| 1. |
- Cöster, Rickard, 1973-
(författare)
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Algorithms and Representations for Personalised Information Access
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Personalised information access systems use historical feedback data, such as implicit and explicit ratings for textual documents and other items, to better locate the right or relevant information for individual users.Three topics in personalised information access are addressed: learning from relevance feedback and document categorisation by the use of concept-based text representations, the need for scalable and accurate algorithms for collaborative filtering, and the integration of textual and collaborative information access.Two concept-based representations are investigated that both map a sparse high-dimensional term space to a dense concept space. For learning from relevance feedback, it is found that the representation combined with the proposed learning algorithm can improve the results of novel queries, when queries are more elaborate than a few terms. For document categorisation, the representation is found useful as a complement to a traditional word-based one.For collaborative filtering, two algorithms are proposed: the first for the case where there are a large number of users and items, and the second for use in a mobile device. It is demonstrated that memory-based collaborative filtering can be more efficiently implemented using inverted files, with equal or better accuracy, and that there is little reason to use the traditional in-memory vector approach when the data is sparse. An empirical evaluation of the algorithm for collaborative filtering on mobile devices show that it can generate accurate predictions at a high speed using a small amount of resources.For integration, a system architecture is proposed where various combinations of content-based and collaborative filtering can be implemented. The architecture is general in the sense that it provides an abstract representation of documents and user profiles, and provides a mechanism for incorporating new retrieval and filtering algorithms at any time.In conclusion this thesis demonstrates that information access systems can be personalised using scalable and accurate algorithms and representations for the increased benefit of the user.
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| 2. |
- Laaksolahti, Jarmo
(författare)
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Plot, Spectacle, and Experience : Contributions to the Design and Evaluation of Interactive Storytelling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Interactive storytelling is a new form of storytelling emerging in the crossroads of many scholarly, artistic, and industrial traditions. In interactive stories the reader/spectator moves from being a receiver of a story to an active participant. By allowing participants to influence the progression and outcome of the story new experiences will arise. This thesis has worked on three aspects of interactive storytelling: plot, spectacle, and experience. The first aspect is concerned with finding methods for combining the linear structure of a story, with the freedom of action required for an interactive experience. Our contribution has focused on a method for avoiding unwanted plot twists by predicting the progression of a story and altering its course if such twists are detected.The second aspect is concerned with supporting the storytelling process at the level of spectacle. In Aristotelian terms, spectacle refers to the sensory display that meets the audience of a drama and is ultimately what causes the experience. Our contribution focuses on graphically making changing emotions and social relations, important elements of dramatic stories in our vision, salient to players at the level of spectacle. As a result we have broadened the view of what is important for interactive storytelling, as well as what makes characters believable. So far not very much research has been done on evaluating interactive stories. Experience, the third aspect, is concerned with finding qualitative methods for evaluating the experience of playing an interactive story. In particular we were interested in finding methods that could tell us something about how a players experience evolved over time, in addition to qualities such as agency that have been claimed to be characteristic for interactive stories. Our contribution consists of two methods that we have developed and adapted for the purposes of evaluating interactive stories that can provide such information. The methods have been evaluated on three different interactive storytelling type games.
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| 3. |
- Zdravkovic, Jelena
(författare)
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Process Integration for the Extended Enterprise
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 4. |
- Boström, Gustav, 1973-
(författare)
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Simplifying development of secure software : Aspects and Agile methods
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reducing the complexity of building secure software systems is an important goal as increased complexity can lead to more security flaws. This thesis aims at helping to reduce this complexity by investigating new programming techniques and software development methods for implementing secure software. We provide case studies on the use and effects of applying Aspect-oriented software development to Confidentiality, Access Control and Quality of Service implementation. We also investigate how eXtreme Programming can be used for simplifying the secure software development process by comparing it to the security engineering standards Common Criteria and the Systems Security Engineering Capability Maturity Model. We also explore the relationship between Aspect-oriented programming and Agile software development methods, such as eXtreme Programming.
