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Denna uppsats syftar till att undersöka användbarheten av metoden Independent Component Analysis (ICA) för brusreducering av bilder tagna av infraröda kameror. Speciellt fokus ligger på att reducera additivt brus. Bruset delas upp i två delar, det Gaussiska bruset samt det sensorspecifika mönsterbruset. För att reducera det Gaussiska bruset används en populär metod kallad sparse code shrinkage som bygger på ICA. En ny metod, även den byggandes på ICA, utvecklas för att reducera mönsterbrus. För varje sensor utförs, i den nya metoden, en analys av bilddata för att manuellt identifiera typiska mönsterbruskomponenter. Dessa komponenter används därefter för att reducera mönsterbruset i bilder tagna av den aktuella sensorn. Det visas att metoderna ger goda resultat på infraröda bilder. Algoritmerna testas både på syntetiska såväl som på verkliga bilder och resultat presenteras och jämförs med andra algoritmer. / The purpose of this thesis is to evaluate the applicability of the method Independent Component Analysis (ICA) for noise reduction of infrared images. The focus lies on reducing the additive uncorrelated noise and the sensor specific additive Fixed Pattern Noise (FPN). The well known method sparse code shrinkage, in combination with ICA, is applied to reduce the uncorrelated noise degrading infrared images. The result is compared to an adaptive Wiener filter. A novel method, also based on ICA, for reducing FPN is developed. An independent component analysis is made on images from an infrared sensor and typical fixed pattern noise components are manually identified. The identified components are used to fast and effectively reduce the FPN in images taken by the specific sensor. It is shown that both the FPN reduction algorithm and the sparse code shrinkage method work well for infrared images. The algorithms are tested on synthetic as well as on real images and the performance is measured.

One of the most important objectives for any countries is to sustain high economic growth. Even though there are main factors that affect economic growth, the concern of this paper is only about inflation. The relationship between economic growth and inflation is debatable. The first objective of this study is to investigate the relationship between inflation and economic growth. This study uses panel data which includes 13 SSA countries from 1969 to 2009. To analyze the data the model is formed by taking economic growth as dependent variable and four variables (i.e. inflation, investment, population and initial GDP) as independent variables. The result indicates that there is a negative relationship between economic growth and inflation. This study is also examined the causality relationship between economic growth and inflation by using panel Granger causality test. Panel granger causality test shows that inflation can be used in order to predict growth for all countries in the sample, while the opposite it is only true for Congo, Dep. Rep and Zimbabwe.

Having an engine model that is accurate but not too complicated is desirable when working with on-board diagnosis or engine control. In this thesis a four state mean value model is introduced. To make the model usable in an on-line automotive application it is discrete and simulated with a fixed step size solver. Modelling is done with simplicity as main object. Some simple static models are also presented. To validate the model measuring is carried out in a Scania R124LB truck with a 12 liter six-cylinder turbo charged diesel engine. In general, for this relatively simple model, the mean errors must be considered low. The inlet manifold pressure mean error during highway driving is 3.4\%.

In order to meet the increasing demand for higher data rates, next generation wireless networks must incorporate additional functionalities to enhance network throughput. Multihop networks are considered as a promising alternative due to their ability to exploit spatial reuse and to extend coverage. Recently, industry has shown increased interest in multihop networks as they do not require additional infrastructure and have relatively low deployment costs. Many advances in physical and network layer techniques have been proposed in the recent past and they have been studied mostly in single-hop networks. Very few studies, if any, have tried to quantify the gains that these techniques could provide in multihop networks. We investigate the impact of simple network coding, advanced physical layer and cooperative techniques on the maximum achievable throughput of wireless multihop networks of practical size. We consider the following advanced physical layer techniques: successive interference cancellation, superposition coding, dirty-paper coding, and some of their combinations. We achieve this by formulating several cross-layer frameworks when these techniques are jointly optimized with routing and scheduling. We also formulate power allocation subproblems for the cases of continuous power control and superposition coding. We also provide numerous engineering insights by solving these problems to optimality.

