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New Conceptions of Power Pulse Converters Using Extremely Fast Switching Semiconductors Based on SiC
Kuzdas, Jan ; Chlebiš,, Petr (referee) ; Drábek,, Pavel (referee) ; Vorel, Pavel (advisor)
This work deals with high power pulse converters (tens of kW) using new semiconductor devices of silicon carbide (SiC). Firstly the current state of the issue is analyzed. A research in a specific area of high power buck converters with pulse transformer follows. There was a strong emphasis on minimizing size and weight. The design process was focused also on reliability and robustness. To achieve the defined objectives, it was necessary to use the latest available switching transistors and diodes, and an unusually high switching frequency (100 kHz at a power of about 16 kW). Due to the high switching frequency, we achieved small size of pulse transformers and output chokes. An optimization of high-frequency pulse transformer with demand on minimum volume and weight of core and windings represents a separate theoretical part of the thesis. There have been proposed several analytical solutions of optimization problems, the results of which could overlap with the implementation in practice of switching power supplies. The combination of high switching frequency, fast semiconductors and the high power brings various parasitic effects to the power circuit. In the thesis, these parasitic effects are analyzed. Solutions which minimize or completely remove those effects were theoretically designed and successfully implemented, tested and finalized in experimental part of the work. Detailed description of the implementation of functional sample and series of validation measurements are included in the final part.
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Long-eared owl (Asio otus) migration within Central Europe
Fraitágová, Iveta ; Řezníček, Jan (advisor) ; Klvaňa, Petr (referee)
The aim of the present thesis is to give a review of the ringing recoveries of the Long - eared owl (Asio otus) in the territory of the former Czechoslovakia and the Czech Republic. The bird ringing data used in this thesis come from the archive of the National Museum in Prague. The parts of the thesis are as follows:1) history of the ringing in the Czech Republic; 2) bird adaptation on the flight and migration; 3) control of the migration; 4) the data of the Long- eared owls ringed as the young birds in the nest (pulli); 5) the data of the Long - eared owls ringed as adults (ad), that were caught and checked during their wintering in the Czech Republic; 6) the recoveries of the Long- eared owls ringed by various European Bird Ringing Centres and found in the Czech Republic; 7) cause of the mortality of the Long eared owl;8) census of the Long - eared owl recoveries in the Czech Republic from 1934 till 2011 (appendix). Key words: Migration, the Long-eared Owl, Ringing, Ringing Recoveries, Mortality
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Altitudinal migrations in animals and their study methods
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Klvaňa, Petr (referee)
Migration as a response to the seasonality of the environment is common in many animal taxa. Strong fluctuation of the climate is usually connected to regions in the temperate zone, quite common is in the tropical regions as well. Typically, it is even more pronounced in high altitudes. In such environment, many animals could migrate altitudinaly as a response to changes in the climatic conditions or food abundance. But determinants of altitudinal and long-distance latitudinal migrations could be different. The objective of this work is to determine factors influencing altitudinal migrations in diverse taxa (particularly in birds and bats) and in different biogeographical regions. I am trying to find some common features of migrating species, such as diet or temperature and rain tolerance. Especially tropical species are partial migrants, which means that only some individuals of the population migrate. I will discuss common features of such migrating infividuals. Study methods of altitudinal migration will be a part of this research as well. The work will be primarily concentrated on tropical regions.
