The thesis focuses on the evaluation of changes in the provision of social benefits for the unemployed, which occurred in the past few years. Specifically, it is mainly changes in the provision of unemployment which have occurred since 2009, and changes in the provision of benefits in material need, effective from 2007. Act No. 111/2006 Coll. providing for the payment of benefits in material joined together with Act No. 110/2006 Coll. the Subsistence Minimum in force from 1.1.2007. Their main task was to motivate the unemployed to actively search for work, and contrary to penalize those who are not interested in finding a job and prefer living on welfare benefits and reduce unemployment. The thesis aims to analyze the impact of these changes on the development of unemployment in the district of Kladno and development spending on social benefits.

In 2006, there were changes in the social security system through the adoption of Act No. 110/2006 Coll., about subsistence level and living wage, Act No. 111/2006 Coll., On assistance in material need and Act No. 435/2004 Coll. on employment. The aim of the newly adopted laws was greater motivation of unemployed persons to find employment as soon as possible and thus to reduce the number of long-term unemployed individuals. At the same time the advantage of individuals who actively solve their situation compared to those who are passive recipients of benefits. With the adoption of these laws was to strengthen the incentive function of the social system, the transition from passive to active solidarity, impaired access to social benefits and avoiding the misuse of social benefits.

The current research is aimed at investigating the explosion behaviour of hazardous materials in relation to particle size. The materials of study are titanium powders having size distributions in both the micron- and nano-size ranges with nominal size distributions: -100 mesh, -325 mesh, ?20 ?m, 150 nm, 60-80 nm, and 40-60 nm. The explosibility parameters investigated explosion severity and explosion likelihood for both size ranges of titanium. Tests include, maximum explosion pressure (Pmax), maximum rate of pressure rise ((dP/dt)max), minimum explosible concentration (MEC), minimum ignition energy (MIE), minimum ignition temperature (MIT) and dust inerting using nano-titanium dioxide. ASTM protocols were followed using standard dust explosibility test equipment (Siwek 20-L explosion chamber, MIKE 3 apparatus, and BAM oven). The explosion behaviour of the micron-size titanium has been characterized to provide a baseline study for the nano-size testing, however, nano-titanium dust explosion research presented major experimental challenges using the 20-L explosion chamber.

After the split of the Czechoslovak Federal Republic (CSFR) to the Czech and Slovak Republics in 1993, both countries retain most ČSFR laws, including law no. 463/1991 Sb., o životním minimu. So the starting position was the same for both countries. A number of modifications of the legislative environment, which happened over the years in both countries, provides a suitable space for the realization of comparative analysis. The aim of this thesis is to compare the institute of subsistence minimum (SM) in the Czech and Slovak Republic between 1993-2015, and prove the assumptions that the institute of SM always held in both countries the same function, was highly motivational to reintegrate the unemployed into the workforce, and the greater amount of SM has always meant a higher income for people in material need in particular country. But the conducted comparative analysis does not confirm the assumptions.

Poverty is one of the most oppressive topics all over the world. It is being fought both in developed and developing countries. As for the Czech Republic, poverty is associated with unemployment, especially with the long-term unemployment. On 1st January 2007, two new acts have come into effect; Act no. 110/2006 about minimum and living wage and Act no. 111/2006 about help in substantial shortage. These acts newly regulate the conditions of social benefits and its income with the objective of lowering the long-term unemployment. They incorporate elements that would sanction those who are unemployed and passive in search of a new job, and on the other hand should give advantage to those seeking actively. The purpose of my work is to examine the impacts and consequences of these two acts, and whether these has been any change in the long-term unemployment rate, positive change in its absolute values or positive change in its structure.

In 2007 came into force amendments to the social security system in the Czech Republic. Agreed amendments aim to strengthen the motivation to enter and remain in the labour market, favouring those who seek to improve their situation through their own effort and unfavouring people living just on welfare benefits. There was thus a redefinition of the social benefits and their construction. And there was a significant reduction in unemployment in 2007. This thesis entitled "Developing long-term unemployment in the years 1998 - 2008" assesses the impact of these changes on the level of unemployment, special attention is paid to long-term unemployment. The work is not overlooked by the economic situation of the Czech Republic in the years 1998 - 2008.

