Nowadays Wireless LAN is playing a more and more important role in network systems. After 1999, in which the IEEE organization published its Wireless Local Network standard 802.11[1], many people saw the advantages of the standard but also the lack of support for multimedia streaming. A lot of research work has been done on the proposed IEEE 802.11e standard draft during the past 4 years. It is supposed to be able to fully support Quality of Service. The final version will be published early in 2004.

This bachelor thesis is about an ultrasonic sensor, implemented in a bubble chamber in Artis. The sensor consists of the piezoelectric sensor and an electronic control circuit. The control circuit consists of a programmable microprocessor, PIC18F2420 and a circuit, which sends the excitation signal to the piezoelectric sensor, and later receives the echo. This bachelor thesis consists also of a theoretical study, which examines different techniques of liquid level sensing in a chamber. The study discusses which factors are important in liquid level sensing and examine accepted methods.

The purpose of this paper is to understand the climate of the street and how it can be modified to better meet the needs of the street and the user groups. At the same time the conditions of the street and its surroundings also has to be taken into account. To accomplish this it is necessary to have a broad knowledge of the climate conditions in the city. Therefore an overview of the climate elements and how these are modified in the built-up areas are given. The part of the paper which deals with the city climate has a global approach to be able to give an as complete picture as possible.

This study presents a methodology that enables the annual average power of a wind turbine to be increased by automatically optimizing it?s airfoil, twist and chord dis- tribution. As a part of the study the software SiteOpt has been developed. This software connects the open source software XFOIL with the blade element momen- tum theory. XFOIL gives lift and drag coefficients which enable the blade element momentum theory to predict the power of a wind turbine at different wind and ro- tational speeds.

The aim of this study was to gain a better understanding of resource schools 1 as a human services organization and institution, based on teachers and principals? perspectives. The purpose of resource schools is to provide the students tools and resources to enable them to return to the regular school within two years. The study also aims to examine more closely how this objective applies to the studied resource schools in the studied municipality, as well as highlighting the success factors and barriers that exist to achieve the goal. Previous studies show that this kind of differential practice tends to become a permanent solution.

The dissertation were performed on SP, Technical Institute of Sweden. The dissertation were carried out on the measurement technical department, this dissertation is a part of a bigger project, project ClampCal. One of SP?s returning assignments are flow-measurement. When flow-measurement is performed, the flow has to be stopped so that a meter can be installed in the pipes where measurement is going to take place. At every stop there is time delay in the flow which causes the customers to loose money. This is why SP wanted to find a better solution so that measurement can be done without any stops in the flow. Usage of a so-called Clamp-on meter was considered, but since the measurement uncertainty is too large it takes some investigation on the parts where the largest uncertainties occur and thus find a solution that can diminish the uncertainty as much as possible. The parts that were considered to have an opportunity to reduce measurement uncertainties were the fluid temperature, its characteristics and the pipe geometry and its characteristics. For the fluid temperature a Pt100-sensor with four different radii for various pipes was used.

Executive summary This master thesis was originally based on a specific assignment given to the authors from ABB Full Service, a unit specializing in providing maintenance outsourcing: ?How can ABB Full Service expand its offering of providing fundamental maintenance by seamlessly incorporating the business concept with competencies and solutions from other ABB divisions?? The academic issue was developed throughout the thesis, resulting in the following formulation: ?From an organizational perspective; how can service providers bring continuous added value to intra-organizational outsourcing partnerships?? Many of the key findings of this thesis are reflected in the issue. The term intra-organizational outsourcing is a proposed addition to the terminology in the academic discourse on outsourcing. The definition of the term is: ? Where an organization outsources a business process interlinked with the physical operations, requiring the service provider to take over a preexisting unit and its employees.This is an accurate description of the form of outsourcing that ABB Full Service is engaged in.

Idag, inte bara i Sverige, bygger man mer och mer i betong. Betongkonstruktioner ses inte längre som något kallt, grått och tråkigt då man kan uppföra byggnadsverk som inte bara är starka och tåliga utan även med originella former och färger. För att få betongen stark, inte bara i tryck måste så gott som alla konstruktioner dock armeras på ett eller annat sätt. Dessa nya och ofta komplicerade former på konstruktionen ställer nya krav på armeringsmetoden som används, trots detta har sättet att armera i stort sätt sett likadant ut i många, många år.I den här rapporten kommer man att utreda möjligheterna för en ny typ av armering att etablera sig på en mycket konservativ marknad där utrymmet för utveckling och nytänkande är till synes mycket litet.Jämförelser mellan traditionell armering och denna nya cellarmering har gjorts, framförallt med avseende på projekterings- och utförandenivå. Detta har gjorts genom intervjuer med sakkunniga, både ute på byggarbetsplatsen och i armeringsverkstad.

