The model and design of a generic security provider provides a comprehensive set of security services, mechanisms, encapsulation methods, and security protocols for Java applications. The model is structured in four layers; each layer provides services to the upper layer and the top layer provide services to applications. The services reflect security requirements derived from a wide range of applications; from small desktop applications to large distributed enterprise environments. Based on the abstract model, this paper describes design and implementation of an instance of the provider comprising various generic security modules: symmetric key cryptography, asymmetric key cryptography, hashing, encapsulation, certificates management, creation and verification of signatures, and various network security protocols. This paper also describes the properties extensibility, flexibility, abstraction, and compatibility of the Java Security Provider.

The model and design of a generic security provider provides a comprehensive set of security services, mechanisms, encapsulation methods, and security protocols for Java applications. The model is structured in four layers; each layer provides services to the upper layer and the top layer provide services to applications. The services reflect security requirements derived from a wide range of applications; from small desktop applications to large distributed enterprise environments. Based on the abstract model, this paper describes design and implementation of an instance of the provider comprising various generic security modules: symmetric key cryptography, asymmetric key cryptography, hashing, encapsulation, certificates management, creation and verification of signatures, and various network security protocols. This paper also describes the properties for extensibility, flexibility, abstraction, and compatibility of the Java security provider.

This paper describes the design and implementation of a comprehensive system for protection of Web contents. In this design, new security components and extended security features are introduced in order to protect Web contents ageist various Web attacks. Components and extended security features are: protection of Web pages using strong encryption techniques, encapsulation of Web contents and resources in PKCS#7, extended secure execution environment for Java Web Server, eXtensible Access Control Markup Language (XACML) based authorization policies, and secure Web proxy. Design and implementation of our system is based on the concepts of generic security objects and component-based architecture that makes it compatible with exiting Web infrastructures without any modification.

This paper describes security extensions of various Windows components based on usage of FIPS 201 (PIV) smart cards. Compared to some other similar solutions, this system has two significant advantages: first, smart cards are based on FIPS 201 standard and not on some proprietary technology; second, smart card security extensions represent an integrated solution, so the same card is used for security of several Microsoft products. Furthermore, our smart card system uses FIPS 201 applet and middleware with smart card APIs, so it can also be used by other developers to extend their own applications with smart card functions in a Windows environment. We support the following security features with smart cards: start-up authentication (based on PIN and/or fingerprint), certificate-based domain authentication, strong authentication, and protection of local resources. We also integrated our middleware and smart cards with MS Outlook and MS Internet Explorer.

We describe experiences and insights from adapting the Subversion version control system to use the network service of two information-centric networking (ICN) prototypes: OpenNetInf and CCNx. The evaluation is done using a local collaboration scenario, common in our own project work where a group of people meet and share documents through a Subversion repository. The measurements show a performance benefit already with two clients in some of the studied scenarios, despite being done on un-optimised research prototypes. The conclusion is that ICN clearly is beneficial also for non mass-distribution applications. It was straightforward to adapt Subversion to fetch updated files from the repository using the ICN network service. The adaptation however neglected access control which will need a different approach in ICN than an authenticated SSL tunnel. Another insight from the experiments is that care needs to be taken when implementing the heavy ICN hash and signature calculations. In the prototypes, these are done serially, but we see an opportunity for parallelisation, making use of current multi-core processors.

In this paper we study the relation between energy-efficiencyand parallel executions when implemented with a fine-grained task-centricprogramming model. Using a simulation framework comprised of an ar-chitectural simulator and a power and area estimation tool, we haveinvestigated the potential energy-savings when employing parallelism onmulti-cores system. In our experiments with 2 - 8 multi-cores systems,we employed frequency and voltage scaling in order to keep the relativeperformance of the systems constant and measured the energy-efficiencyusing the Energy-delay-product. Also, we compared the energy consump-tion of the parallel execution against the serial one. Our results showthat through judicious choice of load balancing parameters, significantimprovements of around 200 % in energy consumption can be acheived.

