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Master in Universal Design of ICT Insufficient contrast between text and the background is a common problem on the web meanwhile very few researchers study the insights of the designers’ design thinking process, how they choose the specific colours from all the colours. WCAG 2.0 addresses the contrast problem, but the requirement is hard to understand for most designers. Therefore, some web designers check their designs with contrast checking tools after the design is finished. If the design does not meet the WCAG 2.0 guidelines the designer will have to go back and make adjustments and check contrast again. The gap between the requirements for designers and the sufficient tool assist them need to be filled. To overcome this problem, a cross culture interview was conducted to identify the factors the designer consider and their actual behavior during the design process. Moreover a colour picker tool is developed that allows designers to select WCAG 2.0 compliant colours during the design process thus eliminating the need for post-design colour adjustments. This dissertation aims to help software developer gain a deeper understanding about designers’ selections and make it easier to achieve readability on the web.

The paper III and IV are excluded from the dissertation with respect to copyright. In this thesis I identify dialectics in public procurement of Information Systems (IS), and for some of the dialectics I identify synthesis. My study is based on a research gap, revealed through a literature review that I conducted. Public procurement in general and public procurement of IS in particular has been a neglected field of study. This is surprising, given the fact that public procurement account for a high proportion of the gross domestic product in the western world, and that procurement of IS especially is a highly complex task. My literature review identified a lack of research on the challenges in public procurement of IS and a lack of research on the actual procurement process. Based on these findings, I conducted a Delphi study to identify the key challenges. This study found that some of the key challenges were related to requirements specification, but further, it found that key stakeholders (vendors, and CIO’s and procurement managers in procuring entities) had different views on these key challenges. This led to my two main research questions: What conflicting goals are held by public entities when procuring IS, and: What strategies do public entities use to cope with these challenges and with contradictory goals?

The University of Tromsø is conducting regular marine seismic acquisition cruises for scientific and educational purposes in the polar regions of the Norwegian Sea and beyond. Leading experts in the field currently employed by the Department of Geology at ui, have found the current seismic visualization tools lacking in several fields. The available seismic software provides a multitude of settings and filters to improve visualization, but has limitations when it comes to user friendliness, and lacks or has shortcomings for data interaction. Because of these limitations the scientists are still reverting back to using thermal paper plots for seismic data interaction. The thermal printers in the possession of UIT are old, bulky and prone to mechanical failure, and are expensive to replace. The work done in this thesis attempts to address the needs of the Department of Geology, and as a response to these needs presents the system RS. A system to process, visualize and interact with both "live" and previously recorded seismic 2D data. RS provides processing and filtering of seismic data, and presents this data in a web based user interface, using an Open Source JavaScript Tile viewer to visualize the seismic data. RS also consists of among other: a Go two tiered backend system, a custom built tile maker, web sockets for bidirectional communication and NoSQL database storage. The goal of the system is to provide a new visualization tool to replace or supplement current visualization platforms. RS does this by presenting a visualization client which can run on any device with a modern browser, giving every authorized person on a seismic vessel the ability to view and interact with seismic data. To present seismic plots to the end user, RS uses binary seismic data acquired by existing seismic software and hardware. This data is a combination of the seismic data and a variety of metadata from sensors aboard the vessel. Data is filtered for noise, and cached before images are created. These images are served by a web server, and made available to the end user through his preferred platform.

With the advent of body sensor technology, athletes can easily record individual physiological metrics such as heart rate, steps, and blood sugar. In parallel, there is an increasing number of web services that use the raw body-sensor data as input to sports analytics. For the individual athletes, this can yield valuable insights on their performance and suggestions on individual training programs, which consequently aid their development. Once the data is imported into these analytics systems, the athletes are however left with little control over their data. This thesis presents code consent, a user-centric mechanism which combines informed consent and capabilities to enables athletes to share their private data in a more controllable manner. Furthermore, it gives both the athletes and analytical services the extensibility, flexibility to delegate the authority across protect domains by chaining keyed cryptographic hashes. The action and terms of informed consent are transformed to the reference to the source code and attributes of a capability. When executing a capability, the policy of access control to the resource is enforced, and the operation to the resource is performed in OpenCPU server which is a R sandbox. With a use case, we demonstrate now a user is able to share with others a graph of his aggregated data by delegating a capability. This paper details the implementation of constructing a code consent capability, and verification, delegation, execution of a capability. The security of the prototype is also discussed when users revokes capabilities. In the prototype implementation, we also evaluate the end-to-end latency of executing a capability, which includes the time of verifying the signature, the time of executing the program code, as well as downloading the output file. The analysis of the performance guides us to investigate the optimization of our prototype such as capability cache and function chaining.

Mastergradsoppgave i digital kommunikasjon og kultur, Avdeling for lærerutdanning og naturvitenskap, Høgskolen i Hedmark, 2014. Norsk sammendrag: Denne oppgaven vil undersøke personlige blogger i forhold til feministisk teori og særlig begrepet «écriture féminine» slik det har blitt skissert av Hélène Cixous og andre. Postinger fra to blogger i en måned blir analystert etter en metode basert på denne feministiske teorien. Målet er å kunne identifisere feministisk skrivepraksis i bloggfeltet, og med det avklare om personlige blogger kan sies å være feministiske i en anti-patriarkalsk forstand. Er det uinteressante betraktinger fra dagligliv og kvinneliv som ikke har noen diskursiv effekt i kjønnsfeltet, eller kan disse bloggene utgjøre en kraft som kan virke mot en forskjellstenkning i språket som tenker i binære opposisjonspar som svart/hvit og kvinnelig/mannlig. Den personlige bloggen har blitt en uavhengig maktfaktor i mediebildet i moderne tid, og med det har den også blitt et demokratisk uttrykksmiddel også for marginaliserte grupper i samfunnet. English abstract: This thesis shall discuss personal blogs according to feministic theory in particular the term «écriture féminine» as laid out by Hélène Cixous and others. Posts from two bloggers in one month are analyzed by a method based on this feministic theory. The goal is to identify feministic writing in the blog sphere and by that clarify if personal blogs can be described as feministic in an anti-patriarchal way. Are these blogs tedious considerations from everyday life and womanhood which has no discourse effect in the gender field, or can they constitute a force that counters a hierarchical opposition in the language, which uses binary opposites such as black/white and female/male. The personal blog has become an independent force in the media, and by that become a democratic expression even for the marginal groups in society.

