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893 Uppsatser om Non-parametric tests - Sida 19 av 60

BIODIVERSITETS P?VERKAN P? M?NGDEN ORGANISKT MATERIAL I ALSUMPSKOG: En fallstudie i fyra alsumpskogar p? svenska v?stkusten

Globally, coastal ecosystems like mangrove forests, sea grass meadows and salt marshes are well known for their ability to capture and store atmospheric carbon effectively. In Sweden, there is still limited knowledge about local coastal ecosystems with similar functions, with alder swamp forests being an interesting example. Therefore, this study aimed to increase knowledge of the factors that can contribute to the potential carbon sequestering ability of alder swamps. Vegetation data and sediment samples were collected from a total of 37 sampling plots across four alder swamps in Bohusl?n on the Swedish west coast.

Utvärdering av kalkstens egenskaper med laboratorie- och fältmetoder.

A pavement construction designed to cope with the different type of traffic loads; it is exposed to and at the same time it can resist the effect of the climate. A road structure consists of sub- and superstructure which is divided by a boundary known as terrace. During the construction of unbound layers (base course and sub-base course) in the superstructure, it is always ensured that the material meet the requirements for bearing capacity and the degree of compaction. These parameters are controlled by various laboratory tests and control methods. To obtain increased knowledge of the material and improve the quality of the compaction in the field, it is necessary to perform laboratory tests in order to determine material properties.A base course material 0/ 32 mm limestone from Gotland (Hejdeby) was investigated in this study.

Halvledare för höga strömmar i fordon

Mechanical relays are more and more being replaced with semiconductortechnology. In this thesis it is investigated if and how the larger loads couldbe controlled by transistors. The main part of this work aims to create andverify a solution that can control the starter motor, as well as protect it incase of any failure. The different malfunctions that the solution protectsagainst is high current, too high peak current, low current, maximum cranktime and minimum cool off time. The timers also protect indirectly againstoverheating of the starter engine.The transistors used are BTS555, from Infineon.

After establishment closure : Individual characteristics that determine re-employment probabilities of displaced workers in Sweden

This paper studies the relationship between individual characteristics of displaced workers and the probability of re-employment. A competing risks hazard model is used, distinguishing between exits from joblessness to self-employment and to paid-employment. All individuals between 25 and 55 years of age, at the time of displacement, that suffered from at least one year of joblessness after being displaced between 1990 and 1998 due to establishment closures that occurred between 1990 and 2001 are included. This allows for the closure procedure to be between one and three years long. Each individual is followed, from the year of displacement until the year of re-employment or at the latest, ten years after displacement.

Studie och riskanalys av sulfidleror i Uppsala stad

Most of the city of Uppsala rests on postglacial clay with a varying content of sulphur. The sulphur occurs naturally in the clay in reduced form as sulphide and the clay is for that reason usually called ?sulphide clay?. Excavation during construction activities gives rise to large amounts of excavation material, of which the sulphide clay is a considerable part.When the clay is exposed to air and water, an oxidation of the sulphides occurs which may produce an acid leachate and the mobilisation of heavy metals bound in the clay or underlying material. The aim of the work has been to improve our understanding of the behaviour of sulphide clays and produce a basis for risk assessment in the future handling of excavation material with high sulphide content.

Statushantering i Virtual Map med ledningssamordning i BIM

For many years, the construction industry in Sweden has not developed much of an integral approach for design across disciplines. The sector?s impact on society, economics and environment is huge. To make the interactions within the construction industry more efficient, a relatively new concept called BIM (Building Information Modeling) has been introduced. The idea with BIM is that the different actors of the construction industry will work through intelligent CAD software, with common file formats and more cooperation between different actors during the various steps of the building and construction process.The technical consultancy company WSP Sweden is working actively to implement BIM within the frame of its activities.

Kommunikationshjälpmedel Sound and Display Communicator

During the last year in the Innovation Engineering Program, at Halmstad University, a degree project was performed that was carried out during Fall semester in 2006 and Spring semester 2007. The project was performed by two students in corporation with LIC Audio AB, a company in Stockholm. The degree project was meant to result in a communication aid for people with a cognitive handicap. The project focused on people suffering from dementia because of the expressed need within this group. This aid should first and foremost help in a conversation between a person with dementia and another person, like a relative or nursing home staff.

Utveckling av arbetsmetod för DFA

Scania is among the leading companies in the heavy vehicle industry. Scania also assemble engines for their trucks and buses, as well as to external marine and industrial applications. Wrongly assembled parts leads to quality problems, which makes it important to secure that the assembly is correct. To do this Design For Assembly (DFA) is used to describe how parts should become easier to assemble. Scania?s production unit for engine assembly has had a working method for DFA in the shape of a checklist, which is not used.