Autonomic computing is a paradigm that aims at reducing administrative overhead by using autonomic managers to make applications self-managing. To better deal with large-scale dynamic environments; and to improve scalability, robustness, and performance; we advocate for distribution of management functions among several cooperative autonomic managers that coordinate their activities in order to achieve management objectives. Programming autonomic management in turn requires programming environment support and higher level abstractions to become feasible.

In this thesis we present an introductory part and a number of papers that summaries our work in the area of autonomic computing. We focus on enabling and achieving self-management for large scale and/or dynamic distributed applications. We start by presenting our platform, called Niche, for programming self-managing component-based distributed applications. Niche supports a network-transparent view of system architecture simplifying designing application self-* code.  Niche provides a concise and expressive API for self-* code. The implementation of the framework relies on scalability and robustness of structured overlay networks. We have also developed a distributed file storage service, called YASS, to illustrate and evaluate Niche.

After introducing Niche we proceed by presenting a methodology and design space for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to the design and development of an improved version of our distributed storage service YASS as a case study.

We continue by presenting a generic policy-based management framework which has been integrated into Niche. Policies are sets of rules that govern the system behaviors and reflect the business goals or system management objectives. The policy based management is introduced to simplify the management and reduce the overhead, by setting up policies to govern system behaviors. A prototype of the framework is presented and two generic policy languages (policy engines and corresponding APIs), namely SPL and XACML, are evaluated using our self-managing file storage application YASS as a case study.

Finally, we present a generic approach to achieve robust services that is based on finite state machine replication with dynamic reconfiguration of replica sets. We contribute a decentralized algorithm that maintains the set of resource hosting service replicas in the presence of churn. We use this approach to implement robust management elements as robust services that can operate despite of churn.

Autonomic managers are the main architectural building blocks for constructing self-management capabilities of computing systems and applications. One of the major challenges in developing self-managing applications is robustness of management elements which form autonomic managers. We believe that transparent handling of the effects of resource churn (joins/leaves/failures) on management should be an essential feature of a platform for selfmanaging large-scale dynamic distributed applications, because it facilitates the development of robust autonomic managers and hence improves robustness of self-managing applications. This feature can be achieved by providing a robust management element abstraction that hides churn from the programmer. In this paper, we present a generic approach to achieve robust services that is based on finite state machine replication with dynamic reconfiguration of replica sets. We contribute a decentralized algorithm that maintains the set of nodes hosting service replicas in the presence of churn. We use this approach to implement robust management elements as robust services that can operate despite of churn. Our proposed decentralized algorithm uses peer-to-peer replica placement schemes to automate replicated state machine migration in order to tolerate churn. Our algorithm exploits lookup and failure detection facilities of a structured overlay network for managing the set of active replicas. Using the proposed approach, we can achieve a long running and highly available service, without human intervention, in the presence of resource churn. In order to validate and evaluate our approach, we have implemented a prototype that includes the proposed algorithm.

  Currently, increasing costs and escalating complexities are primary issues in the distributed system management. The policy based management is introduced to simplify the management and reduce the overhead, by setting up policies to govern system behaviors. Policies are sets of rules that govern the system behaviors and reflect the business goals or system management objectives. This paper presents a generic policy-based management framework which has been integrated into an existing distributed component management system, called Niche, that enables and supports self-management. In this framework, programmers can set up more than one Policy-Manager-Group to avoid centralized policy decision making which could become a performance bottleneck. Furthermore, the size of a Policy-Manager-Group, i.e. the number of Policy-Managers in the group, depends on their load, i.e. the number of requests per time unit. In order to achieve good load balancing, a policy request is delivered to one of the policy managers in the group randomly chosen on the fly. A prototype of the framework is presented and two generic policy languages (policy engines and corresponding APIs), namely SPL and XACML, are evaluated using a self-managing file storage application as a case study.

