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Calculation of optimum slip frequency of induction motor for minimisation of its losses
Bednařík, Václav ; Patočka, Miroslav (referee) ; Vorel, Pavel (advisor)
This master’s thesis focuses on the minimisation of losses by calculation of optimum slip frequency of induction motor. The next point of this master‘s thesis is supersaturation. Supersaturation must be solved for the size of losses, because of the effect that is cause of the losses, when current increases with saturation. However current is not increase proportionally with increasing saturation, but increases several times more. This problem is included in the calculation of the slip frequency. Optimum of slip frequency is solve for modified gamma model of induction machine. In the main point of this thesis is outlined the process, how the optimum can be found. With same process were already were found the equations, but they were too extensit. In the end is solved the optimum of slip frequency be minimum of the flux density.
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The issue of new fly ash aerated concrete production
Bednárik, Vít ; Janovský, Radek (referee) ; Drochytka, Rostislav (advisor)
The master´s thesis deals with the possibility of laboratory verification of the influence of feedstock character, especially lime and fly ash, on quality of fly ash aerated concrete. The experimental study involves taking a series of samples autoclaved and non-autoclaved aerated concrete during two pilot plant verification in the factory. After removal of autoclaved and non-autoclaved aerated concrete samples they were tested and compared with results of non-autoclaved aerated concrete produced in the laboratory. Methodology of comparison technologically-produced autoclaved aerated concrete and laboratory-produced non-autoclaved aerated concrete was designed based on achieved findings.
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Rotor fault diagnosis of induction motors
Bednařík, Václav ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This bachelor thesis focus on the faults of induction motors. In general terms to mechanical and electirc faults and their influence on induction motor. Further on the tests, that are conducted on induction motors to detect faults and states that precede them. Main part is devoted to rotor eccentricity and broken rotor bars. Eccentricity is solved within theoretical analysis and measurements on free damaged motors. As well as broken rotor bars, which are supplemented by measurements on three damaged rotors. There are two types of eccentricity, static and dynamic. Faults of broken rotor bars is solved in terms of postion of broken rotor bars and their number.
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Development of different types of fly ash autoclaved aerated concrete
Bednárik, Vít ; Kulísek,, Karel (referee) ; Drochytka, Rostislav (advisor)
This bachelor´s thesis deals with the current technologies of production and raw materials used in the production of fly ash autoclaved aerated concrete. The choice of suitable materials is an important prerequisite for achieving the desired properties of the finished product. Fly ash autoclaved aerated concrete has become one of the options, how to use fly ash, produced as a secondary raw material in the combustion of coal in heating power plants. This work deals with the comparison the physico - chemical properties of the fly ash in the Czech Republic and the subsequent optimization of the composition of the raw mix for the production of fly ash autoclaved aerated concrete with the maximum use of alternative raw materials.
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Bivariate distributions
Bednárik, Vojtěch ; Pawlas, Zbyněk (advisor) ; Klebanov, Lev (referee)
The thesis deals with three selected constructions of bivariate distributions. The first approach is to use the Fréchet bounds, which determine restrictions on the distribution function and the correlation coefficient of bivariate distribution. The second construction is the Plackett distribution which is a class of distributions containing the Fréchet bounds and the member corresponding to independent random variables. The third construction is a trivariate reduction method that is used for a construction of bivariate gamma, exponen- tial and Poisson distribution. Only bivariate Dirichlet distribution has slightly different construction. For the last four mentioned distributions the following basic characteris- tics are derived: density function, marginal distributions, correlation coefficient and some conditional moments, in case of exponential and Dirichlet distribution even conditional distribution. 1
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Loss reserving for individual claim-by-claim data
Bednárik, Vojtěch ; Pešta, Michal (advisor)
This thesis covers stochastic claims reserving in non-life insurance based on individual claims developments. Summarized theoretical methods are applied on data from Czech Insurers' Bureau created for educational purposes. The problem of estimation is divided into four parts: occurence process generating claims, delay of notification, times between events and payments. Each part is estimated separately based on maximum likelihood theory and final estimates allow us to obtain an estimate of future liabilities distribution. The results are very promising and we believe this method is worth of a further research. Contribution of this work is more rigorous theoretical part and application on data from the Czech market with some new ideas in practical part and simulation. 1
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Loss reserving for individual claim-by-claim data
Bednárik, Vojtěch ; Pešta, Michal (advisor) ; Hurt, Jan (referee)
This thesis covers stochastic claims reserving in non-life insurance based on individual claims developments. Summarized theoretical methods are applied on data from Czech Insurers' Bureau for educational purposes. The problem of estimation is divided into four parts: oc- curence process generating claims, delay of notification, times between events and payments. Each part is estimated separately based on maximum likelihood theory and final estimates allow us to obtain an estimate of future liabilities distribution. The results are very promis- ing and we believe this method is worth of a further research. Contribution of this work is more rigorous theoretical part and application on data from the Czech market with some new ideas in practical part and simulation. 1
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Bivariate distributions
Bednárik, Vojtěch ; Pawlas, Zbyněk (advisor) ; Klebanov, Lev (referee)
The thesis deals with three selected constructions of bivariate distributions. The first approach is to use the Fréchet bounds, which determine restrictions on the distribution function and the correlation coefficient of bivariate distribution. The second construction is the Plackett distribution which is a class of distributions containing the Fréchet bounds and the member corresponding to independent random variables. The third construction is a trivariate reduction method that is used for a construction of bivariate gamma, exponen- tial and Poisson distribution. Only bivariate Dirichlet distribution has slightly different construction. For the last four mentioned distributions the following basic characteris- tics are derived: density function, marginal distributions, correlation coefficient and some conditional moments, in case of exponential and Dirichlet distribution even conditional distribution. 1
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Rotor fault diagnosis of induction motors
Bednařík, Václav ; Cipín, Radoslav (referee) ; Vítek, Ondřej (advisor)
This bachelor thesis focus on the faults of induction motors. In general terms to mechanical and electirc faults and their influence on induction motor. Further on the tests, that are conducted on induction motors to detect faults and states that precede them. Main part is devoted to rotor eccentricity and broken rotor bars. Eccentricity is solved within theoretical analysis and measurements on free damaged motors. As well as broken rotor bars, which are supplemented by measurements on three damaged rotors. There are two types of eccentricity, static and dynamic. Faults of broken rotor bars is solved in terms of postion of broken rotor bars and their number.
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The issue of new fly ash aerated concrete production
Bednárik, Vít ; Janovský, Radek (referee) ; Drochytka, Rostislav (advisor)
The master´s thesis deals with the possibility of laboratory verification of the influence of feedstock character, especially lime and fly ash, on quality of fly ash aerated concrete. The experimental study involves taking a series of samples autoclaved and non-autoclaved aerated concrete during two pilot plant verification in the factory. After removal of autoclaved and non-autoclaved aerated concrete samples they were tested and compared with results of non-autoclaved aerated concrete produced in the laboratory. Methodology of comparison technologically-produced autoclaved aerated concrete and laboratory-produced non-autoclaved aerated concrete was designed based on achieved findings.
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