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7117 Uppsatser om General linear mixed model - Sida 2 av 475

Modell av en synkronmaskin för PSCAD/EMTDC med magnetisk mättning i d-led och elektriskt gränssnitt för fältmatare

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Gestaltningsförslag till ny förskola på Zakrisdal

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

The effects of Joint Ventures announcements on stock returns behaviour - An Event Study of the Stock Market

The purpose of this study is to examine the effects of joint venture announcements on stock prices behavior and simultaneously to test the German stock market (Frankfurter Wertpapierbörse) for efficiency. We tried not only to analyze the general impacts of a JV-announcement but also to look for differences in the market response to announcements of different types of joint ventures, namely: domestic, international, horizontal and vertical. Our expectations of efficient market were confirmed during our paper, which employed the technique of the standard event study. The calculation of abnormal returns which are the signals for market efficiency or inefficiency respectively were based on the market model, establishing linear relationship between the return on the market and the return on an individual security. The parameters of the model were obtained through regression analysis..

Optimering av ett småskaligtvattenkraftsystem

This master thesis covers the seasonal planning of a small scale hydropower system. The system in this study is owned and operated by Mälarenergi Vattenkraft AB. The total system consists of 4 different main rivers with 24 hydropower stations and several dams. The total installed power in the system is 43.75 MW. Most of the hydropower stations are regarded as small scale hydropower stations and thus entitled to green certificates.In this report the issue of planning is formulated as an optimization problem.

Modellbaserad temperaturregleringav partikelfiltrets regenereringsprocess

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Skriftspråksskillnader? : En jämförande studie av flickor och pojkars skriftspråk på gymnasienivå

Our society has faced monumental changes and therefore our working life has changed as well. We are now in the twentieth first century and still our labor market is gender-segregated. Today networking is an important part of working life and one cannot emphasize enough the importance of having good connections in your network. Networking is now seen as an important tool when it comes to your career. In the past networking has been the men?s arena and it has almost been seen as a male institution.

Timmerkvalitet hos björk i blandskog med gran

Birch is the dominant deciduous tree species in Sweden but only 16 % is found in pure birch stands. The majority of the birch (51 %) is to be found in conifer dominated stands. Swedish forest land comprises approximately of 23 % mixed stands and one problem is that for mixed stands there are few management recommendations. The underlying aim of this thesis was to study the management of mixed forest stands of spruce and birch to achieve good timber quality of birch. The study was based on a literature study and measurement in a field experiment launched in 1998 by the Swedish University of Agricultural Sciences (SLU).

En jämförelse mellan linjära och traditionella bedömningssystem hos hästar

In Sweden the breeding organization for the Swedish Warmblood horse uses a traditional scoring system when evaluating horses. The horse is scored subjectively in relation to how good each trait is in relation to the breeding objective. Other countries, for example the Netherlands, instead use a linear scoring system. The linear scoring system evaluates the horse on a scale between two, for the breed, biological extremes which makes the evaluation more objective since the judges personal values does not influence as much. The breeding organization for the Swedish Warmblood is today planning a change towards a linear scoring system.

Missilstyrning med Model Predictive Control

This thesis has been conducted at Saab Bofors Dynamics AB. The purpose was to investigate if a non-linear missile model could be stabilized when the optimal control signal is computed considering constraints on the control input. This is particularly interesting because the missile is controlled with rudders that have physical bounds. This strategy is called Model Predictive Control. Simulations are conducted to compare this strategy with others; firstly simulations with step responses and secondly simulations when the missile is supposed to hit a moving target.

Jämförelse mellan MultiScat och konventionell beräkning av intensiteter till koncentrationer vid analys med röntgenflourescensspektrometri

In this master thesis work, a new method called MultiScat, is compared with the conventional method with alfa-correction, for computing concentrations from intensities in X-ray spectrometric analysis. The conventional model is a linear model, which only takes the photoelectric effect into consideration. It doesn't consider Rayleigh and Compton scattering even though it has a great impact on the measured intensities. Here MultiScat differs a lot. MultiScat is based on a solution of the Boltzmann transport equation.

Prediktion av bostadsrättspriser i Stockholms innerstad.

A frequently asked question in real estate marketing is at what time of the year it is optimal to invest or sell. The aim of the project was to answer this question and to generate a prediction model over real estate located in the centre of Stockholm that takes seasons into account. With acquired sales statistics in Stockholm between 2010 and 2013 it was possible to perform a linear least square regression, also known as Ordinary Least Square (OLS), with describing qualities and season of sale as parameters. Statistical problems such as Multicollinearity and Heteroskedasticity have been taken into account when deriving the model. The result was a highly accurate prediction model indicating the profitability of investing in real estate during the summer and selling during the autumn..

Feldiagnos för RM12 baserad på identifierade modeller

The jetengines of today are growing in complexity. Reliability for aircraft engines are of extreme importance, mainly due to safety reasons but also economical ones. This master thesis deals with faultdiagnosis in the turbine section of RM12, the engine used in Saab/BAe's Gripen. Three different faults which can occur in the turbine section was studied. These faults are: clogged fuel nozzle, hole in outlet guide vane and sensor fault.

Den enda likheten mellan könsblandade och kvinnliga nätverk är att det serveras bulle och kaffe : En studie om betydelsen av kvinnors relationer till professionella nätverk

Our society has faced monumental changes and therefore our working life has changed as well. We are now in the twentieth first century and still our labor market is gender-segregated. Today networking is an important part of working life and one cannot emphasize enough the importance of having good connections in your network. Networking is now seen as an important tool when it comes to your career. In the past networking has been the men?s arena and it has almost been seen as a male institution.

FEM?modeller för expansionsanalys av piplines

REINERTSEN AS performs expansion and buckling analyses of pipelines using ANSYS, afinite element modelling and analysis tool. In an expansion analysis the pipeline is modelledwith thin?walled pipe elements called PIPE20 which allows plastic deformation. However, ina recent analysis the results retrieved from the PIPE20 element were incorrect for strainsabout 1 percent. One main issue was that the PIPE20 element overestimated the strains.The purpose with this Master Thesis was to become familiar with the theories and analysismethods used in pipeline design.

Nivågruppering

The aim of this essay is to examine if the attitudes and the experiences of Ability Grouping are the same on different levels of the school organisation.I have chosen to answer the following two questions:· Have the teachers, the students and the headmaster the same idea concerning the educational model at the school, that is, the pros and cons of Ability Grouping?· Does the intentions of the curriculum agree with this educational model?I knew what I thought about the educational model at the school that is the object of this essay, after spending ten weeks at it as a trainee, but I felt that I would be interesting to know what the people who are part of that system everyday think about it.In order to be able to answer my questions, I used both the qualitative and the quantitative method. I interviewed the headmaster and five teachers to find out what they thought about Ability Grouping. I also distributed inquiries to 70 students from 6th to 9th grade to get their point of view. In the theoretical discussion I explain the meaning of different conceptions that I use throughout this essay.

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