<p>Mobility of people and their interactions with devices and services that every day become more pervasive in our life is a valuable challenge for system engineers. Locate friends, retrieve multimedia informations from physicals objects, have medical assistance remotely is going to be a commodity for a more and more wide part of the population, including elderly people. In this scenario have an easy way for discovering and communicating with third party services and resources that we encounter in our every day life is going to make the difference between an enjoyable user experience or a frustrating ones that quickly leads to the abandon of a system. Building on the work done in the past about resources discovery and management I study a solution for user-centered interactions with resources and services dynamically discovered and used by the user in nomadic environments. The solution designed make use of embedded devices, addressing the problem encountered in the research from both end-user and developer point of views. The solution proposal make a full use of the service oriented architecture (SOA) concepts focusing on the goal of achieving the most natural human interaction with devices that the user discover on his way, keeping at the same time the framework architecture lightweight and easily extendible by third-party developers, as the SOA paradigm requires. Accessibility and extensibility are achieved on the end-user side by deploying software needed for the personal device (UbiNode) on most common smartphones and providing a easily understable Graphical User Interface; on the developer side by creating a pluggable framework based on xml and Eclipse eRCP runtimes for a fast development of multiple user interface that fits the constrains of the device in which are them deployed in. Work done consists in design and implementation of several platform components and development of prototypes that takes profit from the overall architecture. Developed modules have been deployed end tested on handled devices. UbiCollab provides a solution platform for ubiquitous collaboration scenarios and this thesis has been carried out as a contribution to it. Keywords: Ubiquitous Computing, User Centered collaboration, User Interfaces, Mobile Devices, Discovery Gestures, Object Tagging, UbiCollab.</p>

<p>This report covers the research, design and prototype implementation of a social application for mobile ad-hoc networks, InstantSocial. The main goals of this project has been to look at this exciting field and examine how the European scientific collaborative project MUSIC can be used to develop such an application. The project has been conducted using a Design Science approach. First the field of interest, existing similar applications and technology was examined to get a good view of the current state-of-the-art and choose a suitable prototype application. Then the design of the application was constructed, emphasizing the important features outlined in the project goals. Finally a prototype was developed and tested as a means to prove the correctness and applicability of the design. The results of the project was somewhat divided. Although the developed prototype had limited functionality, mostly because of the current limitations of the used framework, the tests that were performed where positive. Not all of the requirements of the system was successfully implemented, but this was due to limited time available or limitations in the currently available version of the framework rather than a shortage of the design. We conclude that the presented design and approach to context-adaptation is very plausible as a way in which the MUSIC project can be used to develop social application for mobile ad-hoc networks, but that much more work and testing is required before such an application can be fully realized.</p>

<p>System logs contain messages from a wide range of applications. They are the natural starting point when troubleshooting a system. The usual approach for analysing system logs is to write a number of regular expressionsto match specific keywords and events. When the number of expressions grows large, the analysis solution becomes unmaintainable. In addition, the use of regular expressions requires the system administrator to have extensive knowledge of the system at hand. This thesis presents methods for performing log analysis without regular expressions. This is an area of system administration that has attracted very few researchers. Therefore, little published research is available on the subject. Much effort has been put into the task of generating patterns from log file. These patterns are an important prerequisites for statistical analysis. Patterns could also be used to identify transactions for use in Markov models. None of the existing pattern mining algorithm for system logs produce satisfactory results. To solve the task at hand, a new method for mining patterns is developed. Several different approaches were tested. An approach based on inserting log lines into a tree structure turned out to be a very promising. It outputs good quality patterns and its resource use is moderate. Log analysis without prior knowledge of the system at hand have been proven difficult. This thesis shows that methods where some basic knowl- edge of systems in general is exploited, are the most promising ones. Other approaches based on Markov models and neural networks are suggested in this thesis, but they have not been tested to full extend and require some more work before being useful.</p>

<p>This document is the report for the authors' joint effort in researching and designing a query optimizer for Fast's next-generation search platform, known as MARS. The work was done during our master's thesis at the Department of Computer and Information Science at the Norwegian University of Science and Technology, spring 2009. MARS does not currently employ any form of query optimizer, but does have a parser and a runtime system. The report therefore focuses on the core query optimizing aspects, like plan generation and optimizer design. First, we give an introduction to query optimizers and selected problems. Then, we describe previous and ongoing efforts regarding query optimizers, before shifting focus to our own design and results. MARS supports DAG-structured query plans for more efficient execution, which means that the optimizer must do so too. This turned out to be a greater task than what it might seem like --- since we must use algorithms that greatly differ from the optimizers we were familiar with. The optimizer also needed to be extensible, including the ability to deal with future query operators, as well as supporting arbitrary cost models. During the course of the master's thesis, we have laid out the design of an optimizer that satisfies these goals. The optimizer is able recognize common sub-expressions and construct DAGs from non-DAG inputs. Extensibility is solved by loose coupling between optimizer components. Rules are used to model operators, and the cost model is a separate, customizable component. We have also implemented a prototype that demonstrates that the design actually works. The optimizer itself is designed as separate component, not tied up to MARS. We have been able to inject it into the MARS query pipeline and run queries end-to-end with optimization enabled, improving the query evaluation time. For now, the project depends on MARS assemblies, but reusing it for another engine and algebra is entirely feasible.</p>