EXCESS deliverable D2.1. More information at http://www.excess-project.eu/ This deliverable reports our early energy models for data structures and algorithms based on both micro-benchmarks and concurrent algorithms. It reports the early results of Task 2.1 on investigating and modeling the trade-off between energy and performance in concurrent data structures and algorithms, which forms the basis for the whole work package 2 (WP2). The work has been conducted on the two main EXCESS platforms: (1) Intel platform with recent Intel multi-core CPUs and (2) Movidius embedded platform.

IFI-UITØ Technical Report ; 2013-73 Python is a dynamic language well suited to build a run-time providing adaptive support to distributed applications. Python has dynamic typing where variables are given a type when they are assigned a value. To introduce type safety, interfaces, and a component model in Python NOOP introduces a type language and a way to apply typing to functions (and methods). This type system is described in the first part of this paper. The second part use this type system to create interfaces and a software component model. And finally it is discussed how NOOP can provide adaptive support to distributed applications.

Papers 1,2,3,4,5,6,8,9 & 10 of this thesis are not available in Munin: 1. Niels Windfeld Lund, Bernt Ivar Olsen, Otto Anshus, Tore Larsen, John Markus Bjørndalen and Gunnar Hartvigsen: '"Watch the Document on the Wall!” An Analytical Model for Health Care Documents on Large Displays', in Goos, G., Hartmanis, J. & Leeuwen, J. V. (Eds.) Lecture Notes in Computer Science, proceedings from Web Information Systems Engineering – WISE 2007 Workshops. (2007), vol. 4832/2007:395-406. Available at http://dl.acm.org/citation.cfm?id=1781545&CFID=254149216&CFTOKEN=96596662 2. Bernt Ivar Olsen, Sanjaya Babu Dhakal, Odd Petter Eldevik, Per Hasvold and Gunnar Hartvigsen: 'A large, high resolution tiled display for medical use : experiences from prototyping of a radiology scenario', Studies in health technology and informatics (2008), vol.136:535-40. Available at http://ebooks.iospress.nl/publication/11635 3. Bernt Ivar Olsen, Bruno Laeng, Kari-Ann Kristiansen and Gunnar Hartvigsen: 'Spatial tasks on a large, high-resolution tiled display : females mentally rotate large objects faster than men', In Engineering Psychology and Cognitive Ergonomics (2009), D. Harris, Springer Berlin / Heidelberg. 5639: 233-242. Available at http://link.springer.com/content/pdf/10.1007%2F978-3-642-02728-4_25 4. Bernt Ivar Olsen, Bruno Laeng, Kari-Ann Kristiansen and Gunnar Hartvigsen: 'Spatial tasks on a large, high-resolution, tiled display : a male inferiority in performance with a mental rotation task', In 'Engineering Psychology and Cognitive Ergonomics' D. Harris, Springer Berlin / Heidelberg (2011), vol. 6781:63-71. Available at http://link.springer.com/content/pdf/10.1007%2F978-3-642-21741-8_8 5. Bernt Ivar Olsen, Bruno Laeng, Kari-Ann Kristiansen and Gunnar Hartvigsen: 'Remember to Control for the (un)expected while Designing Controlled Experiments in HCI: The case of Sex Differences in the Spatial Ability of Mental Rotation and Display Size' (manuscript). 6. Bernt Ivar Olsen, Bruno Laeng, Kari-Ann Kristiansen and Gunnar Hartvigsen: 'Size does matter : females mentally rotate large objects faster than men' (manuscript) 8. Olsen, B.I., Hartvigsen, G, Lund, N.W.: 'Leaving twentiethcentury understanding of documents. From book to eBook to digital ecosystem', 4th IEEE International Conference on Digital Ecosystems and Technologies (2010), pp 600-605. Available at http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05610589 9. Olsen, B.I., Lund, N.W., Ellingsen, G. & Hartvigsen, G: 'Document theory for the design of socio-technical systems : a document model as ontology of human expression', Journal of Documentation (2012), vol. 68(1):pp.100-126. Available at http://dx.doi.org/10.1108/00220411211200347 10. Olsen, B. I., Kristiansen, K-A., Eldevik, O. P. & Hartvigsen, G.: 'Large, high-resolution displays for co-located collaboration within healthcare : information proliferation for medical decision-making', Presented at INTERACT2009 Workshop: Team meetings within clinical domains – exploring the use of routines and technical support for communication. Uppsala, Sweden (2009). The work summarized in this thesis has its basis in technology to support human collaboration. I have investigated how large, high-resolution display (LaHiRD) technology, implemented using display wall technology (large, tiled displays implemented as one coherent display surface) could support clinical work. Hence, I have worked with the topic of technological support for human collaboration (or –interaction) in a medical context. This thesis is three-tiered; one layer is related to how a certain novel technology, (very-) large-high-resolution displays may be of clinical use. The second layer relates to specific cognitive effects users of the novel technology may experience. The third layer relates to a novel analysis framework for sosiotechnical (STS) systems (LaHiRD technology creates STSs in use). Summarized, I found LaHiRD technology’s most prominent and interesting features to be the possibility for arbitrary sized displays and vast pixel-counts achievable. This affords a wide-range of uses, but is particularly interesting for group work situations and may enable a more ‘natural’ and embodied ‘arena’ for reasoning. In collaboration with the Radiology department at UNN an implementation of a prototype radiology interface for a Display Wall was made. A crude interface was designed, which was presented in a demo for the UNN radiologists and a couple of other invited specialists. This demo was videotaped and transcribed and the main results were extracted from these data, and others from the notes and interviews made in the design process for the radiology interface. It was found that yes: the clinicians were quite positive towards