och leverans av IT-tjänster, samt vilka effekter det
ger. Avhandlingen baseras på en fallstudie som genomförts
på Vägverket med fokus på
trafikinformationstjänsten RDS-TMC (Radio Data System -
Traffic Message Chanel).
I avhandlingen identifieras och
karaktäriseras tre olika användningsprocesser,
d.v.s. systemutvecklings-, tjänsteleverans- och
systemförvaltningsprocessen. Det beskrivs också hur
konceptuella standarder används och påverkar dessa
användningsprocesser.
Avhandlingen visar även
på att konceptuella standarder utgör beskrivningar av en
systemarkitektur på konceptuell nivå. Detta innebär
att konceptuella standarder har stor betydelse för
systemutvecklingsprocessen och för IT-strategiska beslut
för de organisationer som berörs av denna typ av
standarder.
Avhandlingen beskriver även hur konceptuella
standarder påverkar den informationssamverkan som sker
mellan olika IS och aktörer i samband med
tjänsteleveransen. Tjänsteleveransen påverkas
av konceptuella standarder genom att standardens beskrivningar
är implementerad i den informationssystemarkitektur (ISA)
som används i samband med tjänsteleveransen. Standarder
påverkar även vilken information som bör skapas och
hur meddelande bör kommuniceras på en instansnivå i
samband med tjänsteleveransen.
No 1171
Yu-Hsinig
Huang
Accident models are essential for all efforts
in safety engineering. They influence the investigation and analysis
of accidents, the assessment of systems and the development of
precautions. Looking at accident statistics, the trend for Swedish
roads is not pointing towards increased safety. Instead, the number
of fatalities and accidents remains stable, and the number of
injuries is increasing. This thesis proposes that this deterioration
of road safety is due to the utilization of inadequate traffic
accident models. The purpose of the thesis is to develop an adequate
traffic accident model. This is done in two steps. The first step is
to identify a proper type of general accident model. The second step
is to adapt the general accident model to road traffic. Two reviews
are made for this purpose. The first review identifies different
categories of accident models. The second review surveys eleven
existing traffic accident models. The results of these surveys
suggest that an adequate accident model for modern road safety
should be based on the systemic accident model. Future work will
focus on the development of a risk assessment method for road
traffic based on the systemic
accident model.
No FiF-a 86
ATT MODELLERA UPPDRAG -
GRUNDER FÖR FÖRSTÅELSE AV PROCESSINRIKTADE
INFORMATIONSSYSTEM I TRANSAKTIONSINTENSIVA VERKSAMHETER
Jan Olausson
Ett informationssystem skall
stödja den verksamhet som det är en del av. Vid
systemutveckling finns det behov av att göra en
verksamhetsanalys för att utveckla kunskap om den nuvarande
verksamheten. Teorier och modeller är viktiga redskap för
att fånga väsentliga aspekter vid en
verksamhetsanalys. Detta arbete syftar till att visa på hur
uppdrag, som en väsentlig aspekt, kan modelleras. I en
verksamhet utför aktörer handlingar. Relationer mellan
aktörer etableras genom uppdrag. Det gäller rolluppdrag
mellan ”chef” och annan aktör, produktuppdrag
mellan aktörer i organisationer såväl som
produktuppdrag mellan organisationen och dess kunder.
Arbetet
har sin utgångspunkt i två aktionsforskningsfall, ett
postorderföretag och ett ehandelsföretag, där
processkartläggningar har genomförts. De verksamheter som
är kartlagda är att betrakta som transaktionsintensiva,
det vill säga verksamheter som hanterar många order och
som har låg marginal per order. Det gör att en
sådan typ av verksamhet är komplex, och beroende av
IT-system. Komplexiteten har ställt krav på att skapa
modeller på olika generaliseringsnivåer (praktik,
process och handling). En verksamhet kan ses som en praktik
bestående av processer som i sin tur byggs upp av
handlingar. Arbetet har resulterat i en teori om att tänka i
uppdrag, samt hur uppdrag kan beskrivas i olika modeller för
att skapa en kongruens mellan teori och modell.
En slutsats
från arbetet är att det krävs en växelverkan,
mellan såväl teorier och metoder som olika
generaliseringsnivåer vid modellering av verksamheter. En
fokusering på uppdrag tydliggör de olika
förväntningar som olika aktörer har. Det skapar
även förutsättning för att utveckla verksamhet
och informationssystem som infriar dessa
förväntningar.
No 1172
AFFÄRSSTRATEGIER FÖR
SENIORBOSTADSMARKNADEN
Petter Ahlström
Den demografiska utvecklingen i Sverige går mot en
befolkningssammansättning med allt högre medelålder.
Enligt svenska befolkningsprognoser kommer nästan var fjärde
svensk år 2025 att vara över 65 år. Den äldre
andelen av befolkningen utgör en välbeställd grupp med
relativt stora realekonomiska tillgångar.
Attitydundersökningar på morgondagens pensionärer
talar för att denna grupp ställer högre krav på
boendeutformning, kringservice, vård och omsorg än tidigare
generationer. Flera studier visar på en ökad
betalningsvilja och betalningsförmåga för alternativa
service- och boendeformer. Samtidigt försöker olika
marknadsaktörer att positionera ett produkt- och
tjänsteutbud inom en bostadsmarknadens nischer, här
definierad som seniorbostadsmarknaden. På
seniorbostadsmarknaden har ett särskilt segment identifierats
där utöver seniorboende även service-, vård- och
omsorgsrelaterade kringtjänster bjuds ut. Mot den bakgrunden har
avhandlingens problemställning formulerats enligt följande:
vad skapar en stark marknadsposition för en aktör på
seniorbostadsmarknaden med integrerad service, vård och
omsorg?
Utgångspunkten har varit ett sannolikt scenario
där privata initiativ i allt större utsträckning kommer
att bidra till framtida boendelösningar riktade till
samhällets seniora och äldrebefolkningsgrupper. Syftet med
avhandlingen har varit dels att identifiera de framgångsfaktorer
som kan antas ligger till grund för en stark marknadsposition,
dels att skapa en typologi över olika
affärsstrategier. Genom en branschanalys har det i avhandlingen
påvisats att seniorbostadsmarknaden är en nischmarknad med
marginell omfattning. Avhandlingens empiriska undersökning har
designats som en fältstudie. Fältstudien har i sin tur bl.a.
genomförts i form av en förstudie och en intervjustudie.
Intervjustudien ägde rum under hösten 2004 med
platsbesök och intervjuer av verksamhetsföreträdare
för elva utvalda fallstudieorganisationer. Utifrån ett
antal i förhand uppställda kriterier har
marknadsaktörernas framgångsfaktorer identifierats. Den
bearbetnings- och analysmodell som konstruerats för detta syfte
och som använts för att analysera fältstudiens empiri
är baserad på studier inom strategiområdet. Modellen
har bl.a. inspirerats av forskare som Miles & Snow (1978), Porter
(1980) och Gupta & Govindarajan (1984). Vidare bygger den på
antagandena om resursers och kompetensers betydelse för
strategiformuleringen. Service management, och då särskilt
tjänsters sammansättning, är ett annat område som
beaktas. Analysmodellen har byggts upp kring fem dimensioner:
omgivning, strategi, resurser, tjänstekoncept och konkurrens. De
identifierade framgångsfaktorerna har baserats på
intervjustudiens två mest framgångsrika aktörer.
Resultatet har formulerats i ett antal strategiska vägval vilka
kan sammanfattas i begreppen: differentiering, fokus, integration,
samverkan, kontroll, verksamhetsutveckling, kärnkompetens och
resurser. I avhandlingen påvisas att aktörer som bedriver
framgångsrik verksamhet på seniorbostadsmarknaden till
stora delar följer det Porter (1980) definierat som en
differentieringsstrategi med fokus. Avhandlingen har också
utmynnat i en affärsstrategisk typologi för
seniorbostadsmarknaden. Dessa tentativa slutsatser har formulerats i
fyra strategiska idealtyper: förvaltare, konceptbyggare,
entreprenörer och idealister.
No 1183
BEYOND IT AND PRODUCTIVITY - HOW
DIGITIZATION TRANSFORMED THE GRAPHIC INDUSTRY
Mathias
Cöster
This thesis examines how IT and the
digitization of information have transformed processes of the
graphic industry. The aim is to show how critical production
processes have changed when information in these processes have been
digitized. Furthermore it considers if this has influenced changes
in productivity while also identifying other significant benefits
that have occurred as a result of the digitization. The debate
concerning the productivity paradox is one important starting point
for the thesis. Previous research on this phenomenon has mainly used
different types of statistical databases as empirical sources. In
this thesis though, the graphic industry is instead studied from a
mainly qualitative and historical process perspective.
The
empirical study shows that digitization of information flows in the
graphic industry began in the 1970s, but the start of the
development and use of digitized information happened in the early
1980s. Today almost all types of materials in the industry, for
example text and pictures, have developed into a digital form and
the information flows are hereby more or less totally digitized. A
common demand in the industry is that information produced should be
adaptable to the different channels in which it may be
presented. The consequences from use of IT and the digitization of
information flows are identified in this thesis as different
outcomes, effects, and benefits. The outcomes are identified
directly from the empirical material, whilst the resulting effects
are generated based on theories about IT and business value. The
benefits are in turn generated from a summarization of the
identified effects.
Identified effects caused by IT and
digitization of information include integration and merging of
processes; vanishing professions; reduced number of operators
involved; decreased production time; increased production capacity;
increased amount and quality of communication; and increased quality
in produced originals. One conclusion drawn from the analysis is
that investments and use of IT have positively influenced changes in
productivity. The conclusion is based on the appearance of different
automational effects, which in turn have had a positive influence on
factors that may be a part of a productivity index. In addition to
productivity other benefits, based on mainly informational effects,
are identified. These benefits include increased capacity to handle
and produce information, increased integration of customers in the
production processes, increased physical quality in produced
products, and options for management improvements in the production
processes. The conclusions indicate that it is not always the most
obvious benefit, such as productivity, that is of greatest
significance when IT is implemented in an industry.
No 1184
BEYOND IT AND PRODUCTIVITY -
EFFECTS OF DIGITIZED INFORMATION FLOWS IN GROCERY DISTRIBUTION
Åsa Horzella
During the last decades
organizations have made large investments in Information Technology
(IT). The effects of these investments have been studied in business
and academic communities over the years. A large amount of research
has been conducted on the relation between the investments in IT and
productivity growth. Researchers have however found it difficult to
present a clear-cut answer; an inability defined as the productivity
paradox.
Within the Impact of IT on Productivity (ITOP) research
program the relevance of the productivity measure as an indicator of
the value of IT is questionned. IT has over the years replaced
physical interfaces with digital and in this way enabled new ways to
process information. A retrospective research approach is therefore
applied where the effects of digitized information flows are studied
within specific organizational settings.
In this thesis the
effects of digitized information flows within Swedish grocery
distribution are studied. A comprehensive presentation of the
development is first conducted and three focal areas are thereafter
presented. The study identifies a number of effects from the
digitization of information flows. The effects are analyzed according
to a predefined analytical framework. The effects are divided into
five categories and are thereafter evaluated when it comes to
potential for generating value.
The study shows that the
digitization of information flows has generated numerous, multifaceted
effects. Automational, informational, transformational, consumer
surplus and other effects are observed. They are difficult to evaluate
using a single indicator. Specific indicators that are closely
related to the effects can however be defined. The study also
concludes that the productivity measure does not capture all positive
effects generated by digitized information flows.
No 1185
BEYOND IT AND PRODUCTIVITY -
EFFECTS OF DIGITIZED INFORMATION FLOWS IN THE LOGGING INDUSTRY
Maria Kollberg
The IT and productivity
paradox has been the subject of considerable research in recent
decades. Many previous studies, based mainly on macroeconomic
statistics or on aggregated company data, have reached disparate
conclusions. Consequently, the question whether IT investments
contribute to productivity growth is still heavily debated. More
recent research, however, has indicated that IT contributes
positively to economic development but that this contribution is not
fully revealed when only productivity is measured.
To explore
the issue of IT and productivity further, the ITOP (Impact of IT On
Productivity) research program was launched in 2003. An alternative
research approach is developed with the emphasis on the
microeconomic level and information flows in processes in specific
industry segments. In the empirical study, the development of
information flows is tracked over several decades. Effects of
digitized information flows are hereby identified and quantified in
order to determine their importance in terms of productivity.
The purpose of this study is to explore effects of information
technology by studying digitized information flows in key processes
in the logging industry. The research shows that several information
flows in the logging process have been digitized leading to new ways
to capture, use, spread, process, refine and access information
throughout the logging process. A large variety of effects have also
been identified from this development.
The results show that
only a minor part of the effects identified have a direct impact on
productivity and thus that a large number of significant effects do
not. Effects with a major direct impact on productivity include
increased efficiency in timber measurement registration, lower costs
of timber accounting and increased utilization of harvesters and
forest resources. Other significant effects with no direct impact on
productivity are related to a more open timber market, increased
timber customization, control, decisionmaking and access to
information, as well as skill levels and innovation. The results
thus demonstrate that it is questionable whether conventional
productivity measures are sufficient for measuring the impact of
IT.
No 1190
ROLE AND IDENTITY – EXPERIENCE
OF TECHNOLOGY IN PROFESSIONAL SETTINGS
David
Dinka
In order to make technology easier to handle for
its users, the field of Human-Computer Interaction is increasingly
dependent on an understanding of the individual user and the context
of use. By investigating the relation between the user and the
technology, this thesis explores how roles and professional identity
affect and interact with the design, use and views of the technology
used.
By studies in two different domains, involving clinical
medicine and media production respectively, professional identities
were related to attitudes towards technology and ways of using
computer-based tools. In the clinical setting, neurosurgeons and
physicists using the Leksell GammaKnife for neurosurgical dose
planning were studied. In the media setting, the introduction of new
media technology to journalists was in focus. The data collection
includes interviews, observations and participatory design oriented
workshops. The data collected were analyzed with qualitative methods
inspired by grounded theory.
In the study of the Leksell
GammaKnife two different approaches towards the work, the tool and
development activities were identified depending on the professional
identity. Depending on if the user was a neurosurgeon or a
physicist, the user's identity or professional background has a
significant impact both on how he or she views his or her role in
the clinical setting, and on how he or she defines what improvements
are necessary and general safety issues. In the case of the media
production tool, the study involved a participatory design
development process. Here it was shown that both the identities and
the roles possessed by individual participants affect how they want
to use new technology for different tasks.
No 1191
INCREASING THE STORAGE CAPACITY OF
RECURSIVE AUTOASSOCIATIVE MEMORY BY SEGMENTING DATA
Andreas Hansson
Recursive Auto-associative
Memory (RAAM) has been proposed as a connectionist solution for all
structured representations. However, it fails to scale up to
representing long sequences of data. In order to overcome this, a
number of different architectures and representations have been
proposed. It is here argued that part of the problem of, and
solution to, storing long sequences in RAAM is data
representation. It is proposed that by dividing the sequences to be
stored into smaller segments that are individually compressed the
problem of storing long sequences is reduced.
This licentiate
thesis investigates which different strategies there are for
segmenting the sequences. Several segmentation strategies are
identified and organized into a taxonomy. Also, a number of
experiments based on the identified segmentation strategies that
aims to clarify if, and how, segmentation affect the storage
capacity of RAAM are performed. The results of the experiments show
that the probability that a sequence of a specific length stored in
RAAM can be correctly recalled is increased by up to 30% when
dividing the sequence into segments. The performance increase is
explained by that segmentation reduces the depth at which a symbol
is encoded in RAAM which reduces a cumulative error effect during
decoding of the symbols.
No 1192
TOWARDS DETACHED COMMUNICATION FOR
ROBOT COOPERATION
Nicklas Bergfeldt
This
licentiate thesis deals with communication among cooperating mobile
robots. Up until recently, most robotics research has focused on
developing single robots that should accomplish a certain task. Now,
it looks like we have come to a point where the need for multiple,
cooperating robots is increasing since there are certain things that
simply are not possible to do with a single robot. The major
reasons, as described in this thesis, that make the use of multiple
robots particularly interesting are distribution (it may be
impossible to be in two places at the same time),
parallelism (major speed improvements can be achieved by
using many robots simultaneously), and simplicity (several,
individually simpler, robots might be more feasible than a single,
more complex robot). The field of cooperative robotics is
multi-faceted, integrating a number of distinct fields such as
social sciences, life sciences, and engineering. As a consequence
of this, there are several sub-areas within cooperative robotics
that can be identified and these are subsequently described here as
well. To achieve coordinated behaviour within a multi-robot team
communication can be used to ease the necessity of individual
sensing (because of, for instance, calculation complexity), and with
respect to this two different explicit approaches have been
identified. As the survey presented here shows, the first of these
approaches has already been extensively investigated, whereas the
amount of research covering the second approach within the domain of
adaptive multi-robot systems has been very limited. This second path
is chosen and preliminary experiments are presented that indicate
the usefulness of more complex representations to accomplish
cooperation. More specifically, this licentiate thesis presents
initial experiments that will serve as a starting point where the
role and relevance of the ability to communicate using detached
representations in planning and communication about future actions
and events will be studied. Here, an unsupervised classifier is
found to have the basic characteristics needed to initiate future
investigations. Furthermore, two projects are presented that in
particular serve to support future research; a robot simulator and
an extension turret for remote control and monitoring of a physical,
mobile robot. Detailed descriptions of planned future investigations
are also discussed for the subsequent PhD work.
No. 1194
TOWARDS DEPENDABLE VIRTUAL
COMPANIONS FOR LATER LIFE
Dennis Maciuszek
When we grow older, we become more vulnerable to certain reductions
in quality of life. Caregivers can help, however human care is
limited, and will become even scarcer in the near future. This
thesis addresses the problem by contributing to the development of
electronic assistive technology, which has the potential of
effectively complementing human support. In particular, we follow
the vision of a virtual companion for later life – an
interactive computer-based entity capable of assisting its elderly
user in multiple situations in everyday life.
Older adults will
only benefit from such technology if they can depend on it and it
does not intrude into their lives against their will. Assuming a
software engineering view on electronic assistive technology, this
thesis thus formulates both dependability requirements and ethical
guidelines for designing virtual companions and related technology
(such as smart homes).
By means of an iterative development
process (the thesis covers the first iteration), a component-based
design framework for defining dependable virtual companions is
formed. Personalised applications can be generated efficiently by
instantiating our generic architecture with a number of
special-purpose interactive software agents. Scenario-based
evaluation of a prototype confirmed the basic concepts of the
framework, and led to refinements.
The final part of the thesis
concerns the actual framework components and the applications that
can be generated from them. From a field study with elders and
experts, we construct a functional design space of electronic
assistive technology applications. It relates important needs of
different older people to appropriate patterns of assistance. As an
example application, the feasibility of driving support by vehicular
communication is studied in depth.
Future iterations with
real-world experiments will refine our design framework further. If
it is found to scale to the dynamic diversity of older adults, then
work can begin on the ultimate project goal: a toolkit on the basis
of the framework that will allow semi-automatic generation of
personalised virtual companions with the involvement of users,
caregivers, and experts.