<p>The goal for this master thesis is finding trends and behaviors in a highly available database cluster using InfiniBand and RDMA. This will be used to optimize configuration of the segment size in such systems. To find these trends and behaviors, a mockup model has been developed. The model consists of a simple DBMS that uses only the main memory for storing data and a checkpoint method to repair nodes after a node failure. During a repair, the model simulates use of InfiniBand and RDMA during checkpointing. To simulate clients connecting to and using the database, the model includes write operations on the database and measures how many write operations it can process per second. During a repair in a database cluster, one node will flush all of its data to a new node. This is done in small batches, just like in a checkpoint. In this model, it is simulated by a checkpoint module continuously simulating flushing data from one node to another. When the checkpoint is flushing a small part of the database fragment, the model uses Copy on Write to prevent lockout for the transactions. When a node fails the system is repaired by a second node which takes over as fast as possible. The second node must process transactions while transferring all of its data to a spare node. To achieve fast repair time, the system should transfer as big segments as possible. The problem with big segments is that it takes a long time to perform Copy on Write on them. With the mockup model, the repair time is measured, how many write operations are being performed per second and CPU usage depending on the segment size and number of clients using the database. This will give a good indication of what segment size is preferable. The results from the thesis show that there are huge advantages by using state-of-the-art technology such as InfiniBand and RDMA for repair in highly available database clusters. This technology and optimal configuration improves the availability and this thesis gives an indication that the segment size should not be more than 1 % of the database size. With use of InfiniBand and RDMA using this configuration and physical repair, the availability reaches class 9.</p>

<p>This project continues the work started in our depth study project in the fall of 2004, develop- ing a framework for mobile collaborative applications on mobile phones utilizing Personal Area Networks (PANs). This paper describes central, theoretical concepts connected to the Peer-to-Peer (P2P) comput- ing, the Mobile Ad Hoc NETworks (MANETs) and the Computer Supported Cooperative Work (CSCW) domains, focusing on "Same-Place-Same-Time" collaboration. We argue how the spread of PAN technology and mobile phones enable for a broad range of new collaborative applications supporting both collocated work and spontaneous interaction. Updated information about relevant technologies and related projects are discussed and evaluated. The requirements for the Peer2Me framework are presented and updated along with a revised and improved design. The design and the requirements are a product of an explorative development effort to develop the next generation of the Peer2Me framework using Java 2 Micro Edition and the Java APIs for Bluetooth wireless technology (JABWT). The Peer2Me framework is then tested on actual developers in a workshop arranged in May 2005. Data gathered from this workshop is used to illustrate the benefits of using a framework like Peer2Me for developing mobile collaborative applications. In addition to the actual Peer2Me framework implementation along with its Bluetooth network module, example applications are designed, implemented and tested in order to verify the suit- ability of the Peer2Me framework in the problem domain. These applications illustrate different kinds of aspects of the Peer2Me framework and the domain of mobile collaborative applications. The tests of these applications are done through enactment of the usage scenarios from which the applications were derived. The main results of this project are the technical products comprised of the Peer2Me framework, the Bluetooth Network module and the example Peer2Me applications, as well as the empirical data supporting the advantages of Peer2Me and the evaluations upon the suitability of the applied technologies.</p>

<p>This report investigates different methods in computer graphics and virtual reality that can be applied to develop a system that provides analysis for the changes that occur when removing outlier points in plots for principal component analysis. The main results of the report show that the use of animation gives a better understanding for the movement of individual points in the plots, before and after removal.</p>

<p>Denne oppgaven presenterer et rammeverk for representasjon av og resonnering med temporale data i CBR-systemet TrollCreek. Slik funksjonalitet vil forbedre TrollCreek’s ytelse innenfor prediksjonsproblemer, det vil si: Kunne prediktere hva som vil skje i en ny problemsituasjon basert på sammenligninger med lagrede problemsituasjoner. Representasjonen er basert på å legge til en eller flere tidslinjer til et case. Resonneringsmekanismen abstraherer disse tidslinjene inn i en enkelt tidslinje, og sammenligner deretter denne tidslinjen med andre abstraherte tidslinjer i case-basen. I denne oppgaven har vi implementert en enkel ikke-kunnskapsintensiv metode for denne abstraksjonsoppgaven og vi har brukt metoder for sekvenssammenligning for å sammenligne tidslinjene. Oppgaven inneholder også et eksempel av rammeverket i bruk. Eksempelet er av en ”proof-of-concept”-type, og involverer et imagniært domene.</p>

<p>Multiarch is a mechanism for packages supporting multiple architectures to be installed at the same time on the same machine in the same operating system. This paper shows a sample implementation of one way do do this on a UNIX-like system using the dpkg package manager. It shows the needed changes to both packages and the package manager itself.</p>

<p>A framework for JIT compilation that specifically caters to the resource constraints of new generations of small devices is presented. Preliminary results obtained from a prototype implementation show average speedup of 5.5 over a conventional interpreter-based Java implementation, with only a 15% increase in the static memory footprint and an adjustable, highly predictable dynamic footprint.</p>