the clinical potential for technology, such as the Display Wall. Focus in future studies should be information design with more diverse and currently (visually-) unavailable information – and specific information to support the workflow and specific cognitive processes of group work-settings. Regarding the Second layer, contemporary research was at this time focusing on cognitive effects of display size. For instance: how does it affect our experience of the documents displayed that size increases? Does increasing size help our problem solving? Does increasing size help some groups of users more than others? Which tasks are affected by display size in this regard? Such questions have been posed and answered during the last decade and some of the results were intriguing for my work as well. In collaboration with Department of Psychology at UiT we found that we could try and figure out how tasks similar to those performed at a Radiology department is affected by display size. We designed an experiment to test how display size affects a spatial ability called ‘mental rotation’ (MR). Mental rotation is the task of deciding whether two images of arm-like structures, made from cubes attached face to face, are the same. This task is intuitively similar to the kind of work performed at a radiology department. ‘Objects’ (organs, body-parts, blood vessels, etc.) are viewed from different angles (‘coronal’, ‘sagittal’, ‘transverse’) and ‘healthy objects’ are compared to ‘pathological’. We designed two separate experiments. Both were a mixed design with Display Size and Angle (-of rotation between the MR stimuli objects) were within-subjects factors, while Sex was between-subjects factor. Our first study included 40 subjects of 4 groups where we alternated the two groups of males/females of which display condition they were tested first in. We presented half of the participants in the first experiment with a hypothesis stating that large displays should yield better performance, while the other half were presented with the opposite hypothesis – that smaller displays provides better performance. We found that females were indeed faster than males on the large display (but no difference in accuracy). However, the group of females who had been presented prior to the experiment with the hypothesis that large displays are better were performing significantly faster than all other three groups (females ‘believing’ that small displays are superior and both male groups). In order to strengthen this finding, or reject the hypothesis that the display size was affecting female performance (and that ‘belief’ alone was making females better), we designed a new experiment where we left out any explicit information regarding hypothesis. In the second experiment we also recruited more subjects in order to provide more evidence to our finding. We had 36 males and 32 females perform the same task as in the first experiment and we improved the research design. We used a high-speed camera to compute – and ‘control’ – a network delay in stimulus onset for the large display condition. This made within-subjects comparison in performance on small contra large display more reliable. Again we found that females significantly outperformed males in the large display condition. On average, females were about 20% faster than males in the large display condition. However, females did not perform faster on the Display Wall than on the laptop display. What we found, rather, was that males and females performed similar in the smaller laptop display condition and that the Display Wall condition had a significant detrimental effect on male performance, actually deteriorating their small-display performance by 20%. In summary, we have found that visually enlarging objects may have a detrimental effect on work-tasks that involve mental rotation of three-dimensional objects – a task that resembles the work typically performed in Radiology departments. This effect was observed with objects about twice the size of typical object sizes used in the traditional Shepard-Metzler MR task (comparing two objects at a time). As for the Third layer of this thesis, this involved establishing a document lens – processing (and ‘extracting) ‘document theory’ and developing a model – in collaboration with Documentation Studies at UiT, for systems analysis. The document model which I have assembled is comprised of 7 components: agent, means, modes, configuration, connection, construction and results (Olsen et al., 2012). This model encompasses all issues that have been a part of this thesis; the agents (Radiologists/other healthcare personnel) the technical infrastructure (means and modes; the ‘what’ and the ‘how’), the perceptual qualities of the Display Wall (how ‘larger’ may not always better – i.e. the perceptual Configuration of the document) and the social affordances (Connection) and finally – the Result (resulting document): the radiology interface (although only a crude prototype). The document model, I found, is a holistic and broad model that arguably encompass traditional ‘physical objects’ (a printed book; a contract) and all novel, digital documents. I have tried to explicate- and place this model, concept and the theory behind in relation to other ‘sociotechnical methodology’. In the Document Analysis (DA), we use the framework of traditional document analysis to try and analyse, or predict novel documents. Analysing present documents (already created), or historical documents may create a basis, or casting mould for experimental analysis. A document analysis, as presented in my work, may well have value as a communicating artefact, or Boundary Object in the requirements phase of systems development and –design, especially for sociotechnical systems where non-technical (non-functional) requirements are important. As for how to utilize DA in this context, the novel document model provides a framework and a template for document analysis.

