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Induction Machine Operation Mode Type Effect Onto The Losses
Skalka, Miroslav ; Schreier, Luděk ; Janda, M. ; Ondrůšek, Č.
This paper deals with analysis of losses behavior of Induction Machine for both operation mode types (motor/generator). The purpose of this work is the definition of eqiuvalent circuit parameters and theirs non-linear behavior depending on various factors - slip, mechanical torque, temperature. In this paper would be presented behavior of iron losses and joule losses of rotor and stator with specific parameters behavior. The whole analysis is done in ANSYS (by FEM) and MATLAB program.
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Modelování profilů rychlosti větru naměřených sodarem v komplexním terénu
Hošek, Jiří
The wind profiles with two Doppler sodars were measured in wide range of synoptic situations in Ore mountains (Erzgebirge) and in the region of Orlické hory (mountains), both in the Czech republic. Ore mountains represent the region most suitable for construction of wind turbines in the Czech republic. Concerning the observed wind profiles, their generalization may serve for improvement of precision of the simulated wind profile fields. In the second part of the work, we performed the modelling of wind speed profiles in the complex terrain of above-mentioned mountain ranges. We have applied the non-hydrostatic meso-scale models KAMM and PIAP. The numerical simulations with the models were performed for different situations of the ambient flow, described by geostrophic wind speed and direction, and temperature stratification.
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Evaluation of elastic parameters for models of isolated cells
Krbálek, Jaroslav ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This diploma thesis focuses on computational modeling of the cell mechanical tests. The goal of this thesis is to build a cell model and to simulate compression test on this model. If necessary, the model should be adjusted so the model reflects real cell behavior. It was created the cell model reflecting cytoplasm, nucleus, membrane and cell cytoskeleton. Cytoskeleton was modeled as tensegrity structure. After this, the pressure test was simulated on this model. The behavior of the cell model and real cell was compared using the stress force. The stress force - cell deformation curve was markedly different for the cell model and the real cell. For this reason, the cytoplasm material model was adjusted. The difference between the curves was acceptable after this modification. It was found during computations that the cytoskeleton model influence on the cell load is minimal. These results does not reflects real cell behavior, which means that the model is considered inadequate for performing stress load simulation.
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Valuation of employee stock options in accordance with IFRS 2 at fair value basis
Červený, Martin ; Mařík, Miloš (advisor) ; Strouhal, Jiří (referee)
This master's thesis is dealing with the topic of employee stock options (ESOs), primarily with the valuation of ESOs in accordance with the accounting standard IFRS 2 at corresponding fair value basis. The goal of this thesis is a critical analysis of the standard mentioned, with respect to the conditions of the Czech Republic. The theoretical part comes with the basic characteristics of employee stock options and explains how the traditional option-valuation models can be modified for the purpose of ESOs valuation. It is also concerned with discussion about fundamental features of the fair value basis necessary for the valuation process. The essential part of this thesis is the critical analysis focusing on the rationality of accounting methods, disclosure requirements and also on a theoretically correct determination of model inputs. Critical analysis is followed by case study aimed on evaluation of an authentic option plan. The practical part also demonstrates advanced methods of valuation using the Black-Scholes and the binominal models as well as the Monte Carlo simulation. In the conclusion, I present proposals for changes of the IFRS 2. According to the results of the critical analysis, supported by case study, greatest shortcomings were identified in the disclosure requirements. Proposals for changes are aimed mainly on this problem.
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Analysis and modification of thin layers using ion beams
Jonner, Jakub ; Lörinčík, Jan (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with analysis and modification of thin layers using ion beams. The first part of this diploma thesis deals with phenomena accompanying ion beam bombardment of solid matter. The second part of this diploma thesis is concerned with Secondary Ion Mass Spectroscopy (SIMS) and Low Energy Ion Scattering (LAIS). This work convey some basic information about these two techniques and it also deals with some benefits result in their connection into parallel depth profiling mode (such as better depth resolution of the LEIS profile, quantification of the SIMS). These benefits are demonstrated on MoSi film measurement. Within the framework of this thesis a new UHV manipulator was designed. This new UHV manipulator is equipped with precise stepper UHV motor and since the proportions are smaller, the manipulation with a sample in a space limited UHV chamber is much more comfortable and more precise. The third part of this diploma thesis deals with ion-beam induced transformation of epitaxially grown Fe films with thickness of 22 monolayer (ML) and 44 ML on Cu(100) single crystal at room temperature. Metastable Fe films of 22 ML thickness were prepared in CO pressure and 44 ML Fe films were prepared by co-evaporation of Fe with Fe64Ni36 (invar). Structural changes are analyzed by scanning tunneling microscopy and low-energy electron diffraction. The aim of this thesis is to discuss the influence of the sputtering parameters such as ion dose and ion energy on the nucleation of bcc nanocrystals, their growth, final shape and size. The influence of different Ni concentration on stability of 44 ML thick Fe films is also discussed.