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| 5. |
- Bylund, Markus, 1971-
(författare)
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A Design Rationale for Pervasive Computing : User Experience, Contextual Change and Technical Requirements
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The vision of pervasive computing promises a shift from information tech-nology per se to what can be accomplished by using it, thereby fundamen-tally changing the relationship between people and information technology. In order to realize this vision, a large number of issues concerning user ex-perience, contextual change, and technical requirements should be ad-dressed. We provide a design rationale for pervasive computing that encom-passes these issues, in which we argue that a prominent aspect of user ex-perience is to provide user control, primarily founded in human values. As one of the more significant aspects of the user experience, we provide an extended discussion about privacy. With contextual change, we address the fundamental change in previously established relationships between the practices of individuals, social institutions, and physical environments that pervasive computing entails. Finally, issues of technical requirements refer to technology neutrality and openness—factors that we argue are fundamen-tal for realizing pervasive computing. We describe a number of empirical and technical studies, the results of which have helped to verify aspects of the design rationale as well as shap-ing new aspects of it. The empirical studies include an ethnographic-inspired study focusing on information technology support for everyday activities, a study based on structured interviews concerning relationships between con-texts of use and everyday planning activities, and a focus group study of laypeople’s interpretations of the concept of privacy in relation to informa-tion technology. The first technical study concerns the model of personal service environments as a means for addressing a number of challenges con-cerning user experience, contextual change, and technical requirements. Two other technical studies relate to a model for device-independent service de-velopment and the wearable server as a means to address issues of continu-ous usage experience and technology neutrality respectively.
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| 6. |
- Ciobanu Morogan, Matei, 1973-
(författare)
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Security system for ad-hoc wireless networks based on generic secure objects
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As computing devices and wireless connectivity become ubiquitous, new usage scenarios emerge, where wireless communication links between mobile devices are established in an ad-hoc manner. The resulting wireless ad-hoc networks differ from classical computer networks in a number of ways, lack of permanent access to the global network and heterogeneous structure being some of them. Therefore, security services and mechanisms that have been designed for classical computer networks are not always the optimal solution in an ad-hoc network environment. The research is focused on analyzing how standard security services that are available in classical networks can be provided in an ad-hoc wireless network environment. The goal is to design a security system optimized for operation in ad-hoc wireless networks that provides the same security services – authentication, access control, data confidentiality and integrity, non-repudiation – currently available in classic wired networks. The first part of the thesis is the design and implementation of a security platform based on generic secure objects. The flexible and modular nature of this platform makes it suitable for deployment on devices that form ad-hoc networks – ranging from Java-enabled phones to PDAs and laptops. We then investigate the problems that appear when implementing in ad-hoc networks some of the security technologies that are standard building blocks of secure systems in classical computer networks. Two such technologies have been found to present problems, namely the areas of certification and access control. In a series of articles, we have described the problems that appear and devised solutions to them by designing protocols, techniques and extensions to standards that are optimized for usage in the ad-hoc network environment. These techniques, together with the functionality provided by the underlying security platform, are used to implement all standard security services – confidentiality, authentication, access control, non repudiation and integrity, allowing to integrate ad-hoc networks into the existing security infrastructure.
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| 7. |
- Davies, Guy, 1962-
(författare)
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Mapping and integration of schema representations of component specefications
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Specification for process oriented applications tends to use languages that suffer from infinite, intractable or unpredictably irregular state spaces that thwart exhaustive searches by verification heuristics. However, conceptual schemas based on FOL, offer techniques for both integrating and verifying specifications in finite spaces. It is therefore of interest to transform process based specifications into conceptual schemata. Process oriented languages have an additional drawback in that reliable inputs to the integration of diverse specifications can result in unreliable outputs. This problem can more easily be addressed in a logic representation in which static and dynamic properties can be examined separately. The first part of the text describes a translation method from the process based language SDL, to first order logic. The usefulness of the method for industrial application has been demonstrated in an implementation. The method devised is sufficiently general for application to other languages with similar characteristics. Main contributions consist of: formalising the mapping of state transitions to event driven rules in dynamic entity-relationship schemas; analysing the complexity of various approaches to decomposing transitions; a conceptual representation of the source language that distinguishes meta- and object models of the source language and domain respectively. The second part of the text formally describes a framework for the integration of schemata that allows the exploration of their properties in relation to each other and to a set of integration assertions. The main contributions are the formal framework; an extension to conflicts between agents in a temporal action logic; complexity estimates for various integration properties.