Achieving self-management can be challenging, particularly in dynamic environments with resource churn (joins/leaves/failures). Dealing with the effect of churn on management increases the complexity of the management logic and thus makes its development time consuming and error prone. We propose the abstraction of robust management elements (RMEs), which are able to heal themselves under continuous churn. Using RMEs allows the developer to separate the issue of dealing with the effect of churn on management from the management logic. This facilitates the development of robust management by making the developer focus on managing the application while relying on the platform to provide the robustness of management. RMEs can be implemented as fault-tolerant long-living services. We present a generic approach and an associated algorithm to achieve fault-tolerant long-living services. Our approach is based on replicating a service using finite state machine replication with a reconfigurable replica set. Our algorithm automates the reconfiguration (migration) of the replica set in order to tolerate continuous churn. The algorithm uses P2P replica placement schemes to place replicas and uses the P2P overlay to monitor them. The replicated state machine is extended to analyze monitoring data in order to decide on when and where to migrate. We describe how to use our approach to achieve robust management elements. We present a simulation-based evaluation of our approach which shows its feasibility.

The wide spread of Web 2.0 applications with rapidly growing amounts of user generated data, such as, wikis, social networks, and media sharing, have posed new challenges on the supporting infrastructure, in particular, on storage systems. In order to meet these challenges, Web 2.0 applications have to tradeoff between the high availability and the consistency of their data. Another important issue is the privacy of user generated data that might be caused by organizations that own and control datacenters where user data are stored. We propose a large-scale, robust and fault-tolerant key-value object store that is based on a peer-to-peer network owned and controlled by a community of users. To meet the demands of Web 2.0 applications, the store supports an API consisting of different read and write operations with various data consistency guarantees from which a wide range of web applications would be able to choose the operations according to their data consistency, performance and availability requirements. For evaluation, simulation has been carried out to test the system availability, scalability and fault-tolerance in a dynamic, Internet wide environment.

  Autonomic computing is a paradigm that aims at reducing administrative overhead by providing autonomic managers to make applications selfmanaging. In order to better deal with dynamic environments, for improved performance and scalability, we advocate for distribution of management functions among several cooperative managers that coordinate their activities in order to achieve management objectives. We present a methodology for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to design and development of a distributed storage service as a case study. The storage service prototype has been developed using the distributing component management system Niche. Distribution of autonomic managers allows distributing the management overhead and increased management performance due to concurrency and better locality.

An on-chip novel design of a single clock charge pump for high voltage applications is being presented in this paper. The proposed charge pump is designed using AMS 0.35μm technology. Three stages of the proposed charge pump are being used for the results verification and comparing them with the six stages of Dickson charge pump designed with diode connected PMOS. The proposed charge pump gives an output voltage of 5.34V at no-load. The proposed charge pump gives maximum efficiencies of 89% on 1MHz frequency and 87.4% on 5MHz frequency using 1Mohm load resistance. The efficiency and the output voltage including voltage gain per stage of the proposed charge pump are higher than the Dickson charge pump measured under similar conditions mediating that the performance of proposed charge pump is better than the Dickson charge pump.

We present a framework for building and evaluating P2P systems in simulation, local execution, and distributed deployment. Such uniform system evaluations increase confidence in the obtained results. We briefly introduce the Kompics component model and its P2P framework. We describe the component architecture of a Kompics P2P system and show how to define experiment scenarios for large dynamic systems. The same experiments are conducted in reproducible simulation, in real-time execution on a single machine, and distributed over a local cluster or a wide area network. This demonstration shows the component oriented design and the evaluation of two P2P systems implemented in Kompics: Chord and Cyclon. We simulate the systems and then we execute them in real time. During real-time execution we monitor the dynamic behavior of the systems and interact with them through their web-based interfaces. We demonstrate how component-oriented design enables seamless switching between alternative protocols.

At the core of any distributed system is a set of concurrent distributed algorithms that coordinate the functionality of the distributed system. We present a software architecture, Kompics that is component-based and compositional which facilitates building distributed protocols. The underlying computation model subsumes that of event-based systems, SEDA (staged event-driven architecture.) and thread-based models. We illustrate various salient features of Kompics such as ease of use, compositionality and configurability through a series of well chosen distributed protocols.

