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Jünemann, Theresa [Verfasser], Konrad [Akademischer Betreuer] Reinhart, Hubert [Akademischer Betreuer] Scheuerlein, and Maximilian [Akademischer Betreuer] Ragaller. "Untersuchung der ZVK-Lage bei beatmeten Patienten : Bestimmung der Positionsänderung mittels EKG-Methode und Röntgen / Theresa Jünemann. Gutachter: Konrad Reinhart ; Hubert Scheuerlein ; Maximilian Ragaller." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2015. http://d-nb.info/1080521860/34.
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von, Au Felix [Verfasser], Axel [Akademischer Betreuer] Kramer, Lutz [Gutachter] Jatzwauk, and Axel [Gutachter] Kramer. "Kann bei Gabe von Kurzzeitinfusionen mit Zwischenspülung die Verwendungsdauer von ZVK-Infusionssystemen verlängert werden? / Felix von Au ; Gutachter: Lutz Jatzwauk, Axel Kramer ; Betreuer: Axel Kramer." Greifswald : Universität Greifswald, 2020. http://d-nb.info/1217783865/34.
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von, Au Felix Verfasser], Axel [Akademischer Betreuer] [Kramer, Lutz [Gutachter] Jatzwauk, and Axel [Gutachter] Kramer. "Kann bei Gabe von Kurzzeitinfusionen mit Zwischenspülung die Verwendungsdauer von ZVK-Infusionssystemen verlängert werden? / Felix von Au ; Gutachter: Lutz Jatzwauk, Axel Kramer ; Betreuer: Axel Kramer." Greifswald : Universität Greifswald, 2020. http://nbn-resolving.de/urn:nbn:de:gbv:9-opus-39262.
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Čtvrtník, Jan. "Zvuk jako nástroj herce." Master's thesis, Akademie múzických umění v Praze.Divadelní fakulta. Knihovna, 2015. http://www.nusl.cz/ntk/nusl-202906.
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My diploma thesis deals with the use of sound in the theater, especially the sound that is formed by the actor. The work consists of insight into the theory of sound in the theater, which includes rather general view of the issue and tries to formulate the concepts. Hereafter I use these in the second part, which is a reflection of the practical work, for which I selected three concrete examples of completed performances.
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Slivka, Jan. "Vlna zvuku / zvuk vlny." Master's thesis, Vysoké učení technické v Brně. Fakulta výtvarných umění, 2011. http://www.nusl.cz/ntk/nusl-232316.
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Richtr, Jan. "Čas a zvuk ve filmu." Master's thesis, Akademie múzických umění v Praze.Filmová a televizní fakulta. Knihovna, 2017. http://www.nusl.cz/ntk/nusl-371147.
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The theme of this diploma thesis is perception of time within the
audiovisual work. Particular attention is paid to the audio component of the
audiovisual work, from which perspective is seen the phenomenon of time. First
there is briefly introduced understanding of time evolved within the philosophical
context. The next part presents film as a medium that, from its formal nature,
brings new impetus that further develops the thinking of time. After this
introduction work focuses on the way of perceiving time within the sound itself,
respectively in music composition. It is based on the findings of psychoacoustics
and, above all, on the theoretical considerations of French composer Gérard
Grisey, to which is trying to find parallels in the context of the sound dramaturgy
of the film work. The last part deals with time relations arising from the
relationship between film image and sound. It is trying to question and then
generalize specific formal relationships within the audiovisual work, influencing
the subjective perception of time.
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Zoubková, Hana. "Strategická analýza firmy ZAK Praha." Master's thesis, Vysoká škola ekonomická v Praze, 2007. http://www.nusl.cz/ntk/nusl-1523.
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Cílem práce je provedení strategické analýzy živnostenského podnikání fyzické osoby. Aplikací teoretického aparátu se odhalují příležitosti a hrozby vyplývající pro analyzovanou firmu z jejího okolí a také silné a slabé stránky firmy samotné. Syntéza nejvýznamnějších poznatků formou SWOT analýzy je pak východiskem pro strategická doporučení firmě.
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Dequigiovani, Tiago. "Conversor CC-CA utilizando célula ZVT." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/872.
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Este trabalho trata sobre a utilização de técnicas de comutação suave aplicadas `a conversores estáticos de potência. A técnica analisada em particular consiste em proporcionar comutação em zero de tensão aos interruptores controlados, sendo referenciada na literatura como Zero Voltage Switching (ZVS). Dentre as diversas topologias de circuitos que implementam a técnica ZVS, neste trabalho é utilizada uma célula de comutação Zero Voltage Transition (ZVT), no qual utiliza interruptores controlados e elementos em paralelo com o circuito principal. O foco do trabalho é a aplicação desta célula ZVT a um conversor CC-CA PWM monofásico com saída senoidal. Nesse sentido inicialmente é feita uma revisão das topologias básicas dos inversores, é das técnicas PWM utilizadas para obtenção de saída senoidal. São apresentados os circuitos ZVT convencional e aprimorado descritos na literatura, no qual o ZVT aprimorado é empregado ao conversor CC-CA ponte completa. São apresentadas as etapas de funcionamento e análise matemática. É descrita uma metodologia de projeto para a determinação dos componentes do circuito auxiliar, com base em restrições definidas para o correto funcionamento da célula e das características dos semicondutores utilizados como chave. Um protótipo do conversor é implementado em laboratório para a validação do projeto, verificação das formas de onda nos interruptores e análise do rendimento. Outros dois circuitos de auxílio à comutação são implementados para efeitos de comparação, sendo o circuito ZVT convencional e o dissipativo snubber de Undeland. Os resultados experimentais comprovam a obtenção da comutação suave nos interruptores e o conversor apresentou rendimento de no mínimo 1% superior ao ZVT convencional e 2% ao snubber de Undeland, valores estes para toda a faixa de carga.This paper discusses above the application of soft-switching techniques to static power conver-ters. The technique discussed in particular consists in provide zero voltage switching (ZVS) to controlled switches. Among the various circuit topologies to implement the ZVS technique, in this work is used a cell Zero-Voltage Transition (ZVT), in which uses controlled switches and elements in parallel with the main circuit. The main objective of the work is the application of this cell ZVT to a single-phase PWM inverter with sinusoidal output. In this sense initially is made a review of the basic topologies of inverters , and of the PWM techniques used to obtain sinusoidal output. Are presented the circuits ZVT conventional and improved described in the literature, in which the improved ZVT is employed on DC-AC full bridge converter. Steps of operation and mathematical analysis are presented. A design methodology is described for the determination of the components of the auxiliary circuit, based on constraints set for the correct functioning of the cell and of the characteristics of semiconductor. A prototype of the converter is implemented in the laboratory for the validation of the project, verification of waveforms the switches and analysis of efficiency. This converter is compared with other two circuits, ZVT conventional and the Undeland snubber. Experimental results show the achievement of soft switching the switches and the converter presenting an efficiency of at least 1% over for the ZVT conventional and 2% to the undeland snubber, these values for all load range.