This thesis contains three essays on topics in agricultural economics. Essays one and two share a focus on international trade and economic development, and essays two and three apply dynamic tools to agricultural economic policy issues.<p>Essay one analyses trade-related implications of a developing country's decision to adopt genetically-modified crop technology. A fixed-proportions model is constructed that evaluates the welfare implications of a range of adoption policies and export market responses. The model in this essay illustrates the importance of the prospective adopter formulating a projection of probable export market effects before making an adoption decision and of the role that high transaction costs may play in a developing country's adoption decision. The model also considers the effects of a new policy tool; a check-off style levy on genetically-modified technology in place of a technology-use agreement. A levy could be useful tool in developing countries, which are characterised by high transaction costs. <p>Essay two models the effects of emergency food aid on a recipient country's agricultural industry. This essay formulates a definition of needed aid in the context of a food emergency and constructs an optimal control model that solves a path of aid shipments that best meets that need. The effects of a range of food aid paths on recipient-country agricultural production are illustrated through numerical simulations. There are two key results. First, a non-optimal amount of aid can hinder a recipient-country's recovery from an exogenous food shock. Second, an exogenous shock can affect farmer revenue and therefore impact planting decisions. This effect must be considered in aid allocation policies. <p>Essay three uses time-series econometric techniques to develop a demand model that assesses the effectiveness of commodity advertising. This essay describes the importance of considering long-run and dynamic effects in demand systems, especially in the case of closely substitutable commodities. A demand system that tests for and accommodates dynamic and time-series properties is developed and applied to US meat data. The results of this model are compared to a traditional static demand system. The dynamic model produces econometrically and theoretically sound results and generates some more intuitively appealing estimates.

Abstract Hydrogen sulfide (H2S) is an environmentally hazardous, corrosive, and toxic gas, mostly generated in gas and oil industry. For small-scale natural gas processing sites (less than 10 tonne S/day), the use of regenerable iron oxide adsorbent to adsorb H2S from natural gas is still an economical and effective method. The objective of this research project was to understand the performance of an iron oxide adsorbent, recently emerging in the Canadian market, in removing H2S from gas streams. To accomplish this, the breakthrough behaviors of H2S adsorption in a fixed-bed reactor under elevated pressures were studied. The effects of variations in superficial velocity from 0.09 m/s to 0.26 m/s, operating pressure from 4 to 50 atm absolute, and the height of the fixed-bed from 11.7 cm to 24.5 cm on breakthrough curves and sulfur loading were investigated. In all the experiments, the H2S concentration profiles of the exiting gas from the reactor were measured until the bed was saturated. It was found that the shape of the breakthrough curves depend on the superficial velocity and the inlet H2S concentration in gas streams. Under both higher superficial velocity and higher inlet H2S concentration, the shape of the breakthrough curve becomes steeper. The sulfur loading of the adsorbent depends on the superficial velocity, the inlet H2S concentration in gas streams, and the bed height. The sulfur loading decreases as the superficial velocity and the inlet H2S concentration increase, but increases as the bed height increases. The change of operating pressure does not have a significant effect on the shape of the breakthrough curve or sulfur loading of the adsorbent. The investigation was also extended using the regenerated adsorbents. A mathematical formula was developed to describe the breakthrough curves.

I denna studie undersöks hur införandet av jobbskatteavdraget 2007 och de två utbyggnaderna 2008-2009 påverkade arbetsmarknaden i form av sysselsättning, arbetslöshet, långtidsarbetslöshet och sysselsättning i åldersgruppen 55-64 år. Med utgångspunkt från en tillämpning av konsumtionsteorin, med arbetsutbudet i fokus, så görs en difference-in-differences analys av reformens tre första år i jämförelse med tre år innan dess införande. Resultaten visar att införandet av jobbskatteavdraget har haft en positiv effekt på arbetsmarknaden i form av en större andel avbefolkningen i arbete, medan ytterliggare steg av jobbskatteavdraget ger estimat som tyder på att effekten blir en minskad aktivitet på arbetsmarknaden.

