The purpose of this master thesis is to implement and validate a Power System Stabilizer (PSS) to a generator at Trängslet hydropower station in Dalarna, Sweden. Problems with local rotor oscillations can occur at the hydropower station when power is transferred on a new power line (130 kV) from Northern to Southern part of Dalarna. To ensure good operation properties on this power line Fortum Generation AB and Fortum Distribution AB wants to activate a PSS on a generator.There have been investigations in which situations and what equipment that contributes to rotor oscillations. When this is known the PSS is tuned to damp these oscillations by choosing a good set of parameters. The most important parameters for good performance are to choose amount of gain and phase compensation.

The interest in tiny wireless applications raises the demand for an integrated reference oscillator with the same performance as the macroscopic quartz crystal reference oscillators. The main challenge of the thesis is to prove that it is possible to build a MEMS based oscillator that approaches the accuracy level of existing quartz crystal oscillators. The MEMS resonator samples which Philips provides are measured and an equivalent electrical model is designed for them. This model is used in the simulations of the Pierce oscillator and the transresistance amplifier oscillator that are evaluated in this thesis. Finally the Pierce oscillator is implemented in the A BCD2 process and manufactured at Philips Semiconductors in Nijmegen, The Netherlands.

Abstract The purpose of writing this thesis was to improve methods during requirements engineering phase. Usercentred system engineering has some problem areas, which are examined and verified to create a new guideline for developers. This guideline tends to make requirements engineering more effective and help developers create more concrete requirements. It is not uncommon that system development projects ends up with unsatisfied users or delay in deliveries. The reasons are different kinds of communication problems between users and developers during verification of requirements.

Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

Concentration of protein in bovine milk is one of the most significant milk quality parameters, to a large extent determining the price for milk to the producer. Mastitis is a common disease among dairy cows, negatively affecting not only milk yield but also milk protein composition. Milk from mastitic cows tends to have lower cheese yield, negatively affected processability properties and sensory quality, due to changed protein quality and composition. Poorer milk protein quality would have an economically negative impact on dairy industry. Only few studies have investigated the short term effects of mastitis on milk protein composition.

The purpose of this essay was to examine female immigrants of South East Asia who have lived together with a drug addict and how they were affected and let themselves be influenced by that, and to study their reactions to such situations.The main questions were:· How do the women describe their personal relationship matters with their husbands with focus on abuse / co-dependency?· How do they show their co-dependency in actions?· How do the women handle their co-dependency?I chose a qualitative method because my purpose was to get a comprehension and hopefully find a pattern in the life situation in this specific target group. Regarding the collection of dataI used both primary data in the frame of interviews with persons connected to the problem, and secondary data in the form of earlier studies in that field.As the main result I found that these women lived in a severe stress. They were affected both psychically and physically by the abuse of their partners. They developed different strategies of survival to stand the reality and to save the family.

Swedish preschools have a variety of children of different ethnic origins. The intention of this thesis is twofold; firstly to deeply examine how preschool teachers work with languages and secondly how to integrate the Swedish language with other native languages in practice. Hence, the aim is to get a deeper understanding and knowledge about how to integrate multilingual children that have other languages than Swedish as their mother tongue. The data collection for this dissertation is based on observations and interviews with three preschool teachers and child minders. The theoretical background is taken from literature which describes the social cultural perspective.

  The study aims to gain a better understanding and explore how a selected group (receivers) perceive two elected advertising images from Indiska and Vila and then compare their opinions to what Indiska and Vila themselves want to communicate. We base the study on theories of encoding / decoding, which deals with how the companies charge their advertising images with values and how recipients decodes these values.A qualitative study was carried out based on analytical induction (planning, collection and analysis). Through the analytical method of induction, we created categories based on the collected data and put them in relation to each other. The result showed that the overall impression of the images' and the context are of great importance for how our respondents perceive the advertising images. The overall impressions convey emotion that reinforces the expression and the message.

The aim of this study was to, from a special educational approach, describe and analyse nine teachers and headmasters experiences and perceptions of the use of laptos, ?1-1?, as a tool for working with 13-16 year old pupils born outside of Sweden and with special educational needs (SEN). Interviews were used for data collection. The interview material was analysed with the phenomenografic analysis method and with meaning condensation method. The result was analysed through three perspectives on special education and the concept of inclusion as the study?s frame of reference.

The aim of this research is to develop a better understanding of how preschool-teachers respond to children in preschool, when they show that they want to have some influence. I have concentrated this study on how the preschool-teachers respond to the children in the gatherings and when the children are playing freely indoors, where the questions at issue are:How do the preschool-teachers respond to the children?s initiative for participation in the gathering and while playing freely?There have been four preschool-teachers and 14 children who have taken part in this study. The children who took part are in the ages of three to five. The study was done at a section in a preschool in middle Sweden.The method used in this study is unstructured observations.

The electric vehicle market has potential to contribute to Sweden?s national goal to have a fossil fuel independent transport sector by 2030. However, the market answers to a lot of challenges making it difficult for the market to fully reach its potential. The volume of electric vehicles has seen a steady increase during the last year (2012), although many of these vehicles are mostly for PR purposes or bought by the public sector that wants to lead by example. Still, barriers in the form of high purchase costs, an anxiety for the limited battery capacity and the lack of standardisation are some of the problems that the market is struggling to solve.

SEP Modular Armoured Tactical System is the next generation of military vehicles developedby BAE Systems Hägglunds AB. At present time, BAE Systems Hägglunds AB aredeveloping a 6-wheel electrical hybrid and a conventional 8-wheel vehicle. The questionformulation was summarized as: ?In which ways can the electrical transmission in a hybriddriveline for SEP be designed, when the surrounding fixed interfaces are kept and the unity ofcomponents within SEP is maximized??. The purpose of this master thesis was to study avariety of concepts for hybrid propulsion.

Bakgrund: Perioden innan den aktiva förlossningsfasens start benämns latensfas. Den är svårdefinierad eftersom den kan yttra sig på olika sätt och varierar i längd. Blivande föräldrar som anländer till förlossningsavdelning söker stöd och bekräftelse hos barnmorskan när de tror att förlossningen har startat men är oroliga för att bli hemskickade igen. Syftet: Att undersöka och belysa förstagångsföräldrars upplevelser av latensfas. Metod: Semistrukturerad intervjustudie, data bearbetades med hjälp av kvalitativ innehållsanalys.

The aim of the study is to examine which present conceptions of sexuality there are in treatment of substance abuse for men. The intention is to examine how staff members in these environments perceive clients? sex and sexuality as well as studying if and in that case how they work with sexuality in treatment. A qualitative method formed the methodological approach and semistructured interviews were carried out for the collection of data. Four staff members from two different treatment institutions for substance abuse were interviewed.

The purpose of the study is to highlight educators' preferences and attitudes towards tablet in preschool by describing the use of this digital tool in the preschool educational activities. The use of tablet in preschool is in the study looked upon as a phenomenon. The description of the phenomenon is built on the analysis and interpretation of educators' statements about it. The research questions focus on the following aspects: educators' attitudes towards the tablet and its use in pre-school educational activities, the tablet's current area of use, the culture surrounding the use of this digital tool and the educators? statements about advantages and disadvantages of tablet's use in preschool.