Computing devices are becoming wireless, smaller and embedded into other artifacts. Some of them are mobile while others are built into the environment. The novel technologies are also becoming more dependent of communication with other computing devices over different kinds of networks. These interconnected devices constitute locally and globally distributed service environments that will enforce new requirements on the design of software systems. These new type of environments provide both opportunities for new types of applications as well as a number of new problems that will have to be addressed. One approach that have been suggested both in order to provide new functionalities and as a possible solution to some of the problems is to try and collect and incorporate aspects of the /context/ of a person, activity or device as a part of the computer system. This thesis addresses some issues that have to be considered when designing this kind of systems. In particular the thesis examines how to design middleware that can support the creation of context aware applications. As a part of this work several instances of such systems have been implemented and put in use and tested in various applications. Some key problems with respect to the design of context information middleware are also identified and examined. One question that is addressed concerns the clash between the need for internal representations of context information and the goal of middleware to support a broad range of applications. Another problem that has been addressed concerns how to create means for context aware service discovery in ubiquitous computing environments. Various mechanisms that address these problems have been implemented and tested. Finally the work addresses issues related to the role of the users in this kind of systems. Implementations and experiments have been performed where users take more active roles in aspects of system maintenance and adaptation as well as in the interpretation and representation of context information. / QC 20100802

A theory of many-sorted implicative conceptual systems (abbreviated msic-systems) is presented. Examples of msic-systems include legal systems, normative systems, systems of rules and instructions, and systems expressing policies and various kinds of scientific theories. In computer science, msic-systems can be used in, for instance, legal information systems, decision support systems, and multi-agent systems. In the thesis, msic-systems are studied from a logical and algebraic perspective aiming at clarifying their structure and developing effective methods for representing them. Of special interest are the most narrow links or joinings between different strata in a system, that is between subsystems of different sorts of concepts, and the intermediate concepts intervening between such strata. Special emphasis is put on normative systems, and the role that intermediate concepts play in such systems, with an eye on knowledge representation issues. Normative concepts are constructed out of descriptive concepts using operators based on the Kanger-Lindahl theory of normative positions. An abstract architecture for a norm-regulated multi-agent system is suggested, containing a scheme for how normative positions will restrict the set of actions that the agents are permitted to choose from. Technical results inlude a characterization of an msic-system in terms of the most narrow joinings between different strata, characterization of the structure of the most narrow joinings between two strata, conditions for the extendability of intermediate concepts, and finally, a specification of the conditions such that the Boolean operations on intermediate concepts will result in intermediate concepts and characterization of most narrow joinings in terms of weakest grounds and strongest consequences. / QC 20100901

Object-oriented programming relies on sharing and the mutable states of objects for common data structures, patterns and programming idioms. Sharing and mutable state is a powerful but dangerous combination. Uncontrolled aliasing risks causing representation exposure, where an object's state is exposed and modifiable out of the control of its conceptually owning object. This breaks encapsulation, and hence, in extension, abstraction. Contemporary object-oriented programming languages' support for alias encapsulation is mediocre and easily circumvented. To this end, several proposals have been put forward that strengthen encapsulation to enable construction of more reliable systems and formally reasoning about properties of programs. These systems are vastly superior to the constructs found in for example C++, Java or C#, but have yet to gain acceptance outside the research community. In this thesis, we present three constructs for alias management on top of a deep ownership types system in the context of the Joline programming language. Our constructs are fully statically checkable and impose little run-time overhead. We show the formal semantics and soundness proof for our constructs as well as their formal and informal aliasing properties. We show applications and extensions and perform a practical evaluation of our system with our implemented Joline compiler. The evaluation suggests that our constructs are compatible with real-world programming, makes use of some of our own proposed patterns, and encourages further practical studies of programming with ownership-based constructs for alias management. / QC 20100928

In many industries today, the speed and costs with which new products are delivered to customers provide the basis for competitive advantage. Electronic business (e-business) is a concept that shortens the “time to market” and enables transacting at lower costs. Currently, one of the main limitations in the exploitation of e-business is the lack of efficient Information System (IS) integration, both in intra- and cross-enterprise environments. Intra-enterprise integration is complex, as the business needs and the underlying information systems do not evolve in accordance. In the cross-enterprise context, transparent system integration is hardly achievable due to the incompatibility of the services of the involved partners. This means that the future success of the integration depends heavily on the possibilities offered in terms of interoperability among the involved enterprises. The Business Process Management (BPM) discipline addresses this challenge, as processes have been recognized as key mechanisms through which most intra- and cross-enterprise interactions take place. The development of methods for successful integration of process models is one of the essential issues for the use of the BPM approach in the application and evolution of e-business. In this thesis, we address two topics in the area of business process management: 1) intra-enterprise process integration which concerns alignment between the internal business processes and information systems enclosed in the form of software services and 2) cross-enterprise integration which concerns coordination of the internal business processes of an enterprise with the processes of its suppliers, intermediaries, or customers. The goal of the thesis is to add theoretical and applicable knowledge to the field of business process management by using the proposed approaches for improvement of process integration in intra- and cross-enterprise contexts. / QC 20100929