Multiple constellations has been proposed recently as a way of improving the system performance when used in conjunction with Orthogonal Transmit Diversity (OTD) for high level linear modulation schemes. This paper considers the use of multiple constellations in Multiple Input Multiple Output (MIMO) antenna systems. The premise is that the same modulation scheme is used with different bits to symbols mapping for each branch. This improved beamforming results in better performance as compared to MIMO-MRC where the same bits to symbols mapping is used on all branches. Analytical expression for Symbol Error Probability (SEP) is derived. The results obtained show that the new proposed improved beamforming scheme outperforms conventional MIMO-MRC with a performance dividend that increases with the linear modulation level.

The importance of domain knowledge in the design of effective evolutionary algorithms (EAs) is widely acknowledged in the meta-heuristics community. In the last few decades, a plethora of EAs has been manually designed by domain experts for solving domain-specific problems. Specialization has been achieved mainly by embedding available domain knowledge into the algorithms. Although programming libraries have been made available to construct EAs, a unifying framework for designing specialized EAs across different problem domains and branches of evolutionary computing does not exist yet. In this paper, we address this issue by introducing an evolutionary computing modeling language (ECML) which is based on the unified modeling language (UML). ECML incorporates basic UML elements and introduces new extensions that are specially needed for the evolutionary computation domain. Subsequently, the concept of meta evolutionary algorithms (MEAs) is introduced as a family of EAs that is capable of interpreting ECML. MEAs are solvers that are not restricted to a particular problem domain or branch of evolutionary computing through the use of ECML. By separating problem-specific domain knowledge from the EA implementation, we show that a unified framework for evolutionary computation can be attained. We demonstrate our approach by applying it to a number of examples.

This paper revisits the problem of the readiness for field deployments of wireless sensor networks by assessing the relevance of using Open Hardware and Software motes for environment monitoring. We propose a new prototype wireless sensor network that fine-tunes SquidBee motes to improve the life-time and sensing performance of an environment monitoring system that measures temperature, humidity and luminosity. Building upon two outdoor sensing scenarios, we evaluate the performance of the newly proposed energy-aware prototype solution in terms of link quality when expressed by the Received Signal Strength, Packet Loss and the battery lifetime. The experimental results reveal the relevance of using the Open Hardware and Software motes when setting up outdoor wireless sensor networks.

Soft-core programmable processors mapped onto fieldprogrammable gate arrays (FPGA) can be considered as equivalents to a microcontroller. They combine central processing units (CPUs), caches, memories, and peripherals on a single chip. Soft-cores processors represent an increasingly common embedded software implementation option. Modern FPGA soft-cores are parameterized to support application-specific customization. However, these softcore processors are designed to be used in uniprocessor system, not for multiprocessor system. This project describes an implementation to solve the cache coherency problem in an ALTERA Nios II soft-core multiprocessor system.

User experience has been extensively discussed in literature, yet the idea of applying it to explain and comprehend the conceptualization of Mobile Learning (ML) is relatively new. Consequently much of the existing works are mainly theoretical and they concentrate to establish and explain the relationship between ML and experience. Little has been done to apply or adopt it into practice. In contrast to the currently existing approaches, this paper presents an ontology to support Citywide Mobile Learning (CML). The ontology presented in this paper addresses three fundamental aspects of CML, namely User Model, User Experience and Places/Spaces which exist in the city. The ontology presented here not only attempts to model and translate the theoretical concepts such as user experience and Place/Spaces for citywide context for Mobile Learning, but also apply them into practice. The discussed ontology is used in our system to support Place/Space based CML.

Failure detection and traffic redirection are implemented in an OpenFlow switch. Link failure detection packets, such as Bidirectional Forwarding Detection (BFD) packets, are periodically sent out on links to peer OpenFlow switches, such as via the Multi-protocol Label Switching (MPLS) Transport Profile (MPLS-TP). Link failure detection packets are received from the peer OpenFlow switches on the links, and monitored. A link failure is detected if no incoming link failure detection packets are received on a link for a predetermined interval. In the event of a link failure, traffic is redirected from the failed link to a backup link by altering entries on a flow table of the OpenFlow switch.