No 1204
DECISION-MAKING IN THE REQUIREMENTS
ENGINEERING PROCESS: A HUMAN-CENTRED APPROACH
Beatrice
Alenljung
Complex decision-making is a prominent aspect
of requirements engineering and the need for improved decision
support for requirements engineers has been identified by a number
of authors. A first step toward better decision support in
requirements engineering is to understand decision-makers’
complex decision situations. To gain a holistic perspective of the
decision situation from a decision-makers perspective, a decision
situation framework has been created. The framework evolved through
a literature analysis of decision support systems and
decision-making theories. The decision situation of requirements
engineers has been studied at Ericsson Microwave Systems and is
described in this thesis. Aspects of decision situations are
decision matters, decision-making activities, and decision
processes. Another aspect of decision situations is the factors
that affect the decision-maker. A number of interrelated factors
have been identified. Each factor consists of problems and these are
related to decision-making theories. The consequences of this for
requirements engineering decision support, represented as a list
that consists of desirable high-level characteristics, are also
discussed.
No 1206
SYSTEM-ON-CHIP TEST SCHEDULING AND
TEST INFRASTRUCTURE DESIGN
Anders Larsson
There are several challenges that have to be considered in order to
reduce the cost of System-on-Chip (SoC) testing, such as test
application time, chip area overhead due to hardware introduced to
enhance the testing, and the price of the test equipment.
In
this thesis the test application time and the test infrastructure
hardware overhead of multiple-core SoCs are considered and two
different problems are addressed. First, a technique that makes use
of the existing bus structure on the chip for transporting test data
is proposed. Additional buffers are inserted at each core to allow
test application to the cores and test data transportation over the
bus to be performed asynchronously. The non-synchronization of test
data transportation and test application makes it possible to
perform concurrent testing of cores while test data is transported
in a sequence. A test controller is introduced, which is responsible
for the invocation of test transportations on the bus. The hardware
cost, introduced by the buffers and test controller, is minimized
under a designer-specified test time constraint. This problem has
been solved optimally by using a Constraint Logic Programming
formulation, and a tabu search based heuristic has also been
implemented to generate quickly near-optimal solutions.
Second,
a technique to broadcast tests to several cores is proposed, and the
possibility to use overlapping test vectors from different tests in
a SoC is explored. The overlapping tests serve as alternatives to
the original, dedicated, tests for the individual cores and, if
selected,they are broadcasted to the cores so that several cores are
tested concurrently. This technique allows the existing bus
structure to be reused; however, dedicated test buses can also be
introduced in order to reduce the test time. Our objective is to
minimize the test application time while a designer-specified
hardware constraint is satisfied. Again Constraint Logic Programming
has been used to solve the problem optimally.
Experiments using
benchmark designs have been carried out to demonstrate the
usefulness and efficiency of the proposed techniques.
No 1207
POLICY AND IMPLEMENTATION ASSURANCE
FOR SOFTWARE SECURITY
John Wilander
To
build more secure software, accurate and consistent security
requirements must be specified. We have investigated current
practice by doing a field study of eleven requirement specifications
on IT systems. The overall conclusion is that security requirements
are poorly specified due to three things: inconsistency in the
selection of requirements, inconsistency in level of detail, and
almost no requirements on standard security solutions.
To build
more secure software we specifically need assurance requirements on
code. A way to achieve implementation assurance is to use effective
methods and tools that solve or warn for known vulnerability types
in code. We have investigated the effectiveness of four publicly
available tools for run-time prevention of buffer overflow
attacks. Our comparison shows that the best tool is effective
against only 50 % of the attacks and there are six attack forms
which none of the tools can handle. We have also investigated the
effectiveness of five publicly available compile-time intrusion
prevention tools. The test results show high rates of false
positives for the tools building on lexical analysis and low rates
of true positives for the tools building on syntactical and
semantical analysis.
As a first step toward a more effective
and generic solution we propose dependence graphs decorated with
type and range information as a way of modeling and pattern matching
security properties of code. These models can be used to
characterize both good and bad programming practice. They can also
be used to visually explain code properties to the programmer.
No 1209
Andreas
Käll
ÖVERSÄTTNINGAR AV EN
MANAGEMENTMODELL - EN STUDIE AV INFÖRANDET AV BALANCED
SCORECARD I ETT LANDSTING
Ekonomistyrningsområdet har till
viss del förändrats i takt med nyare teknik, plattare
organisationer och ökad konkurrens. Nya tekniker har
introducerats som svar på förändringen. Dessa har
många gånger fått akronymer och vissa har som
produkter marknadsförts, lanserats och spritt sig över
världen. Innehållet i dessa modeller kan dock variera
då de har förts in i olika organisationer. Studiens
övergripande syfte är att förstå hur modeller
medvetet och omedvetet omformas då de börjar
användas i en organisation. Studien använder sig av en
fallstudieansats, där fallet utgörs av ett landsting i
Sverige som tar emot och formar Balanced Scorecard. Ett
översättningsperspektiv har i studien använts till
att förstå vad som sker då ett verktyg, vars delar
är mer eller mindre tolkningsbara, förs in och formas av
organisationens olika aktörer genom en serie av
förhandlingar. Inledningsvis studeras utvecklingen av BSC,
vilket visar att konceptet inte är homogent utan har
översatts till olika varianter då modellen har kommit
till nya miljöer och nya organisationer. Införandet av BSC
i organisationen beskrivs för att sedan analyseras
utifrån översättningsperspektivet. Analysen pekar
på flera aspekter som påverkat
översättningsprocessen och i förlängningen
modellens slutliga utseende, bl.a. hur och i vilket form BSC kom in
i organisationen, vilka aktörer som på ett tidigt stadium
engagerade sig i modellens utveckling, vilka problem modellen
initialt skulle lösa samt hur pass väl tekniska element
lyckats stabilisera dess tänkta användning.
No 1225
He Tan
ALIGNING
AND MERGING BIOMEDICAL ONTOLOGIES
Due to the explosion of the
amount of biomedical data, knowledge and tools that are often
publicly available over the Web, a number of difficulties are
experienced by biomedical researchers. For instance, it is difficult
to find, retrieve and integrate information that is relevant to
their research tasks. Ontologies and the vision of a Semantic Web
for life sciences alleviate these difficulties. In recent years
many biomedical ontologies have been developed and many of these
ontologies contain overlapping information. To be able to use
multiple ontologies they have to be aligned or merged. A number of
systems have been developed for aligning and merging ontologies and
various alignment strategies are used in these systems. However,
there are no general methods to support building such tools, and
there exist very few evaluations of these strategies. In this thesis
we give an overview of the existing systems. We propose a general
framework for aligning and merging ontologies. Most existing systems
can be seen as instantiations of this framework. Further, we develop
SAMBO (System for Aligning and Merging Biomedical Ontologies)
according to this framework. We implement different alignment
strategies and their combinations, and evaluate them in terms of
quality and processing time within SAMBO. We also compare SAMBO with
two other systems. The work in this thesis is a first step towards
a general framework that can be used for comparative evaluations of
alignment strategies and their combinations.
No 1228
DESCRIPTIVE TYPES FOR XML QUERY
LANGUAGE XCERPT
Artur Wilk
The thesis
presents a type system for a substantial fragment of XML query
language Xcerpt. The system is descriptive; the types associated
with Xcerpt constructs are sets of data terms and approximate the
semantics of the constructs. A formalism of Type Definitions,
related to XML schema languages, is adopted to specify such
sets. The type system is presented as typing rules which provide a
basis for type inference and type checking algorithms, used in a
prototype implementation. Correctness of the type system wrt.the
formal semantics of Xcerpt is proved and exactness of the result
types inferred by the system is discussed. The usefulness of the
approach is illustrated by example runs of the prototype on Xcerpt
programs.
Given a non-recursive Xcerpt program and types of
data to be queried, the type system is able to infer a type of
results of the program. If additionally a type specification of
program results is given, the system is able to prove type
correctness of a (possibly recursive) program. Type correctness
means that the program produces results of the given type whenever
it is applied to data of the given type. Non existence of a
correctness proof suggests that the program may be incorrect. Under
certain conditions (on the program and on the type specification),
the program is actually incorrect whenever the proof attempt
fails.
No 1229
SAMPLING-BASED PATH PLANNING FOR AN
AUTONOMOUS HELICOPTER
Per Olof Pettersson
Many of the applications that have been proposed for future small
unmanned aerial vehicles (UAVs) are at low altitude in areas with
many obstacles. A vital component for successful navigation in such
environments is a path planner that can .nd collision free paths for
the UAV. Two popular path planning algorithms are the probabilistic
roadmap algorithm (PRM) and the rapidly-exploring random tree
algorithm (RRT). Adaptations of these algorithms to an unmanned
autonomous helicopter are presented in this thesis, together with a
number of extensions for handling constraints at di.erent stages of
the planning process. The result of this work is twofold: First, the
described planners and extensions have been implemented and
integrated into the software architecture of a UAV. A number of
.ight tests with these algorithms have been performed on a physical
helicopter and the results from some of them are presented in this
thesis. Second, an empirical study has been conducted, comparing the
performance of the di.erent algorithms and extensions in this
planning domain. It is shown that with the environment known in
advance, the PRM algorithm generally performs better than the RRT
algorithm due to its precompiled roadmaps, but that the latter is
also usable as long as the environment is not too complex. The study
also shows that simple geometric constraints can be added in the
runtime phase of the PRM algorithm, without a big impact on
performance. It is also shown that postponing the motion constraints
to the runtime phase can improve the performance of the planner in
some cases.
No 1231
ADAPTIVE REAL-TIME ANOMALY DETECTION
FOR SAFEGUARDING CRITICAL NETWORKS
Kalle
Burbeck
Critical networks require defence in depth
incorporating many different security technologies including
intrusion detection. One important intrusion detection approach is
called anomaly detection where normal (good) behaviour of users of
the protected system is modelled, often using machine learning or
data mining techniques. During detection new data is matched against
the normality model, and deviations are marked as anomalies. Since
no knowledge of attacks is needed to train the normality model,
anomaly detection may detect previously unknown attacks.
In this
thesis we present ADWICE (Anomaly Detection With fast Incremental
Clustering) and evaluate it in IP networks. ADWICE has the following
properties:
(i) Adaptation - Rather than making use of extensive
periodic retraining sessions on stored off-line data to handle
changes, ADWICE is fully incremental making very flexible on-line
training of the model possible without destroying what is already
learnt. When subsets of the model are not useful anymore, those
clusters can be forgotten.
(ii) Performance - ADWICE is linear
in the number of input data thereby heavily reducing training time
compared to alternative clustering algorithms. Training time as well
as detection time is further reduced by the use of an integrated
search-index.
(iii) Scalability - Rather than keeping all data
in memory, only compact cluster summaries are used. The linear time
complexity also improves scalability of training.
We have
implemented ADWICE and integrated the algorithm in a software agent.
The agent is a part of the Safeguard agent architecture, developed
to perform network monitoring, intrusion detection and correlation
as well as recovery. We have also applied ADWICE to publicly
available network data to compare our approach to related works with
similar approaches. The evaluation resulted in a high detection rate
at reasonable false positives rate.
No 1233
IMPLEMENTATION METHODOLOGY IN ACTION
A STUDY OF AN ENTERPRISE SYSTEMS IMPLEMENTATION METHODOLOGY
Daniela Mihailescu
Enterprise Systems create
new opportunities but also new challenges and difficulties for
implementers and users. The clear distinction between the
development and the implementation of Enterprise Systems Software
seems to influence not only the characteristics of methodologies but
also how implementers use the Enterprise Systems implementation
methodologies. The general aim of this thesis is to study an
Enterprise Systems implementation methodology, SAP’s
AcceleratedSAP implementation methodology.
An exploratory case
research approach is employed and is initiated with the development
of a framework which integrates current views on Method in Action
and Information Systems Development with insights from Enterprise
Systems research. The theoretically grounded framework outlines the
characteristics of the implementation methodology recommended by SAP
and used by implementers in Enterprise Systems implementations. The
framework is enhanced by an empirical study.
Findings add a
number of insights to the body of knowledge in the Information
Systems field and the Enterprise Systems implementation
methodology. For example, the Implementation
Methodology in Action framework developed in this
study outlines a set of components which influence the use
of an implementation methodology, and implementers’ actions
which occur through the use of an implementation methodology. The
components have varying characteristics and exert a significant
influence on the effectiveness of implementation methodology use,
which may explain differences in implementers’ actions and
consequently in the outcomes of the Enterprise Systems
implementation processes. The notion of implementation
methodology in action, as articulated in this study, integrates
two complementary views, i.e. a technology view focusing on a
formalised aspect and a structural view focusing a situational
aspect, emphasising different features of the implementation
methodology.
No 1244
PUBLIC AND NON-PUBLIC GIFTING ON
THE INTERNET
Jörgen Skågeby
This
thesis contributes to the knowledge of how computer-mediated
communication and information sharing works in large groups and
networks. In more detail, the research question put forward is: in
large sharing networks, what concerns do end-users have regarding to
whom to provide material? A theoretical framework of gift-giving was
applied to identify, label and classify qualitative end-user
concerns with provision. The data collection was performed through
online ethnographical research methods in two large sharing
networks, one music-oriented and one photo-oriented. The methods
included forum message elicitation, online interviews, application
use and observation. The result of the data collection was a total
of 1360 relevant forum messages. A part from this there are also 27
informal interview logs, field notes and samples of user profiles
and sharing policies. The qualitative analysis led up to a model of
relationships based on the observation that many users experienced
conflicts of interest between various groups of receivers and that
these conflicts, or social dilemmas, evoked concerns regarding
public and non-public provision of material. The groups of potential
recipients were often at different relationship levels. The levels
ranged from the individual (ego), to the small group of close peers
(micro), to a larger network of acquaintances (meso) to the
anonymous larger network (macro). It is argued that an important
focal point for analysis of cooperation and conflict is situated in
the relations between these levels. Deepened studies and analysis
also revealed needs to address dynamic recipient groupings, the need
to control the level of publicness of both digital material and its
metadata (tags, contacts, comments and links to other networks) and
that users often refrained from providing material unless they felt
able to control its direction. A central conclusion is that public
and non-public gifting need to co-emerge in large sharing networks
and that non-public gifting might be an important factor for the
support of continued provision of goods in sustainable networks and
communities.
No 1248
THE USE OF CASE-BASED REASONING IN A
HUMAN-ROBOT DIALOG SYSTEM
Karolina Eliasson
As long as there have been computers, one goal has been to be able
to communicate with them using natural language. It has turned out
to be very hard to implement a dialog system that performs as well
as a human being in an unrestricted domain, hence most dialog
systems today work in small, restricted domains where the permitted
dialog is fully controlled by the system.
In this thesis we
present two dialog systems for communicating with an autonomous
agent:
The first system, the WITAS RDE, focuses on constructing
a simple and failsafe dialog system including a graphical user
interface with multimodality features, a dialog manager, a
simulator, and development infrastructures that provides the
services that are needed for the development, demonstration, and
validation of the dialog system. The system has been tested during
an actual flight connected to an unmanned aerial vehicle.
The
second system, CEDERIC, is a successor of the dialog manager in the
WITAS RDE. It is equipped with a built-in machine learning algorithm
to be able to learn new phrases and dialogs over time using past
experiences, hence the dialog is not necessarily fully controlled by
the system. It also includes a discourse model to be able to keep
track of the dialog history and topics, to resolve references and
maintain subdialogs. CEDERIC has been evaluated through simulation
tests and user tests with good results.
No 1263
MANAGING COMPETENCE DEVELOPMENT
PROGRAMS IN A CROSS-CULTURAL ORGANISATION – WHAT ARE THE
BARRIERS AND ENABLERS?
Misook Park-Westman
During the past decade, research on competence development and
cross-cultural organisation has been acknowledged both in academic
circles and by industrial organisations. Cross-cultural
organisations that have emerged through globalisation are a
manifestation of the growing economic interdependence among
countries. In cross-cultural organisations, competence development
has become an essential strategic tool for taking advantage of the
synergy effects of globalisation. The objective of this thesis is
to examine how competence development programs are conducted and to
identify barriers and enablers for the success of such programs,
especially in a cross-cultural organisation.
To identify the
processes involved in managing competence development programs in a
cross-cultural organisation, a case study method was chosen. A total
of 43 interviews and 33 surveys were held with participants,
facilitators and managers in competence development programs at four
units of IKEA Trading Southeast Asia located in Thailand, Vietnam,
Malaysia and Indonesia, respectively. In addition to the
observations made on these four competence development programs, a
study of the literature in related research areas was conducted. The
interviews were held and the survey data collected in 2003 and
2004.
In the findings, the barriers identified were cultural
differences, assumptions, language, and mistrust; the enablers were
cultural diversity, motivation, management commitment, and
communication. The conclusions are that competence development is a
strategic tool for cross-cultural organisations and that it is
extremely important to identify barriers to, and enablers of,
successful competence development, and to eliminate the barriers and
support the enablers right from the early stages of competence
development programs.
No FiF a 90
ETT PRAKTIKPERSPEKTIV PÅ
HANTERING AV MJUKVARUKOMPONENTER
Amra Halilovic
Nyutveckling och förvaltning av ett informationssystem
står ständigt inför nya krav och
förutsättningar. Utvecklingen skall ske på kortare
tid och med ökad produktivitet. Ur förvaltningssynpunkt
skall IT-systemen snabbt kunna anpassas till förändringar
i verksamhet och teknik, samtidigt som dessa IT-system även
skall ha en hög kvalitet och säkerhet. Allt detta
kräver nya sätt att arbeta och att organisera
IT-verksamheten på. Ett av dessa nya arbetssätt
gäller hantering av mjukvarukomponenter. Den grundläggande
idén med detta arbetssätt är att utveckling och
förvaltning av IT-system inte skall basera sig på
nyutveckling av mjukvara, utan på återanvändning av
befintliga mjukvarukomponenter.
Forskningsprocessen har haft en
kvalitativ ansats med induktiva och deduktiva
inslag. Datainsamlingen har skett via källstudier och
intervjuer. Hanteringen av mjukvaru-komponenter har studerats
på två interna IT-avdelningar hos två
myndigheter. Syftet har varit att kartlägga vad
komponenthantering innebär och på vilket sätt
arbetet på IT-avdelningarna har
förändrats. Komponenthanteringen beskrivs ur ett
praktikperspektiv, vilket innebär att IT-verksamhetens
förutsättningar, handlingar, resultat och klienter
analyseras.
Avhandlingens resultat utgörs av en
praktikteori för komponenthantering. Praktiken
”Komponenthantering” består av fyra subpraktiker:
komponentanskaffning, komponent-förvaltning, komponentbaserad
systemutveckling och komponentbaserad
systemförvaltning. Produkten av denna praktik är
användbara IT-system. I avhandlingen diskuteras olika sätt
att organisera denna praktik, samt vilka grundläggande
förutsättningar som behövs för att bedriva denna
praktik. Syftet med den praktikteori som presenteras är att den
skall visa på hur intern IT-verksamhet kan bedrivas för
att kunna möta de nya krav på effektivitet,
förändringsbarhet, kvalitet och säkerhet som
ställs på verksamheten.
No 1272
A FRAMEWORK FOR THE STRATEGIC
MANAGEMENT OF INFORMATION TECHNOLOGY
Raquel
Flodström
Strategy and IT research has been
extensively discussed during the past 40 years. Two scientific
disciplines Management Science (MS) and Management Information
Science (MIS) investigate the importance of IT as a competitive
factor. However, although much research is available in both
disciplines, it is still difficult to explain how to manage IT to
enable competitive advantages. One reason is that MS research
focuses on strategies and competitive environments but avoids the
analysis of IT. Another reason is that MIS research focuses on IT as
a competitive factor but avoids the analysis of the competitive
environment. Consequently, there is a gap of knowledge in the
understanding of the strategic management of information technology
(SMIT).