The advent of cloud computing alongside with pervasive form factors such as smart devices, introduces a new meaning to asymmetric system models. These new clients act as a presentational layer alleviating much of the computational and storage concerns to cloud services. The application platforms associated with these creates new opportunities for third party developers to provide domain specific applications (apps) to smart devices. Restricted interaction surfaces on smart device introduce new challenges to how apps are managed on these. Moreover, for security purposes as well as strict resource requirements, apps running in these environments are commonly subject to very strict isolation. We conjure that there are benefits with allowing automatic configuration apps onto a client system. Furthermore, we suggest that integration between apps residing at the same host, as well as different hosts, is beneficial to system functionality. By enabling this we could alleviate much of the interaction necessary for users and reduce the time consumed in using such smart devices. The concrete asymmetric system explored in this thesis is the Windows 8 app platform. This platform poses several hindrances to our conjecture. For security reasons, automatic configuration of apps onto a client system is prohibited. Apps run inside a sandboxed environment where they are isolated from the system and other apps. Access to resources is prohibited unless explicitly allowed by the user. As a consequence, communication between apps is forbidden. This is further complicated by the fact that apps in this environment are suspended when not in use. This thesis introduces Javza, a runtime to support dynamic app configuration and integration in Windows 8. Javza provides support for automatic installment of apps based on simplified contextual information. Furthermore, it provides app integration by allowing apps to share data, both within the same and across different systems. We present and evaluate the associated performance costs of deploying Javza inside a Windows 8 environment. We further evaluate the applicability of Javza by implementing a specific use case involving collaborative search. Lastly we discuss some of the security implications associated with our design, and some future improvements in Windows 8 to support our conjecture.

© 2011 Elsevier Ireland Ltd. All rights reserved. The author accepted manuscrip is posted here with permission from Elsevier. For article, see doi:10.1016/j.resuscitation.2011.12.022, for journal, see www.elsevier.com/locate/resuscitation. Where exactly is the chest compression, where does it begin, when does it end, how deep does it go and at what rate are they performed? In short – how good or bad is the chest compression? These are some of the questions researchers ask themselves repeatedly. As well as these data, we need to know the proportion of resuscitation time spent giving quality compressions, the ratio of interruptions and several other parameters and we need to evaluate the effect on survival. Considering the increasing capacity for data storage and growing repositories of resuscitation data one might also ask what proportion of valuable research time is spent in analysing compressions.

We describe a psychoeducational program integrated in a basic computer skills course for participants suffering from social anxiety. The two main aims of the course were: that the participants learn basic computer skills, and that the participants learn to cope better with social anxiety. Computer skills were taught by a qualified teacher. Psychoeducation and cognitive therapy skills, including topics such as anxiety coping, self-accept, and self-regulation, were taught by a clinical psychologist. Thirteen of 16 participants completed the course, which lasted 11 weeks. A qualitative analysis was performed, drawing on observations during the course and on interviews with the participants. The participants were positive about the integration of psychoeducation sessions in the computer course, and described positive outcomes for both elements, including improved computer skills, improved self-esteem, and reduced social anxiety. Most participants were motivated to undertake further occupational rehabilitation after the course.

Innlegg på seminaret "Science - who cares?" ved NT-fak, Universitetet i Tromsø.

Innlegg på seminaret "Science - who cares?" ved NT-fak, Universitetet i Tromsø.

A non-experimental study in 2005 suggested that immediate, automatic feedback on assignments helped to increase study motivation as well as pass rate among engineering students attending an introductory course in statistics at Oslo University College. In the follow-up study reported here we used an experimental design assigning the participants randomly to one of two experimental conditions: The ‘web-supported’ students received immediate, automatic feedback after having entered their responses to the assignments electronically. The ‘paper-supported’ students received written feedback on their paper-based submissions several days later. The findings contradicted the results of the non-experimental study: no significant differences between the groups were found with regard to final examination grades, study effort (with a certain qualification) and preferences with regard to the method for submitting answers. Running tutoring costs, however, were much lower for the web-supported than for the paper-supported students.Therefore, the present methodologically improved study strengthens the evidence that such learning support may help reduce running tutoring costs without significantly lowering final examination grades. Reinforcing this conclusion, certain remaining weaknesses in the experimental procedure open the possibility that the final examination grades of the paper-supported students have been inflated relative to those of the web-supported students. Moreover, questionnaire data and informal observations obtained during this experiment suggest that the tested web-based system of learning support can be combined with more traditional ways of promoting learning that may help increase learning with only a small increase in tutoring costs. These challenges with regard to the test methodology and the design of the learning-support system need to be addressed in new experiments. Keywords: web-supported learning; automatic feedback; immediate feedback; tutoring costs; statistics

A model of information ethics used to analyze intellectual property rights versus public access rights (Vaagan and Koehler, 2004/2005) is refined in two ways. First, the model is expanded to include new media which have become the primary information source for many in today's globalized information society (Webster, 2004; Lievrouw and Livingstone, 2006). Second, since freedom of expression is a primary concern for a majority of new media users worldwide (BBC , 2010), there is a need to incorporate freedom of expression in the model for it to retain explanatory value in the emerging system of "mass self communication" (Castells, 2009). Se refina un modelo anterior de informacion ética, utilizada para analizar los derechos de propiedad intelectual frente a derechos de acceso publico (Vaagan y Koehler, 2004/2005) de dos maneras. Primero, el modelo se expande para incluir los nuevos medios que constituyen ya hoy la fuente de informacion plincipal para muchos en la sociedad globalizada de la informacion (Webster, 2004; Lievrouw y Livingstone, 2006). En segundo lugar, ya que la libertad de expresion es una preocupacion primordial para una mayoria de los usuarios de los nuevos medios de comuhicacion en todo el mundo (BBC, 2010), se necesita incorporar la libertad de expresion en el modelo para que pueda mantener su valor explicativo en el emergente sisterna de "autocomunicacion de masas" (Castells, 2009).

