This thesis compares four relevance feedback methods. The Rocchio and Ide dec-hi algorithms for the vector space model and the binary independence model and Okapi BM25 within the probabilistic framework. This is done in a custom-made Information Retrieval system utilizing a collection containing 131 896 LA-Times articles which is part of the TREC ad-hoc collection. The methods are compared on two grounds, using only the relevance information from the 20 highest ranked documents from an initial search and also by using all available relevance information. Although a significant effect of choice of method could be found on the first ground, post-hoc analysis could not determine any statistically significant differences between the methods where Rocchio, Ide dec-hi and Okapi BM25 performed equivalent.

The report aims to describe the austenitic stainless steel Sanicro 25 from a thermomechanical point of view. The thermal and mechanical properties of the material make it suitable for use in coal ? and thermal power plants. By the use of Sanicro 25 it would be possible to bring the efficiency of these plants up while bringing the carbon emissions down.A material model is created from material testing and validated through simulation in the finite element software Abaqus. The model that has been derived describes the material behavior during loading and stress relaxation for the first cycle in a thermomechanical fatigue test well.

The aim of this study was to develop a load prognosis model for Uppsala district heating system to be used as a tool for heat production optimization. The methodwas to build three models for the different customer types; housing, industry andoffices and then scale them for the total system using data from Uppsala districtheating system. The heat load consists of two parts, one that is temperaturedependent and one that is dependent of the social behavior of the customers. Thetemperature part was modelled with an ARX model using an outdoor temperatureprognosis as input signal. The social behavior part was modelled using the mean ofthe social behavior from some days before and additionally by distinguishing betweenweekdays and weekends.

This Masters thesis concerns epistemology in Knowledge Organization KO, as a field of study in Library and Information Science LIS. Using a theoretical model by Birger Hjørland and foucauldian discourse analysis as springboards, this study analyses three epistemological discourses in the practice of KO. The aim of the study is to show how these discourses are constituted and demarcated in relation to KO, as well as to examine how they fit into Hjørlands model. A brief historical outline of some epistemological trends in LIS is sketched, as well as examples of how different epistemological schools influence different parts of KO, e.g. information retrieval, indexing- and classification theory.

Simulation is a vital tool during development of JAS 39 Gripen, since money and time can be saved.The Auxiliary and Emergency Power System, AEPS, is a subsystem of the secondary power system in Gripen. It has the function of providing the aircraft with electrical and hydraulical power before activation and after deactivation of the main engine. The system also functions as backup in case of a safety critical problem in the main power supply system. The system basically consists of a control unit and an auxiliary gearbox. The gearbox is driven by an air turbine.

This study examines if the prediction of cardiovascular disease in hypertensive patients can be improved upon when renal function and microalbuminuria are added to the classical risk factors The predictive capability of a model is measured by discrimination, calibration, reclassification and Harrell's C.The results are ambigious. In most cases, microalbuminuria should be included in the model, but the results regarding the other measures of renal function are varied. Therefore, the selection of risk factors to include in the model depends on which measure of prediction one prioritizes..

In system development it is today increasingly common to use a model-based system development method. These methods that are suited for Agile work with simple and quick updates and implementations of new applications in systems conform to the requirements that are becoming more important today, namely more flexible and less expensive system that still maintain high quality and safety.A company that has been working with this type of system development method for a long time is Genicore AB, which also has developed their own tools and model language in order to better model the information management systems in complex and abstract operations. Genicore AB is trying to spread their method other developers and have therefore taken the initiative to start this study. The method is evaluated and tested by two students with relatively little experience in model-based systems engineering in order to gain a new perspective on how the method functions. The method has been applied to an educational activity in order to test it in a new domain, and this led us to our research question;?What criteria are of particular relevance in the implementation of a MBSD method on on complex businesses??Through literature reviews and interviews, we formed an idea of how model-based system development works from a theoretical perspective, and then continued to the case study conducted on the educational activities at the faculty of IT at University of Gothenburg.

AbstractPurpose:The purpose of the study is to describe the internationalization process of one firm when in a country culturally diverse from the firm?s original market.Methodology/approach:The study is a single case study which examines one firm?s internationalization process when entering the Chinese market. The approach has been an empiric interaction between empirical and theoretical data.Findings:The theory of the Uppsala model was applied to the case-company to test the model?s completeness. The authors found weaknesses and added three more aspects to the model.

Today?s farmers are constantly affected by the fluctuating world market prices on grain and thereby the price risk that comes with the price fluctuations. The volatile prices of grain increase the price risk within the business, which in turn affects the profitability of the business. The fluctuating prices together with the increased price risk within the farm business have opened up the market for hedging instruments. In this master thesis project, the aim is to identify the underlying end-values of 30 Swedish farmers? related to their choice of using hedging and the product; forward contract.

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.

AbstractIn urban societies people spend more and more time indoors, which put great demands on the indoor environment. If the ventilation is to manage the removal of unwanted substances in the indoor air, a good mixing of the air is required. The question arises that, whether the buoyancy forces will counteract a good mixing of the indoor air or not?This report aims to clear up the difficulties whether you need to consider the buoyancy forces or not, when adjusting a ventilation unit. For studying the indoor mixing of the air a two dimensional model is constructed in COMSOL Multiphysics.

The power system modelled in this thesis work has been developed for simulationwhen e.g. the production in some part of the power system is changed. The powersystem has been modelled according to the swing mass of the system, the frequencydependency of the load and the turbine governor. The model determines the systemfrequency, the period of regulation and the power exchange between the differentsubsystems in the Nordic synchronized system.In this model the system frequency is assumed to be the same in all different parts ofthe power system and the voltage conditions in the power system are neglected. Forthat reason power swings does not occur between different subsystems in the powersystem, which usually occur as a result of the swinging connection between thetransmissions line.

A well, situated on Listerlandet in the western part of Blekinge in Sweden, has a very high content of nitrate. Water with a too high content of nitrate is hazardous to human health, in particular to small children. The area surrounding the well is mostly drained agricultural land with some larger farms for chicken and mink. The well takes its water from the bedrock and is deeper than most other wells affected by nitrate. The bedrock in the area is dominated by limestone with a relatively high flow of water.This thesis was performed in order to find the source of the nitrate.

Using leaching test is a way to get a picture of pollutants retention and leaching in a risk assessment on contaminated land. There are several different types of standardised leaching tests today, where the natural leaching processes are speeded up to make it possible to predict the leaching of pollutants. These leaching tests have been developed for waste and there are no specific guidelines on how to judge the results from the tests, when making a risk assessment on contaminated land. This work is an investigation on how to use leaching test in this type of risk assessments. The strengths and weaknesses of the different types of tests are discussed. Depending on what type of information you want from your leaching test, different types of tests are suitable.

Modern democracies rest on a foundation of values essential to their prosperity. Two of those values are freedom of speech and political equality. To many, these values appear to coexist effortlessly. However, what this thesis aims to expose are some of the problems that quickly arise when attempts to interpret the values fail.The thesis investigates a specific US Supreme Court ruling called Citizens United. The ruling enabled corporations and unions to use their own treasuries for unlimited independent political expenditures.