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Klusák, Martin. "Zvuk v celovečerním filmu beze slov." Master's thesis, Akademie múzických umění v Praze.Filmová a televizní fakulta. Knihovna, 2013. http://www.nusl.cz/ntk/nusl-172875.
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The main goal of this thesis is to describe the unofficial genre of films without speech and to analyze principles of the use of sound and film language in such films.
Initial chapters speak generally about the phenomenon of feature nonverbal cinema with the focus on its historical development and general film language.
The middle part presents, and briefly describes chosen films without speech, and suggests their sorting into sub-genres.
The last, vastest part of the work, is an analytic study of various approaches to reduce speech generally throughout film. This part leads into the final theoretical description of soundtrack in films without speech.
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Bandeira, Junior Delvanei Gomes. "Conversor CC-CC tipo T ZVS PWM." reponame:Repositório Institucional da UFSC, 2014. https://repositorio.ufsc.br/xmlui/handle/123456789/128980.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2014.Made available in DSpace on 2015-02-05T20:33:38Z (GMT). No. of bitstreams: 1 328199.pdf: 4702209 bytes, checksum: 62903d21034e4a8f1e3f3dc9e00b4d66 (MD5) Previous issue date: 2014
Este trabalho apresenta o estudo de um conversor CC-CC isolado com comutação suave, saída em corrente, para aplicações envolvendo altas potências, com nome T-Type Zero Voltage Switching Pulse Width Modulated dc-dc converter(TT-ZVS-PWM). O conversor a ser estudado possui quatro interruptores. Dois deles são submetidos à tensão de entrada, já os outros dois são submetidos à metade da tensão de entrada. Todos os interruptores comutam sob tensão nula. O conversor proposto possui as seguintes semelhanças com os conversores Full Bridge Zero Voltage Switching(FB-ZVS-PWM) e Three Level Zero Voltage Switching(TL-ZVS-PWM): (a) Operação simétrica (b) Modulação por largura de pulso com frequência constante (c) comutação sob tensão nula e (d) tensão de saída do conversor com três níveis, a ser aplicada nos terminais do primário do transformador. O trabalho é dividido em análise teórica, análise do modelo de pequenos sinais do conversor e roteiro para projeto do conversor. Um protótipo com 3 kW, 400 V de entrada, 60V de saída e frequência de comutação de 50 kHz comprova a análise desenvolvida. A eficiência obtida no protótipo foi de 93% para carga nominal e de 95,2% para 1,2 kW.
Abstract : This work presents the analysis of the T-Type Zero Voltage Switching Pulse Width Modulated isolated DC-DC converter (TT-ZVS-PWM Converter). The topology is composed of four switches. Two of them are subjected to the input voltage level and the other two to half the input voltage. All primary side switches commutate under zero-voltage. The proposed converter has the following in common with the Full Bridge Zero-Voltage Switching (FB-ZVS-PWM) and the Three-Level Zero-Voltage Switching (TL-ZVS-PWM) converters: (a) symmetrical operation of the isolation transformer, (b) modulation by pulse-width with constant frequency, (c) zero voltage switching, and (d) three-level voltage applied to the primary winding of the transformer. Theoreticalanalysis, small signal model, design example and experimental results for a 3 kW, 400 VDC input, 60 VDC output, and 50 kHz switching frequency laboratory prototype, are included. Measured efficiency was 93% at full load and a peak efficiency of 95.2% occured at 1.2 kW.
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Rataj, Jakub. "Převod pohybu lidského těla na zvuk pomocí senzorů." Master's thesis, Akademie múzických umění v Praze.Hudební a taneční fakulta. Knihovna, 2015. http://www.nusl.cz/ntk/nusl-253950.
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This work treats about the permeation of two different compositional approaches (real time technologie and instrumental composition) in proper piece of art - music and dance performance The Art of Manipulation. First I treat about the development of interactive motion sensing systems in the last fifty years and further I describe to different possibilities of their categorisation. In the next part I describe the performance The Art of Manipulation in terms of its dramaturgy and musical content. Further I deal with compositional methods that I used in the instrumental and electroacoustic musical plane and concurrently I analyze their relationship. In the end I describe the architecture and function of the virtual instrument used for real time sound recording and processing.
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Laberge, Gino. "Identification des activateurs potentiels de la protéine kinase ZPK." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0017/MQ56921.pdf.
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Laberge, Gino. "Identification des activateurs potentiels de la protéine kinase ZPK." Sherbrooke : Université de Sherbrooke, 1999.
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Agostini, Junior Eloi. "Conversor CC-CC trifásico ZVS PWM de três níveis." Florianópolis, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/100579.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Made available in DSpace on 2013-06-25T20:33:13Z (GMT). No. of bitstreams: 1 310350.pdf: 17052017 bytes, checksum: 4e316fff0da3fb0057a4349a83edb3ce (MD5)
Esta tese propõe uma topologia de conversor CC-CC trifásico de três níveis, modulado por largura de pulso e com comutação suave. A análise estática dos sete modos de condução descontínua e dos seis modos de condução contínua é apresentada no decorrer do documento. A análise dinâmica do conversor voltada para a operação em condução contínua também é apresentada, fornecendo a função de transferência que relaciona a tensão de saída com a razão cíclica. A comutação dos doze interruptores comandados é investigada em detalhes, enfatizando-se a condução contínua, onde há a possibilidade de obtenção de comutação suave do tipo ZVS em todos os doze interruptores do conversor. Para a comprovação das análises apresentadas, realiza-se a simulação numérica e a experimentação através de um protótipo de 10 kW, 800 V de tensão de entrada, 200 V de tensão de saída e 40 kHz do conversor proposto.