To enhance the wireless bandwidth utilization, new forms of innovative spectrum policies, dynamically sharing channels over time and space, have been discussed. Dynamic spectrum access lets systems share the spectrum, to achieve better band-width utilization and trunking gains. In this work, we consider a case where such access is performed in an uncoordinated fashion. The paradigm shift to open frequency bands implies a need to investigate and verify resulting capacity gains. Herein, we give a general method for evaluating system capacity subject to outage probability constraints over fading channels, in an unlicensed band environment with uncoordinated systems. The channel fading effects include both attenuation, shadowing and multipath propagation and we end up with expressions, which are solved by numerical integration. The spectrum sharing is here performed by means of autonomous dynamic channel allocation (DCA), and we compare two DCA methods, maximum SIR DCA and random DCA.

Lane detection is an important element of most driver assistance applications. A new lane detection technique that is able to withstand some of the common issues like illumination changes, surface irregularities, scattered shadows, and presence of neighboring vehicles is presented in this paper. At first, inverse perspective mapping and color space conversion is performed on the input image. Then, the images are cross-correlated with a collection of predefined templates to find candidate lane regions. These regions then undergo connected components analysis, morphological operations, and elliptical projections to approximate positions of the lane markers. The implementation of the Kalman filter enables tracking lane markers on curved roads while RANSAC helps improve estimates by eliminating outliers. Finally, a new method for calculating errors between the detected lane markers and ground truth is presented. The developed system showed good performance when tested with real-world driving videos containing variations in illumination, road surface, and traffic conditions.

At the present Net Work Period of the IT history deep changes are taken place in collaboration between people and human communication, its structure, quantity, and quality. A dominating steering factor for the design and structure of work life as well as private life is the convergence of three technologies, computer technology, tele technology and media technology (ICT). Telecommunication technology has come to play a more a more dominant role in this convergence, especially internet and web technology. Embedded (ubiquitous) computer technology is making the process invisible, and media technology converges within itself (multimedia or cross media). Well functioning organizational and psychosocial communication are an important prerequisite for successful industrial and social change in the ICT society. Managing and working in an organization organized as a network, involves communication between people, groups, units, other organisations, and various combinations of these entities. ICT applications together with deep knowledge and insights in organisational design and management (ODAM) are the keys to social change. The author describes her convergence theory on ICT and Psychosocial Life Environment with special emphasis on psychosocial communication and sustainability in the Net Era of the ICT society.

As a discipline, Informatics has developed over the years from its initial focus on data processing and software development, towards a more recent emphasis on people’s use of technology and its impact on their working and private lives. Gunilla Bradley, an internationally recognized expert in this field, has researched this area for many years and here, authors this indispensable volume on the topic. Providing a broad and deep analysis of the relationship between people, ICT, society and the environment, Bradley examines the impact on/change in organizations and individuals, both in the workplace and in the home. Taking a firmly humanistic view she also looks to the future as ICT increasingly transforms and impacts on our lives, and explores issues including stress, power, competence and psychosocial communication. She proposes normative research questions for the future and presents actions to achieve the Good ICT society. This thought-provoking book will be of interest to students and academics studying social informatics, computing and MIS as well as organizational behaviour, sociology, psychology and communications. Research-based and cross-disciplinary, Bradley’s book is valuable, and topical, resource.

The area of Information and Communication Technology (ICT) and its interaction with social changes on organizational, individual and societal levels has, in the 21st Century attracted increasing attention, due to the depth and wide use of ICT. The focus on the ICT related disciplines has focused far too much on the technology push in contrast to human needs and requirements of the development, introduction and use of ICT. This was also the reason, when organising and chairing the Fourth ODAM conference (Organisational Design and Management) in Stockholm in 1994, that this author gave the conference the subtitle - Development, Introduction and Use of New Technology - Challenges for Human Organisation and Human Resource Development in a Changing World.

