The purpose of this thesis is to construct an endogenous macroeconomic model explaining the cause of financial cycles and systemic instability based on the financial instability hypothesis (FIH) published by Hyman Minsky (1982). FIH maintains that capitalist financial systems have an inherent disposition to fi- nancial instability because periods of economic prosperity encourage borrowers and lenders to be increasingly reckless which in turn lead to the formation of financial bubbles. The problem is approached by employing an adaptive ex- pectations model based on stylized facts from Kaldor's and Kalecki's models with addition of behavioral equations implemented in an attempt to simulate market expectations. JEL Classification E02, E11, E32 Keywords Instability, Macromodel, Cycles Author's e-mail ales.z@hotmail.com Supervisor's e-mail jaromir.baxa@fsv.cuni.cz

Master thesis focused on the research of the effervescent atomizers. Effervescent atomizers belong to a group of two-phase atomizers, which are often used in combustion applications. Right there in combustion applications, the degree of the stability sprays has a significant impact on combustion efficiency and exhaust gas emissions. The main aim of this work was to asses the level of spray unsteadiness depending on the atomizer design and its operating mode. The effect of construction was studied on the diameter and length of mixing chamber, and then on the size, number and location of aeration holes. Seventeen specific variants of the atomizer were constructed by different combinations of these design parameters. Each of these variants was measured in three operating modes, which were represented by a liquid pressure at the inlet to the atomizer and gas-to-liquid mass flow ratio (GLR). To evaluate the level of spray unsteadiness was used a methodology, which compares the ideal element´s distribution into the interparticle time bin, defined for the ideal (stable) spray, with the experimentally observed distribution. The laser measurement system P/DPA (Phase Doppler Particle Analyzer) was used to determine the experimental interparticle distribution. The result of the comparison of the ideal and the experimental distribution was the parameter , which expresses the level of spray unsteadiness for a specific atomizer and operating mode. With that parameter it was possible to compare the individual atomizers and determinate to the benefit of various construction´s correction of the atomizer. The results showed the recommendation for the modifications of the atomizer, creating a spray with a minimum level of spray´s unsteadiness. For the surveyed atomizer and his individual costruction´s variations the drawing was made.

Massive stars are powerful energetic sources shaping their surrounding interstellar medium, which is often swept up into a cold dense shell. If the shell fragments and forms a new generation of massive stars, the stars may form new shells, and this sequence repeats recursively leading to propagating star formation. Using three dimensional hydrodynamic simulations, we investigate fragmentation of the shell in order to estimate masses of stars formed in the shell. We develop a new numerical method to calculate the gravitational potential, which enables us to approximate a part of the shell with a plane-parallel layer. Our main results are as follows. Firstly, we compare our numerical calculations to several analytical theories for shell fragmentation, constrain the parameter space of their validity, and discuss the origin of their limitations. Secondly, we report a new qualita- tively different mode of fragmentation - the coalescence driven collapse. While layers with low pressure confinement form monolithically collapsing fragments, layers with high pressure confinement firstly break into stable fragments, which subsequently coalesce. And thirdly, we study whether layers tend to self-organise and form regular patterns as was suggested in literature, and we find no evidence for this conjecture. Based on our...

Presented diploma thesis deals with experimental study of fluid induced instabilities which occur in rotating machinery with journal bearings. The first part describes the oil whirl and oil whip instabilities. It also gives an example of optical methods used for observation of journal bearings. Next part is dedicated to modifications of an existing test rig that were necessary for carrying out experiments. Finally, there are presented results of experiments that define the effect of initial conditions on appearance of instabilities.

This diploma thesis discusses the issue of the fluid flow instabilities due to rotating discs. It also deals with the calculation of axial force in centrifugal pumps and pressure distribution on cover and support disc of the impeller. Computational simulation of rotating disc is presented with the aim of capturing flow instabilities. Next computational simulation focuses on modelling a gap between the support disc (rotor) and the stator part of the pump for three different geometries, where axial force, pressure distribution on the support disc and loss torque are calculated for each of three models. Obtained results are then compared with the experiment in the conclusion

This dissertation describes the relationship between inflation and unemployment with the concept of the natural rate of unemployment at which inflation remains unchanged. By comparing NAIRU, as defined in this manner, with the actual unemployment rate, we obtain the gap in unemployment. In connection with the analysed substitution between inflation and unemployment, there can be found a decrease in the importance of the PC in the 1970s, a very popular New Keynesian PC in the 1990s, and doubts over the robustness of the estimates. On the other hand, the concept of the PC and the NAIRU had previously been developed in accordance with the real data. There is a broad consensus on the impact of monetary policy on nominal variables (inflation) and real variables (unemployment). Methods are also being combined and continuously improved This dissertation is seeking to prove or disprove the hypothesis of the NAIRU concept's usability in estimating the economic cycle on the labor market. This hypothesis has helped in the acceptance of: the support for the concept and estimating PC and NAIRU in the literature; the application of measures to refine the estimate of the NAIRU and PC in the empirical analysis of the dissertation; the dissertation conclusion's compliance with the latest international research, with the local authors and with the own research. The contribution of the dissertation can be identified thusly: distribution methods depend upon the different time periods, their treatment and the best methods for the conditions of the countries in the Visegrad Group; the specification of an unstable environment and its impact upon the estimation of the NAIRU and the economic cycle; the calculation of the unemployment rate of the sectors, age categories and their use in estimating the NAIRU and cycle on the meso-level; to determine the effect of different pricing structure indicators in order to estimate the NAIRU and the economic cycle on the labor market and the topicality of their estimates.

This thesis deals with study of dynamics of the swirling flow. The swirling flow occurs frequently in hydraulic machinery (e.g., vortex rope in draft tube of the hydraulic turbine) and often influences operation of these machines. For this reason, sufficient knowledge regarding this characteristic flow is necessary for subsequent improvement of hydraulic machines. The theoretical part of this thesis contains description of flow instabilities and their manifestations, notably Kármán vortex street and vortex rope. In the next part, two methods are applied to these two transient flows in order to identify their specific dynamic properties. The first method, Fourier transform, enables to find frequencies of transient flow. The second method, proper orthogonal decomposition (POD), enables to identify planar or spatial eigenmodes of a specific swirling flow. Proper orthogonal decomposition is used in this thesis to identify planar eigenmodes of Kármán vortex street and spatial eigenmodes of vortex rope.