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| 8. |
- Jansson, Eva, 1971-
(författare)
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Working together when being apart : An analysis of distributed collaborative work through ICT from an organizational and psychosocial perspective
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of the research is to analyze collaboration and communication in distributed teams working together through ICT (Information and Communication Technology), to provide an overview and a broader understanding of important areas that require consideration. The analysis is from an organizational, psychosocial and managerial perspective, with the aim to support the development of strategies and the creation of more efficient and pleasant distributed work environments. Research questions concern the psychosocial work environment; differences, problems and opportunities for distributed teams, with deeper analysis of areas that was demonstrated particularly difficult. The analysis is concretized into advice to guide distributed teams; common problem areas are pointed out and an attempt on a theoretical model of distributed project work is made. A solid ground for continued research in the area as well as possibilities to support distributed teams is provided. The research was mainly conducted in globally distributed project courses at a university level, where students communicated and collaborated through ICT. The results apply on distributed projects, but can also be relevant for other areas in the new ICT facilitated work environment. The research has been conducted by investigating how team members behave in and perceive distributed work environments; analyzing how i.e. variations in organization, work, social activities and behavior affect how well the collaboration and communication work Teams working in distributed projects go through the same stages and encounter the same problems as any other team. Some problems become harder to overcome, there are new obstacles, at the same time as other problems become less noticeable and new opportunities arise. The base for collaboration and communication changes when team members don't see each other regularly. Teams are entailed to use ICT for basically all communication and various media demands alterations in behavior, as well as it alters the relation between senses and how people perceive things. Distributed team members don't have the same awareness of each other and get fewer cues to interpret situations and handle teambuilding, motivational problems and conflicts. Several of the regular ways to start socializing, build trust and get a common base for understanding and collaboration are not present in a distributed environment. There is no physical team space to meet in and team members don't "see" each other on a regular basis. It is possible to successfully work in distributed teams without regular face-to-face meetings even if it is more intricate. It will always be different, and the big danger is believing that it won't. Working in distributed teams is not necessarily worse, but there are no effortless solutions for replacing face-to-face encounters. Distributed projects require effort, but conducted right it can be a rewarding experience that brings an extra dimension to the project work. To make distributed projects work well it is necessary to consider technological issues as well as their effects on individuals. It is essential to understand the new issues people encounter when moving to a distributed work environment and the interrelations between different areas and variables.
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| 9. |
- Jonsson, Martin, 1973-
(författare)
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Sensing and Making Sense : Designing Middleware for Context Aware Computing
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 10. |
- Juell-Skielse, Gustaf, 1964-
(författare)
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ERP adoption in small and medium sized enterprises
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Enterprise resource planning (ERP) is established among a majority of small and medium sized companies in Kista Science City and seems to have a positive effect on organizational effectiveness. Kista Science City is Sweden’s largest corporate centre, with more companies and employees in a limited area than anywhere else in Europe. This study looks at the level of adoption of ERP functions, perceived organizational effectiveness and critical success factors. The most common use of ERP is for financial control and reporting, followed by order entry and purchasing. A significant relationship between the level of adoption and organizational effectiveness was found. Although Enterprise Resource Planning has become an established phenomenon the investments in ERP software are far from fully utilized. Most companies have started to use ERP to integrate functional areas but few companies have moved to extended ERP (ERPII). The adoption of functionality for customer relationship management seems to have started, but the use of e-commerce, business intelligence and supply chain management is very low. Different reasons for the low level of adoption are discussed and it is suggested that the interrelationship between SMEs and ERP-consultants be investigated further. ERP-consultants are important change agents and knowledge transfers for ERP and one way to interpret the data is that ERP-consultants are caught in a negative spiral where they focus on installations and technical maintenance of core ERP, which prevents them from developing new, extended ERP competence. An analysis of critical success factors showed that although technical competence was important socially oriented factors such as project teamwork and composition as well as communication had a greater effect on organizational effectiveness. Surprisingly enough, project management did not have any effect on organizational effectiveness. Common implementation methods for ERP focus on project management. It is suggested to further analyse if these methods could be improved by an increased adaptability to differences in company settings and requirements as well as through a better use of critical success factors. Organizational effectiveness can be measured in many ways and it was found that the success factors varied in terms of how they correlated with different measures. In the next step, the doctorial thesis, it is suggested that a prototype environment is developed to stimulate an increased use of extended ERP among small and medium sized companies. Several actors, such as SMEs, consultants, vendors and students would be involved. The prototype environment could facilitate enhancements of implementation methods and reduction of implementation costs through the development of reusable objects such as add-on solutions, process maps and system configurations. It could also help small and medium sized companies to investigate the business benefits of ERP by increasing involvement and familiarity while on the same time decrease costs and risks.