The convergence model illustrates ongoing changes in the Net Society. However the theoretical model goes back and synthesises the theoretical framework in research on psychosocial work environment and computerization. Interdisciplinary research programs were initiated by the author in the 70th and then analyzed changes in society related to various periods in "the history" of ICT. The description of the convergence model is structured with reference to the concepts Globalization, ICT, Life Environment, Life Role, Effects on Humans. Both Convergence and Interactions are important features in the model. There are four levels of analysis - individual, organisational, community, and societal.

The convergence model illustrates ongoing changes in the Net Society. The theoretical model synthesises the theoretical framework in the author's research on the psychosocial work environment and computerization. Interdisciplinary research programs were initiated by the author in the 1970s, leading to analysis of societal changes related to various periods in 'the history' of ICT. The description of the convergence model is structured with reference to the core concepts of Globalisation, ICT, Life Environment, Life Role, and Effects on Humans. Convergence and Interactions are important features of the model that organizes analysis at the individual, organisational, community, and societal levels.

 This paper is treating the interdomain QoS signaling between the home and access domains with a focus on applying it for providing QoS between a UPnP-QoS based home network and GMPLS based access network. The work presented here is defining a possible approach for an interface between UPnP-QoS and GMPLS in order to move towards end-to-end QoS establishment as well as investigating the complexity of such a solution. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent QoS architecture.

This thesis addresses the problem of low-cost multicast delivery of multimedia content in future mobile networks. The trend towards reuse of existing infrastructure for cellular and broadcasting for building new systems is challenged, with respect to the opportunities for low cost service provision and scalable deployment of networks.

The studies outline significant potential of hybrid cellular-broadcasting infrastructure to deliver lower-cost mobile multimedia, compared to conventional telecom or broadcasting systems. Even with simple interworking techniques the achievable cost savings can be significant, at least under some specific settings.

The work starts with a foresight study shaped around four scenarios of the future, and continues with the introduction of a high-level framework for radio resource management in Ambient Networks. Two approaches on the hybrid system architecture are considered. The first one assumes different degrees of interworking between conventional cellular and broadcasting systems, in single and multi-operator environments. Second, is a broadcast only system where cellular sites are used for synchronized, complementary transmitters for the broadcasting site. In the first approach, the key issue is the multi-radio resource management, which is strongly affected by the degree of integration between the two networks. Two case studies deal with the problem of delivering, for lowest cost, a data item to a certain number of recipient users. A flexible broadcasting air interface, which offers several transmission data rates that can be dynamically changed, is demonstrated to significantly increase cost efficiency under certain conditions. An interesting result is that real-time monitoring of the user reception conditions is not needed, at least when multicast group is large. This indicates a high degree of integration between cellular and broadcasting networks may not by generally justified by visible cost savings.

Scalability of the hybrid infrastructure deployment is the main topic in the second approach. For a DVB-H type of network, the numerical evaluations show that achievement of economies of scale while increasing network capacity and coverage, by employing higher modulation and coding rate or installing new transmission sites, is difficult. Therefore, a technique based on application-layer forward error correction with Raptor codingA is suggested for enabling a flexible trading between system capacity, perceived coverage and delay, in the case of mobile users.

Computer animation is a tool which nowadays is used in more and more fields. In this paper we describe the use of computer animation to support the learning of computer organization itself. MipsIt is a system consisting of a software development environment, a system and cache simulator and a highly flexible microarchitecture simulator used for pipeline studies. It has been in use for several years now and constitutes an important tool in the education at Lund University and KTH, Royal Institute of Technology in Sweden.

Dictionary code compression is a technique where long instructions in the memory are replaced with shorter code words used as index in a table to look up the original instructions. We present a new view of dictionary code compression for moderately high-performance processors for embedded applications. Previous work with dictionary code compression has shown decent performance and energy savings results which we verify with our own measurement that are more thorough than previously published. We also augment previous work with a more thorough analysis on the effects of cache and line size changes. In addition, we introduce the concept of aggregated profiling to allow for two or more programs to share the same dictionary contents. Finally, we also introduce dynamic dictionaries where the dictionary contents is considered to be part of the context of a process and show that the performance overhead of reloading the dictionary contents on a context switch is negligible while on the same time we can save considerable energy with a more specialized dictionary contents.