The strategic analysis of IT as a competitive factor
is important for achieving the competitive advantages of IT. This
thesis explores factors related to strategy and IT that should be
considered for the strategic analysis of IT as a competitive factor,
and proposes a framework for SMIT. The research is conducted by
means of a qualitative analysis of theoretical data from the
disciplines of MS and MIS. Data is explored to find factors related
to SMIT.
The results of the analysis show that the strategic
management of information technology is a continuous process of
evaluation, change, and alignment between factors such as
competitive environment, competitive strategies (business and IT
strategies), competitive outcome, and competitive factors
(IT). Therefore, the understanding of the relationships between
these factors is essential in order to achieve the competitive
advantages of using IT.
This thesis contributes to strategic
management research by clarifying the relationships between
strategic management, competitive environment, and IT as competitive
factor into a holistic framework for strategic analysis. The
framework proposed is valuable not only for business managers and
for IT managers, but also for academics. The framework is designed
to understand the relationship between competitive elements during
the process of strategic analysis prior to the formulation of
competitive strategies. Moreover, it can also be used as a
communication tool between managers, in order to achieve alignment
among company strategies. To academics, this thesis presents the
state-of-the-art related to strategic management research; it can
also be a valuable reference for strategic managers, as well as
researchers interested in the strategic management of IT.
No 1277
SCHEDULING AND OPTIMIZATION OF
FAULT-TOLERANT EMBEDDED SYSTEMS
Viacheslav
Izosimov
Safety-critical applications have to
function correctly even in presence of faults. This thesis deals
with techniques for tolerating effects of transient and intermittent
faults. Reexecution, software replication, and rollback recovery
with checkpointing are used to provide the required level of fault
tolerance. These techniques are considered in the context of
distributed real-time systems with non-preemptive static cyclic
scheduling.
Safety-critical applications have strict time and
cost constrains, which means that not only faults have to be
tolerated but also the constraints should be satisfied. Hence,
efficient system design approaches with consideration of fault
tolerance are required.
The thesis proposes several design
optimization strategies and scheduling techniques that take fault
tolerance into account. The design optimization tasks addressed
include, among others, process mapping, fault tolerance policy
assignment, and checkpoint distribution.
Dedicated scheduling
techniques and mapping optimization strategies are also proposed to
handle customized transparency requirements associated with
processes and messages. By providing fault containment, transparency
can, potentially, improve testability and debugability of
fault-tolerant applications.
The efficiency of the proposed
scheduling techniques and design optimization strategies is
evaluated with extensive experiments conducted on a number of
synthetic applications and a real-life example. The experimental
results show that considering fault tolerance during system-level
design optimization is essential when designing cost-effective
fault-tolerant embedded systems.
No FiF-a 91
VERKSAMHETSAPNPASSADE
IT-STÖD - DESIGNTEORI OCH METOD
Hanna
Broberg
Det finns IT-stöd i verksamheter som
inte fungerar som bra stöd för personalen att utföra
arbetet. Att IT-stöd inte fungerar kan bero på olika
brister i utvecklingen. En brist som förs fram i denna
avhandling är att IT-stödet inte har utvecklats så
att det är verksamhetsanpassat. Ett förslag är att
IT-stöd kan bli mer verksamhetsanpassade genom att ha ett
lämpligt synsätt på IT och verksamhet samt
använda en designteori baserad på synsättet och en
metod baserad på designteorin. Begreppen verksamhet och
IT-stöd har undersökts och ett förslag på ett
synsätt för att utveckla verksamhetsanpassade IT-stöd
består av ett pragmatiskt perspektiv på verksamhet, ett
kontextuellt perspektiv på IT och ett systemiskt perspektiv
på relationen mellan verksamhet och IT. Handlingsbarhet och
aktivitetsteori antogs tillsammans utgöra en designteori som
täckte in det föreslagna synsättet. En
undersökning har gjorts av hur handlingsbarhet skulle kunna
vidareutvecklas med aktivitetsteori och användas som
designteori för att utveckla verksamhetsanpassade
IT-stöd. Detta har gjorts genom en konceptuell teoretisk
jämförelse mellan teorierna. Undersökningen kan
också ses som teoretisk grundning av
handlingsbarhet. Kravhanteringsmetoden VIBA (Verksamhets- och
Informationsbehovsanalys) är baserad på handlingsbarhet
och har undersökts som metod för att utveckla
verksamhetsanpassade IT-stöd. För att pröva
aktivitetsteori som kompletterande designteori till handlingsbarhet
har det undersökts hur aktivitetsteori skulle kunna
användas för att vidareutveckla VIBA till en metod
för att utveckla verksamhetsanpassade IT-stöd.
Metodutvecklingen har gjorts genom att jämföra VIBA med en
metod för arbetsutveckling som är baserad på
aktivitetsteori. Detta har genererat ett metodförslag som sedan
har prövats praktiskt genom tillämpning i två
IT-utvecklingsprojekt. Båda projekten har handlat om
utveckling av mobilt IT-stöd för vård och
omsorgsverksamhet. Jämförelsen mellan handlingsbarhet och
aktivitetsteori visade på att teorierna delvis hade gemensamma
begrepp och delvis hade begrepp som enbart fanns inom respektive
teori. Detta visar att aktivitetsteori skulle kunna vidareutveckla
handlingsbarhet inom dessa begrepp, både som designteori
för att utveckla verksamhetsanpassade IT-stöd och som
sådan. Metodförslaget gick att tillämpa
praktiskt. För att styrka dess användbarhet måste
dock ytterligare prövning och validering
göras.
No 1283
A BLUEPRINT FOR USING COMMERCIAL
GAMES OFF THE SHELF IN DEFENCE TRAINING, EDUCATION AND RESEARCH
SIMULATIONS
Håkan Hasewinkel
There are two types of simulations, those made for business and
those made for pleasure. The underlying technology is usually the
same, the difference being how and for what purpose the simulation
is used. Often the two purposes can be combined. Nowhere is this
more obvious than in the mutual benefit that exists between the
military community and the entertainment business. These mutual
benefits have only in recent years begun to be seriously explored.
The objective of this work is to explore how to modify and
use commercial video games off the shelf, in defence training,
education and research. The work focuses on the process of how and
what to consider when modifying commercial off the shelf games for
military needs.
The outlined blueprint is based on studies
performed with combatants from the Swedish Army. To facilitate the
development of the blueprint, a great number of commercial
games used by military communities around the world are
evaluated. These evaluations, in harmony with literature in the
area, are used to develop a basic theoretical framework. The basic
theoretical framework characterizes the approach and style
throughout the work.
From a general point of view, there are
two overall findings; first there is an urgent need for more
intuitive, pedagogical and powerful tools for preparation,
management and evaluation of game-based simulation, especially since
the real learning often takes place during the modification process
rather the during the playing session. Second, there is a defective
understanding of the differences between and purposes of a defence
simulation and a game. Defence simulations focus on actions and
events, while video games focus on human reactions to actions and
events.
No 1286
TOWARDS AN XML DOCUMENT RESTRUCTURING FRAMEWORK
Robert Kaminski
An XML document has a set of constraints associated, such as validity
constraints and cross-dependencies. When changing its structure these
constraints must be maintained. In some cases a restructuring involves
many dependent documents; such changes should be automated to ensure
consistency and efficiency.
Most existing XML tools support simple updates, restricted to a single
document. Moreover, these tools often do not support concepts defined by
a specific XML-application (an XML-application defines the set of valid
markup symbols, e.g., tags, and their hierarchical structure). This work
aims at developing a framework for XML document restructuring. The
framework facilitates realisation of document restructuring tools by
providing advanced restructuring functions, i.e., provide an environment
where restructuring operations can easily be realised. To avoid
restricting the framework to a specific set of XML-applications, it is
designed for flexibility.
The conceptual part of this work focuses on the definition of an
operation set for XML document restructuring, called the operation
catalogue. The operations are adapted to a document model defined by
this work. The catalogue is divided into three abstraction layers,
corresponding to the concepts defined by XML, XML-applications, and
XML-application policies. The layer structure facilitates extensibility
by allowing new operations to be defined in terms of existing.
In the practical part, an architecture is presented for a document
restructuring framework which supports realisation of the earlier
presented operations. The architecture is based on a layered approach to
facilitate extensibility with new layers that contain restructuring
operations and functions for an XML-application or an XML-application
policy. A new layer component can be added without recompilation of
existing components. To reduce resource consumption during document load
and restructuring the framework allows its user to specify, upon
initialization, the set of active layer components (each layer component
may perform analysis). This part also includes a prototype
implementation of the presented architecture.
This work results in an event-based framework for document restructuring
that is extensible with restructuring support for new XML-application
and XML-application policies. The framework is also well suited to
manage inter document issues, such as dependencies.
No 1293
PREREQUISITES FOR DATA SHARING IN
EMERGENCY MANAGEMENT: JOINT ANALYSIS USING A REAL-TIME ROLE-PLAYING
EXERCISE APPROACH
Jiri Trnka
This thesis
explains how semi-coordinated or separated utilization of information
and communication technologies may affect collaborative work between
different emergency management organizations, and their capabilities
to perform joint tasks during emergency responses. Another aim is to
explore the modeling of emergency management and data collection
methods with respect to utilization of these technologies. The
theoretical basis for the thesis consists of system science, cognitive
system engineering, communication, informatics, simulation, emergency
management, and command and control. Important notions are the joint
cognitive systems concept and the communication infrastructure
concept. The case study method and the real-time role-playing exercise
approach are the main methodological approaches. On the basis of two
main studies, geospatial data and related systems are studied as an
example. Study I focuses on emergency management organizations’
abilities to collaborate effectively by assessing their communication
infrastructure. Study II, on the other hand, highlights the emerging
effects in use of data in collaborative work when responding to a
forest fire scenario. The results from the studies, and from the
general work conducted and presented here, show that the
semi-coordinated or separated utilization of the technologies affects
(a) how well the organizations can collaborate, (b) the capabilities
to carry out collaborative tasks during crises and disasters, and (c)
to what extent the technology can be used in real-life situations. The
results also show that the joint cognitive system notion and the
real-time role-playing exercise approach provided new ways to
conceptualize and study the emergency management and the command and
control system.
No 1302
A FRAMEWORK FOR DESIGNING
CONSTRAINT STORES
Björn Hägglund
A constraint solver based on concurrent search and propagation
provides a well-defined component model for propagators by enforcing
a strict two-level architecture. This makes it straightforward for
third parties to invent, implement and deploy new kinds of
propagators. The most critical components of such solvers are the
constraint stores through which propagators communicate with each
other. Introducing stores supporting new kinds of stored constraints
can potentially increase the solving power by several orders of
magnitude. This thesis presents a theoretical framework for
designing stores achieving this without loss of propagator
interoperability.
No 1303
SLACK-TIME AWARE DYNAMIC ROUTING
SCHEMES FOR ON-CHIP NETWORKS
Daniel
Andreasson
Network-on-Chip (NoC) is a new on-chip
communication paradigm for future IP-core based System-on-Chip
(SoC), designed to remove a number of limitations of today’s
on-chip interconnect solutions. A Nointerconnects cores by means of
a packet switched micro-network, which improves scalability and
reusability, resulting in a shorter time to market. A typical NoC
will be running many applications concurrently, which results in
shared network capacity between different kinds of traffic
flows. Due to the diverse characteristic of applications, some
traffic flows will require real-time communication guarantees while
others are tolerant to even some loss of data. In order to provide
different levels of Quality-of-Service (QoS) for traffic flows, the
communication traffic is separated into different service
classes. Traffic in NoC is typically classified into two service
classes: the guaranteed throughput (GT) and the best-effort (BE)
service class. The GT class offers strict QoS guarantees by setting
up a virtual path with reserved bandwidth between the source
(GT-producer) and destination (GT-consumer), called a GT-path. The
BE class offers no strict QoS guarantees, but tries to efficiently
use any network capacity which may become available from the GT
traffic. The GT traffic may not fully utilize its bandwidth
reservation if its communication volume varies, leading to time
intervals where there is no GT traffic using the bandwidth
reservation. These intervals are referred to as slack-time. If the
slack can not be used this leads to unnecessarily reduced
performance of BE traffic, since a part of the available network
capacity becomes blocked. This thesis deals with methods to
efficiently use the slack-time for BE traffic. The contributions
include three new dynamic schemes for slack distribution in
NoC. First, a scheme to inform the routers of a GT-path about
available slack is evaluated. The GT-producer plans its traffic
using a special playout buffer and issues control packets containing
the actual amount of slack-time available. The results show that
this scheme leads to decreased latency, jitter and packet drops for
BE traffic. Secondly, an extension to this scheme is evaluated,
where slack is distributed among multiple GT-paths (slack
distribution in space). This opens up the possibility to balance the
QoS of BE traffic flows which overlap with the GT-paths. Thirdly, a
scheme to distribute slack among the links of a GT-path (slack
distribution in time) is proposed. In this approach, arriving
GT-packets, at a certain router along the GT-path, can wait for a
maximum defined amount of time. During this time, any waiting BE
traffic in the buffers can be forwarded over the GT-path. The
results confirm that this is especially important during high
BE-traffic load, where this technique decreases the jitter of BE
traffic considerably.
No 1305
MODELLING USER TASKS AND
INTENTIONS FOR SERVICE DISCOVERY IN UBIQUITOUS COMPUTING
Magnus Ingemarsson
Ubiquitous computing
(Ubicomp) increases in proliferation. Multiple and ever growing in
numbers, computational devices are now at the users' disposal
throughout the physical environment, while simultaneously being
effectively invisible. Consequently, a significant challenge is
service discovery. Services may for instance be physical, such as
printing a document, or virtual, such as communicating
information. The existing solutions, such as Bluetooth and UPnP,
address part of the issue, specifically low-level physical
interconnectivity. Still absent are solutions for high-level
challenges, such as connecting users with appropriate services. In
order to provide appropriate service offerings, service discovery in
Ubicomp must take the users' context, tasks, goals, intentions, and
available resources into consideration. It is possible to divide the
high-level service-discovery issue into two parts; inadequate
service models, and insufficient common-sense models of human
activities.
This thesis contributes to service discovery in
Ubicomp, by arguing that in order to meet these highlevel challenges,
a new layer is required. Furthermore, the thesis presents a prototype
implementation of this new service-discovery architecture and
model. The architecture consists of hardware, ontology layer, and
common-sense layer. This work addresses the ontology and common-sense
layers. Subsequently, implementation is divided into two parts; Oden
and Magubi. Oden addresses the issue of inadequate service models
through a combination of service-ontologies in concert with logical
reasoning engines, and Magubi addresses the issue of insufficient
common-sense models of human activities, by using common-sense models
in combination with rule engines. The synthesis of these two stages
enables the system to reason about services, devices, and user
expectations, as well as to make suitable connections to satisfy the
users’ overall goal.
Designing common-sense models and
service ontologies for a Ubicomp environment is a non-trivial
task. Despite this, we believe that if correctly done, it might be
possible to reuse at least part of the knowledge in different
situations. With the ability to reason about services and human
activities it is possible to decide if, how, and where to present the
services to the users. The solution is intended to off-load users in
diverse Ubicomp environments as well as provide a more relevant
service discovery.
No 1306
ONTOLOGY AS CONCEPTUAL SCHEMA WHEN
MODELLING HISTORICAL MAPS FOR DATABASE STORAGE
Gustaf
Svedjemo
Sweden has an enormous treasure in its vast
number of large-scale historical maps from a period of 400 years made
for different purposes, that we call map series. The maps are also
very time and regional dependent with respect to their concepts. A
large scanning project by Lantmäteriverket will make most of
these maps available as raster images. In many disciplines in the
humanities and social sciences, like history, human geography and
archaeology, historical maps are of great importance as a source of
information. They are used frequently in different studies for a
variety of problems. A full and systematic analyse of this material
from a database perspective has so far not been conducted. During the
last decade or two, it has been more and more common to use data from
historical maps in GIS-analysis. In this thesis a novel approach to
model these maps is tested. The method is based on the modelling of
each map series as its own ontology, thus focusing on the unique
concepts of each map series. The scope of this work is a map series
covering the province of Gotland produced during the period
1693-1705. These maps have extensive text descriptions concerned with
different aspects of the mapped features. Via a code marking system
they are attached to the maps. In this thesis a semantic analysis and
an ontology over all the concepts found in the maps and text
descriptions are presented. In our project we model the maps as close
to the original structure as possible with a very data oriented
view. Furthermore; we demonstrate how this ontology can be used as a
conceptual schema for a logical E/R database schema. The Ontology is
described in terms of the Protégé meta-model and the E/R
schema in UML. The mapping between the two is a set of elementary
rules, which are easy for a human to comprehend, but hard to
automate. The E/R schema is implemented in a demonstration
system. Examples of some different applications which are feasibly to
perform by the system are presented. These examples go beyond the
traditional use of historical maps in GIS today.
No 1307
NAVIGATION FUNCTIONALITIES FOR AN AUTONOMOUS UAV HELICOPTER
Gianpaolo Conte
This thesis was written during the WITAS UAV Project where one of the
goals has been the development of a software/hardware architecture for an
unmanned autonomous helicopter, in addition to autonomous functionalities
required for complex mission scenarios. The algorithms developed here have
been tested on an unmanned helicopter platform developed by Yamaha Motor
Company called the RMAX.
The character of the thesis is primarily experimental and it should be
viewed as developing navigational functionality to support autonomous
flight during complex real-world mission scenarios.
This task is multidisciplinary since it requires competence in
aeronautics, computer science and electronics.
The focus of the thesis has been on the development of a control method to
enable the helicopter to follow 3D paths. Additionally, a helicopter
simulation tool has been developed in order to test the control system
before flight-tests.
The thesis also presents an implementation and experimental evaluation of
a sensor fusion technique based on a Kalman filter applied to a vision
based autonomous landing problem.
Extensive experimental flight-test results are presented.
No 1309
USER-CENTRIC CRITIQUING IN COMMAND AND CONTROL: THE DKEXPERT AND COMPLAN APPROACHES
Ola Leifler
This thesis describes two approaches for using critiquing as decision
support for military mission planning. In our work, we have drawn from both human-centered research as well as
results on decision support systems research for military mission planning when devising
approaches for knowledge acquisition and decision support for mission planning.
Our two approaches build on a common set of requirements which have been developed as
the consequence of both literature analyses as well as interview
studies. In short, these criteria
state that critiquing systems should be developed with transparency,
ease of use and integration
in traditional work flow in mind. The use of these criteria is
illustrated in two approaches to decision support in two different settings: a collaborative real-time
war-gaming simulation and a planning tool for training mission commanders.
Our first approach is demonstrated by the DKExpert system, in which
end-users can create
feedback mechanisms for their own needs when playing a two-sided war-game scenario in the
DKE simulation environment. In DKExpert, users can choose to trigger
feedback during the
game by instructing a rule engine to recognize critical situations.
Our second approach, Com-Plan, builds on the insights on knowledge and planning representation gained from DKExpert
and introduces an explicit representation of planning operations,
thereby allowing for better analysis of planning operations and user-controlled feedback. ComPlan also demonstrates a
design for critiquing support systems that respects the traditional
work practice of mission
planners while allowing for intelligent analysis of military plans.
