The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.

This master thesis describes the development of an UPS module. UPS is an acronym for Uninterruptable Power Supply. The UPS module has been developed at the company AerotechTelub AB. The UPS module delivers the necessary voltage and current in case of a power interrupt. If a power interrupt occur, the computer system has one to three minutes available to store data and shut down correctly.

The purpose of this study was to examine if there are gender differences in computer use among the young. Our aim was to find out in what respects boys and girls differ, if at all. The main method of investigation is a literature review. We have also made a complementary empirical study in a public library. The literature studied principally covers computer use at home and in school.

The purpose of the study is to investigate MRSA-positive individual´s perceptions of source isolation and barrier nursing, to find nursing inventions witch can provide these patients wellbeing. Eight scientific research reports have been examined, using the guiding principles of Polit et al (2001). The result of the study shows the patients experiences of mentally health/illness, information and communication, physical restrictions and barrier nursing..

This thesis describes new methods for automatic crack detection in pavements. Cracks in pavements can be used as an early indication for the need of reparation.Automatic crack detection is preferable compared to manual inventory; the repeatability can be better, the inventory can be done at a higher speed and can be done without interruption of the traffic.The automatic and semi-automatic crack detection systems that exist today use Image Analysis methods. There are today powerful methods available in the area of Computer Vision. These methods work in higher dimensions with greater complexity and generate measures of local signal properties, while Image Analyses methods for crack detection use morphological operations on binary images.Methods for digitalizing video data on VHS-cassettes and stitching images from nearby frames have been developed.Four methods for crack detection have been evaluated, and two of them have been used to form a crack detection and classification program implemented in the calculation program Matlab.One image set was used during the implementation and another image set was used for validation. The crack detection system did perform correct detection on 99.2 percent when analysing the images which were used during implementation.

This essay deals with the subject of communication through Facebook. In this survey we studied 100 youths from Karlstad and their communication habits and behavior patterns on Facebook. The social network site Facebook has since its start in 2004 made a mark in modern communication. Today in 2010 the site has more than 500 million users. This paper wants to study what happens to other types of communication.

Om man vill skapa ett realistiskt hav inom Computer Graphics är det viktigt att man har snygga övergångar till andra material. Ett exempel på detta är stränder och det är precis där fokusen på den här studien har legat. Studien gick ut på att hitta en enklare lösning på att visuellt förbättra stränder inom Computer Graphics. För att göra detta så testade två olika metoder i olika experiment. Den ena tekniken som testades var att simulera partiklar för att få fram en bättre strandlinje och de andra var att skapa en shader för att förbättra den.

Rapporten beskriver arbetsgången vid utvecklingen av ett kompressorkit till Yamahas snöskotermodell RX-1. Arbetet innefattar konstruktion och dimensionering av tryckkammare och laddluftkylare. Datorverktyg i form av CAD (Computer Aided Design) och FEA (Finite Element Analysis) har använts till att konstruera och dimensionera ingående komponenter. Arbetet har resulterat i kompletta CAD-modeller av ett prototypkit färdigt för CAM- beredning (Computer Aided Manufacturing) och tillverkning..

The gaming market has become the fastest growing market for leisure and is one of the most popular forms of homeentertainment. This has generated a media debate about how people are affected by gaming and concernes how we are affected by the violence that may occur in games. Games proponents argues that gaming is the future of teaching and computer games are becoming a sustainable and popular instruction strategy. Some studies have long used computer games for educational purposes. By interviewing high school students in focus groups as qualitative research, I studied their attitudes towards computer games as a learning tool.

We are working on the development and design of an approach to agents that can reason, react to the environment and are able to update their own knowledge as a result of new incoming information. In the resulting framework, rational, reactive agents can dynamically change their own knowledge bases as well as their own goals. An agent can make observations, learn new facts and new rules from the environment, and then update its knowledge accordingly. The knowledge base of an agent and its updating mechanism has been implemented in Logic Programming. The agent?s framework is implemented in Java.

The aim of this thesis is to study preschool-teachers? experiences from using the computertablet as a tool for learning and teaching, in order to gain knowledge of how the integrationalprocess of information and communications technology (ICT) in preschool has progressedsince its instatement. The background that caused interest to make this study was the rapidprogression of the use of ICT-tools in childrens? everyday lives and the troubles that havesurrounded the process of integrating these tools into preschool-practices. The theoreticalbasis for the analysis of the research lies within the socio-cultural perspective.

The purpose of this study was to examine what students themselves think about using computers in school. The study was conducted in a school in central Sweden. The students in focus were students with reading and writing difficulties, dyslexia or language difficulties such as an other native language. A total of eight students were interviewed. The interviews were analyzed using thematic analysis.

The purpose of this thesis is to investigate if there are environments that use some kind of central authentication system within institutions/schools. The hypothesis is that an institution not using a form of central authentication service has more need for maintenance and as such is considered a higher cost for the organization. The gathering of data has been done through interviews with technical personal at Blekinge Tekniska Högskola and Linköpings Universitet. Based on the technical background of the authors, and the system limited to discussing Windows and UNIX operating systems, a discussion and analysis of the systems working today has been done, with emphasize on the hypothesis..

Lansen Technology is a security company from Halmstad, Sweden and their focus indeveloping and selling alarm solutions. One of their latest inventions is a vibration sensor thatrecognizes very small movements in the ground.The thesis work was made in cooperation with Lansen Technology AB and the task was toinvent a test equipment that decides whether the sensor is working correctly. By generatingcertain frequencies with specific amplitude, we will expect the sensor to give a similar output.The final report includes all the parts of our work as studying, choosing components,programming, construction, results and conclusion..

In this thesis, a computer program that in a simple way can calculate the performance of control loops at the refinery Preemraff Lysekil has been created. The computer program has been adapted to the environment at Preemraff Lysekil. Theories for evaluation has been studied in aspect of reliability and of automatic implementation. The evaluation has been carried out from data collected directly from control loops at the refinery and from simulated control loops with implemented errors. Among the studied methods are Harris index and Stattin´s oscillation index.