To explore the efficacy of four vaccine-based policy strategies (ring vaccination, targeted vaccination, mass vaccination, and pre-vaccination of healthcare personnel combined with ring vaccination) for controlling smallpox outbreaks in Sweden, disease transmission on a spatially explicit social network was simulated. The mixing network was formed from high-coverage official register data of the entire Swedish population, building on the Swedish Total Population Register, the Swedish Employment Register, and the Geographic Database of Sweden. The largest reduction measured in the number of infections was achieved when combining ring vaccination with a pre-vaccination of healthcare personnel. In terms of per dose effectiveness, ring vaccination was by far the most effective strategy. The results can to some extent be adapted to other diseases and environments, including other countries, and the methods used can be analysed in their own right.

Experiments using a microsimulation platform show that vaccination against pandemic H1N1 influenza is highly cost-effective. Swedish society may reduce the costs of pandemic by about SEK 2.5 billion (approximately EUR 250 million) if at least 60 per cent of the population is vaccinated, even if costs related to death cases are excluded. The cost reduction primarily results from reduced absenteeism. These results are preliminary and based on comprehensive assumptions about the infectiousness and morbidity of the pandemic, which are uncertain in the current situation.

Contemporary trusted execution environments provide a good foundation for implementing secure user credentials, but these are not properly bound to the application instances that implement their use. This paper introduces a framework for application-specific credentials and provides a prototype implementation using TCG MTM and DRTM technologies. Measurements and a security analysis is presented for the realised architecture.

Recent advances in information and communication technologies have made the development and operation of complex disease surveillance systems technically feasible, and many systems have been proposed to interpret diverse data sources for health-related signals. Implementing these systems for daily use and efficiently interpreting their output, however, remains a technical challenge.

This thesis presents a method for understanding disease surveillance systems structurally, examines four existing systems, and discusses the implications of developing such systems. The discussion is followed by two papers. The first paper describes the design of a national outbreak detection system for daily disease surveillance. It is currently in use at the Swedish Institute for Communicable Disease Control. The source code has been licenced under GNU v3 and is freely available. The second paper discusses methodological issues in computational epidemiology, and presents the lessons learned from a software development project in which a spatially explicit micro-meso-macro model for the entire Swedish population was built based on registry data.

A critical investigation into computational models developed for studying the spread of communicable disease is presented. The case in point is a spatially explicit micro-meso-macro model for the entire Swedish population built on registry data, thus far used for smallpox and for influenza-like illnesses. The lessons learned from a software development project of more than 100 person months are collected into a check list. The list is intended for use by computational epidemiologists and policy makers, and the workflow incorporating these two roles is described in detail.

Background: In computer supported outbreak detection, a statistical method is applied to a collection of cases to detect any excess cases for a particular disease. Whether a detected aberration is a true outbreak is decided by a human expert. We present a technical framework designed and implemented at the Swedish Institute for Infectious Disease Control for computer supported outbreak detection, where a database of case reports for a large number of infectious diseases can be processed using one or more statistical methods selected by the user. Results: Based on case information, such as diagnosis and date, different statistical algorithms for detecting outbreaks can be applied, both on the disease level and the subtype level. The parameter settings for the algorithms can be configured independently for different diagnoses using the provided graphical interface. Input generators and output parsers are also provided for all supported algorithms. If an outbreak signal is detected, an email notification is sent to the persons listed as receivers for that particular disease. Conclusions: The framework is available as open source software, licensed under GNU General Public License Version 3. By making the code open source, we wish to encourage others to contribute to the future development of computer supported outbreak detection systems, and in particular to the development of the CASE framework.

Financial markets use complex computer trading systems whose failures can cause serious economic damage, making reliability a major concern. Automated random testing has been shown to be useful in finding defects in these systems, but its inherent test oracle problem (automatic generation of the expected system output) is a drawback that has typically prevented its application on a larger scale.