No 1312
EMBODIED SIMULATION AS OFF-LINE REPRESENTATION
Henrik Svensson
This licentiate thesis argues that a key to understanding the embodiment of cognition is the “sharing” of neural mechanisms between sensorimotor processes and higher-level cognitive processes as described by simulation theories. Simulation theories explain higher-level cognition as (partial) simulations or emulations of sensorimotor processes through the re-activation of neural circuitry also active in bodily perception, action, and emotion. This thesis develops the notion that simulation mechanisms have a particular representational function, as off-line representations, which contributes to the representation debate in embodied cognitive science. Based on empirical evidence from neuroscience, psychology and other disciplines as well as a review of existing simulation theories, the thesis describes three main mechanisms of simulation theories: re-activation, binding, and prediction. The possibility of using situated and embodied artificial agents to further understand and validate simulation as a mechanism of (higher-level) cognition is addressed through analysis and comparison of existing models. The thesis also presents some directions for further research on modeling simulation as well as the notion of embodied simulation as off-line representation.
No 1313
SYSTEM-ON-CHIP TEST SCHEDULING WITH DEFECT-PROBABILITY AND TEMPERATURE CONSERATIONS
Zhiyuan He
Electronic systems have become highly complex, which results in a dramatic
increase of both design and production cost. Recently a core-based
system-on-chip (SoC) design methodology has been employed in order to reduce
these costs. However, testing of SoCs has been facing challenges such as
long test application time and high temperature during test. In this thesis,
we address the problem of minimizing test application time for SoCs and
propose three techniques to generate efficient test schedules.
First, a defect-probability driven test scheduling technique is presented
for production test, in which an abort-on-first-fail (AOFF) test approach is
employed and a hybrid built-in self-test architecture is assumed. Using an
AOFF test approach, the test process can be aborted as soon as the first
fault is detected. Given the defect probabilities of individual cores, a
method is proposed to calculate the expected test application time (ETAT). A
heuristic is then proposed to generate test schedules with minimized ETATs.
Second, a power-constrained test scheduling approach using test set
partitioning is proposed. It assumes that, during the test, the total amount
of power consumed by the cores being tested in parallel has to be lower than
a given limit. A heuristic is proposed to minimize the test application
time, in which a test set partitioning technique is employed to generate
more efficient test schedules.
Third, a thermal-aware test scheduling approach is presented, in which test
set partitioning and interleaving are employed. A constraint logic
programming (CLP) approach is deployed to find the optimal solution.
Moreover, a heuristic is also developed to generate near-optimal test
schedules especially for large designs to which the CLP-based algorithm is
inapplicable.
Experiments based on benchmark designs have been carried out to demonstrate
the applicability and efficiency of the proposed techniques.
No 1317
COMPONENTS, SAFETY INTERFACES AND COMPOSITIONAL ANALYSIS
Jonas Elmqvist
Component-based software development has emerged as a promising approach for developing
complex software systems by composing smaller independently developed components into
larger component assemblies. This approach offers means to increase software reuse, achieve
higher flexibility and shorter time-to-market by the use of off-the-shelf components (COTS).
However, the use of COTS in safety-critical system is highly unexplored.
This thesis addresses the problems appearing in component-based development of
safety-critical systems. We aim at efficient reasoning about safety at system level while
adding or replacing components. For safety-related reasoning it does not suffice to consider
functioning components in their intended environments but also the behaviour of components
in presence of single or multiple faults. Our contribution is a formal component model that
includes the notion of a safety interface. It describes how the component behaves with respect
to violation of a given system-level property in presence of faults in its environment. This
approach also provides a link between formal analysis of components in safety-critical
systems and the traditional engineering processes supported by model-based development.
We also present an algorithm for deriving safety interfaces given a particular safety
property and fault modes for the component. The safety interface is then used in a method
proposed for compositional reasoning about component assemblies. Instead of reasoning
about the effect of faults on the composed system, we suggest analysis of fault tolerance
through pair wise analysis based on safety interfaces.
The framework is demonstrated as a proof-of-concept in two case studies; a hydraulic
system from the aerospace industry and an adaptive cruise controller from the automotive
industry. The case studies have shown that a more efficient system-level safety analysis can
be performed using the safety interfaces.
No 1320
QUESTION CLASSIFICATION IN QUESTION ANSWERING SYSTEMS
Håkan Sundblad
Question answering systems can be seen as the next step in information retrieval, allowing users to pose questions in natural language and receive succinct answers. In order for a question answering system as a whole to be successful, research has shown that the correct classification of questions with regards to the expected answer type is imperative. Question classification has two components: a taxonomy of answer types, and a machinery for making the classifications.
This thesis focuses on five different machine learning algorithms for the question classification task. The algorithms are k nearest neighbours, naïve bayes, decision tree learning, sparse network of winnows, and support vector machines. These algorithms have been applied to two different corpora, one of which has been used extensively in previous work and has been constructed for a specific agenda. The other corpus is drawn from a set of users' questions posed to a running online system. The results showed that the performance of the algorithms on the different corpora differs both in absolute terms, as well as with regards to the relative ranking of them. On the novel corpus, naïve bayes, decision tree learning, and support vector machines perform on par with each other, while on the biased corpus there is a clear difference between them, with support vector machines being the best and naïve bayes being the worst.
The thesis also presents an analysis of questions that are problematic for all learning algorithms. The errors can roughly be divided as due to categories with few members, variations in question formulation, the actual usage of the taxonomy, keyword errors, and spelling errors. A large portion of the errors were also hard to explain.
No 1323
INFORMATION DEMAND AND USE: IMPROVING INFORMATION FLOW WITHIN SMALL-SCALE BUSINESS CONTEXTS
Magnus Lundqvist
Whilst the amount of information readily available to workers in information- and knowledge
intensive business- and industrial contexts only seem to increase with every day, those
workers still have difficulties in finding relevant and needed information as well as storing,
distributing, and aggregating such information. Yet, whilst there exist numerous technical,
organisational, and practical approaches to remedy the situation, the problems seem to
prevail.
This publication describes the first part of the author’s work on defining a methodology for
improving the flow of work related information, with respect to the information demand of
individuals and organisations. After a prefatory description of the perceived problems
concerning information flow in modern organisations, a number of initial conjectures
regarding information demand and use in small-scale business contexts are defined based on a
literature study. With this as the starting point the author sets out to, through an empirical
investigation performed in three different Swedish organisations during 2005, identify how
individuals within organisations in general, and these three in particular, use information with
respect to such organisational aspects as roles, tasks, and resources as well as spatio-temporal
aspects. The results from the investigation are then used to validate the conjectures and to
draw a number of conclusions on which both a definition of information demand, as well as
the initial steps towards defining a methodology for information demand analysis, are based.
Lastly, a short discussion of the applicability of the results in continued work is presented
together with a description of such planned work.
No 1329
DEDUCTIVE PLANNING AND COMPOSITE ACTIONS IN TEMPORAL ACTION LOGIC
Martin Magnusson
Temporal Action Logic is a well established logical formalism for reasoning about action
and change that has long been used as a formal specification language. Its first-order
characterization and explicit time representation makes it a suitable target for automated
theorem proving and the application of temporal constraint solvers. We introduce
a translation from a subset of Temporal Action Logic to constraint logic programs that
takes advantage of these characteristics to make the logic applicable, not just as a formal specification language, but in solving practical reasoning problems. Extensions are
introduced that enable the generation of action sequences, thus paving the road for interesting
applications in deductive planning. The use of qualitative temporal constraints
makes it possible to follow a least commitment strategy and construct partially ordered
plans. Furthermore, the logical language and logic program translation is extended with
the notion of composite actions that can be used to formulate and execute scripted plans
with conditional actions, non-deterministic choices, and loops. The resulting planner and
reasoner is integrated with a graphical user interface in our autonomous helicopter research
system and applied to logistics problems. Solution plans are synthesized together
with monitoring constraints that trigger the generation of recovery actions in cases of
execution failures.
No 1331
RESTORING CONSISTENCY AFTER NETWORK PARTITIONS
Mikael Asplund
The software industry is facing a great challenge. While systems get more complex and
distributed across the world, users are becoming more dependent on their availability.
As systems increase in size and complexity so does the risk that some part will fail.
Unfortunately, it has proven hard to tackle faults in distributed systems without a rigorous
approach. Therefore, it is crucial that the scientific community can provide answers to
how distributed computer systems can continue functioning despite faults.
Our contribution in this thesis is regarding a special class of faults which occurs when
network links fail in such a way that parts of the network become isolated, such faults are
termed network partitions. We consider the problem of how systems that have integrity
constraints on data can continue operating in presence of a network partition. Such a
system must act optimistically while the network is split and then perform a some kind
of reconciliation to restore consistency afterwards.
We have formally described four reconciliation algorithms and proven them correct.
The novelty of these algorithms lies in the fact that they can restore consistency after
network partitions in a system with integrity constraints and that one of the protocols
allows the system to provide service during the reconciliation. We have implemented and
evaluated the algorithms using simulation and as part of a partition-tolerant CORBA
middleware. The results indicate that it pays off to act optimistically and that it is
worthwhile to provide service during reconciliation.
No 1332
TOWARDS INDIVIDUALIZED DRUG DOSAGE - GENERAL METHODS AND CASE STUDIES
Martin Fransson
Progress in individualized drug treatment is of increasing importance, promising to avoid much human suffering and reducing medical treatment costs for society. The strategy is to maximize the therapeutic effects and minimize the negative side effects of a drug on individual or group basis. To reach the goal, interactions between the human body and different drugs must be further clarified, for instance by using mathematical models. Whether clinical studies or laboratory experiments are used as primary sources of information, greatly influences the possibilities of obtaining data. This must be considered both prior and during model development and different strategies must be used. The character of the data may also restrict the level of complexity for the models, thus limiting their usage as tools for individualized treatment. In this thesis work two case studies have been made, each with the aim to develop a model for a specific human-drug interaction. The first case study concerns treatment of inflammatory bowel disease with thiopurines, whereas the second is about treatment of ovarian cancer with paclitaxel. Although both case studies make use of similar amounts of experimental data, model development depends considerably on prior knowledge about the systems, the character of the data and the choice of modelling tools. All these factors are presented for each of the case studies along with current results. Further, a system for classifying different but related models is also proposed with the intention that an increased understanding will contribute to advancement in individualized drug dosage.
No 1333
A VISUAL QUERY LANGUAGE SERVED BY A MULTI-SENSOR ENVIRONMENT
Karin Camara
A problem in modern command and control situations is that much data is available from different sensors. Several sensor data sources also require that the user has knowledge about the specific sensor types to be able to interpret the data.
To alleviate the working situation for a commander, we have designed and constructed a system that will take input from several different sensors and subsequently present the relevant combined information to the user. The users specify what kind of information is of interest at the moment by means of a query language. The main issues when designing this query language have been that (a) the users should not have to have any knowledge about sensors or sensor data analysis, and (b) that the query language should be powerful and flexible, yet easy to use. The solution has been to (a) use sensor data independence and (b) have a visual query language.
A visual query language was developed with a two-step interface. First, the users pose a “rough”, simple query that is evaluated by the underlying knowledge system. The system returns the relevant information that can be found in the sensor data. Then, the users have the possibility to refine the result by setting conditions for this. These conditions are formulated by specifying attributes of objects or relations between objects.
The problem of uncertainty in spatial data; (i.e. location, area) has been considered. The question of how to represent potential uncertainties is dealt with. An investigation has been carried out to find which relations are practically useful when dealing with uncertain spatial data.
The query language has been evaluated by means of a scenario. The scenario was inspired by real events and was developed in cooperation with a military officer to assure that it was fairly realistic. The scenario was simulated using several tools where the query language was one of the more central ones. It proved that the query language can be of use in realistic situations.
No 1337
SAFETY, SECURITY, AND SEMANTIC ASPECTS OF EGUATION-BASED OBJECT-ORIENTED LANGUAGES AND ENVIRONMENTS
David Broman
During the last two decades, the interest for computer aided modeling and simulation of complex physical systems has witnessed a significant growth. The recent possibility to create acausal models, using components from different domains (e.g., electrical, mechanical, and hydraulic) enables new opportunities. Modelica is one of the most prominent equation-based object-oriented (EOO) languages that support such capabilities, including the ability to simulate both continuous- and discrete-time models, as well as mixed hybrid models. However, there are still many remaining challenges when it comes to language safety and simulation security. The problem area concerns detecting modeling errors at an early stage, so that faults can be isolated and resolved. Furthermore, to give guarantees for the absence of faults in models, the need for precise language specifications is vital, both regarding type systems and dynamic semantics. This thesis includes five papers related to these topics. The first paper describes the informal concept of types in the Modelica language, and proposes a new concrete syntax for more precise type definitions. The second paper provides a new approach for detecting over- and under-constrained systems of equations in EOO languages, based on a concept called structural constraint delta. That approach makes use of type checking and a type inference algorithm. The third paper outlines a strategy for using abstract syntax as a middle-way between a formal and informal language specification. The fourth paper suggests and evaluates an approach for secure distributed co-simulation over wide area networks. The final paper outlines a new formal operational semantics for describing physical connections, which is based on the untyped lambda calculus. A kernel language is defined, in which real physical models are constructed and simulated.
No 1339
INVASIVE INTERACTIVE PARALLELIZATION
Mikhail Chalabine
While looking at the strengths and weaknesses of contemporary approaches to parallelization this thesis suggests a form of parallelizing refactoring -- Invasive Interactive Parallelization -- that aims at addressing a number of weaker sides of contemporary methods. Our ultimate goal is to make the parallelization more user and developer friendly. While admitting that the approach adds complexity at certain levels, in particular, it can be said to reduce code understandability, we conclude that it provides a remedy for a number of problems found in contemporary methods. As the main contribution the thesis discusses the benefits we see with the approach, introduces a set of parallelization categories a typical parallelization consists of, and shows how the method can be realized with abstract syntax tree transformations. The thesis also presents a formal solution to the problem of automated round-trip software engineering in aspect-weaving systems.
No 1351
A HOLISTIC APPROACH TO USABILITY EVALUATIONS OF MIXED REALITY SYSTEMS
Susanna Nilsson
The main focus of this thesis is the study of user centered issues in
Mixed and Augmented Reality (AR) systems. Mixed Reality (MR) research is
in general a highly technically oriented field with few examples of user
centered studies. The few studies focusing on user issues found in the
field are all based on traditional Human Computer Interaction (HCI)
methodologies. Usability methods used in MR/AR research are mainly based
on usability methods used for graphical user interfaces, sometimes in
combination with usability for Virtual Reality (VR) applications. MR/AR
systems and applications differ from standard desktop applications in
many ways, but specifically in one crucial respect; it is intended to be
used as a mediator or amplifier of human action, often in physical
interaction with the surroundings. The differences between MR/AR systems
and desktop computer display based systems create a need for a different
approach to both development and evaluations of these systems. To
understand the potential of MR/AR systems in real world tasks the
technology must be tested in real world scenarios. This thesis describes
a theoretical basis for approaching the issue of usability evaluations
in MR/AR applications. It also includes results from two user studies
conducted in a hospital setting where professionals tested an MR/AR
system prototype.
No 1353
A MODEL AND IMPLEMENTATION OF A SECURITY PLUG-IN FOR THE SOFTWARE LIFE CYCLE
Shanai Shardi
Currently, security is frequently considered late in software life cycle. It is often bolted on late
in development, or even during deployment or maintenance, through activities such as add-on
security software and penetration-and-patch maintenance. Even if software developers aim to
incorporate security into their products from the beginning of the software life cycle, they face
an exhaustive amount of ad hoc unstructured information without any practical guidance on
how and why this information should be used and what the costs and benefits of using it are.
This is due to a lack of structured methods.
In this thesis we present a model for secure software development and implementation of a
security plug-in that deploys this model in software life cycle. The model is a structured
unified process, named S3P (Sustainable Software Security Process) and is designed to be
easily adaptable to any software development process. S3P provides the formalism required to
identify the causes of vulnerabilities and the mitigation techniques that address these causes to
prevent vulnerabilities. We present a prototype of the security plug-in implemented for the
OpenUP/Basic development process in Eclipse Process Framework. We also present the
results of the evaluation of this plug-in. The work in this thesis is a first step towards a general
framework for introducing security into the software life cycle and to support software
process improvements to prevent recurrence of software vulnerabilities.
No 1356
MOBILITY AND ROUTING IN A DEALY-TOLERANT NETWROK OF UNMANNED AERIAL VEHICLES
Erik Kuiper
Technology has reached a point where it has become feasible to develop unmanned aerial
vehicles (UAVs), that is aircraft without a human pilot on board. Given that future UAVs can
be autonomous and cheap, applications of swarming UAVs are possible. In this thesis we
have studied a reconnaissance application using swarming UAVs and how these UAVs can
communicate the reconnaissance data. To guide the UAVs in their reconnaissance mission we
have proposed a pheromone based mobility model that in a distributed manner guides the
UAVs to areas not recently visited. Each UAV has a local pheromone map that it updates
based on its reconnaissance scans. The information in the local map is regularly shared with a
UAV’s neighbors. Evaluations have shown that the pheromone logic is very good at guiding
the UAVs in their cooperative reconnaissance mission in a distributed manner.
Analyzing the connectivity of the UAVs we found that they were heavily partitioned which
meant that contemporaneous communication paths generally were not possible to establish.
This means that traditional mobile ad hoc network (MANET) routing protocols like AODV,
DSR and GPSR will generally fail. By using node mobility and the store-carry-forward
principle of delay-tolerant routing the transfer of messages between nodes is still possible. In
this thesis we propose location aware routing for delay-tolerant networks (LAROD). LAROD
is a beacon-less geographical routing protocol for intermittently connected mobile ad hoc
networks. Using static destinations we have shown by a comparative study that LAROD has
almost as good delivery rate as an epidemic routing scheme, but at a substantially lower
overhead.
No 1359
SITUATED PLAY
Jana Rambusch
This thesis addresses computer game play activities from the perspective of embodied and situated cognition. From such a perspective, game play can be divided into the physical handling of the game and the players' understanding of it. Game play can also be described in terms of three different levels of situatedness "high-level" situatedness, the contextual "here and now", and "low-level" situatedness. Moreover, theoretical and empirical implications of such a perspective have been explored more in detail in two case studies.
No 1361
COMPLETING THE PICTURE - FRAGMENTS AND BACK AGAIN
Martin Karresand
"Better methods and tools are needed in the fight against child
pornography. This thesis presents a method for file type
categorisation of unknown data fragments, a method for reassembly of
JPEG fragments, and the requirements put on an artificial JPEG header
for viewing reassembled images. To enable empirical evaluation of the
methods a number of tools based on the methods have been implemented.
The file type categorisation method identifies JPEG fragments with a
detection rate of 100% and a false positives rate of 0.1%. The
method uses three algorithms, Byte Frequency Distribution (BFD), Rate
of Change (RoC), and 2-grams. The algorithms are designed for
different situations, depending on the requirements at hand.
The reconnection method correctly reconnects 97% of a Restart (RST)
marker enabled JPEG image, fragmented into 4 KiB large pieces. When
dealing with fragments from several images at once, the method is able
to correctly connect 70% of the fragments at the first iteration.
Two parameters in a JPEG header are crucial to the quality of the
image; the size of the image and the sampling factor (actually
factors) of the image. The size can be found using brute force and
the sampling factors only take on three different values. Hence it is
possible to use an artificial JPEG header to view full of parts of an
image. The only requirement is that the fragments contain RST markers.
The results of the evaluations of the methods show that it is possible
to find, reassemble, and view JPEG image fragments with high
certainty."