Choosing the right user experience evaluation method can be difficult, choosing the right one for mobile user experience can be even more so. One major cause is that mobile usage is context dependent. Another contributing factor is that there is not one widely adopted theory or framework for user experience due to its complexity.The purpose of this study was to evaluate an existing method artifact in its feasibility for evaluating mobile applications. The chosen method, AttrakDiff2 is a self-reporting semantic differential questionnaire to evaluate the user experience of an interactive product, based on its hedonic and pragmatic qualities.A study was conducted where the participants assessed one mobile and one web application, which were later rated with AttrakDiff2. The completion of the questionnaire was conducted as a think-aloud session subsequently followed by an interview.The results suggest that the participants experience was affected more by the evaluated application style than the different platforms.

This study investigated the possibility of implementing three standards, Transistion Minimized Differential Signaling (TMDS) and two versions of Stub Series Terminated Logic (SSTL), for inter-chip communication in a specific manufacturing process. The two SSTL standards were implemented in one transceiver system while TMDS was implemented in a separate system. The evaluation was done with Spice simulations on schematic level with some parasitic capacitance and resistance. The idea was to investigate the possibility of implementing these standards and get an idea of eventual shortcomings. In order to create models as a basis for evaluation, simulation environments with models for circuit board and packages were created and transmitters and receivers were designed.

The idea to develop  a platform for a PID-controller came from the need to control the temperature in  an espresso machine in a more exact way than a thermostat could perform. In discussions with Syntronic AB the idea developed into PID-control for industrial use. Syntronic AB suggested that the platform should be based on a commercially available processor module to shorten the development time. The suggestion included the use of the microcomputer Raspberry Pi, which supports USB, HDMI, memory card and Ethernet.The work began with establishing a schedule for the 10 weeks of the projects duration, and after that a system specification listing all functions, implementation and limitations was made. When the foundation of the system specification was done, a preliminary system design took shape.Because of the Raspberry Pi´s lack of Analog-to-Digital converter, a circuit board containing Wheatstone bridges, differential amplifiers and a two channel Analog-to-Digital converter was fabricated.

This study had two different aims. The main aim was to investigate the dynamics and impact of African swine fever (ASF) on a farm in Uganda during a recent outbreak through a case study. The second aim was to estimate the presence of two important differential diagnoses of ASF: Classical swine fever (CSF) and Porcine Reproduction and Respiratory syndrome (PRRS).The field and laboratory based case study of the farm level dynamics of ASF virus during a recent outbreak (October-December 2010) on a farm in the district of Mityana, Uganda, was conducted, using interviews, ELISA and RT-PCR. The financial impact on the farm was also estimated. The impact of the outbreak was profound.

I denna studie används en kvalitativ metod i form av intervjuer med fem unga män som har ett kriminellt förflutet. Syftet med studien är att ta reda på vilka faktorer som kan ha påverkat dessa unga män in i en kriminell livsstil. Studien syftar även till att söka svar på varför dessa unga män väljer att stanna kvar i det kriminella livet. Genom att analysera det empiriska materialet vi fått in genom intervjuer med dessa unga män tillsammans med teorier som Nätverksteorin, teorin om ?Differential associations? samt Avvikelseteorin har vi kommit fram till flera aspekter kring vårt syfte.

The concept of function represents a major part of mathematics and becomes more significant in school during high school. Throughout history, it has been a difficult concept to define and may create challenges for contemporary students. This literature study aims to identify students' difficulties with the concept of function, as well as to account for how the definition of a function has evolved historically. The literature study has been conducted through database searches in ERIC, Education Research Complete and MathSciNet via EBSCOhost, as well as through chain searching. The study results in identifying that students' difficulties with the concept of function primarily include the graphical and algebraic forms of representation.

This report describes the results of the project "Concept development of jet engine inspection plugs" carried out in the spring of 2008. The work was done at the department of product definition at the company Volvo Aero in Trollhättan. The objective of the work was to develop concepts for a "Volvo-unique" inspection plug. The work is part of Volvo Aero's focus on proprietary (self-developed) technologies. Inspection plugs can be found on virtually all aircraft engines and gas turbines.