This thesis proposes a three-level three-phase pulse-width-modulated soft-switched DC-DC converter. The static analysis of seven discontinuous conduction modes and six continuous conduction modes is carried out. The dynamic analysis is also performed, providing the output voltage to duty cycle transfer function. The commutation of all converter switches is detailed, emphasizing the continuous conduction, where there is the possibility of achieving zero-voltage-switching for all the twelve converter switches. In order to validate the presented analyses, the computer aided simulation and experimental results from a prototype rated at 10 kW, 800 V input voltage, 200 V output voltage, and 40 kHz are performed.
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Sun, Quan Civil & Environmental Engineering Faculty of Engineering UNSW. "Contaminant degradation using nanosized zero valent iron particles." Publisher:University of New South Wales. Civil & Environmental Engineering, 2009. http://handle.unsw.edu.au/1959.4/43597.
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Zero-valent iron (ZVI) has been successfully used for the degradation of a wide range of organic contaminants in groundwaters in recent years. The rate of degradation of contaminants by ZVI may be enhanced by use of nanoscale zero valent iron (nZVI) particles which possess higher surface area than the more widely used granular materials. However, the most widely used method of producing nZVI involves the reduction of FeIII by sodium borohydride is expensive. Dithionite can be used to reduce Fe(II) and produce cost effective nZVI under conditions of high pH and in the absence of oxygen. The efficiency of trichloroethylene (TCE) degradation using dithionite nZVI particles (nZVIS2O4) is similar to that of the conventional borohydride particles (nZVIBH4). Oxidation of benzoic acid using the nZVIS2O4 particles results in different byproducts than those produced when nZVIBH4 particles are used. The high concentration of phenol compared to hydroxybenzoic acids suggests that OH addition is not the primary oxidation pathway when one is using the nZVIS2O4 particles. It is proposed that sulfate radicals (SO4−) are produced as a result of hydroxyl radical attack on the sulfite matrix surrounding the nZVIS2O4 particles, with these radicals oxidizing benzoic acid via electron transfer reactions rather than addition reactions. Low yields of oxidants limit the application of nZVI. It has recently been demonstrated that nZVI oxidative efficiency can be enhanced in presence of ethlylendiaminetetraacetic acid (EDTA). Additional insight into the nZVI-mediated process has been obtained from comparative studies of degradation of benzoic acid by nZVI particles and Fenton reagents in the absence and presence of EDTA at different pH. The efficiency of nZVI degradation is significantly hindered by the rapid aggregation of the iron nanoparticles, which may result in a decrease in available reactive surface area. These effects of aggregation can be overcome by surface modification through adsorption of capping agents which provide steric and electrosteric repulsive interactions between particles. Several high molecular weight (HMW) organic polymers have been used for preventing agglomeration of nZVI particles, such as water soluble starch, sodium carboxymethyl cellulose (CMC) and alginate. The degradation capabilities of different functionalized nZVIS2O4 particle were investigated. Iron-based bimetallic particles in which metals such as Pd and Ni have been combined with Fe, have been found to both enhance rates of halogenated organic contaminants reduction and generate more fully dehalogenated products relative to unamended iron. The results presented in this thesis demonstrate that formation of bimetallic particles with nZVI formed from the more cost effective dithionite reduction of ferrous salts also results in dramatic enhancement in reducing ability. The oxidising ability of nZVIBH4 particles can be enhanced dramatically by addition of polyoxometallates (POMs), redox catalysts which result in enhanced production of hydrogen peroxide. The extent of enhancement is quantified by examination of the oxidation of formic acid (to CO2) and kinetic modelling of the results obtained used to investigate the mechanism of the POM-mediated oxidation process.
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Senguzel, Ismail. "Design Of A Zvs Qrc Converter For Educational Test Bench." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12608149/index.pdf.
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In this thesis, the conventional pulse-width modulated (PWM) and zero-voltage switching (ZVS) quasi-resonant buck converters are analyzed and a variable-frequency
control technique is proposed to regulate the output voltage due to the immediate input line and load changes. The quasi-resonant technique provides favorable switching conditions for active switch to reduce switching losses and electromagnetic interference (EMI). The method is based on shaping the voltage across the active switch in quasisinusoidal
fashion and the switching action occurs with nearly zero voltage across the active switch. This requires only two additional components to the conventional PWM
buck converter. The proposed quasi-resonant converter is capable of operating in megahertz range with a significant improvement in performance and power density.
Detailed analytic and small-signal models of the ZVS quasi-resonant buck converter are established and the switching behavior is investigated in order to provide nearly zerovoltage
turn-on. The performance of the ZVS quasi-resonant technique is verified with the computer simulations. The results are compared with the experiments in the
laboratory involving both the open-loop and closed-loop operations. The detailed experiment procedure is added to use this converter for educational purposes.
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Zak, Manuel [Verfasser]. "Einfluss pflanzlicher Biofilmträger auf die Vergärung von Speiseresten / Manuel Zak." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2012. http://d-nb.info/1023728907/34.
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Cory, Mark. "CONVENTIONAL AND ZVT SYNCHRONOUS BUCK CONVERTER DESIGN, ANALYSIS, AND MEASUREMENT." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2759.