This thesis describes the research of grading security in private Peer-to-Peer (P2P) networks, and ultimately the development of “The Socialized.Net Embedded – Cryptography Version” (Tsnecv). Tsnecv is a revision of “The Socialized.Net Embedded” (Tsne) which is the embedded version of Njål Borch’s doctorate “The Socialized.Net”. Tsne is a P2P file sharing application which builds it private P2P network as an Ad-Hoc or Distributed Transient Network. Tsnecv focuses on applying different levels of security to the network with respect to authentication of peers and access to resources, primarily through the use of public key cryptography and assignment of varying trust to peers that meet in the network. The goal is to establish secure authenticated communications in such a way that peers may be assigned different policies with respect to access of files and resources, and in this way introduce different levels, or rather grade the security and trust of other peers. An exiting feature is the possibility to use a wireless device to perform a search among the files of all your friends’ and friends’ friends, or other people you have passed by, and automatically having your living room media PC stream the live audio. Files are accessed based on user groups. Someone who forms an Ad-Hoc (spontaneous) network with your wlan unit while passing you by, may autonomously assign you a low trust level, and thus probably access to few or no files. Your close friends however, may grant you access to everything but their most private files. An important aspect was attempting a transparent integration between Tsne and the new levels of security and the mechanisms used to obtain them. It was attempted to inconvenience the users as little as possible, while keeping the accessibility of available resources as high as possible for all peers, while still allowing as much control as possible. Not only is it important to be able to grade the security at different levels, but it would be nice if users did not have to stop and ask each other for passwords, keys, secrets or to carry memory sticks in case they meet someone new and interesting. In other words, to keep the autonomy as intact as possible and the resources plentiful while allowing peers to control access to their shared resources. Public (as in asymmetric) key encryption was the choice of tool to achieve authentication of nodes. Web Of Trust was used as a starting point for the exchange of keys, but Tsnecv grades both nodes and networks at different levels of security, so in some cases you may meet someone new and exchange a key autonomously and publicly, but still consider the security of the key and the association of an identity to the key strong enough to securely authenticate a peer at a later time. Keywords: P2P private peer-to-peer trust security access authentication

Images are commonly used on a daily basis for research, information and entertainment. The introduction of digital cameras and especially the incorporation of cameras in mobile phones makes people able to snap photos almost everywhere at any time since their mobile phone is almost always brought with them. The fast evolution in hardware enables users to store large image collection without high costs. Making use of these image collections requires efficient image retrieval techniques. Traditional image retrieval techniques like text-based image retrieval and content-based image retrieval techniques have shortcomings. New techniques or combination of existing techniques must be established to provide users with adequate image retrieval functionality. This thesis describes two systems enabling users to retrieve information such as images, textual information, WAP-links or videos using SMS or MMS. One of the services, M2S is meant for tourists to retrieve information about attractions in Lofoten. M2S uses content-based image retrieval to retrieve the information requested. This service is designed and implemented in cooperation with Telenor R&I. The other system, CAIR is meant for users who want to retrieve images from an image collection using SMS. CAIR uses a context-based image retrieval to retrieve images. This system is designed, but not yet implemented.

Scalability, reliability and adaptability are among the key requirements for the enactment of distributed workflows. In addition, system resources should be efficiently utilized. Central workflow engines and static analysis of workflow specifications are some of the important obstacles to meeting these requirements. We propose a fully decentralized approach to workflow enactment that is not subject to these obstacles. In addition, it supports automatic recovery. The approach is of continuation-passing style, where continuations, or the reminder of the executions, are passed along with asynchronous messages for workflow enactment. Two continuations are associated to an execution: a success continuation and a failure continuation. Recovery plans for workflows are automatically generated at runtime and included in failure continuations. A prototype is implemented.

Traditionally, transactions are flat and atomic possessing the ACID properties. The traditional ACID transaction model has clear limitations in new application domains where transactions often are long-running and require properties that go beyond ACID. Structuring a long-running transaction as an ACID transaction will impede both performance and concurrency. To meet extended and varying transactional requirements, we have described a flexible transaction model, the xTrans model, providing support for both ACID and non-ACID properties. Further, current transaction processing systems in distributed environments are inflexible with respect to supporting extended transactions. Thus, to assist in the execution of, among others, xTrans transactions, we have designed a flexible commit protocol: FlexCP. This report presents the xTrans transaction model and the FlexCP commit protocol.

Performance isolation is essential to operating systems shared by dependable services. Unfortunately, most such systems, including real-time operating systems and VMMs, only fairly divide and account for CPU cycles. We submit that dependable services require specifying and enforcing policies for all resources, and that current metrics for evaluating fair sharing are insufficient. This paper proposes new policy specifications and metrics, and illustrates these with the help of a new operating system that supports holistic resource sharing.

Because software security patches relay information about vulnerabilities, they can be reverse engineered into exploits. Tools for doing this already exist. As a result, there is a race between hackers and end-users to first obtain patches. In this paper we present and evaluate FirePatch, an intrusion-tolerant dissemination mechanism that combines encryption, replication, and sandboxing such that end-users are able to win the security patch race.

Publisert desember 2005, oppdatert februar 2006 / Published December 2005, updated February 2006 In this report we define the semantics of a language for dynamic QoS expressions which can be evaluated at run-time for conformance. We define how expressions can be constructed from atomic expressions termed ’basic profiles’ using composition operators. Two such operators are defined: The sum ( ’+’ ) which corresponds to simple conjunction and component-sum (’Å’) which assume that the operands denote properties of separate environments and therefore must be satisfied separately. Based on those, algorithms for conformance checking any pair of expressions can be developed. Concrete models are typically defined for specific application domains, they define the basic profile space and explicitly establishes conformance relationships between basic profiles. These are essentially sets of axioms from which we can infer conformance.