The essays main intent is to examine whether there has been a proper implementation of the Council’s directive 1999/70/EG into Swedish law regarding the requirement for measures to prevent the abuse of successive fixed-term employment contracts. To achieve this purpose there is a need for an examination of current law. The essay also has some secondary purposes. One of these secondary purposes is the question of whether the implementation of the Council’s directive 1999/70/EG has lead to a reduction of the workers employment protection, which is closely connected to my main question and the violation case. My other secondary purposes are to make a connection between fixed-term employment and labor market flexibilization and flexicurity, to see if the rules about fixed-term work has affected gender equality, and to discuss whether there has been a shift of power in the relationship between employers and employees. I have come to the conclusion that Sweden has not implemented the Council’s directive 1999/70/EG properly regarding the requirement for measures to prevent abuse of successive fixed-term employments. I have found that the Swedish rules that apply today may be circumvented by combining various forms of fixed-term employments and that some forms of fixed-term employment requires a more clear definition. To prevent the abuse of successive fixed-term contracts, I suggest the introduction of a maximum total duration for all forms of fixed-term employment together, combined with a rule about the maximum number of times a fixed-term employment contract may be renewed. Furthermore I have found factors indicating that a reduction of workers employment protection level has taken place, but I can not draw any firm conclusions about it because the essay has not examined the issue in a completely thorough manner. I have also found a connection between labor market flexibilization and the use of fixed-term employment and that Sweden should examine whether the flexicurity-model can provide some useful solutions to increase employment without reducing workers employment protection level. Gender equality regarding the share of fixed-term employment contracts has slightly increased, both in Sweden and in the EU, since the origin of the Council’s directive 1999/70/EG. Also I have found that the new rules for fixed-term employment may have resulted in a shift of power that favors the employer. / Uppsatsen syftar främst till att undersöka huruvida det skett en korrekt implementering av visstidsdirektivet i svensk rätt avseende kravet på åtgärder för att förhindra missbruk av flera på varandra följande visstidsanställningar. För att uppnå detta syfte krävs en utredning av gällande rätt. Uppsatsen har också några underordnade syften. Ett av dessa underordnade syften är frågan om huruvida implementeringen av visstidsdirektivet inneburit en minskning av arbetstagarnas anställningsskydd, som är nära kopplat till min huvudsakliga fråga och överträdelseärendet. Mina andra underordnade syften är att koppla reglerna om tidsbegränsade anställningar till arbetsmarknadens flexibilisering och flexicurity, att se om reglerna om tidsbegränsade anställningar påverkat jämställdhet mellan könen och att diskutera huruvida det skett förändringar i maktförhållandet mellan arbetsgivare och arbetstagare. Jag har kommit fram till slutsatsen att Sverige inte har implementerat visstidsdirektivet på ett korrekt sätt avseende kravet på åtgärder för att förhindra missbruk av flera på varandra följande visstidsanställningar. Jag har konstaterat att de svenska reglerna som gäller idag kan kringgås genom att olika former av tidsbegränsade anställningar kombineras och att vissa av anställningsformerna kräver en tydligare definition. För att förhindra missbruk av flera på varandra följande visstidsanställningar föreslår jag att det införs en övre sammanlagd tidsgräns för alla tidsbegränsade anställningsformer kombinerat med en regel om maximalt antal gånger ett tidsbegränsat anställningsavtal får förnyas. Jag har funnit faktorer som visar på att en minskning av arbetstagarskyddet har skett, men jag kan inte dra några säkra slutsatser om det eftersom uppsatsen inte behandlat frågan på ett uttömmande sätt. Vidare har jag funnit ett samband mellan arbetsmarknadens flexibilisering och användandet av tidsbegränsade anställningar och att Sverige borde undersöka om flexicurity-modellen kan bidra med några lösningar för att öka sysselsättningen utan att minska nivån på arbetstagarnas anställningsskydd. Jämställdhet mellan könen rörande andelen tidsbegränsat anställda har ökat något, både i Sverige och EU, sedan visstidsdirektivets tillkomst. Jag har också kommit fram till att de nya reglerna om tidsbegränsade anställningar kan ha inneburit en maktförskjutning som gynnar arbetsgivaren.

In this thesis, the dynamical system is used as a function on afinite group, to show how states change. We investigate the'numberof cycles' and 'length of cycle' under finite groups. Using grouptheory, fixed point, periodic points and some examples, formulas tofind 'number of cycles' and 'length of cycle' are derived. Theexamples used are on finite cyclic group Z_6 with respectto binary operation '+'. Generalization using finite groups ismade. At the end, I compared the dynamical system over finite cyclic groups with the finite non-cyclic groups and then prove the general formulas to find 'number of cycles' and 'length of cycle' for both cyclic and non-cyclic groups.