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The role played by power converting circuits is extremely important to almost any electronic system built today. Circuits that use converters of any type depend on power that is consistent in form and reliable in order to properly function. In addition, today s demands require more efficient use of energy, from large stationary systems such as power plants all the way down to small mobile devices such as laptops and cell phones. This places a need to reduce any losses to a minimum. The power conversion circuitry in a system is a very good place to reduce a large amount of unnecessary loss. This can be done using circuit topologies that are low loss in nature. For low loss and high performance, soft switching topologies have offered solutions in some cases. Also, limited study has been performed on device aging effects on switching mode power converting circuits. The impact of this effect on a converter s overall efficiency is theoretically known but with little experimental evidence in support. In this thesis, non-isolated buck type switching converters will be the main focus. This type of power conversion is widely used in many systems for DC to DC voltage step down. Newer methods and topologies to raise converter power efficiency are discussed, including a new synchronous ZVT topology . Also, a study has been performed on device aging effects on converter efficiency. Various scenarios of voltage conversion, switching frequency, and circuit components as well as other conditions have been considered. Experimental testing has been performed in both cases, ZVT s benefits and device aging effects, the results of which are discussed as well.M.S.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
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Bascopé, René Pastor Torrico. "Conversores CC-CC ZVS-PWM duplo forward com acoplamento magnético." Florianópolis, SC, 2000. http://repositorio.ufsc.br/xmlui/handle/123456789/79173.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico.Made available in DSpace on 2012-10-18T00:02:40Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-25T18:42:49Z : No. of bitstreams: 1 176083.pdf: 8925342 bytes, checksum: b9a56afcffcbe133a63cdcdfc03fdaaa (MD5)
Neste trabalho é estudada a associação em série e em paralelo de dois conversores forward para dividir esforços de tensão ou corrente nos interruptores de potência. Para minimizar os problemas de desequilíbrio estático e dinâmico de tensão ou de corrente nos interruptores, os conversores associados são acoplados magneticamente usando um transformador e um indutor de alta freqüência. Os conversores CC-CC estudados, compostos de dois conversores, apresentam características de comutação sob tensão nula (ZVS), modulação por largura de pulso (PWM), operação com freqüência constante e um único circuito de controle para ambos os conversores. Para cada conversor CC-CC são apresentados o princípio de operação, as principais formas de onda, a característica de saída, análises das comutações e uma metodologia de projeto. Para verificar os resultados teóricos e o equilíbrio de tensão ou de corrente nos interruptores, são mostrados resultados experimentais obtidos através de protótipos de 3kW. Para futuras pesquisas, são sugeridas novas topologias de conversores CC-CC associando-se dois conversores isolados clássicos com a finalidade de dividir esforços de tensão e/ou corrente nos interruptores.
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Melo, Francisco Edson Nogueira de. "Estudo e realização de um inversor ZVS a tiristor dual." reponame:Repositório Institucional da UFSC, 1993. https://repositorio.ufsc.br/handle/123456789/111687.
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Duarte, Cláudio Manoel da Cunha. "Estudo e realização de um conversor forward simetrico PWM ZVS." reponame:Repositório Institucional da UFSC, 1993. https://repositorio.ufsc.br/handle/123456789/111695.
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Bascopé, René Pastor Torrico. "Conversor CC-CC ponte completa ZVS-PWM com comando assimetrico." reponame:Repositório Institucional da UFSC, 1994. https://repositorio.ufsc.br/handle/123456789/111792.
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Perold, Zak. "The polymorphic and pseudopolymorphic behaviour of gatifloxacin crystal modifications / Zak Perold." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1420.
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Colling, Ivan Eidt. "Conversor CC-CC meia-ponte ZVS-PWM : análise, projeto e experimentação." reponame:Repositório Institucional da UFSC, 1994. https://repositorio.ufsc.br/handle/123456789/111608.
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Rodrigues, Jean Paulo. "Conversores CC-CC PWM ZVS com grampeamento ativo de três níveis." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/94091.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2010Made available in DSpace on 2012-10-25T06:24:46Z (GMT). No. of bitstreams: 1 282758.pdf: 7911722 bytes, checksum: f3270730c76bfeb2547b67bef4f25fc1 (MD5)
Os conversores CC-CC utilizados em aplicações com tensão de entrada ou de saída elevadas tipicamente demandam transistores para tensões elevadas, causando maiores perdas de comutação. A identificação dessa demanda motivou a pesquisa em topologias de três níveis com grampeamento ativo. Nesse contexto, este trabalho apresenta estudos de conversores CC-CC com novos grampeamentos ativos de três níveis do tipo buck e do tipo boost, operando com comutação ZVS, frequeência constante e modulação PWM. Conforme apresentado de forma analítica e experimental, são alcançados maior rendimento e redução de tensão máxima aplicada aos interruptores. Essas topologias são apropriadas para conversores que requerem maior tensão de entrada ou tensão de saída.
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Martins, Mário Lúcio da Silva. "Inversores ZCZVT com acoplamento magnético: síntese e análise." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/3655.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis Ph. D. Thesis presents a in deep study of the mechanism of resonant transition soft-switching techniques. By means of the principles that rules the PWM resonant transition converters, a novel tool for analysis and synthesis have been developed. This novel tool also permit to be verified some of the main factors that made possible to he ZVT technique to achieve its technology level. By means of this tool and with the definition of the basic requirements of the resonant transition converters a new concept concerning the ZCZVT technique have been generated, the ZCZVT converters with discontinuous auxiliary voltage source . The development of this new concept gives rise to a new family of ZCZVT converters with magnetically coupled auxiliary circuit. It also allowed a better perspective of the ZCZVT converters characteristics, advantages, drawbacks and limitations, which contributed significantly with the grown of the technology. Two of the six topologies with bi-directional auxiliary circuits proposed in the thesis have been mathematically analised. A design methodology based on constrains and dynamic characteristics of the IGBT and diode semiconductors under ZCS and ZVS conditions have been presented. Finally, experimental results proved the efficiency gain of the novel ZCZVT inverters with magnetically coupled auxiliary circuit. The ZCZVT inverter with magnetically coupled auxiliary circuit prototype have been compared with its Undeland snubber counterpart, presenting an efficiency of about 4% superior. It corroborates to the thesis proposal of developing novel topologies with better performance and simplicity.
