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Utilization of local systems for power system regulation
Kostov, Jiří ; Geschwinder, Lukáš (referee) ; Bartošík, Tomáš (advisor)
Bachelor’s Thesis deals general information about methods of regulation of elektrification systems, including basic principles of regulation of frequency, regulation of voltage and regulation of reactive and active power. Work includes information about aggregate remote control system, power plants that participate on regulation and self device for regulation and controlling of reactive power. Work engages on new options in section of regulation and his requirements for distribution sites. Part of work deals information about renewable natural energy sources and his requirements for distribution sites.
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Sensitivity analysis of frequency filters with current active elements
Kupčík, Petr ; Koton, Jaroslav (referee) ; Kubánek, David (advisor)
This bachelor´s thesis is about sensitivity analysis of frequency filters with current active elements. Includes theory of sensitivity analysis and sensitivity function. There are two second order multifunction frequency filters analysed. The first one is filter with Current Mirrors and Inverters (CMI). The second one is filter with Current Operational Amplifiers (COA). Conclusion is description how tolerances of passive and active elements affects frequency characteristics of filters and comparison of these filters in light of sensitivity. Next chapters are occupied by another two analyses: Parametric Sweep and Monte-Carlo. These analyses are applied on two fourth order frequency filters with Differential Input / Output Current Followers (DIOCF) and also on two previous second order filters (only low-pass filters). Parametric Sweep is applied on internal parameters of active filter elements (not in case COA). During Monte-Carlo analysis passive elements have tolerance 5% and active elements are considered ideal. Conclusion is description how tolerances of passive elements (Monte-Carlo) and parametres of active elements (Parametric Sweep) affects frequency characteristics of filters.
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Current distribution on linear antennas
Novák, Tomáš ; Bártík, Hynek (referee) ; Nováček, Zdeněk (advisor)
This work will describe current distribution measurement problems along antenna conductor using a probe (coupling loop), which is attached to selective micro-voltmeter, which will indicate signal level (voltage). The signal level will be used for representing the current distribution. Subsequently, measuring workplace issues from generator to antenna conductor, probe and selective micro-voltmeter, will be discussed. Analysis of voltages of this link-up and additional study will be conducted. Other parameters, which complement this situation, will be calculated from the current distribution. A computer program, which calculates these parameters and speeds up the collected data processing, will be used for this process.
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Testing of room acoustics
Toufarová, Tereza ; Špalek, Karel (referee) ; Sigmund, Milan (advisor)
This paper presents parameters of evaluation of acoustic quality of the space. It is divided into parts presenting physical principle of the origin and movement of the acoustic signal, principles of its processing with current technology and properties of the acoustic field. This is followed by an analysis of the musical part and notes on psychoacoustics. The document contains a description of relevant parameters of acoustic spaces and way in which we can reach desired results, including material analysis. The paper mainly focuses on description of relevant parameters of three acoustic spaces which were measured. The last part of the work is a program for elementary acoustical measurement, which can be provided by means of commonly accessible equipment such as a notebook or a personal computer.
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Linear prediciton and cepstral synthesis of speech signal in the TTS system
Mekyska, Jiří ; Stejskal, Vojtěch (referee) ; Smékal, Zdeněk (advisor)
This work deals with a linear prediction and cepstral synthesis of speech signal in the TTS (Text-to-Speech) systems with the opportunity of modeling the prosody. The work contains a description of speech signal in acoustic and phonetic plane, the principle of speech production and the way we can figure the speech signal in time and frequency domain. Next, there is the TTS block structure mentioned, whereas each block has its own detailed description. In the work, the modeling of prosody using the three most important suprasegmental features (fundamental tone, continuation and speech intensity) is also described. At the end of this work, there is a design and realization of universal Czech TTS system which is based on the speech synthesis in frequency domain. This system is implemented in program MATLAB.
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Automatic measurement of the motor vehicles distance.
Juřica, Lukáš ; Chmelař, Milan (referee) ; Říčný, Václav (advisor)
This work deals with evaluation of equipment used for non-contact measurement of distance between vehicles. First are discussed various principles of measuring and after the selection of the most appropriate solution is proposed a detailed block diagram of modulation, demodulation and evaluation of the whole system and its mathematical description. Another part is devoted to describing the activities of the microprocessor controller, with which is controlled evaluation part and to the control program. It also analyzes the maximal attainable accuracy of measurement and the errors that affect it. The last part includes a circuit design and simulation of selected functional block, which is a coincidence /quadrature/ detector and construction documents for evaluation and demodulation part of the measurement instrument.
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The occurrence of brook lamprey [Lampetra planeri (BLOCH, 1784)] in Novohradské Mountains (South Bohemia, Czech Republic)
Matěnová, V. ; Matěna, Josef
The occurrence of brook lamprey was studied in Novohradské Mountains during 1999-2003. Altogether 83 profiles on 22 second to fourth order brooks and streams were fished by means of electroshockers. The area investigated can be divided into three basins. Significant differences were found between basins with respect to frequency of occurrence and density of lamprey populations. The highest frequency of occurrence was in the Stropnice River basin (6 streams of 8 investigated, average abundance 2598 inds ha-1), followed by the Malše River (4 streams of 8 investigated, average abundance 844 inds ha-1). In the Černá Rivulet basin only in 1 of 6 streams investigated the brook lamprey was found at very low densities - 28 inds ha-1 on average. The lamprey contributed substantially to the whole forming more than 50
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Alternative Utilisation of a Matrix Converter
Flígl, S. ; Lettl, Jiří
The matrix converter seems to be the final name of one of the older static direct frequency changer power electronics circuit configuration, which finds once again new utilisation. This switch topology has the cycloconverter advantage of lacking a DC link, and hence lacks an energy store, while offering a potentially unlimited frequency range.
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