No 1363
DYNAMIC ABSTRACTION FOR INTERLEAVED TASK PLANNING AND EXECUTION
Per Nyblom
It is often beneficial for an autonomous agent that operates in a complex environment to
make use of different types of mathematical models to keep track of unobservable parts
of the world or to perform prediction, planning and other types of reasoning. Since a
model is always a simplification of something else, there always exists a tradeoff between
the model’s accuracy and feasibility when it is used within a certain application due
to the limited available computational resources. Currently, this tradeoff is to a large
extent balanced by humans for model construction in general and for autonomous agents
in particular. This thesis investigates different solutions where such agents are more
responsible for balancing the tradeoff for models themselves in the context of interleaved
task planning and plan execution. The necessary components for an autonomous agent
that performs its abstractions and constructs planning models dynamically during task
planning and execution are investigated and a method called DARE is developed that is a
template for handling the possible situations that can occur such as the rise of unsuitable
abstractions and need for dynamic construction of abstraction levels. Implementations
of DARE are presented in two case studies where both a fully and partially observable
stochastic domain are used, motivated by research with Unmanned Aircraft Systems. The
case studies also demonstrate possible ways to perform dynamic abstraction and problem
model construction in practice.
No 1371
TERRAIN OBJECT RECOGNITION AND CONTEXT FUSION FOR DECISION SUPPORT
Fredrik Lantz
A laser radar can be used to generate three dimensional data about the terrain in a very high resolution. The development of new support technologies to analyze these data is critical to the effective and efficient use of these data in decision support systems, due to the large amounts of data that are generated. Adequate technology in this regard is currently not available and development of new methods and algorithms to this end are important goals of this work.
A semi-qualitative data structure for terrain surface modelling has been developed. A categorization and triangulation process has also been developed to substitute the high resolution 3D model for this semi-qualitative data structure. The qualitative part of the structure can also be used for detection and recognition of terrain features. The quantitative part of the structure is, together with the qualitative part, used for visualization of the terrain surface. Substituting the 3D model for the semi-qualitative structures means that a data reduction is performed.
A number of algorithms for detection and recognition of different terrain objects have been developed. The algorithms use the qualitative part of the previously developed semi-qualitative data structure as input. The taken approach is based on matching of symbols and syntactic pattern recognition. Results regarding the accuracy of the implemented algorithms for detection and recognition of terrain objects are visualized.
A further important goal has been to develop a methodology for determining driveability using 3D-data and other geographic data. These data must be fused with vehicle data to determine the driving properties of the terrain context of our operations. This fusion process is therefore called context fusion. The recognized terrain objects are used together with map data in this method. The uncertainty associated with the imprecision of data has been taken into account as well.
No 1373
ASSISTANCE PLUS: 3D-MEDIATED ADVICE-GIVING ON PHARMACEUTICAL PRODUCTS
Martin Östlund
In the use of medication and pharmaceutical products, non-compliance is a major problem. One thing we can do something about is making sure consumers have the information they need. This thesis investigates how remote communication technology can be used to improve the availability for expressive advice-giving services. Special attention is given to the balancing of expressiveness and availability. A solution is presented that uses 3D visualisation in combination with audio and video communication to convey advice on complex pharmaceutical products. The solution is tested and evaluated in two user studies. The first study is broad and explorative, the second more focused and evaluative. The solution was well received by participating subjects. They welcomed the sense of personal contact that seeing the communicating party over video link produced and appreciated the expressive power and pedagogical value of the 3D materials. Herbert Clark’s theory of use of language is suggested as a framework for the analysis of the dynamics of the relationship between consumer and advisor.
No 1381
AUTOMATIC PARALLELIZATION USING PIPELINING FOR EQUATION-BASED SIMULATION LANGUAGE
Håkan Lundvall
During the most recent decades modern equation-based object-oriented modeling and simulation languages, such as Modelica, have become available. This has made it easier to build complex and more detailed models for use in simulation. To be able to simulate such large and complex systems it is sometimes not enough to rely on the ability of a compiler to optimize the simulation code and reduce the size of the underlying set of equations to speed up the simulation on a single processor. Instead we must look for ways to utilize the increasing number of processing units available in modern computers. However to gain any increased performance from a parallel computer the simulation program must be expressed in a way that exposes the potential parallelism to the computer. Doing this manually is not a simple task and most modelers are not experts in parallel computing. Therefore it is very appealing to let the compiler parallelize the simulation code automatically. This thesis investigates techniques of using automatic translation of models in typical equation based languages, such as Modelica, into parallel simulation code that enable high utilization of available processors in a parallel computer. The two main ideas investigated here are the following: first, to apply parallelization simultaneously to both the system equations and the numerical solver, and secondly. to use software pipelining to further reduce the time processors are kept waiting for the results of other processors. Prototype implementations of the investigated techniques have been developed as a part of the OpenModelica open source compiler for Modelica. The prototype has been used to evaluate the parallelization techniques by measuring the execution time of test models on a few parallel archtectures and to compare the results to sequential code as well as to the results achieved in earlier work. A measured speedup of 6.1 on eight processors on a shared memory machine has been reached. It still remains to evaluate the methods for a wider range of test models and parallel architectures.
No 1386
USING OBSERVERS FOR MODEL BASED DATA COLLECTION IN DISTRIBUTED TACTICAL OPERATIONS
Mirko Thorsensson
Modern information technology increases the use of computers in training systems as well as in command-and-control systems in military services and public-safety organizations. This computerization combined with new threats present a challenging complexity. Situational awareness in evolving distributed operations and follow-up in training systems depends on humans in the field reporting observations of events. The use of this observer-reported information can be largely improved by implementation of models supporting both reporting and computer representation of objects and phenomena in operations.
This thesis characterises and describes observer model-based data collection in distributed tactical operations, where multiple, dispersed units work to achieve common goals. Reconstruction and exploration of multimedia representations of operations is becoming an established means for supporting taskforce training. We explore how modelling of operational processes and entities can support observer data collection and increase information content in mission histories. We use realistic exercises for testing developed models, methods and tools for observer data collection and transfer results to live operations.
The main contribution of this thesis is the systematic description of the model-based approach to using observers for data collection. Methodological aspects in using humans to collect data to be used in information systems, and also modelling aspects for phenomena occurring in emergency response and communication areas contribute to the body of research. We describe a general methodology for using human observers to collect adequate data for use in information systems. In addition, we describe methods and tools to collect data on the chain of medical attendance in emergency response exercises, and on command-and-control processes in several domains.
No 1387
IMPLEMENTATION OF HEALTH INFORMATION SYSTEMS
Bahlol Rahimi
Healthcare organizations now consider increased efficiency, reduced costs, improved patient care and quality of services, and safety when they are planning to implement new information and communication technology (ICT) based applications. However, in spite of enormous investment in health information systems (HIS), no convincing evidence of the overall benefits of HISs yet exists. The publishing of studies that capture the effects of the implementation and use of ICT-based applications in healthcare may contribute to the emergence of an evidence-based health informatics which can be used as a platform for decisions made by policy makers, executives, and clinicians. Health informatics needs further studies identifying the factors affecting successful HIS implementation and capturing the effects of HIS implementation. The purpose of the work presented in this thesis is to increase the available knowledge about the impact of the implementation and use of HISs in healthcare organizations. All the studies included in this thesis used qualitative research methods. A case study design and literature review were performed to collect data.
This thesis’s results highlight an increasing need to share knowledge, find methods to evaluate the impact of investments, and formulate indicators for success. It makes suggestions for developing or extending evaluation methods that can be applied to this area with a multi-actor perspective in order to understand the effects, consequences, and prerequisites that have to be achieved for the successful implementation and use of IT in healthcare. The results also propose that HIS, particularly integrated computer-based patient records (ICPR), be introduced to fulfill a high number of organizational, individualbased, and socio-technical goals at different levels. It is therefore necessary to link the goals that HIS systems are to fulfill in relation to short-term, middle-term, and long-term strategic goals. Another suggestion is that implementers and vendors should direct more attention to what has been published in the area to avoid future failures.
This thesis’s findings outline an updated structure for implementation planning. When implementing HISs in hospital and primary-care environments, this thesis suggests that such strategic actions as management involvement and resource allocation, such tactical action as integrating HIS with healthcare workflow, and such operational actions as user involvement, establishing compatibility between software and hardware, and education and training should be taken into consideration.
No 1392
WORD ALIGNMENT BY RE-USING PARALLEL PHRASES
Maria Holmqvist
In this thesis we present the idea of using parallel phrases for word alignment. Each parallel phrase is extracted from a set of manual word alignments and contains a number of source and target words and their corresponding alignments. If a parallel phrase matches a new sentence pair, its word alignments can be applied to the new sentence. There are several advantages of using phrases for word alignment. First, longer text segments include more context and will be more likely to produce correct word alignments than shorter segments or single words. More importantly, the use of longer phrases makesit possible to generalize words in the phrase by replacing words by parts-of-speech or other grammatical information. In this way, the number of words covered by the extracted phrases can go beyond the words and phrases that were present in the original set of manually aligned sentences. We present experiments with phrase-based word alignment on three types of English–Swedish parallel corpora: a software manual, a novel and proceedings of the European Parliament. In order to find a balance between improved coverage and high alignment accuracy we investigated different properties of generalised phrases to identify which types of phrases are likely to produce accurate alignments on new data. Finally, we have compared phrase-based word alignments to state-of-the-art statistical alignment with encouraging results. We show that phrase-based word alignments can be used to enhance statistical word alignment. To evaluate word alignments an English–Swedish reference set for the Europarl corpus was constructed. The guidelines for producing this reference alignment are presented in the thesis
No 1393
INTEGRATED SOFTWARE PIPELINING
Mattias Eriksson
In this thesis we address the problem of integrated software pipelining for clustered VLIW architectures. The phases that are integrated and solved as one combined problem are: cluster assignment, instruction selection, scheduling, register allocation and spilling.
As a first step we describe two methods for integrated code generation of basic blocks. The first method is optimal and based on integer linear programming. The second method is a heuristic based on genetic algorithms.
We then extend the integer linear programming model to modulo scheduling. To the best of our knowledge this is the first time anybody has optimally solved the modulo scheduling problem for clustered architectures with instruction selection and cluster assignment integrated.
We also show that optimal spilling is closely related to optimal register allocation when the register files are clustered. In fact, optimal spilling is as simple as adding an additional virtual register file representing the memory and have transfer instructions to and from this register file corresponding to stores and loads.
Our algorithm for modulo scheduling iteratively considers schedules with increasing number of schedule slots. A problem with such an iterative method is that if the initiation interval is not equal to the lower bound there is no way to determine whether the found solution is optimal or not. We have proven that for a class of architectures that we call transfer free, we can set an upper bound on the schedule length. I.e., we can prove when a found modulo schedule with initiation interval larger than the lower bound is optimal.
Experiments have been conducted to show the usefulness and limitations of our optimal methods. For the basic block case we compare the optimal method to the heuristic based on genetic algorithms.
No 1401
TOWARDS AN ONTOLOGY DEVELOPMENT METHODOLOGY FOR SMALL AND MEDIUMSIZED ENTERPRISES
Annika Öhgren
This thesis contributes to the research field information logistics. Information logistics aims at improving information flow and at reducing information overload by providing the right information, in the right context, at the right time, at the right place through the right channel.
Ontologies are expected to contribute to reduced information overload and solving information supply problems. An ontology is created to form some kind of shared understanding for the involved stakeholders in the domain at hand. By using this semantic structure you can further build applications that use the ontology and support the employee by providing only the most important information for this person.
During the last years, there has been an increasing number of successful cases in which industrial applications successfully use ontologies. Most of these cases however, stem from large enterprises or IT-intensive small or medium-sized enterprises (SME). The current ontology development methodologies are not tailored for SME and their specific demands and preferences, such as that SME prefer mature technologies, and show a clear preference for to a large extent standardised solutions. The author proposes a new ontology development methodology, taking the specific characteristics of SME into consideration. This methodology was tested in an application case, which resulted in a number of concrete improvement ideas, but also the conclusion that further specialisation of the methodology was needed, for example for a specific usage area or domain. In order to find out in which direction to specify the methodology a survey was performed among SME in the region of Jönköping.
The main conclusion from the survey is that ontologies can be expected to be useful for SME mainly in the area of product configuration and variability modelling. Another area of interest is document management for supporting project work. The area of information search and retrieval can also be seen as a possible application field, as many of the respondents of the survey spend much time finding and saving information.
No 1410
DEADLOCK FREE ROUTING IN MESH NETWORKS ON CHIP WITH REGIONS
Rickard Holsmark
There is a seemingly endless miniaturization of electronic components, which has enabled designers to build sophisticated computing structureson silicon chips. Consequently, electronic systems are continuously improving with new and more advanced functionalities. Design complexity ofthese Systems on Chip (SoC) is reduced by the use of pre-designed cores. However, several problems related to the interconnection of coresremain. Network on Chip (NoC) is a new SoC design paradigm, which targets the interconnect problems using classical network concepts. Still,SoC cores show large variance in size and functionality, whereas several NoC benefits relate to regularity and homogeneity.
This thesis studies some network aspects which are characteristic to NoC systems. One is the issue of area wastage in NoC due to cores of varioussizes. We elaborate on using oversized regions in regular mesh NoC and identify several new design possibilities. Adverse effects of regions oncommunication are outlined and evaluated by simulation.
Deadlock freedom is an important region issue, since it affects both the usability and performance of routing algorithms. The concept of faultyblocks, used in deadlock free fault-tolerant routing algorithms has similarities with rectangular regions. We have improved and adopted one suchalgorithm to provide deadlock free routing in NoC with regions. This work also offers a methodology for designing topology agnostic, deadlockfree, highly adaptive application specific routing algorithms. The methodology exploits information about communication among tasks of anapplication. This is used in the analysis of deadlock freedom, such that fewer deadlock preventing routing restrictions are required.
A comparative study of the two proposed routing algorithms shows that the application specific algorithm gives significantly higher performance.But, the fault-tolerant algorithm may be preferred for systems requiring support for general communication. Several extensions to our work areproposed, for example in areas such as core mapping and efficient routing algorithms. The region concept can be extended for supporting reuse ofa pre-designed NoC as a component in a larger hierarchical NoC.
No 1421
Compound Processing for Phrase-Based Statistical Machine Translation
Sara Stymne
In this thesis I explore how compound processing can be used to improve phrase-based statistical machine translation (PBSMT) between English and German/Swedish. Both German and Swedish generally use closed compounds, which are written as one word without spaces or other indicators of word boundaries. Compounding is both common and productive, which makes it problematic for PBSMT, mainly due to sparse data problems.
The adopted strategy for compound processing is to split compounds into their component parts before training and translation. For translation into Swedish and German the parts are merged after translation. I investigate the effect of different splitting algorithms for translation between English and German, and of different merging algorithms for German. I also apply these methods to a different language pair, English--Swedish. Overall the studies show that compound processing is useful, especially for translation from English into German or Swedish. But there are improvements for translation into English as well, such as a reduction of unknown words.
I show that for translation between English and German different splitting algorithms work best for different translation directions. I also design and evaluate a novel merging algorithm based on part-of-speech matching, which outperforms previous methods for compound merging, showing the need for information that is carried through the translation process, rather than only external knowledge sources such as word lists. Most of the methods for compound processing were originally developed for German. I show that these methods can be applied to Swedish as well, with similar results.
No 1427
Scientific collaboration, workflow, provenance, search engine, query language, data integration
Tommy Ellqvist
Science is changing. Computers, fast communication, and new technologies have created new ways of conducting research. For instance, researchers from different disciplines are processing and analyzing scientific data that is increasing at an exponential rate. This kind of research requires that the scientists have access to tools that can handle huge amounts of data, enable access to vast computational resources, and support the collaboration of large teams of scientists. This thesis focuses on tools that help support scientific collaboration.
Workflows and provenance are two concepts that have proven useful in supporting scientific collaboration. Workflows provide a formal specification of scientific experiments, and provenance offers a model for documenting data and process dependencies. Together, they enable the creation of tools that can support collaboration through the whole scientific life-cycle, from specification of experiments to validation of results. However, existing models for workflows and provenance are often specific to particular tasks and tools. This makes it hard to analyze the history of data that has been generated over several application areas by different tools. Moreover, workflow design is a time-consuming process and often requires extensive knowledge of the tools involved and collaboration with researchers with different expertise. This thesis addresses these problems.
Our first contribution is a study of the differences between two approaches to interoperability between provenance models: direct data conversion, and mediation. We perform a case study where we integrate three different provenance models using the mediation approach, and show the advantages compared to data conversion. Our second contribution serves to support workflow design by allowing multiple users to concurrently design workflows. Current workflow tools lack the ability for users to work simultaneously on the same workflow. We propose a method that uses the provenance of workflow evolution to enable real-time collaborative design of workflows. Our third contribution considers supporting workflow design by reusing existing workflows. Workflow collections for reuse are available, but more efficient methods for generating summaries of search results are still needed. We explore new summarization strategies that considers the workflow structure.
No 1450
Visualisations in Service Design
Fabian Segelström
Service design is a relatively new field which has its roots in the design field, but utilises knowledge from other disciplines focusing on services as well. The service design field can be described as a maturing field. However, much which is considered knowledge in the field is still based on anecdotes rather than research. One such area is visualisations of insights gained throughout the service design process. The goal of this thesis is to provide a scientific base for discussions on visualisations by describing the current use of visualisations and exploring what visualisations communicate. This is done through two different studies.
The first study consists of a series of interviews with practicing service designers. The results show that all interviewees visualise their insights gained throughout the service design process. Further analysis found that there are three main lines of arguments used by the interviewees in regard to why they visualise; as a tool to find insights in the material, to keep empathy with users of the service and to communicate the insights to outside stakeholders.
The second study analysed six visualisation types from actual service design projects by service design consultancies. Four different frameworks were used to analyse what visualisations did, and did not, communicate. Two of the frameworks were based on research in service design; the three reasons to visualise as stated in the interviews in study 1 and a framework for service design visualisations. The two frameworks were adapted from other service disciplines; what differentiates services from goods (the IHIP-framework), and a framework focusing on service as the base for all transactions (Service Dominant Logic). It is found that the visualisation types in general are strong in communicating the design aspects of services, but that they have problems in representing all aspects of service as identified in the service literature.
The thesis provides an academic basis on the use of visualisations in service design. It is concluded that it seems like the service design community currently sees services as being not-goods, a line of thought other service disciplines have discarded the last ten years and replaced with a view of services as the basis for all transactions. The analysis highlights areas where there is a need to improve the visualisations to more accurately represent services.
No 1459
System-Level Techniques for Temperature-Aware Energy Optimization
Min Bao
Energy consumption has become one of the main design constraints in today’s integrated circuits. Techniques for energy optimization, from circuit-level up to system-level, have been intensively researched.
The advent of large-scale integration with deep sub-micron technologies has led to both high power densities and high chip working temperatures. At the same time, leakage power is becoming the dominant power consumption source of circuits, due to continuously lowered threshold voltages, as technology scales. In this context, temperature is an important parameter. One aspect, of particular interest for this thesis, is the strong inter-dependency between leakage and temperature. Apart from leakage power, temperature also has an important impact on circuit delay and, implicitly, on the frequency, mainly through its influence on carrier mobility and threshold voltage. For power-aware design techniques, temperature has become a major factor to be considered. In this thesis, we address the issue of system-level energy optimization for real-time embedded systems taking temperature aspects into consideration.