O presente trabalho apresenta um estudo aprofundado do mecanismo de comutação presente nas técnicas de comutação suave com transição ressonante. Por meio da definição dos princípios que governam as comutações dos conversores PWM com transição ressonante, desenvolveu-se uma nova ferramenta para análise e síntese de novos circuitos com características aperfeiçoadas. Também através desta ferramenta de análise pode-se verificar alguns dos principais fatores que possibilitaram o amadurecimento da técnica de comutação ZVT. Com esta ferramenta e com a definição dos requisitos básicos para a operação dos conversores com transição ressonante foi gerado o conceito de conversores ZCZVT com fonte auxiliar descontínua. O desenvolvimento deste conceito deu origem a uma nova família de conversores ZCZVT com acoplamento magnético. O desenvolvimento de uma nova família de conversores ZCZVT permitiu uma melhor percepção das características destes circuitos e o amadurecimento da técnica de comutação suave ZCZVT. Duas das seis topologias de circuitos auxiliares bidirecionais propostas na tese para os novos inversores ZCZVT monofásicos com acoplamento foram analisadas matematicamente. Uma metodologia de projeto para estes inversores foi apresentada. Esta metodologia é baseada em restrições obtidas das características dinâmicas dos IGBTs e dos diodos que operam sob comutação em zero de corrente (ZCS) e zero de tensão (ZVS). Por fim, foram apresentados resultados experimentais que comprovam o ganho de eficiência do inversores ZCZVT com acoplamento magnético e circuitos auxiliares em derivação proposto. O protótipo do inversor ZCZVT foi comparado experimentalmente com um inversor utilizando snubber de Undeland, apresentando uma eficiência em média 4% superior. O que corroborou com a proposta inicial de desenvolver topologias ZCZVT com desempenho melhorado e maior simplicidade.
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Oudkerk, Richard. "The parabolic implosion for f0(z) = z + zv+1 + O(zv+2)." Thesis, University of Warwick, 1999. http://wrap.warwick.ac.uk/56137/.
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In this thesis we examine the bifurcation in behaviour (for the dynamics) which occurs when we perturb the holomorphic germ fo(z) =z + zv+1 + O(zv+2) defined in a neigh- bourhood of 0, so that the multiple fixed point at 0 splits into v+1 fixed points (counted with multiplicity). The phenomenon observed is called the parabolic implosion, since the perturbation will typically cause the filled Julia set (if it is defined) to "implode. " The main tool used for studying this bifurcation is the Fatou coordinates and the associated Ecalle cylinders. We show the existence of these for a family of well behaved f's close to fo, and that these depend continuously upon f. Each well behaved f will have a gate structure which gives a qualitative description of the "egg-beater dynamic" for f. Each gate between the fixed points of f will have an associated complex number called the lifted phase. (Minus the real part of the lifted phase is a rough measure of how many iterations it takes for an orbit to pass through the gate. ) The existence of maps with any desired gate structure and any (sensible) lifted phases is shown. This leads to a simple parameterisation of the well behaved maps. We are particularly interested in sequences fk → fo where all the lifted phases of the fk converge to some limits, modulo Z. We show that there is a non-trivial Lavaurs reap g associated with these limits, which commutes with fo. The dynamics of fk are shown to (in some sense) converge to the dynamics of the system (fo, g). We also prove that for any Lavaurs map g there is a sequence fk → fo so that fk k → g as k → +oo, uniformly on compact sets.
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Hafeneder, Michael. "Anlage von zentralvenösen Kathetern im Kindesalter: Überprüfung der Lage mittels intrakardialer EKG-Ableitung und Thoraxröntgenbild." Doctoral thesis, 2013. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-81991.
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Vor der Diskussion wo die ZVK-Spitze EKG-gesteuert anhand der P-Welle tatsächlich zum Liegen kommt, soll die, in der Abteilung für Pädiatrische Neurochirurgie des Universitätsklinikums Würzburg, angewandte Methode retrospektiv betrachtet werdenThe correct positioning of central venous catheters (“CVC”) is important in order to prevent catheter-position associated complications such as cardiac arrhythmias and perforation. This retrospective study was conducted to test the hypothesis that ECG-guidance for positioning of CVC in a large pediatric population of neurosurgical patients is not inferior to chest-x-ray confirmation when applied in routine daily practice
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Foltinová, Daniela. "Zvuk." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-299024.
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This diploma thesis is concerned with the philosophical inquiry of sound. The crucial problem of the thesis is the perception of sound and the description of perceived sound. The assumption is that we don't perceive sounds necessarilly as meaningful. A starting point is the analysis of two basic ways of our contact with sound - produced and received sound that are followed by the inquiring of the role of perception of voice as for its corporality; the possibility of hearing the "sound space" and its analysis; and of the way how the body is concerned with the sound perception. On the basis of these analyses that benefit from the philosophical texts and poems analyses in the conclusion of the thesis is being shown that sound is a special entity of reality since we perceive it simultaneously as a concrete and capturable (through word and corporality) and non-concrete, as for neither word meaning nor bodily contact can provide us with the adequate - "sound-based" description of the sound perceived.
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MICHÁLKOVÁ, Olga. "Ticho a zvuk." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-136500.
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This theses focused on the topic of silence and sound is divided in two section. Theoretical part contains information and knowledge from fields of physical phenomena, theory opf colors, psychology and theory of art (mainly based on work of W. Kandinski), that establish theorethical baseline for practical part, in this case realized graphic intent. Realization of practical part is an authorial construction of plastic interpretation of silence and sound. It tries to graphically express these two constructs with combination of pottery and glass in colorful compositions.
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Chen, Han-Ting, and 陳漢庭. "Zak Phase and Winding Number." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/vy7jeb.
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碩士國立臺灣大學
物理學研究所
107
A well known property of topological insulators is the existence of robust edge states. We use the SSH model to illustrate the robustness of the zero energy edge state under arbitrary perturbations. Also, it is known that the polarization is proportional to the Zak phase. By summing over the Zak phase of all the energy bands, the total Zak phase is shown to be always an integer multiple of 2pi even if there is no chiral symmetry. Therefore, we may relate the total Zak phase and the winding number, and we may generalize the bulk-edge correspondence to systems without chiral symmetry.
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Brychtová, Alexandra. "Prvky veřejného interiéru pohlcující zvuk." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-428269.
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The theoretical part deals with the solution of interiors from the perspective of acoustics. The emphasis is on the properties of materials used to reduce noise level and especially on the elements installed in space. In the practical part, the furniture element suitable for the public interior with the purpose to reduce the acoustic intensity of that space is designed.
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Chung, Shin-Kai, and 鍾詩鎧. "ZVS Converter with Low Output Inductance." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/56889548775659371912.