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| 11. |
- Kabilan, Vandana, 1973-
(författare)
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Ontology for Information Systems (04IS) Design Methodology : Conceptualizing, Designing and Representing Domain Ontologies
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Globalization has opened new frontiers for business enterprises and human communication. There is an information explosion that necessitates huge amounts of information to be speedily processed and acted upon. Information Systems aim to facilitate human decision-making by retrieving context-sensitive information, making implicit knowledge explicit and to reuse the knowledge that has already been discovered. A possible answer to meet these goals is the use of Ontology. Ontology has been studied for a long time in the fields of AI, Logic and Linguistics. Current state-of-the art research in Information Systems has focused on the use of ontologies. However, there remain many obstacles for the practical and commercial use of ontologies for Information Systems. One such obstacle is that current Information System designers lack the know-how to successfully design an ontology. Current ontology design methodologies are difficult to use by Information Systems designers having little theoretical knowledge of ontology modeling. Another issue is that business enterprises mostly function in the social domain where there are complex underlying semantics and pragmatics involved. This research tries to solve some of these issues by proposing the Ontology for Information Systems (O4IS) Design Methodology for the design of ontologies for Information Systems. The research also proposes a Unified Semantic Procedural Pragmatic Design for explicit conceptualization of the semantics and pragmatics of a domain. We further propose a set of Semantic Analysis Representations as conceptual analysis patterns for semantic relationship identification. We also put forward the Dual Conceptual Representation so that the designed ontology is understandable by both humans and machines. Finally, a logical architecture for domain ontology design called the Multi-Tier Domain Ontology Architecture is proposed. We follow the design science in Information Systems research methodology. The proposed solutions are demonstrated through two case studies carried out in different domains. The first case study is that of business contract knowledge management, which focuses on the analysis of contractual obligations, their fulfillment via the performance of business actions, and the deduction of a contract compliant workflow model. The second case study relates to military operations simulations and modeling. The emphasis in this case study is to analyze, model and represent the domain knowledge as a re-usable resource to be used in a number of modeling and simulation applications.
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| 12. |
- Li, Wei, 1979-
(författare)
-
Towards a Person-Centric Context Aware System
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A recent trend is to integrate sensing, communication, and computation into every aspect of our daily life, ranging from various user devices to physical environment. The goal is to give computer systems an awareness of the users and their situations, so that they can support their diverse interaction needs at anytime, any place. A major problem hindering achieving this promising goal is that the users usually play a passive role in these systems with little possibility to interfere with the processing. Additionally, there is no option for the user to prevent being monitored by the system. This drawback stems from the lack of an independent and consistent user oriented viewpoint in current ubiquitous computing systems, which can easily result in the occurrence of user privacy invasion and misinterpretation of the user. To overcome this problem, this thesis proposes a Person-Centric Context Aware System architecture, helping to preserve an independent representation for each individual user to different computer systems. The main idea embraced in this system architecture is that the users are the owners of their personal information, thus they should have the control of how their information will be used by others. In the design of this system architecture, a number of important issues have been addressed with their corresponding solutions in terms of different system components. Among these issues, three are identified as the most crucial ones, and hence these issues have received most of our efforts to provide better solutions: Context Data Communication, Location Detection, and Communication Anonymity support. A prototype system constructed during the process of developing each specific solution is also presented. Together these comprise the main contributions of this thesis work. Finally, our concluding remarks are presented together with our planned future work, based on the current implementation of a Person-Centric Context Aware System.