Two main tasks have been carried out in this thesis as a solution to the test oracle problem. First, an independent model of a real trading system based on constraint programming, a method for solving combinatorial problems, has been created. Then, the model has been integrated as a true test oracle in automated random tests. The test oracle maintains the expected state of an order book throughout a sequence of random trade order actions, and provides the expected output of every auction triggered in the order book by generating a corresponding constraint program that is solved with the aid of a constraint programming system.

Constraint programming has allowed the development of an inexpensive, yet reliable test oracle. In 500 random test cases, the test oracle has detected two system failures. These failures correspond to defects that had been present for several years without being discovered neither by less complete oracles nor by the application of more systematic testing approaches.

The main contributions of this thesis are: (1) empirical evidence of both the suitability of applying constraint programming to solve the test oracle problem and the effectiveness of true test oracles in random testing, and (2) a first attempt, as far as the author is aware, to model a non-theoretical continuous double auction using constraint programming.

Computer trading systems are essential for today's financial markets where the trading systems' correctness is of paramount economical significance. Automated random testing is a useful technique to find bugs in these systems, but it requires an independent system to decide the correctness of the system under test (known as oracle problem). This paper introduces a constraint-based oracle for random testing of a real-world trading system. The oracle provides the expected results by generating and solving constraint models of the trading system's continuous double auction. Constraint programming is essential for the correctness of the test oracle as the logic for calculating trades can be mapped directly to constraint models. The paper shows that the generated constraint models can be solved efficiently. Most importantly, the approach is shown to be successful by finding errors in a deployed financial trading system and in its specification.

With the ever increasing importance of social net- working sites and services, socially intelligent agents who are responsible for gathering, managing and maintaining knowledge surrounding individual users are of increasing interest to both computing research communities as well as industries. For these agents to be able to fully capture and manage the knowledge about a user’s interaction with these social sites and services, a social user model needs to be introduced. A social user model is defined as a generic user model (model capable of capturing generic information related to a user), plus social dimensions of users (models capturing social aspects of user such as activities and social contexts). While existing models capture a proportion of such information, they fail to model and present ones of the most important dimensions of social connectivity: trust and privacy. To this end, in this paper, we introduce an ontological model of social user, composed by a generic user model component, which imports existing well-known user model structures, a social model, which contains social dimensions, and trust, reputation and privacy become the pivotal concepts gluing the whole ontological knowledge models together.

Large-scale sensor networks, monitoring an environment at close range with high spatial and temporal resolutions are expected to play an important role in various applications, e.g., assessing the "health" of machines; environmental, medical, food-safety, and habitat monitoring; inventory control, building automation, etc. Ensuring the security of these complex and yet resource-constrained systems has emerged as one of the most pressing challenges for researchers. In this paper (i) we present the major threats, and (ii) we present a new approach for decentralized energy efficient intrusion detection that can be used to improve security from both external and internal adversaries.

An optical communications network ( 10) comprising an optical line termination ( 12), and a first optical multiplexer/demultiplexer (MUX/DEMUX) ( 14), comprising N input ports and N output ports. The network (10) further comprises a plurality of wavelength division multiplexed passive optical network (WDM PON) distribution networks (22) coupled to a respective one of the MUX/DEMUX output ports and comprising optical network units (20). Feeder fibres ( 16) are coupled between the optical line termination and a respective one of the MUX/DEMUX input ports. Interconnection fibres ( 18) are coupled between respective pairs of the optical network units.

While traffic volume of real-time applications is rapidly increasing, current routers do not guarantee minimum QoS values of fairness and they drop packets in a random fashion. If routers provide a minimum QoS, resulting a less delay, reduced delay-jitter, more fairness, and smooth sending rates, TCP-friendly rate control (TFRC) can be adopted for real-time applications. We propose a dynamic buffer management scheme that meets the requirements described above, and can be applied to TCP flow and to data flow for transfer of real-time applications. The proposed scheme consists of a virtual threshold function, an accurate and stable per-flow rate estimation, and a per-flow exponential drop probability. We discuss how this scheme motivates real-time applications to adopt TCP-friendly rate control.