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碩士國立雲林科技大學
電機工程系碩士班
101
This thesis presents a hybrid DC converter composed by a three–level PWM converter and a symmetric half-bridge converter for high input voltage applications. The features of the proposed converter are zero voltage switching (ZVS) turn-on for all active switches, low output inductance and the low current stress on the passive components. At the primary side of the hybrid DC converter the voltage stress of power switches is clamped at half of the DC bus voltage. Therefore, MOSFETs with 600 voltage stress can be used after three-phase power factor corrector. The transformer secondary sides of three-level converter and half-bridge converter are connected in series in order to reduce the voltage across the output inductor. Thus, the size of the output inductor is reduced. The phase-shifted PWM scheme is used in the proposed converter to reglate output voltage. Due to the resonant behavior by the resonant inductance and junction capactitance of switch at the transition interval, all power switches can be turned on at ZVS such that the switching loss is reduced. The experimental results based on a 1440W are provided to verify the effectiveness of the proposed converter.
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Zak-Hunter, Lisa Marie. "The initiation of couple relationship discussions among young women with breast cancer." 2008. http://purl.galileo.usg.edu/uga%5Fetd/zak-hunter%5Flisa%5Fm%5F200812%5Fms.
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LIN, HUA-SHIH, and 林室樺. "The Square Complementary Active-Clamped ZVS Converter." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/18999386679467670856.
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碩士明新科技大學
電機工程研究所
101
This article proves that square complementary active clamp zero voltage switching converter. It is formed by forward converter, active clamp circuit and filter composition. active clamp circuit one auxiliary and one clamp capacitor, recycle absorb energy in the transformer leakage, to reduce the voltage stress and will achieve zero-voltage-switching. Transformer make the DC voltage become two isolated complementary voltages. These two isolated voltages work together and produce new DC voltage. This new DC voltage works with filter to remove noise and form stable output voltage. This circuit can reduce the ripple of output voltage, decrease the frequency of the switch and minimize the impact to the filter to circuit. It is a stable, low cost complementary converter. The accuracy can be proved by the model and the result of experiment in this article.
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Yi-Ming, Chen, and 陳一銘. "Nitrate removal by Zero-valent iron (ZVI)." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/01347762607934752153.
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博士淡江大學
水資源及環境工程學系博士班
95
Zero-valent iron (ZVI) and fluidize technique was successfully integrated in this study for nitrate removal, with three related processes developed, namely fluidized zero valent iron reactor, two fluidized ZVI reactors system, and pressurized CO2/zero valent iron system. Each of these is elaborated in the following three sections. Fluidized zero valent iron bed reactor With fluidized zero valent iron reactor, the pH of solution can be maintained at optimal conditions for rapid nitrate reduction. For hydraulic retention times of 15 min, the nitrate reduction efficiency increases with increasing ZVI dosage. At ZVI loadings of 33 g l-1, results indicate that the nitrate removal efficiency increases from less than 13% for systems without pH control to more than 92% for systems operated at pH of 4.0. By maintaining pH at 4.0, we are able to decrease the hydraulic retention time to 3 min and still achieve more than 87% nitrate reduction. The recovery of total nitrogen which is defined as the total of nitrate, ammonium, and nitrite was less than 50% for the system operated at pH 4.0, and was close to 100% for a system without pH control. The possibility of nitrate and ammonium adsorption onto iron corrosion products was ruled out by studying the behavior of their adsorption onto freshly hydrous ferric oxide at various pHs, suggesting the probable formation of nitrogen gas species during reaction in pH 4.0. Two fluidized ZVI reactors system A two fluidized ZVI reactors system was proposed to treat nitrate-contaminated water. The first column was employed to achieve an efficient nitrate reduction, while the second column was installed as the post-treatment process for neutralizing the effluent pH. The results of experiment show the pH increases and total nitrate removal decreases with increasing by pass ratio (BPR). Results from XRD analyses of the used ZVI taken from conditions at pH4.0 and 8.5 indicate only metallic iron was identified under pH4.0 condition and Fe2O3 and Fe3O4 along with metallic iron were identified for pH 8.5. Regarding to N-recovery deficiency problem, gaseous product was collected and nitrogen gas produced was confirmed. Pressurized CO2/zero valent iron system A fluidized zero valent iron reactor pressurized by CO2 gas for pH control was employed for nitrate reduction. The proposed CO2 pressurized system has advantages of using less CO2 gas and reaching equilibrium pH faster than CO2-bubbled system. However, due to weak acid nature of carbonic acid, system pH gradually increased with increasing oxidation of ZVI and reduction of nitrate. As pH increased with progress of reaction, nitrate removal rate decreased continuously. The results indicate that nitrate removal efficiency increases with increasing initial ZVI dosage but reaches plateau at ZVI doses of higher than 8.25 g l-1, and initial nitrate concentration up to 100 mg l-1 as N has minimal impact on the removal efficiency. Unlike the fluidized system with pH control by strong acid reported in our pervious study, near 100% of nitrogen recovery was observed in the current process, indicating that nitrate reduction by ZVI with different pH controlled mechanisms will have different reaction routes.
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Leskovjanová, Tereza. "Trestný čin pomluvy podle § 184 tr. zák." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-383967.
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1 The crime of defamation under Art. 184 Criminal Code Abstract This thesis deals with the wording and the role of the crime of defamation in criminal law. Since it is a minor offense due to the objective aspect of a criminal offense and the type of object it protects, and it has repeatedly been considered for removal from the Criminal Code for the last 15 years, the author posits whether the existing factual basis of defamation in criminal law is dispensable. The first chapter of this thesis deals with the fundamental right of preservation of human dignity, personal honor, and good reputation. The introduction and differentiation of the enumerated institutes are followed by a summary of the historical development of penal regulation regarding preservation of honor. It aims to record how the definition of the crime of defamation developed starting from the beginning of the First Republic to the present day, and at the same time to explore the most important reasons that led the legislators to retain the crime of defamation in the Criminal Code after the Velvet Revolution. In the central part of the thesis are following two chapters where the author deals with the current wording of the preservation of dignity and reputation in the Czech legal order and detailed characteristics of the factual basis of the...
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Huang, Zhu-En, and 黃主恩. "Digital Realization of ZCS-ZVS Boost Converter." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/n8sqk4.