This article describes an architecture that allows a replicated service to survive crashes without breaking its TCP connections. Our approach does not require modifications to the TCP protocol, to the operating system on the server, or to any of the software running on the clients. Furthermore, it runs on commodity hardware. We compare two implementations of this architecture – one based on primary/backup replication and another based on message logging – focusing on scalability, failover time, and application transparency. We evaluate three types of services: a file server, a web server, and a multimedia streaming server. Our experiments suggest that the approach incurs low overhead on throughput, scales well as the number of clients increases, and allows recovery of the service in near-optimal time.

Masteroppgave i informasjons- og kommunikasjonsteknologi 2005 - Høgskolen i Agder, Grimstad This master thesis investigates how customer involvement enhances new service development and investigates what role the service characteristics play for this development. An exploratory and quantitative empirical research was conducted among small and medium sized firms in selected business categories. Before the empirical work could be conducted a thorough literature study on innovation research, service research and customer involvement was completed. Literature from new product development was also included. The literature study showed that services have been treated as something different from tangible products, but no distinction between services with different service characteristics have been done. All services have been treated alike, despite having very different service characteristics. Customer involvement in the development process is also described. Some authors argue for the use of lead users, whereas others for lay users. The literature shows no link between service characteristics and customer involvement. The type of success a customer contributes to is also not described. Specific firms in service categories were selected to contrast firms offering services were the characteristics of these services were assumed to be different. This strategic selection of participants was done to investigate the effects of the different variables, such as intangibility, inseparability etc. The results of this research reveal that different service characteristics contribute different to the innovation process and to the form of innovation. Perishability and heterogeneity significantly promotes customer involvement in the development process. Inseparability and perishability is found to be the two characteristics contributing the most to customer involvement in development of service innovations, whereas inseparability and information intensity contributes to the development of process innovations. The results also reveal how the different users contribute to innovation success. Service innovations contribute most to increasing customer value, whereas process innovations increase process quality the most. Lay users contribute mainly to increased customer value and market performance, whereas lead user also contributes to process quality. This master thesis concludes that the findings in this research support the view on treating services after their service characteristics and not as a whole.

OOPP is a component based middleware platform with support for complex distributed applications. The main goal of OOPP is to create an expressive programming model for distributed applications where by default details are hidden for the programmer. When necessary, reflection is used to expose and sometimes modify these details. All interaction with an OOPP component are specified by its component model and a at set of well-defined interfaces. The component model specifies how a component interacts with the runtime. The set of interfaces specifies how a component interacts with other components. An OOPP application is created by combining a set of OOPP components. OOPP Studio can be used to create and manage such an application. This paper gives an overview of the OOPP programming model and discusses in more details OOPP Studio. OOPP Studio is a powerful graphical tool used to build, deploy, and manage a distributed OOPP application.

It is becoming clear that modern middleware platforms must provide both deploy-time configuration and run-time reconfiguration to accommodate rapid changing requirements and also to be able to operate in dynamic environments. J2EE is a key example of a middleware architecture that supports enterprise applications via its Enterprise JavaBeans (EJB) component model. EJB provides limited configurability in terms of a fixed set of non-functional middleware services at deployment-time (via a declarative deployment descriptor). However, EJB along with other related enterprise architectures generally do not provide enough support for re-configuration or evolution. At best, there is limited support in some platforms for replacing or updating particular services. This paper discusses the design of configurable and re-configurable middleware architecture and also the key role of separation of concerns for such platforms. The paper also describes the Arctic Beans component model which uses the Composition Filters model to capture such concerns and also support their safe composition.The paper also explains how this model can be used to construct an Arctic Beans container, in the style of EJB. The main contribution of the paper is to demonstrate that adaptable middleware platform can be developed using separation of concern technologies, specifically the composition filters model.

Much of the content of popular Internet information sources is highly dynamic: urgent in nature and sometimes relevant only for a short time. The typical approach to querying such dynamic sources is polling for updates often.1 This strains the traditional pull-based Internet and wastes network resources on transmitting redundant information. This paper focuses on how to structure the Internet to avoid the unnecessary client-server interactions dominating the Internet. To that end, we extend the API of popular existing Internet services trough Web service wrappers. These wrappers use the API of, for instance, Google, but provide functionality that is richer. Initial experience shows that major performance gains can be achieved through this approach.

The main purpose of this paper is to illuminate two types of unwanted traffic in a publish/subscribe system -- malicious (spam, DoS attacks) and vain (unused events) -- and suggest a general mechanism for minimizing their effects. We do this by augmenting the classic publish/subscribe interface with volume-limiting parameters -- a combination of attributes assigned to events by publishers and thresholds specified by subscribers -- and consider the implications of this interface on the unwanted traffic and on the routing infrastructure. Notably, we observe that this mechanism can minimize unwanted traffic without total access control if the routing substrate supports two properties: flow control and routing integrity.

Experiments run on a Grid, consisting of clusters administered by multiple organizations connected by shared wide area networks (WANs), may not be reproducible. First, traffic on the WAN cannot be controlled. Second, allocating the same resources for subsequent experiments can be difficult. Longcut solves both problems by splitting a single cluster into several parts, and for each part having one node emulating a WAN link by delaying messages sent through it. The delay is calculated using latency and bandwidth measurements collected using the Network Weather Service and a parallel application monitor. We evaluate the precision, usability for WAN collective operation research, and scalability of Longcut.