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Long-eared owl (Asio otus) migration within Central Europe
Fraitágová, Iveta ; Řezníček, Jan (advisor) ; Klvaňa, Petr (referee)
The aim of the present thesis is to give a review of the ringing recoveries of the Long - eared owl (Asio otus) in the territory of the former Czechoslovakia and the Czech Republic. The bird ringing data used in this thesis come from the archive of the National Museum in Prague. The parts of the thesis are as follows:1) history of the ringing in the Czech Republic; 2) bird adaptation on the flight and migration; 3) control of the migration; 4) the data of the Long- eared owls ringed as the young birds in the nest (pulli); 5) the data of the Long - eared owls ringed as adults (ad), that were caught and checked during their wintering in the Czech Republic; 6) the recoveries of the Long- eared owls ringed by various European Bird Ringing Centres and found in the Czech Republic; 7) cause of the mortality of the Long eared owl;8) census of the Long - eared owl recoveries in the Czech Republic from 1934 till 2011 (appendix). Key words: Migration, the Long-eared Owl, Ringing, Ringing Recoveries, Mortality
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Altitudinal migrations in animals and their study methods
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Klvaňa, Petr (referee)
Migration as a response to the seasonality of the environment is common in many animal taxa. Strong fluctuation of the climate is usually connected to regions in the temperate zone, quite common is in the tropical regions as well. Typically, it is even more pronounced in high altitudes. In such environment, many animals could migrate altitudinaly as a response to changes in the climatic conditions or food abundance. But determinants of altitudinal and long-distance latitudinal migrations could be different. The objective of this work is to determine factors influencing altitudinal migrations in diverse taxa (particularly in birds and bats) and in different biogeographical regions. I am trying to find some common features of migrating species, such as diet or temperature and rain tolerance. Especially tropical species are partial migrants, which means that only some individuals of the population migrate. I will discuss common features of such migrating infividuals. Study methods of altitudinal migration will be a part of this research as well. The work will be primarily concentrated on tropical regions.
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Intelligent Ringtones in Symbian S60
Kadlas, Jakub ; Jirák, Ota (referee) ; Koutný, Jiří (advisor)
Symbian OS is one of the most popular operating system for smartphones. The most favorite version of Symbian OS is the S60 platform, which is the aim of this thesis. Part of this thesis is focused on theoretical overview of Symbian OS, and a description of integraded sensors in smartphones. The second part is devoted to the implementation of sample application for inteligent ringtones. This application allows smartphone to customize phone ringing according to information obtained from sensors. Application was implemented in C++ language with Symbian-specific modifications. The development environment used was Carbide.c++ with SDK S60 3rd Edition Feature Pack 1.
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New Conceptions of Power Pulse Converters Using Extremely Fast Switching Semiconductors Based on SiC
Kuzdas, Jan ; Chlebiš,, Petr (referee) ; Drábek,, Pavel (referee) ; Vorel, Pavel (advisor)
This work deals with high power pulse converters (tens of kW) using new semiconductor devices of silicon carbide (SiC). Firstly the current state of the issue is analyzed. A research in a specific area of high power buck converters with pulse transformer follows. There was a strong emphasis on minimizing size and weight. The design process was focused also on reliability and robustness. To achieve the defined objectives, it was necessary to use the latest available switching transistors and diodes, and an unusually high switching frequency (100 kHz at a power of about 16 kW). Due to the high switching frequency, we achieved small size of pulse transformers and output chokes. An optimization of high-frequency pulse transformer with demand on minimum volume and weight of core and windings represents a separate theoretical part of the thesis. There have been proposed several analytical solutions of optimization problems, the results of which could overlap with the implementation in practice of switching power supplies. The combination of high switching frequency, fast semiconductors and the high power brings various parasitic effects to the power circuit. In the thesis, these parasitic effects are analyzed. Solutions which minimize or completely remove those effects were theoretically designed and successfully implemented, tested and finalized in experimental part of the work. Detailed description of the implementation of functional sample and series of validation measurements are included in the final part.
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Population ecology of Daubenton's bat \kur{Myotis daubentonii}
LUČAN, Radek
Various aspects of population ecology of Daubenton?s bat (Myotis daubentonii) were analyzed based on long-term data (1968?1984 and 1999?2009) gathered in a single model study area (ca. 10 km2) in South Bohemia, Czech Republic. Among others, population structure, roosting dynamics, movements between roosts and long-term trends in numbers of bats were described. Results of the study on patterns in reuse of tree cavities suggest that tree cavities may be reused for many consecutive seasons and that this has to be taken into consideration by conservation practices. The results of the study on microclimate of one maternity and one male colony roosting in man-made structures revealed that microclimatic differences may be one of the key factors in roosting preference between the two sexes. Further, a profound effect of changing energetic demands in females during different phases of the reproductive cycle may greatly influence their activity rhytms. In further two studies, the effect of climate on reproductive parameters of bats and abundance of ectoparasitic mites was analyzed. The results suggest that climatic variation greatly influenced reproductive parameters and parasitation of Daubenton?s bats. Last but not least, the seasonal dynamics of parasitation by ectoparasitic mites and the possible effect on bats? condition was analyzed. It was found out that seasonal dynamics in abundance of parasites is adjusted to the reproductive cycle and roosting dynamics of its host.
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