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碩士國立臺北科技大學
電力電子產業研發碩士專班
97
As generally acknowledged, the current in and voltage on the switch can not instantaneously go from zero to a fixed value or from a fixed value to zero, and hence there exists switching loss in the boost converter. The higher the switching frequency is, the more the switching loss, thereby causing the switching frequency not to be increased effectively. Base on the mention above, a soft-switching boost converter is presented herein along with quasi-resonance and zero-voltage-transition techniques, so as to realize the zero voltage switching (ZVS) during the turn-on period and the zero current switching (ZCS) during the turn-off period. By doing so, the efficiency of the overall system can be upgraded. In this thesis, the feasibility and effectiveness of the proposed structure topology are verified by IsSpice and the field programmable gate array (FPGA), respectively. Furthermore, under fully-digitalized control, the output voltage is affected by variations in input voltage and load current as little as possible.
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Sedláčková, Kateřina. "Trestný čin krádeže podle § 205 tr. zák." Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435987.
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The crime of theft according to section 205 of Czech Criminal Code Abstract This diploma thesis deals with the crime of theft according to section 205 of Czech Criminal Code. The aim of this report is to analyse the crime of theft and to describe its features, in order to provide its comprehensive knowledge. The work is divided into six chapters, which are then divided into individual subchapters. The first chapter deals with property criminality, whose phenomenon is theft. It is pointed out to the high frequency of theft in property criminality and also for some types of theft to the relatively low level of clarity. The second chapters deal with historical view the historical view of theft in Czech lands. The description begins in the oldest period and ends in year 1989. More space is devoted to the period after year 1945, where it is pointed out to the existence of two types of thefts, which were introduced after year 1945. The third chapter provides a view on the institution of property, which is closely related to theft. The space is mainly dedicated to the protection of property, which takes place on several levels. It is pointed out here to the international, European, and national protection of this institute. The fourth chapter could be considered crucial. The introduction to this chapter explains...
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Šebková, Jana. "Trestný čin opilství podle § 360 tr. zák." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-388885.
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1 The crime of habitual drunkenness under s. 360 of the Criminal C. Abstract The aim of this diploma thesis is to analyze complexly the problems associated with the legal regulation of the crime of drunkenness. The crime of habitual drunkenness or otherwise called the "Rauschdelikt" is an illustrative option of how to deal with the issue of an insane people, which act unlawfully and how to punish them. The person which commits an unlawful act in a state of insanity, committed an act of otherwise criminal, quasi-delict. Where the perpetrator has caused a state of insanity by consuming or applying an addictive substance. The above-mentioned concept of "Rauschdelikt" appears to be the best option, for the sake of consistency with the fundamental principles and principles of criminal law, the nullum crimen sine culpa principle. The thesis is organized in individual chapters, which are gradually dealing with the historical development, and this crime does not present in modern criminal law no novelty; on the contrary, the institute of drunkenness has deep historical roots. The following chapters analyzes some individual basic terms that are necessary for the definition of a crime of habitual drunkenness and include and clarify the legal institutes that are close to and closely related to this crime, such as the...
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Slavíčková, Alžběta. "Trestný čin zpronevěry podle § 248 tr. zák." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-277322.
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Offense embezzlement under § 248 of the Criminal Code The aim of the thesis is to provide a detailed analyzing of crimes against property with a focus on embezzlement. It is aimed at understanding the differences between individual crimes against property by using professional literature and judicature and at taking away at least the basic uncertainties of application practice which consists often in not understanding of the facts of the case. It seemed appropriate to focus on the issue of financial lease or leasing in connection with the crimes against property because of the growing popularity of this topic. The thesis consists of introduction and four chapters. Each of the chapters deals with different aspects of embezzlement and its related issues. In my introduction, I outline the reason of my choice of this topic. The first chapter deals with a historical development of legislation and a general analysis of the current legislation. Chapter 2 is divided into four subchapters where the attention is paid to a detailed analysis of obligatory characters of the facts of embezzlement. The first subchapter describes the object of embezzlement. Second deals with objective site of this crime. It is divided into detailed description of individual elements which are: conduct, legal effect and causal...
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Josef, Filip. "Trestný čin opilství podle § 201a tr. zák." Master's thesis, 2009. http://www.nusl.cz/ntk/nusl-278618.
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Vlásenková, Jana. "Trestný čin opilství podle § 360 tr. zák." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-295919.
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The offence of intoxication - article § 360 of the criminal code Resumé This final thesis deals with the offence of intoxication, possible approaches on to how to punish such offenders whose insanity causes their intoxication. This thesis points out some of the difficulties that could occur while interpreting and applying the law, and is trying to suggest a solution that better corresponds with modern legislation and legal principles. The offence of intoxication - article § 360 of the Criminal Code is actually a special offence based on a construction of the facts of the case, concept of Rauschdelikt. It was restored into our Criminal Code with the amendment of an Act in 1991, which replaced the previous full criminal liability of individuals who caused their insanity voluntarily. The offence of intoxication is an important criminal law theory for its attitude to a "liability for fault" principle, which the criminal offence of intoxication "breaks through" and extends conditions of criminal liability itself. Insanity is generally considered a condition that relieves the perpetrator of criminal liability, but not in the case of the offence of intoxication. From society's point of view it is considered enough to distinguish between the insanity caused by an inborn mental disease and insanity caused by another...
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Velich, Roman. "Trestný čin opilství podle § 360 tr. zák." Master's thesis, 2011. http://www.nusl.cz/ntk/nusl-313260.
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The crime of habitual drunkenness under s. 360 of the Criminal Code The purpose of this thesis could be summarized as a complex analysis of a crime of habitual drunkenness under s. 360 of the Czech Criminal Code. The described crime (sometimes named 'rauschdelikt᾿) represents one of possible approaches to a problematic question: How to hold a perpetrator who has committed a crime in mental state of insanity (irresponsibility), in which he had induced himself by use of alcohol, narcotics or similar substances, liable? As far as conformity with elementary principles of criminal law (such as 'nullum crimen sine culpa᾿) is concerned, the crime of habitual drunkenness seems to be the most suitable answer to the previous question. The crime of 'rauschdelikt᾿ is an old legal institute that is specific in many aspects. I have chosen the topic within the context of recent recodification of substantive criminal law. A previous regulation of this crime was often criticised for many reasons (e.g. improper title, too stringent penal sanction etc.). Thus we can now review if those criticised deficiencies have been set right. The thesis is divided into ten chapters. Chapter One is introductory and defines basic terminology used in the thesis, such as 'insanity᾿, 'culpability᾿ and so on. The third subchapter...