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| 13. |
- Mattsson, Johan, 1971-
(författare)
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Interaction through spells : establishing traces of nvisible onnections
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In post desktop and co-located collaborative computer interaction as well as in real world settings, there are usually both private and shared work threads going on. For example: private, individual activities such thinking, taking notes, (dreaming…) and the shared collaborative work tasks such discussing, presenting or producing sketches or document drafts etc. A central issue in collaborative activities is to share awareness of the ongoing activity as an option for the co-workers to influence the shared work process. Significant passages in cooperative activities are the configurations of common tasks, such as entering, leaving or changing the users acting and participation in shared activities. Spells introduce real-world user interfaces that provide tools to allow the users to easily and intuitively express how and when they intend to contribute to interactive activities. This expression both makes the user and the co-workers able to reveal and interpret the interactive environment and signaling meaning for all participants. The Spells is a metaphor system for interaction within co-located collaborative work settings. The Spells are supported by a platform for implementing artifacts that supports the Spells based on that platform two prototype systems have been implemented cases of the Spells, Magic Bowl and iwand. The Spells provide a user interaction form that bridges gaps between co-located entities, addressing both people and devices in a world of ubiquitous computing.
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| 14. |
- Mattsson, Johan, 1971-
(författare)
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Pointing, Placing, Touching : Physical Manipulation and Coordination Techniques for Interactive Meeting Spaces
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the design and study of dedicated ubiquitous computing environments, efforts to enhance and support co-located collaborative activities and work have been a particular focus. In his vision of ubiquitous computing, Mark Weiser foresees a new era of computing, one that closes and follows on from the era of Personal Computing (Post Desktop). The vision involves simultaneous computations facilitated by a number of technical resources (services and artifacts) available in the environment. Ubiquitous Computing also draws on the perspective of embodied interaction: that our overall physical and social interaction, and the design of artifacts supporting interaction with people, places, and the environment, are two different perspectives sharing a common goal. This thesis addresses three critical aspects of interactive meeting spaces: Multi-device selection, Multi-device setup, and Multi-device direct manipulation. To do so, physical interaction techniques have been designed that make more visible the critical and central co-located manipulation and coordination actions in interactive meeting spaces. The tree designed physical interaction techniques, that have been developed and investigated are: the iwand, a pointing technique; the Magic Bowl, a placing technique; and Physical Cursors, a touching technique. In evaluation of the interaction techniques, addressed five problems that originated in observations during the development of interactive meeting spaces. How to: 1) identify and manipulate a physical object in order to select and control a particular service; 2) support the control of complementary combinations of services through physical manipulation; 3) capture, store and recall a preset group of services; 4) maintain and reuse presets, to preserve the prerequisite for a scene, under continually changing circumstances; and 5) design ways to manipulate physical widgets to enable a social protocol for coordination as an alternative to individual (invisible) manipulation? A tentative design pattern language developed, along with “sharing control”, a further developed sample of a design pattern, which applies to physical manipulations in interactive meeting spaces. Additionally, principles are described for conducting long-term studies of living-laboratory observations and for revisiting central design decisions. The principles and design patterns are drawn from designed interaction techniques and from the design and deployment of interactive meeting spaces.
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| 15. |
- Odelstad, Jan
(författare)
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Many-Sorted Implicative Conceptual Systems
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 16. |
- Sandholm, Thomas, 1974-
(författare)
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Statistical Methods for Computational Markets : Proportional Share Market Prediction and Admission Control
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- We design, implement and evaluate statistical methods for managing uncertainty when consuming and provisioning resources in a federated computational market. To enable efficient allocation of resources in this environment, providers need to know consumers' risk preferences, and the expected future demand. The guarantee levels to offer thus depend on techniques to forecast future usage and to accurately capture and model uncertainties. Our main contribution in this thesis is threefold; first, we evaluate a set of techniques to forecast demand in computational markets; second, we design a scalable method which captures a succinct summary of usage statistics and allows consumers to express risk preferences; and finally we propose a method for providers to set resource prices and determine guarantee levels to offer. The methods employed are based on fundamental concepts in probability theory, and are thus easy to implement, as well as to analyze and evaluate. The key component of our solution is a predictor that dynamically constructs approximations of the price probability density and quantile functions for arbitrary resources in a computational market. Because highly fluctuating and skewed demand is common in these markets, it is difficult to accurately and automatically construct representations of arbitrary demand distributions. We discovered that a technique based on the Chebyshev inequality and empirical prediction bounds, which estimates worst case bounds on deviations from the mean given a variance, provided the most reliable forecasts for a set of representative high performance and shared cluster workload traces. We further show how these forecasts can help the consumers determine how much to spend given a risk preference and how providers can offer admission control services with different guarantee levels given a recent history of resource prices.