The research reported here is about improvement of the ICT security management process in non-commercial organisations in order to reduce possible financial damage, taking into consideration the realities found in developing countries. The research took place in a developing country—Tanzania, where five organisations were involved. The study is organised into seven papers covering: the state of ICT security management in the organisations; prerequisites when utilising the existing ICT security management approaches in attaining a solution for managing ICT security in the organisations; issues and challenges of managing ICT security; important aspects to be taken into consideration in order to successfully manage ICT security; and how the management of ICT security in non-commercial organisations could be improved. Among others, the research was motivated by the observed need for bridging the perception gap between the management and technicians when dealing with the ICT security problem, and consequently extending to a common understanding by the staff in the various departments and specialities within and between the departments. The thesis contributes to increased empirical knowledge on the importance of the holistic ICT security management process. Particularly, our main contribution is the proposed holistic approach for managing ICT security in non-commercial organisations, organised in the form of guidelines with two main phases: the initialisation phase which involved the introduction of the ICT security management process in the organisation; and the internalised and continuous phase.

<p>This thesis concerns the relationship between aspects of cognitive differences and interface design in the context of visual impairment. Among a number of sources of cognitive differences studied, this work focuses on Witkin’s Cognitive Style Theory (1971). According to this theory people are more or less field-dependent. A field-independent person has good analytical and restructuring skills while the field-dependent individual has a more holistic approach and good inter-personal skills. According to several researchers, a number of design aspects such as dialogue style, user versus system guiding etc., can be designed to accommodate these differences in cognitive style. An interview study gives some support to the hypothesis that this relationship between cognitive style and design aspects also is relevant in a context of visual impairment.</p>

<p>Many contemporary development environments rely on CASE tools to store and manipulate development information. To be able to integrate different tools a central place of storage called a repository is used. The content of the repository is defined by a metamodel. CDIF is a standard proposal which supports transfer between many different types of CASE tools. CDIF contains an extensive and extensible metamodel which could be used as a transfer format or as a repository metamodel. In this dissertation a set of requirements for a repository metamodel are then developed and a repository metamodel based on CDIF is defined. The representation of a contemporary CASE tool is mapped into this repository metamodel. The full semantics of the CASE information stored in the repository is then extracted using an external validation system which transfers the CASE data into natural language. An evaluation of the results against the developed requirements conclude that a repository metamodel which is very close to the CDIF metamodel will not fully meet all of these requirements without changes to the metamodel structure.</p>

<p>A prototype is a general description which depicts what an entire set of exemplars, belonging to a certain category, looks like. We investigate how prototypes, in the form of mathematical averages of a category's exemplar vectors, can be represented, extracted, accessed, and used for learning in an Artificial Neural Network (ANN). From the method by which an ANN classifies exemplars into categories, we conclude that prototype access (the production of an extracted prototype) can be performed using a very simple architecture. We go on to show how the architecture can be used for prototype extraction by simply exploiting how the back-propagation learning rule handles one-to-many mappings. We note that no extensions to the classification training sets are needed as long as they conform to certain restrictions. We then go on to show how the extracted prototypes can be used for the learning of new categories which are compositions of existing categories and we show how this can lead to reduced training sets and ultimately reduced learning times. A number of restrictions are noted which have to be considered in order for this to work. For example, the exemplar representations must be systematic and the categories linearly separable. The results, and other properties of our network, are compared with other architectures which also use some kind of prototype concept. Our conclusion is that prototype extraction and learning using prototypes is possible using a simple ANN architecture. Finally, we relate our system to the symbol grounding problem and point out some directions for future work.</p>

<p>One way of avoiding unpredictable delays, in a distributed real-time database, is to allow transactions to commit locally. In a system supporting local commit, and delayed propagation of updates, the replication protocol must be based on eventual consistency. In this thesis, we present a bounded-delay replication method which is based on eventual consistency. The approach used is to divide the replication protocol into three different problems; propagation, conflict detection and conflict resolution, where we focus on the conflict detection and resolution mechanism. We have evaluated different eventual consistency protocols and chosen version vectors as the base for the conflict detection algorithm. We introduce a method of separating policy and mechanism in the conflict resolution mechanism, which is based on forward recovery to avoid unnecessary computation. The protocols presented in this work are aimed to be used in the distributed active real-time database system DeeDS. We conclude that the protocol proposed can be used in DeeDS, under the assumption that no partition failures occur.</p>

<p>Business Rules have gained attention in recent years and are now considered to be important organizational elements. Several sources in the literature argue that there are major achievements to be made with an explicit business rule focus in software engineering, e.g. promoting communication between analysts and users and accounting for changeability and maintenance aspects. However, to fully take advantage of an explicit rule focus in software engineering requires the ability to create business rule models. The problem is that business rule models of realistic size quickly become extensive and complex, hence there is a need for CASE tool support.</p><p>We choose a modeling technique from the literature which is suited to express business rules. Basec on this modeling technique we propose an extension to the Case Data Interchange Format standard (CDIF), thereby allowing the standard to express and support the transfer of business rule models. In addition, we define a mapping procedure that which maps business rules from the conceptual modeling level via CDIF (using the proposed extensions) to SQL3 triggers. The main idea is that the mapping algorithms could be used by a CDIF conformant CASE tool which allows traditional database design, together with extended modeling constructs for expressign business rules.</p>