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Richter, Jiří. "Trestný čin opilství podle § 360 tr. zák." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-327485.
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The crime of habitual drunkenness under s. 360 of the Criminal Code This thesis about drunkenness offense under § 360 of Act No. 40/2009 Criminal Code consists of ten chapters. Author defines the basic concepts of this offense, analyze legislation, and deals with theoretical approaches and criminological aspects of this crime. The first chapter is devoted to the reasons for the very existence of this specific instrument and the concept of insanity, including a treatise on the assessment of sanity in practice in the form of an expert evidence. The second chapter briefly summarizes development of legislation connected with drunkenness in our country for the period from Maria Theresa criminal law reform to the present. The third and fourth chapter contains analysis of the present legislation of drunkenness in its current version, including actio libera in causa contained in § 360 paragraph 2 of the Criminal Code. In the fifth chapter, the author discusses the arguments of theoretical approaches to punishment of willfully insane offenders and formulate his own critical attitudes. At the same time, author compares the effects of the application of the theory to examples from recent case law of the Czech courts. The sixth and seventh chapter deals with the crime of drunkenness in terms of the possibility...
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Kárász, Martin. "Trestný čin opilství podle § 360 tr. zák." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-337242.
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The subject matter of this thesis is a crime of habitual drunkenness under s. 360 of the Act No. 40/2009 - Criminal Code. The offense of drunkenness is atypical one among other offenses and unique in many ways. The aim of this work is to intelligibly and comprehensively describe the issue of the crime of drunkenness and aspects associated with it. The thesis is divided into five chapters. The first chapter is devoted to the possible starting points and concepts. There are three basic approaches on the issue of the crime of drunkenness and four more which are based on the concept of so-called rauschdelikt. The second chapter examines the historical development of this issue in our country. There were different regimes over time and each of them approached resolved legal issues differently. For proper grasp and understanding of the current legal situation it is therefore necessary to look back in history. This chapter overviews the most important legislation, case law, and it also contains comparison of historical development with the present one, amended with regard to the development of the institute of insanity. Chapter three is the basis of this work. It consists of a detailed analysis of current legislation and careful analysis of the elements contained in s. 360 of the Criminal Code, then again...
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Chen, Chien-Chih, and 陳健致. "A Novel Switching Power Supply with ZVS." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/53180758185148602889.
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碩士國立雲林科技大學
電機工程系碩士班
95
This thesis discuss on analyzing and implementation how active clamp technology apply to push pull converter and forward converter.To suppress high voltage stress of power switch device that switching in classic push pull converter, an RCD snubber circuit is mostly added on primary. Although the switching way belongs to hard switching, it increases switching loss. It makes efficiency of converter to go down. The conventional forward converter only works in the first quadrant, hence demagnetize technology makes the operated point of transformer to return the start point of every cycle in one switching cycle, and prevent a transformer to reach saturated condition. There are many approaches to apply forward converter in demagnetize technology by adding a RCD Snubber. This way not only offers a converter skill of demegnetization but also restrains the excessive voltage stress causing from the power switching. The switching way of the power switch device and push pull converter are hard switching, efficiency improvement becomes an important problem. The main aim of this thesis discusses how ZVS applies to push pull converter and forward converter. Using Soft switching technology, power switches can achieve ZVS during switching process reduce the switching loss. Soft switching technology absorb the stored energy in the transformer leakage that minimizes the spike voltage at the transformer primary side, and resolve the problem of power switch voltage stress. Finally, we verify it through the experimental result.
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Chen, Jyun-Ji, and 陳俊吉. "The Study of Sepic Converters with ZVS." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/10938026742337662261.
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碩士國立雲林科技大學
電機工程系碩士班
95
This thesis presents the zero voltage switching (ZVS) isolated and non-isolated Sepic converters with different types of active clamp topology. Generally speaking, the active clamp techniques are used to absorb the energy stored in the transformer leakage inductor and to create the ZVS conditions for the main and auxiliary switches. Thus, the switching losses and EMI problems can be reduced. The non-isolated Sepic Converters with power factor correction (PFC) and active clamp technique are also presented in this thesis. Hence, the current harmonics can be reduced and the efficiency is increased. Finally, the operational principle, steady state analysis and design consideration of the proposed converters have presented and supported by experimental results.
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Kuo, Deng-Ren, and 郭登仁. "Study and implementation of interleaved ZVS converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/60699202220124640666.
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碩士國立雲林科技大學
電機工程系碩士班
95
This thesis presents a soft switching forward converter to achieve ZVS turn-on of power switches .Two converter cells are adopted in the circuit and operated with interleaved PWM scheme to share the load current. Each converter cell includes one main switch, one isolated transformer, one active clamp circuit and one current double rectifier. Active clamp circuit is used to achieve ZVS operation for both stitches during the transition interval of both switches. The energy stored in leakage inductor of transformer can be recycled by active clamp circuit so that the voltage stress on power switch can be limited. The current double rectifier is adopter in the secondary side. The advantages of current double rectifier are one diode conduction drop, ripple current cancellation on the output inductors and low current rating of transformer secondary winding. The circuit configuration, principle of operation and design considerations of the proposed converter are presented. Finally, experimental results based on a 240W (12V/ 20A) prototype circuit are presented to verify in the circuit performance.
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Li, Wei-Chun, and 李威俊. "Analysis and Implementation of The Interleaved ZVS Converters." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/31539935292110756980.
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碩士雲林科技大學
電機工程系碩士班
96
This thesis presents the interleaved asymmetry half-bridge converter with active-clamp technique. The active-clamp technique utilizes energy stored in the transformer leakage inductance and magnetizing inductance to achieve a zero voltage switching (ZVS). The ZVS technique can reduce switching losses and electromagnetic interference (EMI). Two transformers connected in series are used in each half-bridge converter. One of two transformers can act as inductor or transformer in the primary and secondary winding.In secondary side,the interleaved pulse-width modulation is used to reduce the output current ripple. Finally, experimental results with a laboratory prototype based on a 110V input and 12V output with 240W rated power were provided to verify prove the feasibility of the proposed converter.