We have investigated two problems in this thesis: (1) Energy optimization via temperature-aware dynamic voltage/frequency scaling (DVFS). (2) Energy optimization through temperature-aware idle time (or slack) distribution (ITD). For the above two problems, we have proposed off-line techniques where only static slack is considered. To further improve energy efficiency, we have also proposed online techniques, which make use of both static and dynamic slack. Experimental results have demonstrated that considerable improvement of the energy efficiency can be achieved by applying our temperature-aware optimization techniques. Another contribution of this thesis is an analytical temperature analysis approach which is both accurate and sufficiently fast to be used inside an energy optimization loop.
No 1466
Exploring Biologically Inspired Interactive Networks for Object Recognition
Mohammad Saifullah
This thesis deals with biologically-inspired interactive neural networks for the task of object recognition. Such networks offer an interesting alternative approach to traditional image processing techniques. Although the networks are very powerful classification tools, they are difficult to handle due to their bidirectional interactivity. It is one of the main reasons why these networks do not perform the task of generalization to novel objects well. Generalization is a very important property for any object recognition system, as it is impractical for a system to learn all instances of an object class before classifying. In this thesis, we have investigated the working of an interactive neural network by fine tuning different structural and algorithmic parameters. The performance of the networks was evaluated by analyzing the generalization ability of the trained network to novel objects. Furthermore, the interactivity of the network was utilized to simulate focus of attention during object classification. Selective attention is an important visual mechanism for object recognition and provides an efficient way of using the limited computational resources of the human visual system. Unlike most previous work in the field of image processing, in this thesis attention is considered as an integral part of object processing. Attention focus, in this work, is computed within the same network and in parallel with object recognition.
As a first step, a study into the efficacy of Hebbian learning as a feature extraction method was conducted. In a second study, the receptive field size in the network, which controls the size of the extracted features as well as the number of layers in the network, was varied and analyzed to find its effect on generalization. In a continuation study, a comparison was made between learnt (Hebbian learning) and hard coded feature detectors. In the last study, attention focus was computed using interaction between bottom-up and top-down activation flow with the aim to handle multiple objects in the visual scene. On the basis of the results and analysis of our simulations we have found that the generalization performance of the bidirectional hierarchical network improves with the addition of a small amount of Hebbian learning to an otherwise error-driven learning. We also conclude that the optimal size of the receptive fields in our network depends on the object of interest in the image. Moreover, each receptive field must contain some part of the object in the input image. We have also found that networks using hard coded feature extraction perform better than the networks that use Hebbian learning for developing feature detectors. In the last study, we have successfully demonstrated the emergence of visual attention within an interactive network that handles more than one object in the input field. Our simulations demonstrate how bidirectional interactivity directs attention focus towards the required object by using both bottom-up and top-down effects.
In general, the findings of this thesis will increase understanding about the working of biologically-inspired interactive networks. Specifically, the studied effects of the structural and algorithmic parameters that are critical for the generalization property will help develop these and similar networks and lead to improved performance on object recognition tasks. The results from the attention simulations can be used to increase the ability of networks to deal with multiple objects in an efficient and effective manner.
No 1468
Dealing with Missing Mappings and Structure in a Network of Ontologies
Qiang Liu
With the popularity of the World Wide Web, a large amount of data is generated and made available through the Internet everyday. To integrate and query this huge amount of heterogeneous data, the vision of Semantic Web has been recognized as a possible solution. One key technology for the Semantic Web is ontologies. Many ontologies have been developed in recent years. Meanwhile, due to the demand of applications using multiple ontologies, mappings between entities of these ontologies are generated as well, which leads to the generation of ontology networks consisting of ontologies and mappings between these ontologies. However, neither developing ontologies nor finding mappings between ontologies is an easy task. It may happen that the ontologies are not consistent or complete, or the mappings between these ontologies are not correct or complete, or the resulting ontology network is not consistent. This may lead to problems when they are used in semantically-enabled applications.
In this thesis, we address two issues relevant to the quality of the mappings and the structure in the ontology network. The first issue deals with the missing mappings between networked ontologies. Assuming existing mappings between ontologies are correct, we investigate whether and how to use these existing mappings, to find more mappings between ontologies. We propose and test several strategies of using the given correct mappings to align ontologies. The second issue deals with the missing structure, in particular missing is-a relations, in networked ontologies. Based on the assumption that missing is-a relations are a kind of modeling defects, we propose an ontology debugging approach to tackle this issue. We develop an algorithm for detecting missing is-a relations in ontologies, as well as algorithms which assist the user in repairing by generating and recommending possible ways of repairing and executing the repairing. Based on this approach, we develop a system and test its use and performance.
No 1469
Mapping Concurrent Applications to Multiprocessor Systems with Multithreaded Processors and Network on Chip-Based Interconnections
Ruxandra Pop
Network on Chip (NoC) architectures provide scalable platforms for designing Systems on Chip (SoC) with large number of cores. Developing products and applications using an NoC architecture offers many challenges and opportunities. A tool which can map an application or a set of applications to a given NoC architecture will be essential.
In this thesis we first survey current techniques and we present our proposals for mapping and scheduling of concurrent applications to NoCs with multithreaded processors as computational resources.
NoC platforms are basically a special class of Multiprocessor Embedded Systems (MPES). Conventional MPES architectures are mostly bus-based and, thus, are exposed to potential difficulties regarding scalability and reusability. There has been a lot of research on MPES development including work on mapping and scheduling of applications. Many of these results can also be applied to NoC platforms.
Mapping and scheduling are known to be computationally hard problems. A large range of exact and approximate optimization algorithms have been proposed for solving these problems. The methods include Branch-and–Bound (BB), constructive and transformative heuristics such as List Scheduling (LS), Genetic Algorithms (GA) and various types of Mathematical Programming algorithms.
Concurrent applications are able to capture a typical embedded system which is multifunctional. Concurrent applications can be executed on an NoC which provides a large computational power with multiple on-chip computational resources.
Improving the time performances of concurrent applications which are running on Network on Chip (NoC) architectures is mainly correlated with the ability of mapping and scheduling methodologies to exploit the Thread Level Parallelism (TLP) of concurrent applications through the available NoC parallelism. Matching the architectural parallelism to the application concurrency for obtaining good performance-cost tradeoffs is another aspect of the problem.
Multithreading is a technique for hiding long latencies of memory accesses, through the overlapped execution of several threads. Recently, Multi-Threaded Processors (MTPs) have been designed providing the architectural infrastructure to concurrently execute multiple threads at hardware level which, usually, results in a very low context switching overhead. Simultaneous Multi-Threaded Processors (SMTPs) are superscalar processor architectures which adaptively exploit the coarse grain and the fine grain parallelism of applications, by simultaneously executing instructions from several thread contexts.
In this thesis we make a case for using SMTPs and MTPs as NoC resources and show that such a multiprocessor architecture provides better time performances than an NoC with solely General-purpose Processors (GP). We have developed a methodology for task mapping and scheduling to an NoC with mixed SMTP, MTP and GP resources, which aims to maximize the time performance of concurrent applications and to satisfy their soft deadlines. The developed methodology was evaluated on many configurations of NoC-based platforms with SMTP, MTP and GP resources. The experimental results demonstrate that the use of SMTPs and MTPs in NoC platforms can significantly speed-up applications.
No 1476
Positioning Algorithms for Surveillance Using Unmanned Aerial Vehicles
Per-Magnus Olsson
Surveillance is an important application for unmanned aerial vehicles (UAVs). The sensed information often has high priority and it must be made available to human operators as quickly as possible. Due to obstacles and limited communication range, it is not always possible to transmit the information directly to the base station. In this case, other UAVs can form a relay chain between the surveillance UAV and the base station. Determining suitable positions for such UAVs is a complex optimization problem in and of itself, and is made even more difficult by communication and surveillance constraints.
To solve different variations of finding positions for UAVs for surveillance of one target, two new algorithms have been developed. One of the algorithms is developed especially for finding a set of relay chains offering different trade-offs between the number of UAVsand the quality of the chain. The other algorithm is tailored towards finding the highest quality chain possible, given a limited number of available UAVs.
Finding the optimal positions for surveillance of several targets is more difficult. A study has been performed, in order to determine how the problems of interest can besolved. It turns out that very few of the existing algorithms can be used due to the characteristics of our specific problem. For this reason, an algorithm for quickly calculating positions for surveillance of multiple targets has been developed. This enables calculation of an initial chain that is immediately made available to the user, and the chain is then incrementally optimized according to the user’s desire.
No 1481
Contributions to Web Authentication for Untrusted Computers
Anna Vapen
Authentication methods offer varying levels of security. Methods with one-time credentials generated by dedicated hardware tokens can reach a high level of security, whereas password-based authentication methods have a low level of security since passwords can be eavesdropped and stolen by an attacker. Password-based methods are dominant in web authentication since they are both easy to implement and easy to use. Dedicated hardware, on the other hand, is not always available to the user, usually requires additional equipment and may be more complex to use than password-based authentication.
Different services and applications on the web have different requirements for the security of authentication. Therefore, it is necessary for designers of authentication solutions to address this need for a range of security levels. Another concern is mobile users authenticating from unknown, and therefore untrusted, computers. This in turn raises issues of availability, since users need secure authentication to be available, regardless of where they authenticate or which computer they use.
We propose a method for evaluation and design of web authentication solutions that takes into account a number of often overlooked design factors, i.e. availability, usability and economic aspects. Our proposed method uses the concept of security levels from the Electronic Authentication Guideline, provided by NIST.
We focus on the use of handheld devices, especially mobile phones, as a flexible, multi-purpose (i.e. non-dedicated) hardware device for web authentication. Mobile phones offer unique advantages for secure authentication, as they are small, flexible and portable, and provide multiple data transfer channels. Phone designs, however, vary and the choice of channels and authentication methods will influence the security level of authentication. It is not trivial to maintain a consistent overview of the strengths and weaknesses of the available alternatives. Our evaluation and design method provides this overview and can help developers and users to compare and choose authentication solutions.
No 1485
Sustainable Interactions: Studies in the Design of Energy Awareness Artefacts
Loove Broms
This thesis presents a collection of experimental designs that approach the problem of growing electricity consumption in homes. From the perspective of design, the intention has been to critically explore the design space of energy awareness artefacts to reinstate awareness of energy use in everyday practice. The design experiments were used as vehicles for thinking about the relationship between physical form, interaction, and social practice. The rationale behind the concepts was based on a small-scale ethnography, situated interviews, and design experience. Moreover, the thesis compares designer intention and actual user experiences of a prototype that was installed in nine homes in a residential area in Stockholm for three months. This was done in order to elicit tacit knowledge about how the concept was used in real-world domestic settings, to challenge everyday routines, and to enable both users and designers to critically reflect on artefacts and practices.
From a design perspective, contributions include design approaches to communicating energy use: visualizations for showing relationships between behaviour and electricity consumption, shapes and forms to direct action, means for turning restrictions caused by energy conservation into central parts of the product experience, and ways to promote sustainable behaviour with positive driving forces based on user lifestyles.
The general results indicate that inclusion is of great importance when designing energy awareness artefacts; all members of the household should be able to access, interact with, and reflect on their energy use. Therefore, design-related aspects such as placement and visibility, as well as how the artefact might affect the social interactions in the home, become central. Additionally, the thesis argues that these types of artefacts can potentially create awareness accompanied by negative results such as stress. A challenge for the designer is to create artefacts that communicate and direct energy use in ways that are attractive and can be accepted by all household members as a possible way of life
FiF-a 101
Conceptualising Prototypes in Service Design
Johan Blomkvist
To date, service prototyping has been discussed academically as an unproblematic add-on to existing prototyping techniques, or as methods for prototyping social interaction. In fact, most of the knowledge on how services are prototyped comes from organisations and practicing design consultants. Some attempts to define service prototyping have been made but generally without concern about how complete service experiences should or could be represented. Building on existing knowledge about prototyping, a draft of a service prototyping conceptualisation is generated. Based on the draft, the question of how to prototype holistic service experiences is raised and in total, 5 studies have been conducted that contribute knowledge to that overarching question. In addition, each study has its own research question. Study 1 conceptualises prototypes and prototyping in a framework while study 2 and 3 looks at what practicing service designers say they do to prototype services and how they involve different stakeholders in the process. Study 4 examines aspects of design communication and how service experiences are communicated and used during design meetings, and study 5 finally, attempts to generate a process that can be used to evaluate the impact of location oriented service prototypes in e.g. healthcare settings. A number of challenges for service prototyping are identified in the studies, along with the issue of who authors prototypes. The conceptualisation of prototyping is adjusted based on the studies and a framework is constructed that support the conceptualisation. Little evidence for holistic approaches to prototyping services is found in the interviews and service designers involve their clients primarily when prototyping. Service experiences are introduced in communication using a format termed micro-narratives. This format and the purpose of using references to previous experiences are discussed. The thesis is concluded with a suggestion of a process for service prototyping. This process is specific for service design and attempts to support service designers in making holistic service representations when prototyping. Service prototyping requires further research.
No 1490
Computer-Assisted Troubleshooting for Efficient Off-board Diagnosis
Håkan Warnquist
This licentiate thesis considers computer-assisted troubleshooting of complex products such as heavy trucks. The troubleshooting task is to find and repair all faulty components in a malfunctioning system. This is done by performing actions to gather more information regarding which faults there can be or to repair components that are suspected to be faulty. The expected cost of the performed actions should be as low as possible.
The work described in this thesis contributes to solving the troubleshooting task in such a way that a good trade-off between computation time and solution quality can be made. A framework for troubleshooting is developed where the system is diagnosed using non-stationary dynamic Bayesian networks and the decisions of which actions to perform are made using a new planning algorithm for Stochastic Shortest Path Problems called Iterative Bounding LAO*.
It is shown how the troubleshooting problem can be converted into a Stochastic Shortest Path problem so that it can be efficiently solved using general algorithms such as Iterative Bounding LAO*. New and improved search heuristics for solving the troubleshooting problem by searching are also presented in this thesis.
The methods presented in this thesis are evaluated in a case study of an auxiliary hydraulic braking system of a modern truck. The evaluation shows that the new algorithm Iterative Bounding LAO* creates troubleshooting plans with a lower expected cost faster than existing state-of-the-art algorithms in the literature. The case study shows that the troubleshooting framework can be applied to systems from the heavy vehicles domain.
No 1503
Predictable Real-Time Applications on Multiprocessor Systems-on-Chip
Jakob Rosén
Being predictable with respect to time is, by definition, a fundamental requirement for any real-time system. Modern multiprocessor systems impose a challenge in this context, due to resource sharing conflicts causing memory transfers to become unpredictable. In this thesis, we present a framework for achieving predictability for real-time applications running on multiprocessor system-on-chip platforms. Using a TDMA bus, worst-case execution time analysis and scheduling are done simultaneously. Since the worst-case execution times are directly dependent on the bus schedule, bus access design is of special importance. Therefore, we provide an efficient algorithm for generating bus schedules, resulting in a minimized worst-case global delay.
We also present a new approach considering the average-case execution time in a predictable context. Optimization techniques for improving the average-case execution time of tasks, for which predictability with respect to time is not required, have been investigated for a long time in many different contexts. However, this has traditionally been done without paying attention to the worst-case execution time. For predictable real-time applications, on the other hand, the focus has been solely on worst-case execution time optimization, ignoring how this affects the execution time in the average case. In this thesis, we show that having a good average-case global delay can be important also for real-time applications, for which predictability is required. Furthermore, for real-time applications running on multiprocessor systems-on-chip, we present a technique for optimizing for the average case and the worst case simultaneously, allowing for a good average case execution time while still keeping the worst case as small as possible. The proposed solutions in this thesis have been validated by extensive experiments. The results demonstrate the efficiency and importance of the presented techniques.
No 1504
Skeleton Programming for Heterogeneous GPU-based Systems
Usman Datsgeer
In this thesis, we address issues associated with programming modern heterogeneous systems while focusing on a special kind of heterogeneous systems that include multicore CPUs and one or more GPUs, called GPU-based systems.We consider the skeleton programming approach to achieve high level abstraction for efficient and portable programming of these GPU-based systemsand present our work on SkePU library which is a skeleton library for these systems.
We extend the existing SkePU library with a two-dimensional (2D) data type and skeleton operations and implement several new applications using newly made skeletons. Furthermore, we consider the algorithmic choice present in SkePU and implement support to specify and automatically optimize the algorithmic choice for a skeleton call, on a given platform.
To show how to achieve performance, we provide a case-study on optimized GPU-based skeleton implementation for 2D stencil computations and introduce two metrics to maximize resource utilization on a GPU. By devising a mechanism to automatically calculate these two metrics, performance can be retained while porting an application from one GPU architecture to another.
Another contribution of this thesis is implementation of the runtime support for the SkePU skeleton library. This is achieved with the help of the StarPUruntime system. By this implementation,support for dynamic scheduling and load balancing for the SkePU skeleton programs is achieved. Furthermore, a capability to do hybrid executionby parallel execution on all available CPUs and GPUs in a system, even for a single skeleton invocation, is developed.
SkePU initially supported only data-parallel skeletons. The first task-parallel skeleton (farm) in SkePU is implemented with support for performance-aware scheduling and hierarchical parallel execution by enabling all data parallel skeletons to be usable as tasks inside the farm construct.
Experimental evaluations are carried out and presented for algorithmic selection, performance portability, dynamic scheduling and hybrid execution aspects of our work.
No 1506
Complex Task Allocation for Delegation: From Theory to Practice
David Landén
The problem of determining who should do what given a set of tasks and a set of agents is called the task allocation problem. The problem occurs in many multi-agent system applications where a workload of tasks should be shared by a number of agents. In our case, the task allocation problem occurs as an integral part of a larger problem of determining if a task can be delegated from one agent to another.
Delegation is the act of handing over the responsibility for something to someone. Previously, a theory for delegation including a delegation speech act has been specified. The speech act specifies the preconditions that must be fulfilled before the delegation can be carried out, and the postconditions that will be true afterward. To actually use the speech act in a multi-agent system, there must be a practical way of determining if the preconditions are true. This can be done by a process that includes solving a complex task allocation problem by the agents involved in the delegation.
In this thesis a constraint-based task specification formalism, a complex task allocation algorithm for allocating tasks to unmanned aerial vehicles and a generic collaborative system shell for robotic systems are developed. The three components are used as the basis for a collaborative unmanned aircraft system that uses delegation for distributing and coordinating the agents' execution of complex tasks.
No 1507
Contributions to Parallel Simulation of Equation-Based Models on Graphics Processing Units
Kristian Stavåker
In this thesis we investigate techniques and methods for parallel simulation of equation-based, object-oriented (EOO) Modelica models on graphics processing units (GPUs). Modelica is being developed through an international effort via the Modelica Association. With Modelica it is possible to build computationally heavy models; simulating such models however might take a considerable amount of time. Therefor techniques of utilizing parallel multi-core architectures for simulation are desirable. The goal in this work is mainly automatic parallelization of equation-based models, that is, it is up to the compiler and not the end-user modeler to make sure that code is generated that can efficiently utilize parallel multi-core architectures. Not only the code generation process has to be altered but the accompanying run-time system has to be modified as well. Adding explicit parallel language constructs to Modelica is also discussed to some extent. GPUs can be used to do general purpose scientific and engineering computing. The theoretical processing power of GPUs has surpassed that of CPUs due to the highly parallel structure of GPUs. GPUs are, however, only good at solving certain problems of data-parallel nature. In this thesis we relate several contributions, by the author and co-workers, to each other. We conclude that the massively parallel GPU architectures are currently only suitable for a limited set of Modelica models. This might change with future GPU generations. CUDA for instance, the main software platform used in the thesis for general purpose computing on graphics processing units (GPGPU), is changing rapidly and more features are being added such as recursion, function pointers, C++ templates, etc.; however the underlying hardware architecture is still optimized for data-parallelism.