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Clustering and regression analysis of micro panel data
Sobíšek, Lukáš ; Pecáková, Iva (advisor) ; Komárek, Arnošt (referee) ; Brabec, Marek (referee)
The main purpose of panel studies is to analyze changes in values of studied variables over time. In micro panel research, a large number of elements are periodically observed within the relatively short time period of just a few years. Moreover, the number of repeated measurements is small. This dissertation deals with contemporary approaches to the regression and the clustering analysis of micro panel data. One of the approaches to the micro panel analysis is to use multivariate statistical models originally designed for crosssectional data and modify them in order to take into account the within-subject correlation. The thesis summarizes available tools for the regression analysis of micro panel data. The known and currently used linear mixed effects models for a normally distributed dependent variable are recapitulated. Besides that, new approaches for analysis of a response variable with other than normal distribution are presented. These approaches include the generalized marginal linear model, the generalized linear mixed effects model and the Bayesian modelling approach. In addition to describing the aforementioned models, the paper also includes a brief overview of their implementation in the R software. The difficulty with the regression models adjusted for micro panel data is the ambiguity of their parameters estimation. This thesis proposes a way to improve the estimations through the cluster analysis. For this reason, the thesis also contains a description of methods of the cluster analysis of micro panel data. Because supply of the methods is limited, the main goal of this paper is to devise its own two-step approach for clustering micro panel data. In the first step, the panel data are transformed into a static form using a set of proposed characteristics of dynamics. These characteristics represent different features of time course of the observed variables. In the second step, the elements are clustered by conventional spatial clustering techniques (agglomerative clustering and the C-means partitioning). The clustering is based on a dissimilarity matrix of the values of clustering variables calculated in the first step. Another goal of this paper is to find out whether the suggested procedure leads to an improvement in quality of the regression models for this type of data. By means of a simulation study, the procedure drafted herein is compared to the procedure applied in the kml package of the R software, as well as to the clustering characteristics proposed by Urso (2004). The simulation study demonstrated better results of the proposed combination of clustering variables as compared to the other combinations currently used. A corresponding script written in the R-language represents another benefit of this paper. It is available on the attached CD and it can be used for analyses of readers own micro panel data.
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Intanke and exhaust manifold for racing engine
Chuchma, Ondřej ; Zháňal, Lubor (referee) ; Beran, Martin (advisor)
This Master’s thesis is focused on design and optimalization of intake and exhaust system of the C20XE engine. It is four-cylinder gasoline engine with stroke volume of two litres, which was produced by car company Opel. This engine is determined for Opel Astra F automobile, that is build for racing. For optimalization of dimension parameters there is used a Lotus Engine simulation software, which simulates one-dimension gas flowing in manifold. 3D CAD models are made in Pro ENGINNER software.
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Strain stress analysis of proximal tibia end with replacement
Tekalová, Soňa ; Mrázek, Michal (referee) ; Florian, Zdeněk (advisor)
This thesis deals with stress analysis strain proximal end of tibia with total joint replacements. The analysis is done on the basis of deformation characteristics of voltage, through the finite element method (FEM). We have developed two-dimensional models of the proximal end of tibia with tibial components total endoprosthesis (TEP), without loss and bone loss. Geometry model is created based on data obtained from computerized tomography, which were further processed in the program, Rhinoceros 3.0 and SolidWorks 2009th Computational solution was carried out by finite element method in Ansys Workbench 12.0. The model without loss of bone tissue was tested the hypothesis that the deformation is very small and there is no violation of the shank prosthesis. Due to loss of bone tissue is lost support to the tibial pulse in the proximal tibia and by a progressive increase in stress, which can lead to a breach of the shank total joint replacement. The analysis results show that, if the loss of bone tissue, so that the tibial part of the TEP will lose support, there is a crack stem total hip replacement due to stress.
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Using DEA models to assess efficiency of public transport
Hanousek, Jakub ; Borovička, Adam (advisor) ; Soldatyuk, Nataliya (referee)
This thesis deals with using DEA models to assess efficiency of the bus public transport in the Czech Republic regions. It is a method based on linear programming used to measuring efficiency of units. The main problem of public transport is the constant pressure to increase subsidies into this sector whilst the efficiency decreases. In the theoretical part of thesis, there will be explained the term 'efficiency' and will be introduced the basic principles of data envelopment analysis method including the mathematical formulations of the classic and modified DEA models, which will be then used in the practical part. The analysis of the resulting efficiency rates of all the different regions will be carried out with respect to the regions' specific characteristics. In the conclusion the optimal values will be proposed.
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