An accurate satellite attitude and orbit control is a key factor for a successful mission. It guarantees for example sun acquisition on solar panels, fine pointing for optimal telescope usage or satellite lifting to reach higher orbits, when required. Furthermore attitude and orbit control is applied to compensate any occurring disturbances within the space environment. The problem tackled in the present thesis is the optimization of thruster commanding to perform spacecraft orbital manoeuvres. The main objective is to develop different algorithms that are suitable for on-board implementation and to compare their performance. For an optimal thruster command distribution the algorithms shall solve linear programming (or optimization) problems, more exact they shall compute thruster on-times to generate desired torques and/or forces, which are requested by the on-board software. In total three different algorithms are developed of which the first one is based on the pseudoinverse of a matrix, the second one is a variation of the Simplex method and the third one is based on Karmarkar’s algorithm, which belongs to the interior-point methods. The last two methods are well known procedures to solve linear programming problems and in theory they have been analyzed before. However this paper proves their practical application and industrial feasibility for orbital manoeuvres of the weather satellites of ESA’s MTG project and their scalability to any number of thrusters on a generic satellite for 6 degrees of freedom manoeuvres. There are 6 MTG satellites and each has 16 one-sided reaction control thrusters, placed at specific positions and pointed towards defined directions. Physical mechanisms limit the thrusters output to minimum on- and off-times. The focus of this thesis will be on the orbital transfer mode, due to the high disturbances that arise during four motor firing sessions at the apogee, executed to reach higher orbits and finally GEO. The firing sessions are performed by a liquid apogee engine and while this engine is in boost mode, the thrusters shall be used for attitude control only. The technique (nominal case) developed by OHB for this maneuver and currently operational uses 4 thrusters only, which are all pointing in the engine’s direction. They are also used to settle the fuel before the engine is turned on. For control the Pseudoinverse method is applied. If one of the 4 thrusters fails, the backup scenario takes place, which includes using 4 totally different thrusters and no fuel settling, due to their unfavorable position with respect to the engine. The initial idea of this work was to develop a controller for 6 thrusters, using only 2 of the 4 nominal case thrusters, to have a better control performance in the backup case. The Pseudoinverse method was developed by OHB before, thus only small changes needed to be applied to work with 6 thrusters. The two other algorithms, based on the Simplex and Karmarkar method, were completely developed from scratch. To analyze their performance several tests were executed. This includes unit tests on a simple computer hardware with different input, Monte Carlo simulations on a cluster to test if the algorithms are suitable for MTG orbital manoeuvres and the application to 12 thrusters, mounted on a generic satellite to generate torques and forces at the same time for 6 degrees of freedom manoeuvres. For each thruster configuration the worst case outputs are shown in so called minimum control authority plots. The performance analysis consists of the maximum and average deviation between requested and generated torque/force, the average computed thruster on-times, the algorithms computation(running) time and iteration steps. For MTG the test results clearly confirm that the usage of 6 thrusters leads to more accurate generated torques and better control authority, than using only 4 thrusters. The Simplex method stands out here in particular, showing excellence performance regarding torque precision. Nevertheless the accuracy goes at the expense of computation effort. While the Pseudoinverse method is very fast and needs only one iteration step, the Simplex is half a magnitude, the Karmarkar one magnitude slower. But the latter lead to lower thruster on-times in terms of firing duration and thus fuel consumption is reduced. Also it is shown that Simplex and Karmarkar can control 12 thrusters at the same time to generate torques and forces, which proves their scalability to any thruster distribution. In the end it comes to the question whether generating a more accurate torque/force or the computational effort, which is strongly hardware dependent, is more important. A decision which depends on the mission’s objective. This paper shows that all three implemented algorithms are able to handle attitude control in the MTG backup scenario and beyond.

Master of Science / Department of Statistics / Haiyan Wang / We introduce a new classification method that is applicable to classify image pixels. This work was motivated by the test-based classification (TBC) introduced by Liao and Akritas(2007). We found that direct application of TBC on image pixel classification can lead to high mis-classification rate. We propose a method that combines the minimum distance and evidence from hypothesis testing to classify image pixels. The method is implemented in R programming language. Our method eliminates the drawback of Liao and Akritas (2007).Extensive experiments show that our modified method works better in the classification of image pixels in comparison with some standard methods of classification; namely, Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA), Classification Tree(CT), Polyclass classification, and TBC. We demonstrate that our method works well in the case of both grayscale and color images.

Surface integrity is of great significance in grinding performance since grinding process is often used as a finishing step. For metallic materials, residual stresses play an important role in surface integrity for its strong effect on fatigue life, corrosion resistance, and part distortion. For ceramic materials, the surface damage induced by grinding process could greatly affect the mechanical strength and surface finish of the component. The functional behavior of machined components can be enhanced or impaired by the grinding process. Because of this, understanding the surface integrity imparted by grinding is very important. The use of fluid is common in grinding process, however, the high cost and environmental impact of the conventional flood cooling is very undesirable. The minimum quantity lubrication (MQL) have been introduced in industry for about two decades as a promising alternative to conventional flood cooling for economical and environmental advantages. A comprehensive understanding of the MQL effect on the process performances and surface integrity is of great value to the implementation of MQL technique in industrial situation. Grinding-induced residual stress prediction has been a topic of research since the 1970’s while the studies of MQL grinding is still on the early stage with experimental investigations. A comprehensive study and quantitative description of MQL effect on the residual stress generation in grinding is highly demanded. On the other hand, although there has been significant research in the area of surface damage in ceramic grinding, there are still opportunities for advancing predictive methods. Therefore, the objectives of the current research are set as follows: (1) develop a method of predicting residual stress based on an analytical description of the grinding process under MQL condition, (2) develop a method of predicting surface finish and damage in ceramic grinding, and (3) validate the model with experimental data. The research will first focus on predicting residual stresses in MQL grinding based on first principles. This includes predictive models of grinding forces, and grinding temperature stemmed from grinding kinematics and dynamics principles as part of the overall modeling effort. The effect of MQL on both lubrication and cooling aspects has been integrated into these models. The mechanical and thermal output parameters will serve as the basis for determining the loading history which generate residual stresses. The research will also aim at surface roughness modeling in ceramic grinding. A ductile-brittle mixed surface generation is predicted based on the nature of ceramic materials and grinding kinematics. The crack system developed from indentation fracture mechanics approach will be utilized in evaluating the brittle mode surface generation. The modeling techniques will be applied to a range of grinding conditions and materials. This research would aid in evaluating various surface integrities in grinding of metallic and ceramic materials with little experimental efforts. The output could be used to machine these materials effectively to order to improve the functionality of the component.

This paper finds an insignificant negative correlation between youth employment and minimum wages for the panel of U.S. states, 1976-2015. Such a correlation is not observed in earlier panels. The source of the new results is traced to the greatest decline in employment-population ratio since the 1970s emerging during the financial crisis of 2008. Moreover, I discuss the likely causes of the recent sharp decline in employment-population ratio and propose that more factors should be taken into account when examining the effect of the minimum wage policy.