1509
Selected Aspects of Navigation and Path Planning in Unmanned Aircraft Systems
Mariusz Wzorek
Unmanned aircraft systems (UASs) are an important future technology with early generations already being used in many areas of application encompassing both military and civilian domains. This thesis proposes a number of integration techniques for combining control-based navigation with more abstract path planning functionality for UASs. These techniques are empirically tested and validated using an RMAX helicopter platform used in the UASTechLab at Linköping University. Although the thesis focuses on helicopter platforms, the techniques are generic in nature and can be used in other robotic systems.
At the control level a navigation task is executed by a set of control modes. A framework based on the abstraction of hierarchical concurrent state machines for the design and development of hybrid control systems is presented. The framework is used to specify reactive behaviors and for sequentialisation of control modes. Selected examples of control systems deployed on UASs are presented. Collision-free paths executed at the control level are generated by path planning algorithms.We propose a path replanning framework extending the existing path planners to allow dynamic repair of flight paths when new obstacles or no-fly zones obstructing the current flight path are detected. Additionally, a novel approach to selecting the best path repair strategy based on machine learning technique is presented. A prerequisite for a safe navigation in a real-world environment is an accurate geometrical model. As a step towards building accurate 3D models onboard UASs initial work on the integration of a laser range finder with a helicopter platform is also presented.
Combination of the techniques presented provides another step towards building comprehensive and robust navigation systems for future UASs.
1510
Increasing Autonomy of Unmanned Aircraft Systems Through the Use of Imaging Sensors
Piotr Rudol
The range of missions performed by Unmanned Aircraft Systems (UAS) has been steadily growing in the past decades thanks to continued development in several disciplines. The goal of increasing the autonomy of UAS's is widening the range of tasks which can be carried out without, or with minimal, external help. This thesis presents methods for increasing specific aspects of autonomy of UAS's operating both in outdoor and indoor environments where cameras are used as the primary sensors.
First, a method for fusing color and thermal images for object detection, geolocation and tracking for UAS's operating primarily outdoors is presented. Specifically, a method for building saliency maps where human body locations are marked as points of interest is described. Such maps can be used in emergency situations to increase the situational awareness of first responders or a robotic system itself. Additionally, the same method is applied to the problem of vehicle tracking. A generated stream of geographical locations of tracked vehicles increases situational awareness by allowing for qualitative reasoning about, for example, vehicles overtaking, entering or leaving crossings.
Second, two approaches to the UAS indoor localization problem in the absence of GPS-based positioning are presented. Both use cameras as the main sensors and enable autonomous indoor ight and navigation. The first approach takes advantage of cooperation with a ground robot to provide a UAS with its localization information. The second approach uses marker-based visual pose estimation where all computations are done onboard a small-scale aircraft which additionally increases its autonomy by not relying on external computational power.
1513
The Evolution of the Connector View Concept: Enterprise Models for Interoperability Solutions in the Extended Enterprise
Anders Carstensen
People around the world who are working in companies and organisations need to collaborate, and in their collaboration use information managed by different information systems. The requirements of information systems to be interoperable are therefore apparant. While the technical problems, of communicating or sharing information between different information systems, have become less difficult to solve, the attention has turned to other aspects of interoperability. Such aspects concern the bussiness processes, the knowledge, the syntax and the semantics that involves the information managed by information systems.
Enterprise modelling is widely used to achieve integration solutions within enterprises and is a research area both for the integration wihin an enterprise (company or organisation) and the integration between several different enterprises. Enterprise modelling takes into account several of the aspects, mentioned as important for interoperability, in the models that are created.
This thesis describes a research which has resulted in the connector view concept. The main contribution with this framework comprises a model structure and an approach, for performing the modelling of the collaboration between several partners in an extended enterprise. The purpose of the enterprise models thus created, by using the connector view concept, is to find solutions to interoperability problems, that exist in the collaboration between several enterprises.
1523
Computational Terminology: Exploring Bilingual and Monolingual Term Extraction
Jody Foo
Terminologies are becoming more important to modern day society as technology and science continue to grow at an accelerating rate in a globalized environment. Agreeing upon which terms should be used to represent which concepts and how those terms should be translated into different languages is important if we wish to be able to communicate with as little confusion and misunderstandings as possible.
Since the 1990s, an increasing amount of terminology research has been devoted to facilitating and augmenting terminology-related tasks by using computers and computational methods. One focus for this research is Automatic Term Extraction (ATE).
In this compilation thesis, studies on both bilingual and monolingual ATE are presented. First, two publications reporting on how bilingual ATE using the align-extract approach can be used to extract patent terms. The result in this case was 181,000 manually validated English-Swedish patent terms which were to be used in a machine translation system for patent documents. A critical component of the method used is the Q-value metric, presented in the third paper, which can be used to rank extracted term candidates (TC) in an order that correlates with TC precision. The use of Machine Learning (ML) in monolingual ATE is the topic of the two final contributions. The first ML-related publication shows that rule induction based ML can be used to generate linguistic term selection patterns, and in the second ML-related publication, contrastive n-gram language models are used in conjunction with SVM ML to improve the precision of term candidates selected using linguistic patterns.
No 1550
Models and Tools for Distributed User Interface Development
Anders Fröberg
The way we interact with computers and computer systems are constantly changing as technology evolves. A current trend is that users interact with multiple andinterconnected devices on a daily basis. They are beginning to request ways and means of dividing and spreading their applications acrossthese devices.Distributed user interfaces (DUIs) have been proposed as a means ofdistributing programs over multiple interconnected devices through theuser interface (UI). DUIs represent a fundamental change foruser-interface design, enabling new ways of developing distributedsystems that, for instance, support runtime reorganization ofUIs. However developing DUIs presents a far more complex task compared totraditional UI development, due to the inherent complexity thatarises from combining UI development with distributed systems. Thetraditional approach in software engineering and computer science toovercoming complexity is to build tools and frameworks, to allowfor good code reuse and higher level of abstraction for applicationprogramers.Conventional GUI programming tools and frameworks are not developedto support DUIs specifically. In this thesis we explore key issues increating new programming tools and frameworks (APIs) for DUI-based UIdevelopment. We also present and discuss the DUI framework Marve,which adds DUI support to Java Swing.A unique feature of Marve is that it is designedfor industrial-scale development, extending a standard UIframework. The framework has beentested and evaluated in a project where an operator control stationsystem was developed.
No 1558
Optimizing Fault Tolerance for Real-Time Systems
Dimitar Nikolov
For the vast majority of computer systems correct operation is defined as producing the correct result within a time constraint (deadline). We refer to such computer systems as real-time systems (RTSs). RTSs manufactured in recent semiconductor technologies are increasingly susceptible to soft errors, which enforces the use of fault tolerance to detect and recover from eventual errors. However, fault tolerance usually introduces a time overhead, which may cause an RTS to violate the time constraints. Depending on the consequences of violating the deadlines, RTSs are divided into hard RTSs, where the consequences are severe, and soft RTSs, otherwise. Traditionally, worst case execution time (WCET) analyses are used for hard RTSs to ensure that the deadlines are not violated, and average execution time (AET) analyses are used for soft RTSs. However, at design time a designer of an RTS copes with the challenging task of deciding whether the system should be a hard or a soft RTS. In such case, focusing only on WCET analyses may result in an over-designed system, while on the other hand focusing only on AET analyses may result in a system that allows eventual deadline violations. To overcome this problem, we introduce Level of Confidence (LoC) as a metric to evaluate to what extent a deadline is met in presence of soft errors. The advantage is that the same metric can be used for both soft and hard RTSs, thus a system designer can precisely specify to what extent a deadline is to be met. In this thesis, we address optimization of Roll-back Recovery with Checkpointing (RRC) which is a good representative for fault tolerance due to that it enables detection and recovery of soft errors at the cost of introducing a time overhead which impacts the execution time of tasks. The time overhead depends on the number of checkpoints that are used. Therefore, we provide mathematical expressions for finding the optimal number of checkpoints which leads to: 1) minimal AET and 2) maximal LoC. To obtain these expressions we assume that error probability is given. However, error probability is not known in advance and it can even vary over runtime. Therefore, we propose two error probability estimation techniques: Periodic Probability Estimation and Aperiodic Probability Estimation that estimate error probability during runtime and adjust the RRC scheme with the goal to reduce the AET. By conducting experiments, we show that both techniques provide near-optimal performance of RRC.
No 1582
Mission Experience: How to Model and Capture it to Enable Vicarious Learning
Dennis Andersson
Organizations for humanitarian assistance, disaster response and military activities are characterized by their special role in society to resolve time-constrained and potentially life-threatening situations. The tactical missions that these organizations conduct regularly are significantly dynamic in character, and sometimes impossible to fully comprehend and predict. In these situations, when control becomes opportunistic, the organizations are forced to rely on the collective experience of their personnel to respond effectively to the unfolding threats. Generating such experience through traditional means of training, exercising and apprenticeship, is expensive, time-consuming, and difficult to manage.
This thesis explores how and why mission experience should be utilized in emergency management and military organizations to improve performance. A multimedia approach for capturing mission experience has further been tested in two case studies to determine how the commanders’ experiences can be externalized to enable vicarious learning. These studies propose a set of technical, methodological, and ethical issues that need to be considered when externalizing mission experience, based on two aforementioned case studies complemented by a literature review. The presented outcomes are (1) a model aligning abilities that tactical organizations need when responding to dynamic situations of different familiarity, (2) a review of the usefulness of several different data sources for externalization of commanders’ experiences from tactical operations, and (3) a review of methodological, technical, and ethical issues to consider when externalizing tactical military and emergency management operations. The results presented in this thesis indicate that multimedia approaches for capturing mission histories can indeed complement training and exercising as a method for generating valuable experience from tactical missions.
No 1586
Anomaly Detection and its Adaptation: Studies on Cyber-Physical Systems
Massimiliano Raciti
Cyber-Physical Systems (CPS) are complex systems where physical operations are supported and coordinated by Information and Communication Technology (ICT).
From the point of view of security, ICT technology offers new opportunities to increase vigilance and real-time responsiveness to physical security faults. On the other hand, the cyber domain carries all the security vulnerabilities typical to information systems, making security a new big challenge in critical systems. This thesis addresses anomaly detection as security measure in CPS. Anomaly detection consists of modelling the good behaviour of a system using machine learning and data mining algorithms, detecting anomalies when deviations from the normality model occur at runtime. Its main feature is the ability to discover the kinds of attack not seen before, making it suitable as a second line of defence.
The first contribution of this thesis addresses the application of anomaly detection as early warning system in water management systems. We describe the evaluation of an anomaly detection software when integrated in a Supervisory Control and Data Acquisition (SCADA) system where water quality sensors provide data for real-time analysis and detection of contaminants. Then, we focus our attention to smart metering infrastructures. We study a smart metering device that uses a trusted platform for storage and communication of electricity metering data, and show that despite the hard core security, there is still room for deployment of a second level of defence as an embedded real-time anomaly detector that can cover both the cyber and physical domains. In both scenarios, we show that anomaly detection algorithms can efficiently discover attacks in the form of contamination events in the first case and cyber attacks for electricity theft in the second. The second contribution focuses on online adaptation of the parameters of anomaly detection applied to a Mobile Ad hoc Network (MANET) for disaster response. Since survivability of the communication to network attacks is as crucial as the lifetime of the network itself, we devised a component that is in charge of adjusting the parameters based on the current energy level, using the trade-off between the node's response to attacks and the energy consumption induced by the intrusion detection system. Adaption increases the network lifetime without significantly deteriorating the detection performance.
No 1588
Towards an Approach for Efficiency Evaluation of Enterprise Modeling Methods
Banafsheh Khademhosseinieh
Nowadays, there is a belief that organizations should keep improving different aspects of theirenterprise to remain competitive in their business segment. For this purpose, it is required to understand the current state of the enterprise, analyze and evaluate it to be able to figure out suitable change measures. To perform such a process in a systematic and structured way, receiving support from powerful tools is inevitable. Enterprise Modeling is a field that can support improvement processes by developing models to show different aspects of an enterprise. An Enterprise Modeling Method is an important support for the Enterprise Modeling. A method is comprised of different conceptual parts: Perspective, Framework, Method Component (which itself contains Procedure, Notation and Concepts), and Cooperation Principles. In an ideal modeling process, both the process and the results are of high quality. One dimension of quality which is in focus in this thesis is efficiency. The issue of efficiency evaluation in Enterprise Modeling still seems to be a rather unexploited research area.
The thesis investigates three aspects of Enterprise Modeling Methods: what is the meaning of efficiency in this context, how can efficiency be evaluated and in what phases of a modeling process could efficiency be evaluated. The contribution of the thesis is an approach for evaluation of efficiency in Enterprise Modeling Methods based also on several case studies. The evaluation approach is constituted by efficiency criteria that should be met by (different parts of) a method. While a subset of these criteria always need to be fulfilled in a congruent way, fulfillment of the rest of the criteria depends on the application case. To help the user in initial evaluation of a method, a structure of driving questions is presented.
No 1589
Resilience in High Risk Work: Analysing Adaptive Performance
Amy Rankin
In today’s complexsocio-technical systems it is not possible to foresee and prepare for allfuture events. To cope with the intricacy and coupling between people,technical systems and the dynamic environment people are required tocontinuously adapt. To design resilient systems a deepened understanding ofwhat supports and enables adaptive performance is needed. In this thesis two studiesare presented that investigate how adaptive abilities can be identified andanalysed in complex work settings across domains. The studies focus onunderstanding adaptive performance, what enables successful adaptation and how contextual factors affect the performance. The first study examines how acrisis command team adapts as they lose important functions of their teamduring a response operation. The secondstudy presents a framework to analyse adaptive behaviour in everyday work wheresystems are working near the margins of safety. The examples that underlie theframework are based on findings from focus group discussion withrepresentatives from different organisations, including health care, nuclear,transportation and emergency services. Main contributions of this thesis includethe examination of adaptive performance and of how it can be analysed as ameans to learn about and strengthen resilience. By using contextual analysis enablersof adaptive performance and its effects the overall system are identified. Theanalysis further demonstrates that resilience is not a system property but aresult of situational circumstances and organisational structures. Theframework supports practitioners and researchers in reporting findings,structuring cases and making sense of sharp-end adaptations. The analysismethod can be used to better understand system adaptive capacities, monitoradaptive patterns and enhance current methods for safety management.
No 1592
Tools for Understanding, Debugging, and Simulation Performance Improvement of Equation-based Models
Martin Sjölund
Equation-based object-oriented (EOO) modelling languages provide a convenient, declarative method for describing models of cyber-physical systems.Because of the ease of use of EOO languages, large and complex models can be built with limited effort.However, current state-of-the-art tools do not provide the user with enough information when errors appear or simulation results are wrong.It is paramount that the tools give the user enough information to correct errors or understand where the problems that lead to wrong simulation results are located.However, understanding the model translation process of an EOO compiler is a daunting task that not only requires knowledge of the numerical algorithms that the tool executes during simulation, but also the complex symbolic transformations being performed.
In this work, we develop and explore methods where the EOO tool records the transformations during the translation process in order to provide better diagnostics, explanations, and analysis.This information can be used to generate better error-messages during translation.It can also be used to provide better debugging for a simulation that produces unexpected results or where numerical methods fail.
Meeting deadlines is particularly important for real-time applications.It is usually important to identify possible bottlenecks and either simplify the model or give hints to the compiler that enables it to generate faster code.When profiling and measuring execution times of parts of the model the recorded information can also be used to find out why a particular system is slow.Combined with debugging information, it is possible to find out why this system of equations is slow to solve, which helps understanding what can be done to simplify the model.
Finally, we provide a method and tool prototype suitable for speeding up simulations by compiling a simulation executable for a parallel platform by partitioning the model at appropriate places.
No 1606
Towards an Ontology Design Pattern Quality Model
Karl Hammar
The use of semantic technologies and Semantic Web ontologies in particular have enabled many recent developments in information integration, search engines, and reasoning over formalised knowledge. Ontology Design Patterns have been proposed to be useful in simplifying the development of Semantic Web ontologies by codifying and reusing modelling best practices.
This thesis investigates the quality of Ontology Design Patterns. The main contribution of the thesis is a theoretically grounded and partially empirically evaluated quality model for such patterns including a set of quality characteristics, indicators, measurement methods and recommendations. The quality model is based on established theory on information system quality, conceptual model quality, and ontology evaluation. It has been tested in a case study setting and in two experiments.
The main findings of this thesis are that the quality of Ontology Design Patterns can be identified, formalised and measured, and furthermore, that these qualities interact in such a way that ontology engineers using patterns need to make tradeoffs regarding which qualities they wish to prioritise. The developed model may aid them in making these choices.
This work has been supported by Jönköping University.
No 1624
Designing Security-enhanced Embedded Systems: Bridging Two Islands of Expertise
Maria Vasilevskaya
The increasing prevalence of embedded devices and a boost in sophisticated attacks against them make embedded system security an intricate and pressing issue. New approaches to support the development of security-enhanced systems need to be explored. We realise that efficient transfer of knowledge from security experts to embedded system engineers is vitally important, but hardly achievable in current practice.This thesis proposes a Security-Enhanced Embedded system Design (SEED) approach, which is a set of concepts, methods, and tools that together aim at addressing this challenge of bridging the gap between the two areas of expertise.
First, we introduce the concept of a Domain-Specific Security Model (DSSM) as a suitable abstraction to capture the knowledge of security experts in a way that this knowledge can be later reused by embedded system engineers. Each DSSM characterises common security issues of a specific application domain in a form of security properties, which are further linked to a range of solutions.
As a next step, we complement a DSSM with the concept of a Performance Evaluation Record (PER) to account for the resource-constrained nature of embedded systems. Each PER characterises the resource overhead created by a security solution, a provided level of security, and the evaluation technique applied.
Finally, we define a process that assists an embedded system engineer in selecting a relevant set of security solutions. The process couples together (i) the use of the security knowledge accumulated in DSSMs and PERs, (ii) the identification of security issues in a system design, and (iii) the analysis of resource constraints of a system and available security solutions. The approach is supported by a set of tools that automate its certain steps.
We use a case study from a smart metering domain to demonstrate how the SEED approach can be applied. We show that our approach adequately supports security experts in description of knowledge about security solutions in the form of formalised ontologies and embedded system engineers in integration of an appropriate set of security solutions based on that knowledge.
No 1627
Exploiting Energy Awareness in Mobile Communication
Ekhiotz Vergara
Although evolving mobile technologies bring millions of users closer to the vision of information anywhere-anytime, device battery depletions hamper the quality of experience to a great extent. The massive explosion of mobile applications with the ensuing data exchange over the cellular infrastructure is not only a blessing to the mobile user, but also has a price in terms of rapid discharge of the device battery. Wireless communication is a large contributor to the energy consumption. Thus, the current call for energy economy in mobile devices poses the challenge of reducing the energy consumption of wireless data transmissions at the user end by developing energy-efficient communication.
This thesis addresses the energy efficiency of data transmission at the user end in the context of cellular networks. We argue that the design of energy-efficient solutions starts by energy awareness and propose EnergyBox, a parametrised tool that enables accurate and repeatable energy quantification at the user end using real data traffic traces as input. EnergyBox abstracts the underlying states for operation of the wireless interfaces and allows to estimate the energy consumption for different operator settings and device characteristics.
