The problems with train-induced vibrations are increasing with heavier and faster trains. Therefore the work with propagating vibrations is of outmost importance, and that is what this thesis relates to.To get a sensible idea of the propagation, calculation models are often used. Propagation calculation models takes into account factors such as distance to the railway, the ground material and the velocity and weight of the train. This work is mainly about finding suitable existing models and, if necessary, adjust them to be more useful with modern trains and railways.The report contains the work of adjusting one such model and does, despite the fully functional adjusted model, describe how much more there can be done within this topic. Finally, a few tips about specific areas that preferably should be studied to get even further knowledge about the troublesome problems from railways..

The aim and purpose of the following study is twofold. The first part aims at clarifying different models of migration policy available within research of political science. The second part of the study applies the identified models onto an analysis of the official report ?Integrationens svarta bok? and the suggestions the reports presents. The findings of the study are multiple.

Wind is used as an energy source all over the world. To be able to use this effectively, there is a need for as good forecasts and forecast models as possible. One of these models is Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) that is used to calculate short time forecasts. This model is used here to calculate wind speeds at two different areas in Västra Götaland, Bengtsfors and Vänersborg. There are also wind measurements with SODAR stations for these areas.

Today, activities funded with public funds needs to present relevant and reliable information which shows the results obtained. Requirements increase in welfare activities to be run based on scientific, empirical knowledge. This applies particularly to social work. The social work is, however, poorly researched in areas such as knowledge of interventions in the content, context and effects. One way to evidence-base social work can be to conduct regular and qualified assessments.

This paper describes a study examining four different GARCH models AR(1)-GARCH(1,1), AR(1)-EGARCH(1,1), AR(1)-APGARCH(1,1) and AR(1)-GJR-GARCH(1,1), and their ability to predict future volatility and thereby providing more reliable estimates for Value-at-Risk. The study is based on daily observations for the return of the OMX Stockholm 30 Index, during the time period 31st December 1996 to 29th December 2006. The coefficients for these GARCH models have been estimated using a five-year rolling estimation window, with one-year lags, for five different in-sample-periods. These five in-sample-periods, and the coefficients given by them, have been used to generate five out-of-sample predictions for the volatility in each year. Using these volatility predictions, the daily Value-at-Risk has been calculated for confidence intervals of 90 percent, 95 percent, and 99 percent, respectively, during the time period between 1st January 2001 and 29th December 2006.

This thesis studies the way valuation of investment properties is conducted in accordance with IAS 40 and how reliable these valuations are. This has been conducted by studying ten Swedish real estate companies listed on the NASDAQ OMX, during the period 2005-2008. The study shows that all companies use valuation models to determine the fair value of investment properties. Two different types of models have been identified. Companies that use the cash flow model show inconsistencies in time horizon, and how they determine the horizon value.

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulencemodel used in simulation of turbulent flow called PRNS (Partially Resolved NumericalSimulation). This model has promising properties and may be of use in savingcomputational resources. The purpose of this thesis was to analyze this model andcompare it with industrially applied models such as k-omega SST and LES (Large EddySimulations).PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation)where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1are selected. This constant is then used in the calculations and determines thebehavior of the simulation. When RCP is set to zero the equation are the same as fora DNS simulation and when RCP is set to one the equations for k-omega SST issolved.

Because of new emission and on board diagnostics legislations, heavy truck manufacturers are facing new challenges when it comes to improving the engines and the control software. Accurate and real time executable engine models are essential in this work. One successful way of lowering the NOx emissions is to use Exhaust Gas Recirculation (EGR). The objective of this thesis is to create a mean value model for Scania's next generation EGR system consisting of a poppet valve and a two stage cooler. The model will be used to extend an existing mean value engine model.

In this paper I have sought a suitable level of abstraction in my models describing the landscape; the models are made to be viewed from eyelevel. Because of the spectator being ?in the model? the objects included need a certain degree of realism. I have sought what is needed in the model to be able to comprehend that the model is showing a landscape. Some details might be unnecessary.

The aim of this essay was to examine whether 10 Swedish newspapers editorial pages and their leader writers changed their view on Mikhail Gorbachev before, during and after the August Coup in 1991. Moreover, the aim was also to see if the editorial pages used the same sources when they wrote about Gorbachev.In this essay four main questions were asked:- How is Gorbachev described before the August Coup?- How is Gorbachev described during the August Coup?- How is Gorbachev described after the August Coup?- What sources did the editorial pages use when they wrote about Gorbachev?Ten newspapers and their editorial pages from the period of 1-31 August and 1-6 September, as well as 10-31 December 1991 and 1 January 1992 were examined. It was discovered that most of the editorial pages changed their view from being negative in August to being more positive in December.As a conclusion it can be stated that the examined editorial pages did not write much about Gorbachev in the beginning of August and if they did mention him it was in a negative tone. One of the reasons for the lack of mentioning during the August Coup could be that the leader writers were not sure whether Gorbachev would return back to power.

Good comfort for the driver of a construction machine is crucial. Gearshift comfort is an important part of the total comfort. Volvo Construction Equipment Components has a simulation environment of the powertrain, SimPow, which is implemented in Matlab/Simulink. SimPow is mostly used for simulation of control strategies and performance. In order to be able to study gearshifting comfort, Volvo has an interest in developing new models for SimPow.

Being able to take a decision on an area you've never seen is a difficult task. It is also complicated to introduce an environment in the best way to benefit its purpose. This study focuses on the differences people notice between 2D and 3D models. To make it more concrete, the study has been linked to a case study called Ha?lsans va?g 255.

This paper thoroughly investigates needs and requirements for overhead distribution feeder inspection and develops models to investigate possible relations between short term inspections remarks and outages. The study was conducted in collaboration with Fortum Distribution AB that supplied extensive information about their overhead power feeders concerning both inspection and power outages. The investigated models where lognormal linear model, Poisson generalized linear model and negative binomial generalized linear model. All models were implemented utilizing offset terms to compensate for differences in feeder length and amount of overhead versus underground feeders. The Poisson generalized linear model was rejected at an early stage due to overdispersion and neither of the remaining models fit the data perfectly.

Predicting corporate failure is an increasingly important topic in the world of economics today. This paper, with the help of the credit ranking company Syna AB, aims to investigate a few different statistic strategies to do just that. This task is accomplished by using a data material of 250 000 Swedish companies divided into two subsamples. The first sample is used to develop the model and the second as a validation sample. The model developing sample holds 160 000 companies divided into five different subgroups based on size and age.

Nowadays the majority of the thinnings made in Swedish forests are done by machines, harvesters and forwarders. The most common model in thinning with a harvester is strip-road operated thinning and stand-operated thinning with one intermediate passage between the strip-roads. This study is a time study with some quality follow ups on a strip-road operated thinning model, a stand-operated thinning model with one intermediate passage between the strip-roads and a stand-operated thinning model with two intermediate passages between the strip-roads. The machines in the study were a small harvester (Forestline MPM C90) and a medium sized forwarder (Timberjack 1110). The study was made in Litsnäset outside the city of Östersund in Sweden and was made during the autumn 2007. In a lodgepole pine stand six study units (0,6 ha) were thinned with the three different models, two study units per model.