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| 17. |
- Sundgren, David
(författare)
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Distribution of expected utility in second-order decision analysis
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In decision analysis maximising the expected utility is an often used approach in choosing the optimal alternative. But when probabilities and utilities are vague or imprecise expected utility is fraught with complications. Studying second-order effects on decision analysis casts light on the importance of the structure of decision problems, pointing out some pitfalls in decision making and suggesting an easy to implement and easy to understand method of comparing decision alternatives. The topic of this thesis is such second-order effects of decision analysis, particularly with regards to expected utility and interval-bound probabilities. Explicit expressions for the second-order distributions inherent in interval-bound probabilities in general and likewise for distributions of expected utility for small decision problems are produced. By investigating these distributions the phenomenon of warping, that is concentration of belief, is studied.
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| 18. |
- Sundgren, David
(författare)
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Distribution of expected utility in second-order decision analysis
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In explicatione consiliorum, maxima facere communis utilitas saepe trita ratio deligendi meliorem optionem est. Verum si probabilitates et utilitates incertae vel dubiae sint, communis utilitas perturbationes affert. Studium secundi ordinis effectuum in explicatione consiliorum explanat momentum structurae quaestionium consilii, insidias aliquas ad consilium capiendum indicat et facilem ad efficiendum et intellegendum rationem comparandi varia consilia suadet. Haec thesis tractat de secundi ordinis effectibus explicationis consilii, praesertim de commune utilitate et de probabilitatibus coniunctis intervallo. Voces apertae distributionum ordinis secundi in probabilitatibus intervallo conjunctis insitarum omnino et item distributionum utilitatis expectatae in parvis quaestionibus consiliorum eduntur. His distributionibus cognitis studetur res inflexionis, aliter dictu intentio fidei.
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| 19. |
- Svensson, Harald, 1973-
(författare)
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Developing support for agile and plan-driven methods
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software development processes provide means to develop software in a structured and disciplined way. Although these processes provide support for how to develop software, there is still a challenge to successfully apply them in practice. Thus, there is a need to support management of software development processes so that their use generate as good results as possible. The thesis presents support for agile and plan-driven methods, which represent different approaches for developing software. The support for agile methods was developed after performing a case study and a survey, in order to gather empirical data. The support for plan-driven methods was developed after applying a combination of research methods such as a controlled experiment, grounded theory and theoretical analysis. The developed support for managing agile and plan-driven methods is based on the results from an extensive empirical basis consisting of five studies, with both qualitative and quantitative approaches. The developed support for agile methods consists of a set of guidelines for organizations to consider when introducing agile methods. The developed support for plan-driven methods concerns support for the Business Process Analyst role to manage its work in a software development context. Further, the Personal Software Process is allocated to several roles in order to increase its applicability.
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| 20. |
- Vanourek, Gregg, 1970-
(författare)
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Life Entrepreneurs
- 2008. - 1
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Bok (populärvet., debatt m.m.)