Next, we devise an energy-efficient algorithm that schedules the packet transmissions at the user end based on the knowledge of the network parameters that impact the handset energy consumption. The solution focuses on the characteristics of a given traffic class with the lowest quality of service requirements. The cost of running the solution itself is studied showing that the proposed cross-layer scheduler uses a small amount of energy to significantly extend the battery lifetime at the cost of some added latency.
Finally, the benefit of employing EnergyBox to systematically study the different design choices that developers face with respect to data transmissions of applications is shown in the context of location sharing services and instant messaging applications. The results show that quantifying energy consumption of communication patterns, protocols, and data formats can aid the design of tailor-made solutions with a significantly smaller energy footprint.
No 1644
Integration of Ontology Alignment and Ontology Debugging for Taxonomy Networks
Valentina Ivanova
Semantically-enabled applications, such as ontology-based search and data integration, take into account the semantics of the input data in their algorithms. Such applications often use ontologies, which model the application domains in question, as well as alignments, which provide information about the relationships between the terms in the different ontologies.
The quality and reliability of the results of such applications depend directly on the correctness and completeness of the ontologies and alignments they utilize. Traditionally, ontology debugging discovers defects in ontologies and alignments and provides means for improving their correctness and completeness, while ontology alignment establishes the relationships between the terms in the different ontologies, thus addressing completeness of alignments.
This thesis focuses on the integration of ontology alignment and debugging for taxonomy networks which are formed by taxonomies, the most widely used kind of ontologies, connected through alignments.
The contributions of this thesis include the following. To the best of our knowledge, we have developed the first approach and framework that integrate ontology alignment and debugging, and allow debugging of modelling defects both in the structure of the taxonomies as well as in their alignments. As debugging modelling defects requires domain knowledge, we have developed algorithms that employ the domain knowledge intrinsic to the network to detect and repair modelling defects.
Further, a system has been implemented and several experiments with real-world ontologies have been performed in order to demonstrate the advantages of our integrated ontology alignment and debugging approach. For instance, in one of the experiments with the well-known ontologies and alignment from the Anatomy track in Ontology Alignment Evaluation Initiative 2010, 203 modelling defects (concerning incomplete and incorrect information) were discovered and repaired.
No 1647
A Study of Chain Graph Interpretations
Dag Sonntag
Probabilistic graphical models are today one of the most well used architectures for modelling and reasoning about knowledge with uncertainty. The most widely used subclass of these models is Bayesian networks that has found a wide range of applications both in industry and research. Bayesian networks do however have a major limitation which is that only asymmetric relationships, namely cause and eect relationships, can be modelled between its variables. A class of probabilistic graphical models that has tried to solve this shortcoming is chain graphs. It is achieved by including two types of edges in the models, representing both symmetric and asymmetric relationships between the connected variables. This allows for a wider range of independence models to be modelled. Depending on how the second edge is interpreted this has also given rise to dierent chain graph interpretations.
Although chain graphs were first presented in the late eighties the field has been relatively dormant and most research has been focused on Bayesian networks. This was until recently when chain graphs got renewed interest. The research on chain graphs has thereafter extended many of the ideas from Bayesian networks and in this thesis we study what this new surge of research has been focused on and what results have been achieved. Moreover we do also discuss what areas that we think are most important to focus on in further research.
No 1657
Grounding Emotion Appraisal in Autonomous Humanoids
Kiril Kiryazov
The work presented in this dissertation investigates the problem for resource management of autonomous robots. Acting under the constraint of limited resources is a necessity for every robot which should perform tasks independent of human control. Some of the most important variables and performance criteria for adaptive behavior under resource constraints are discussed. Concepts like autonomy, self-sufficiency, energy dynamics, work utility, effort of action, and optimal task selection are defined and analyzed as the emphasis is on the resource balance in interaction with a human. The primary resource for every robot is its energy. In addition to the regulation of its “energy homeostasis”, a robot should perform its designer’s tasks with the required level of efficiency. A service robot residing in a human-centered environment should perform some social tasks like cleaning, helping elderly people or delivering goods. Maintaining a proper quality of work and, at the same time, not running out of energy represents a basic two-resource problem which was used as a test-bed scenario in the thesis. Safety is an important aspect of any human-robot interaction. Thus, a new three – resource problem (energy, work quality, safety) is presented and also used for the experimental investigations in the thesis.
The main contribution of the thesis is developing an affective cognitive architecture. The architecture uses top-down ethological models of action selection. The action selection mechanisms are nested into a model of human affect based on appraisal theory of emotion. The arousal component of the architecture is grounded into electrical energy processes in the robotic body and is modulating the effort of movement. The provided arousal mechanism has an important functional role for the adaptability of the robot in the proposed two- and three resource scenarios. These investigations are part of a more general goal of grounding highlevel emotion substrates - Pleasure Arousal Dominance emotion space in homeostatic processes in humanoid robots. The development of the architecture took inspiration from several computation architectures of emotion in robotics, which are analyzed in the thesis.
Sustainability of the basic cycles of the essential variables of a robotic system is chosen as a basic performance measure for validating the emotion components of the architecture and the grounding process. Several experiments are performed with two humanoid robots – iCub and NAO showing the role of task selection mechanism and arousal component of the architecture for the robot’s self-sufficiency and adaptability.
No 1683
Completing the Is-a Structure in Description Logics Ontologies
Zlatan Dragisic
The World Wide Web contains large amounts of data and in most cases this data is without any explicit structure. The lack of structure makes it dicult for aut mated agents to understand and use such data. A step towards a more structured World Wide Web is the idea of the Semantic Web which aims at introducing se mantics to data on the WorldWideWeb. One of the key technologies in this endeavour are ontologies which provide means for modeling a domain of interest.
Developing and maintaining ontologies is not an easy task and it is often the case that defects are introduced into ontologies. This can be a problem for semantically-enabled applications such as ontology-based querying. Defects in ontologies directly influence the quality of the results of such applications as correct results can be missed and wrong results can be returned.
This thesis considers one type of defects in ontologies, namely the problem of completing the is-a structure in ontologies represented in description logics. We focus on two variants of description logics, the EL family and ALC, which are often used in practice.
The contributions of this thesis are as follows. First, we formalize the problem of completing the is-a structure as a generalized TBox abduction problem (GTAP) which is a new type of abduction problem in description logics. Next, we provide algorithms for solving GTAP in the EL family and ALC description logics. Finally, we describe two implemented systems based on the introduced algorithms. The systems were evaluated in two experiments which have shown the usefulness of our approach. For example, in one experiment using ontologies from the Ontology Alignment Evaluation Initiative 58 and 94 detected missing is-a relations were repaired by adding 54 and 101 is-a relations, respectively, introducing new knowledge to the ontologies.
No 1688
Code Generation and Global Optimization Techniques for a Reconfigurable PRAM-NUMA Multicore Architecture
Erik Hansson
In this thesis we describe techniques for code generation and global optimization for a PRAM-NUMA multicore architecture. We specifically focus on the REPLICA architecture which is a family massively multithreaded very long instruction word (VLIW) chip multiprocessors with chained functional units that has a reconfigurable emulated shared on-chip memory. The on-ship memory system supports two execution modes, PRAM and NUMA, which can be switched between at run-time.PRAM mode is considered the standard execution mode and targets mainly applications with very high thread level parallelism (TLP). In contrast, NUMA mode is optimized for sequential legacy applications and applications with low amount of TLP. Different versions of the REPLICA architecture have different number of cores, hardware threads and functional units. In order to utilize the REPLICA architecture efficiently we have made several contributionsto the development of a compiler for REPLICA target code generation. It supports both code generation for PRAM mode and NUMA mode and can generate code for different versions of the processor pipeline (i.e. for different numbers of functional units). It includes optimization phases to increase the utilization of the available functional units. We have also contributed to quantitative the evaluation of PRAM and NUMA mode. The results show that PRAM mode often suits programs with irregular memory access patterns and control flow best while NUMA mode suites regular programs better. However, for a particular program it is not always obvious which mode, PRAM or NUMA, will show best performance. To tackle this we contributed a case study for generic stencil computations, using machine learning derived cost models in order to automatically select at runtime which mode to execute in. We extended this to also include a sequence of kernels.
No 1715
Energy-Efficient Computing over Streams with Massively Parallel Architectures
Nicolas Melot
The rise of many-core processor architectures in the high-performance computing market answers to a constantly growing need of processing power to solve more and more challenging problems such as the ones in computing for big data. Fast computation is more and more limited by the very high power required and the management of the considerable heat produced. Many programming models compete to take prot of many-core architectures to improve both execution speed and energy consumption, each with their advantages and drawbacks. The work described in this thesis is based on the dataflow computing approach and investigates the benets of a carefully designed pipelined execution of streaming applications, focusing on particular on off- and on-chip memory accesses. We implement classic and on-chip pipelined versions of mergesort for the SCC. We see how the benets of the on-chip pipelining technique are bounded by the underlying architecture, and we explore the problem of ne tuning streaming applications for manycore architectures to optimize for energy given a throughput budget. We propose a novel methodology to compute schedules optimized for energy eciency for a fixed throughput target. We introduce Schedeval, a tool to test schedules of communicating streaming tasks under throughput constraints for the SCC. We show that streaming applications based on Schedeval compete with specialized implementations and we use Schedeval to demonstrate performance dierences between schedules that are otherwise considered as equivalent by a simple model.
No 1716
Automatic and Explicit Parallelization Approaches for Mathematical Simulation Models
Mahder Gebremedhin
The move from single core and processor systems to multi-core and many-processors systemscomes with the requirement of implementing computations in a way that can utilizethese multiple units eciently. This task of writing ecient multi-threaded algorithmswill not be possible with out improving programming languages and compilers to providethe mechanisms to do so. Computer aided mathematical modeling and simulationis one of the most computationally intensive areas of computer science. Even simpli-ed models of physical systems can impose a considerable amount of computational loadon the processors at hand. Being able to take advantage of the potential computationpower provided by multi-core systems is vital in this area of application. This thesis triesto address how we can take advantage of the potential computation power provided bythese modern processors to improve the performance of simulations. The work presentsimprovements for the Modelica modeling language and the OpenModelica compiler.
Two approaches of utilizing the computational power provided by modern multi-corearchitectures are presented in this thesis: Automatic and Explicit parallelization. Therst approach presents the process of extracting and utilizing potential parallelism fromequation systems in an automatic way with out any need for extra eort from the modelers/programmers side. The thesis explains improvements made to the OpenModelicacompiler and presents the accompanying task systems library for ecient representation,clustering, scheduling proling and executing complex equation/task systems with heavydependencies. The Explicit parallelization approach explains the process of utilizing parallelismwith the help of the modeler or programmer. New programming constructs havebeen introduced to the Modelica language in order to enable modelers write parallelizedcode. the OpenModelica compiler has been improved accordingly to recognize and utilizethe information from this new algorithmic constructs and generate parallel code toimprove the performance of computations.
No 1722
Efficient Temporal Reasoning with Uncertainty
Mikael Nilsson
Automated Planning is an active area within Artificial Intelligence. With the help of computers we can quickly find good plans in complicated problem domains, such as planning for search and rescue after a natural disaster. When planning in realistic domains the exact duration of an action generally cannot be predicted in advance. Temporal planning therefore tends to use upper bounds on durations, with the explicit or implicit assumption that if an action happens to be executed more quickly, the plan will still succeed. However, this assumption is often false. If we finish cooking too early, the dinner will be cold before everyone is at home and can eat. Simple Temporal Networks with Uncertainty (STNUs) allow us to model such situations. An STNU-based planner must verify that the temporal problems it generates are executable, which is captured by the property of dynamic controllability (DC). If a plan is not dynamically controllable, adding actions cannot restore controllability. Therefore a planner should verify after each action addition whether the plan remains DC, and if not, backtrack. Verifying dynamic controllability of a full STNU is computationally intensive. Therefore, incremental DC verification algorithms are needed.
We start by discussing two existing algorithms relevant to the thesis. These are the very first DC verification algorithm called MMV (by Morris, Muscettola and Vidal) and the incremental DC verification algorithm called FastIDC, which is based on MMV.
We then show that FastIDC is not sound, sometimes labeling networks as dynamically controllable when they are not. We analyze the algorithm to pinpoint the cause and show how the algorithm can be modified to correctly and efficiently detect uncontrollable networks.
In the next part we use insights from this work to re-analyze the MMV algorithm. This algorithm is pseudo-polynomial and was later subsumed by first an n5 algorithm and then an n4 algorithm. We show that the basic techniques used by MMV can in fact be used to create an n4 algorithm for verifying dynamic controllability, with a new termination criterion based on a deeper analysis of MMV. This means that there is now a comparatively easy way of implementing a highly efficient dynamic controllability verification algorithm. From a theoretical viewpoint, understanding MMV is important since it acts as a building block for all subsequent algorithms that verify dynamic controllability. In our analysis we also discuss a change in MMV which reduces the amount of regression needed in the network substantially.
In the final part of the thesis we show that the FastIDC method can result in traversing part of a temporal network multiple times, with constraints slowly tightening towards their final values. As a result of our analysis we then present a new algorithm with an improved traversal strategy that avoids this behavior.  The new algorithm, EfficientIDC, has a time complexity which is lower than that of FastIDC. We prove that it is sound and complete.
No 1732
Automatic Verification of Parameterized Sytems by Over-Approximation
Vladislavs Jahundovics
This thesis presents a completely automatic verification framework to check safety properties of parameterized systems. A parameterized system is a family of finite state systems where every system consists of a finite number of processes running in parallel the same algorithm. All the systems in the family differ only in the number of the processes and, in general, the number of systems in a family may be unbounded. Examples of parameterized systems are communication protocols, mutual exclusion protocols, cache coherence protocols, distributed algorithms etc.
Model-checking of finite state systems is a well-developed formal verification approach of proving properties of systems in an automatic way. However, it cannot be applied directly to parameterized systems because the unbounded number of systems in a family means an infinite state space. In this thesis we propose to abstract an original family of systems consisting of an unbounded number of processes into one consisting of a fixed number of processes. An abstracted system is considered to consist of k+1 components—k reference processes and their environment. The transition relation for the abstracted system is an over-approximation of the transition relation for the original system, therefore, a set of reachable states of the abstracted system is an over-approximation of the set of reachable states of the original one.
A safety property is considered to be parameterized by a fixed number of processes whose relationship is in the center of attention in the property. Such processes serve as reference processes in the abstraction. We propose an encoding which allows to perform reachability analysis for an abstraction parameterized by the reference processes.
We have successfully verified three classic parameterized systems with replicated processes by applying this method.
No 1771
Timing Predictability in Future Multi-Core Avionics Systems
Andreas Löfwenmark
With more functionality added to safety-critical avionics systems, new platforms are required to offer the computational capacity needed. Multi-core platforms offer a potential that is now being explored, but they pose significant challenges with respect to predictability due to shared resources (such as memory) being accessed from several cores in parallel. Multi-core processors also suffer from higher sensitivity to permanent and transient faults due to shrinking transistor sizes. This thesis addresses several of these challenges. First, we review major contributions that assess the impact of fault tolerance on worst-case execution time of processes running on a multi-core platform. In particular, works that evaluate the timing effects using fault injection methods. We conclude that there are few works that address the intricate timing effects that appear when inter-core interferences due to simultaneous accesses of shared resources are combined with the fault tolerance techniques. We assess the applicability of the methods to COTS multi-core processors used in avionics. We identify dark spots on the research map of the joint problem of hardware reliability and timing predictability for multi-core avionics systems. Next, we argue that the memory requests issued by the real-time operating systems (RTOS) must be considered in resource-monitoring systems to ensure proper execution on all cores. We also adapt and extend an existing method for worst-case response time analysis to fulfill the specific requirements of avionics systems. We relax the requirement of private memory banks to also allow cores to share memory banks.
No 1777
Extensions for Distributed Moving Base Driving Simulators
Anders Andersson
Modern vehicles are complex systems. Different design stages for such a complex system include evaluation using models and submodels, hardware-in-the-loop systems and complete vehicles. Once a vehicle is delivered to the market evaluation continues by the public. One kind of tool that can be used during many stages of a vehicle lifecycle is driving simulators. The use of driving simulators with a human driver is commonly focused on driver behavior. In a high fidelity moving base driving simulator it is possible to provide realistic and repetitive driving situations using distinctive features such as: physical modelling of driven vehicle, a moving base, a physical cabin interface and an audio and visual representation of the driving environment. A desired but difficult goal to achieve using a moving base driving simulator is to have behavioral validity. In other words, \A driver in a moving base driving simulator should have the same driving behavior as he or she would have during the same driving task in a real vehicle.". In this thesis the focus is on high fidelity moving base driving simulators. The main target is to improve the behavior validity or to maintain behavior validity while adding complexity to the simulator. One main assumption in this thesis is that systems closer to the final product provide better accuracy and are perceived better if properly integrated. Thus, the approach in this thesis is to try to ease incorporation of such systems using combinations of the methods hardware-in-the-loop and distributed simulation. Hardware-in-the-loop is a method where hardware is interfaced into a software controlled environment/simulation. Distributed simulation is a method where parts of a simulation at physically different locations are connected together. For some simulator laboratories distributed simulation is the only feasible option since some hardware cannot be moved in an easy way. Results presented in this thesis show that a complete vehicle or hardware-in-the-loop test laboratory can successfully be connected to a moving base driving simulator. Further, it is demonstrated that using a framework for distributed simulation eases communication and integration due to standardized interfaces. One identified potential problem is complexity in interface wrappers when integrating hardware-in-the-loop in a distributed simulation framework. From this aspect, it is important to consider the model design and the intersections between software and hardware models. Another important issue discussed is the increased delay in overhead time when using a framework for distributed simulation.
No 1780
Methods for Scalable and Safe Robot Learning
Olov Andersson
Robots are increasingly expected to go beyond controlled environments in laboratories and factories, to enter real-world public spaces and homes. However, robot behavior is still usually engineered for narrowly defined scenarios. To manually encode robot behavior that works within complex real world environments, such as busy work places or cluttered homes, can be a daunting task. In addition, such robots may require a high degree of autonomy to be practical, which imposes stringent requirements on safety and robustness. \setlength{\parindent}{2em}\setlength{\parskip}{0em}The aim of this thesis is to examine methods for automatically learning safe robot behavior, lowering the costs of synthesizing behavior for complex real-world situations. To avoid task-specific assumptions, we approach this from a data-driven machine learning perspective. The strength of machine learning is its generality, given sufficient data it can learn to approximate any task. However, being embodied agents in the real-world, robots pose a number of difficulties for machine learning. These include real-time requirements with limited computational resources, the cost and effort of operating and collecting data with real robots, as well as safety issues for both the robot and human bystanders.While machine learning is general by nature, overcoming the difficulties with real-world robots outlined above remains a challenge. In this thesis we look for a middle ground on robot learning, leveraging the strengths of both data-driven machine learning, as well as engineering techniques from robotics and control. This includes combing data-driven world models with fast techniques for planning motions under safety constraints, using machine learning to generalize such techniques to problems with high uncertainty, as well as using machine learning to find computationally efficient approximations for use on small embedded systems.We demonstrate such behavior synthesis techniques with real robots, solving a class of difficult dynamic collision avoidance problems under uncertainty, such as induced by the presence of humans without prior coordination. Initially using online planning offloaded to a desktop CPU, and ultimately as a deep neural network policy embedded on board a 7 quadcopter.
Page responsible: Anne Moe
Department of Computer and Information Science
Linköping University
581 83 LINKÖPING
Tel: +46 13 28 10 00