Effektivt nyttjande av högeffektslysdioder i mobil belysning

The purpose of this master thesis has been to find different solutions to the design of a headlamp with a cluster of three or possibly four high power LEDs (Light Emitting Diodes). During the work, two different problems have been considered; how to design a lens in order to shape the light beam in a desirable way, and how to design a cooling system which will lower the temperature of the LEDs as efficiently as possible, still taking into account the geometry set by the optical solution as well as other given geometries. The results presented in this thesis are partly the outcome of a literature study, but derive mainly from a number of tests and measurements made on two test rigs and one concept prototype..

Browser Wars : Kampen om webbläsarmarknaden

The first browser war took place during the second half the 1990s, and Internet Explorer cameout as the winner over Netscape Navigator. Today a new browser war is being fought withmany competitors and the future is uncertain. The purpose of the thesis is to find out how theweb browser market has developed since the start of the previous conflict, and we ask ourselveshow it will continue to develop in the future. This is accomplished with, among otherthings, interviews, tests and already existing statistics. The thesis' conclusions shows that theweb browser market has developed in a positive way from several perspectives, both for theusers as well as for the web developers.

Definition av stötdämpares fyllnadsgrad

Shock absorber units play a key role in establishing the driving dynamics and performance of automobiles. Öhlins Racing has manufactured high-tech automotive shock absorbers for over 30 years. Öhlins Racing?s advanced technology has contributed to over 200 world championships in automobile racing. Öhlin?s manufacturing process has long utilized automated fluid filling equipment during the final shock absorber unit assembly stage. The filling process consists of vacuum pumping the shock absorber unit and subsequent transfer of fluid. Vacuum pumping is necessary to remove residual air from the shock absorber unit prior to initiating the liquid filling stage. The presence of undesirable gases drastically compromises the performance of a shock absorber. The filling degree, defined as the final ratio of air to oil, is determined by the specific filling protocol as well as the specific equipment utilized.The current investigation aims to develop a viable technique to accurately determine residual air content in shock absorber units. If the filling degree can be appropriately quantified for a specific manufacturing process, then the air/oil ratio may be quantitatively related to shock absorber performance. The utilized measurement method must be completely integrated into the manufacturing process to guarantee shock absorber performance specifications according to the manufacturer?s standards. By utilizing the measurement method developed in this work, the manufacturing process, manufacturing equipment and product specifications can all be tailored to provide improved filling conditions.The developed measurement method provides accurate quantification of the filling degree under a wide range of processing conditions. The method establishes the relative quantity of air in the shock absorber unit by performing in-situ compressibility tests. The fill ratio can be controlled and varied by manipulating the vacuum pressure exerted during the filling process. Performance tests, however, indicate no correlation between filling degree and unit performance..

Barn- och ungdomars uppfattning om sin övervikt och fetma som ett problem samt skillnader i aktivitetsnivån hos barn- och ungdomar beroende på deras sociala familjesituation

BackgroundIncreased prevalence of obesity in children- and young adults and risk for diseases related to obesity will increase the burden on medical care. It is important to identify early risk factors that can be noticed by nurses in the daily work.AimThe aim was to investigate whether children- and young adults themselves perceive overweight as a problem and if there was a difference in the measured activity levels between overweight children- and young adults in families with different socio-economic family status.Method descriptionExisting survey from the Obesity Centre at the Akademiska Sjukhuset were examined together with the results from an accelerometer, where children- and young adults activity was recorded, compared to their perception of how active they were. The results were compared using a statistical software program and compiled with descriptive and non-parametric statistics.ResultsThe results do suggest that the majority of children- and young adults experiencing excessive weight have a problem in their everyday lives. Nearly half overestimate themselves as more active than what the actual measurements with accelerometer demonstrated. Much time is spent in front of the TV and computers.

En statistisk undersökning av transkriptionsnoggrannheten i kodande DNA-sekvenser i E.coli-bakterien

Bacteria are exposed to evolutionary pressure to an extent unlike other organisms. This leads to a high degree of adaptation to its surrounding. This thesis investigates the degree of adaptation towards higher accuracy in the transcription of DNA to RNA in coding sequences in the DNA of the E. coli bacteria. Two coding sequences with different nucleotide contents were investigated.

Analys av off-design prestanda för ett absorptionskylsystem

This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.

Aktieåterköp och undervärdering: : En empirisk studie av signalling-teorin

This paper tests the information signalling hypothesis on a sample of firms making open market stock repurchases. Using an earnings-based valuation model, we find that a majority of repurchasing firms are undervalued relative to their economic value. This result is consistent with previous academic studies, which claim that undervaluation is the prevalent factor explaining the observed abnormal return following the announcement of a repurchase program. We do not, however, find any evidence that the repurchase is consciously made by management to provide the market with new information. .

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