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| 21. |
- Wrigstad, Tobias, 1976-
(författare)
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Ownership-Based Alias Managemant
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 22. |
- Aggestam, Lena
(författare)
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IT-supported Knowledge Repositories : Increasing their Usefulness by Supporting Knowledge Capture
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organizations use various resources to achieve business objectives, and for financial gain. In modern business, knowledge is a critical resource, and organizations cannot afford not to manage it. Knowledge Management (KM) aims to support learning and to create value for the organization. Based on three levels of inquiry (why, what, how), work presented in this thesis includes a synthesized view of the existing body of knowledge concerning KM and hence a holistic characterization of KM. This characterization reveals a strong dependency between KM and Learning Organization (LO). Neither of them can be successful without the other. We show that a KM project resulting in an IT-supported knowledge repository is a suitable way to start when the intention is to initiate KM work. Thus, our research focuses on ITsupported knowledge repositories.Large numbers of KM projects fail, and organizations lack support for their KM undertakings. These are the main problems that our research addresses. In order for an IT-supported knowledge repository to be successful, it must be used. Thus, the content of the repository is critical for success. Our work reveals that the process of capturing new knowledge is critical if the knowledge repository is to include relevant and updated knowledge. With the purpose of supporting the capture process, this thesis provides a detailed characterization of the capture process as well as guidance aiming to facilitate the implementation of the capture process in such a way that knowledge is continuously captured, also after the KM implementation project is completed. We argue that the continuous capture of new knowledge which can potentially be stored in the knowledge repository will, in the long term perspective, have a positive influence on the usefulness of the repository. This will most likely increase the number of users of the repository and accordingly increase the number of successful KM projects.All the work presented in this thesis is the result of a qualitative research process comprising a literature review and an empirical study that were carried out in parallel. The empirical study is a case study inspired by action research, which involved participation in the project Efficient Knowledge Management and Learning in Knowledge Intensive Organizations (EKLär).
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| 23. |
- Aidemark, Jan
(författare)
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Strategic Planning of Knowledge Management Systems : A Problem Exploration Approach
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Knowledge management (KM) is focused on the problems and opportunities of using organizational knowledge as a resource. Information systems that are used to support KM processes are called knowledge management systems (KMS). A KMS is distinguished from any information system by the organizational processes that it supports, that is, creation, capture, storage and dissemination of competences and knowledge. The research area can be summarized as: “Perspectives and frameworks for the strategic planning of knowledge management systems, i.e. information systems for the support of organizational knowledge processes”. We approach the problem area from a strategic point of view, assuming that the problems of the area are based on a socio-technical dimension and that a multiple-paradigm approach is necessary for dealing with the problems of the various KM areas. The research strategy applied to achieve this is interpretative case studies. A number of case studies are used for exploring KM planning areas, developing frameworks for planning and testing the resulting approach. The empirical material consists of three main case studies, together with a number of secondary cases by other writers in the KM field. The outcome of the research is a planning approach, which is given the name: “The problem exploration approach”. The approach is intended for the generation of ideas of possible systems, as a strategic part of knowledge management systems planning. The purpose of the planning approach is to support the creation of a portfolio of KMS. A KMS portfolio is a structured set of information systems that could be developed for an organizational unit. The approach consists of five planning frameworks, all targeting different aspects of an organization. “The problem exploration approach” and its development process are then examined for more general insights into the subject of strategic KM planning. As an outcome of this examination a 12-point program for balancing a planning approach is presented.
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| 24. |
- Bakari, Jabiri Kuwe, 1970-
(författare)
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A Holistic Approach for Managing ICT Security in Non-Commercial Organisations : A Case Study in a Developing Country
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 25. |
- Björck, Fredrik, 1972-
(författare)
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Discovering Information Security Management
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is concerned with issues relating to the management of information security in organisations, motivated by the need for cost-efficient information security.It is based on the assumption that: in order to achieve cost-efficient information security, the point of departure must be knowledge about the empirical reality in which the management of information security takes place.The data gathering instruments employed are questionnaires with open-ended questions and unstructured research interviews. The empirical material is analysed, and conclusions are drawn following the principles of Grounded Theory. Data sources are professionals in the area of information security management, including information security consultants (n=13), certification auditors (n=8), and information security managers (n=8).The main contributions are: an integrated model illustrating the experts’ perceptions concerning the objectives, actors, resources, threats, and countermeasures of information security management; a framework for the evaluation, formation, and implementation of information security management systems; a new approach for the evaluation of information security in organisations; a set of success factors concerning the formation of information security management systems; and a problem inventory concerning the value and assessment of information security education and training.
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