The performance of the collective operations provided by a communication library is important for many applications run on clusters. The communication structure of collective operations can be organized as a tree. Performance can be improved by configuring and mapping the tree to the clusters in use. We describe and demonstrate an approach for evaluating the performance of different configurations and mappings of allreduce run on clusters of different size, consisting of single-CPU hosts, and SMPs with a different number of CPUs. A breakdown of the cost of allreduce using the best configuration on different clusters is provided. For all, the broadcast part is more expensive than the reduce part. Inter-host communication contributes more to the time per allreduce than the synchronization in the allreduce components. For the small messages sizes used (4 and 256 bytes), the time spent computing the partial reductions is insignificant. Reconfiguring hierarchy aware trees improved performance up to a factor of 1.49, by avoiding scalability problems of the components on SMPs, and by finding the right balance between available concurrency, load on 'root' hosts and the number of network links in a tree. Extending a tree by adding more threads, or by combining two trees does not have a negative influence on the performance of a configuration, but increasing message size does.

Transactional middleware platforms must accommodate an increasingly diverse range of requirements from both applications and the underlying systems. It is clear that applications have characteristics and requirements that vary a lot, and that transactional middleware must be able to support the potential variety in transaction execution requirements. In this paper we describe ReflecTS, a reflective platform for transaction services that will meet the diverse needs of applications. The platform, which is composed of components and component frameworks, supports concurrently running transaction services and exposes the ability to configure and reconfigure the services by adopting the principles of reflection.

Events injected by publishers into a publish/subscribe system may reach users through a variety of devices: a stationary desktop, a laptop, a mobile phone, etc. We argue that the "last hop" -- from the network to the output device -- has unique properties, owing to the mobile nature of these devices, and as such demands special consideration. In particular, user's preferences and location may limit what should be forwarded to a device. Furthermore, technological constraints, such as network bandwidth availability and battery power, suggest that the decision when to forward messages is also important for optimizing user's experience. We describe a new publish/subscribe system with volume-limiting mechanisms and explain how user preferences, context, and device constraints can be accommodated in such a system. Notably, based on results of simulations, we propose a simple algorithm for low-cost "prefetching" of notifications to mobile devices in cases when network bandwidth is insufficient.

In this position paper, we focus on issues related to middleware support for software mobility in ad hoc and pervasive systems. In particular, we are interested in moving the computational environment of a mobile user following his or her trajectory. We present details of WAIFARER, a prototype implementation that automatically saves and restores application level state to support this mobility. Security, integrity, and fault-tolerance are just some of the key problems that need to be addressed in the future.

This exstended abstract presents an asymmetric and programmable (extensible) approach to pervasive computing. The idea is to off-load computations from light portable clients into a back-bone of seamlessly integrated servers. This way, a user can extend and personalize his pervasive computational environment by installing computations following his trajectory throughout the day. Focus on this extended abstract is on structural issues related to the back-end servers running mobile code off-loaded from the mobile user.

We present a technical description of the Movitz development platform for stand-alone applications on the x86 PC architecture.

Vortex is a new multiprocessor operating system that is entirely event-driven. The Vortex kernel, as well as its applications, are structured as stagesthat communicate through event passing. Each stage is a small finite state machine. The event architecture is efficient and allows Vortex to balance load across the processors automatically. Vortex uses an Event Scheduling Tree (EST) on each CPU. An EST is a tree of event queues, where each event queue can be instantiated with its own scheduling policy. The EST mechanism unifies all CPU and I/O scheduling and allows for a wide variety of scheduling policies including weighted performance isolation between applications. The paper shows how a high-performance web server can be supported on Vortex. Compared to running the same web server on Linux on the same hardware, Vortex can sustain up to 80% higher throughput. Experiments with running multiple web servers on Vortex show that we can precisely divide resources between the web servers at low overheads. Microbenchmarks break down the costs of these overheads.

How to implement process synchronization in a general-purpose software library while incurring a minimum of policy decisions on the system as a whole? We propose that in dealing with the problem of mutual exclusion in concurrent systems, a separation of concerns between the mechanism of detecting contention and the policy decision of what to do when such contention is detected is appropriate. We show with code how a waiting protocol can guide and aid the design and implementation of both lower-level primitives and the higherlevel, policy-making parts of a system. We also show how the technique can be extended so as to help preventing some deadlock situations.

Masteroppgave i informasjons- og kommunikasjonsteknologi 2003 - Høgskolen i Agder, Grimstad In the mobile data service market there are several different actors. The main actors are the operator, the content provider, the aggregator and the sub-contractor. The operator is often in control of the market and has the content providers and aggregators connected to them. The sub-contractors are connected to the operator via the aggregators. All operators have a business model towards their content providers, and are in this area often referred to as content provider access (CPA). The model is the connection between the operator and a content provider or aggregator. The CPA agreement contains a lot of information concerning the revenue model, the collaboration model, the adoption facilitation. To find this information can be very hard, and to figure out how to get it is more demanding than analyzing it. The existing models are mainly open or closed. The differences between them are the operators’ relation to their content providers and aggregators, and the adoption facilitations. The closed model uses a high degree of quality control on the services, as well. The revenue models to the operators are mostly based on a percentage that the content providers and the aggregators receive of the traffic generated by the services provided. The revenue share is very different from operator to operator but it seems like most of the content providers and aggregators are pleased with the share they receive. But the revenue model is not just about what that content provider and the aggregator receives. They often have to pay a startup fee and monthly fees to be a part of the partnership provided by the operators’ business model. Few operators with an open business model have made any adoption facilitations to their content providers and aggregators. They consider service providers as been a company working on their own with no responsibilities for the operator. The closed model has a much more close relationship with their service suppliers due to a larger degree of adoption facilitation and quality control of the services. The content providers and aggregators consider their respective operators business model as very successful both when it comes to the amount of services offered and number of users to the services.

Publisert 2. november 1995, revidert 17. mai 2003 / Published 1995, revised 2003 Authentication in Distributed Systems: Theory and Practice provides considerable insight. However, it can be hard to read, as many details are left out, probably for brevity; it is still 45 pages long. We provide detailed explanations of tricky points.

We have developed EventSpace, a configurable data collecting, management and observation system for monitoring low-level synchronization and communication events with the purpose of understanding the behavior of parallel applications on clusters and multi-clusters. Applications are instrumented by adding data collecting code in the form of event collectors to an applications communication paths. When triggered these create and store virtual events to a virtual event space. Based on the meta-data describing the communication paths, virtual events can be combined to provide different views of the applications communication behavior. We used the data collected by EventSpace to do a post-mortem analysis of a wind-tunnel application, a river simulator, global clock synchronization, and a hierarchical barrier benchmark. The views allowed us to detect anomalous communication behavior, detect load balance problems, analyze hierarchical barriers, synchronize the Pentium timestamp counters on the cluster nodes, and analyze the accuracy of the synchronization.

Vortex is a new multiprocessor operating system kernel intended for emerging Internet service applications. The architecture is based on SEDA's staged computational model. Vortex provides mechanisms for performance isolation and dynamic adaptation. Performance results validate that the resource control mechanisms of Vortex are effective, and that Vortex significantly outperforms Linux on single-threaded web servers. The paper concludes with a description of how we plan to support a highly scalable event stream filtering service.

Pesto aims at providing highly available and secure storage for longlived data to mobile users roaming into untrusted environments. Security in Pesto encompasses the following three aspects: availability, safety, and privacy. A mechanism supporting one aspect may adversely affect another. For example, replication may increase availability but complicates supporting confidentiality, and simply encrypting data for confidentiality may defeat the whole purpose of replication. We show that an integral approach to these aspects leads to considerable savings in overall system complexity, and thus to a more secure system. In Pesto, users may specify different levels of trust in different parts of the infrastructure. In particular, a user may trust a node to merely store (encrypted) data, and/or to distribute replicas to other nodes on his behalf, and/or he may trust a node to enforce access control on his behalf to his (plaintext) content. This report gives an overview of the main security mechanisms that makes this separation of concerns possible. We present its novel encryption framework and its trust management and discuss how it can be used to build distributed infrastructures with advanced security and safety properties.

Masteroppgave i informasjons- og kommunikasjonsteknologi 2002 - Høgskolen i Agder, Grimstad The development of ICT in recent years, and speed of this development is extremely rapid. ICT also spreads widely and influences deeply not only economic activities of business, households and governments but also various areas of people’s daily life. The adoption rate of mobile Internet was estimated by analogy to adoption pattern. This study examines patterns of mobile commerce adoption and usage in early adopters. One hundred and ninety mobile users were surveyed about their pattern of usage, demographic and socioeconomic characteristics, perception about the technology, and their motivation to use mobile phone services. A model which is based on modified theory of planned behavior (TPB), Technology acceptance model (TAM), and TRA is used to hypotheses a model of MCommerce. We found that TPB and TAM most useful in explaining MCommerce acceptance on early adopter.

In this paper we argue that the traditional model of a mobile agent provides a poor programming structure. We base our argument on our experience since 1993 in building distributed applications and mobile agent platforms. We have observed that every distributed applications contain three distinct aspects, which we call function, mobility and management. Separating an application into these three aspects and programming them separately affords great flexibility and leverage when designing mobile agent applications for distributed system management. Because of these observations, we have developed a programming model and a mobile agent system in which these three aspects are clearly separated.

For the past seven years, the TACOMA project has investigated software support for mobile agents. Several prototypes have been developed, with experiences in distributed applications directing the effort. This paper presents a new mechanism that supports implementing agent applications by creating troops of agents using wrappers. This solution requires little extra support from the agent system, and may be used to construct applications with a wide variety of functionality requirements.

The Pesto distributed storage platform is geared towards a computing model where private machines play a pivotal r ˆ ole. We argue that no centralized solutions are acceptable in its design and that it supports allocation of separate tasks to separate system components found in its target environment. Hence, Pesto separates trust from responsibility, storage from access control policy, and replication from consistency control. Pesto is designed around a few clean-cut abstractions, that make the above separations possible and efficient to implement. This report gives an overview of the main tasks typically supported by a distributed storage system, how Pesto supports these, how Pesto separates these from each other and what benefits such separation of concerns provides.

Pesto is a storage system geared towards a computing model where private machines play a pivotal role. Sharing of data is crucial, both between partners, and between the many devices owned by individual users. Replication is the only sensible means to provide ubiquitous access to private data. However, without provisions, replication endangers privacy by enlarging the Trusted Computing Base. The Pesto project aims at investigating security and safety issues in concert, such that security and safety measures and mechanisms can be identified that strengthen each other and, when that is not possible, to identify tradeoffs between safety and security of data in distributed systems. This report introduces the Pesto project and system; the motivation behind it and its design goals.

Distributed systems are becoming harder to manage, in part because the uses we put to distributed systems are rapidly changing. Hence, the software used to manage a distributed system needs to be flexible enough to accommodate these new uses. It also has to be secure enough to not allow unauthorized changes to be made to the system. We present a library and a kernel that supports the management of distributed systems. This kernel, called the TACOMA Operating System (TOS), is an outgrowth of our research into mobile agent systems and applications. We have used TOS to implement several novel distributed management policies, one of which is discussed in detail in this paper. We conclude the paper with a discussion on the applicability of mobile agents to self-managing distributed applications.

In this paper we will show that it is possible to combine mobile agent technology with existing non-mobile data mining applications. The motivation for this is the advantage mobile agents offer in moving the computation closer to the data in a distributed system. This can save bandwidth and increase performance when the data is condensed as a result of data mining.