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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Automatizované pracoviště pro stejnosměrná měření / Automated workplace for the direct current measurements

Plocr, Radek January 2009 (has links)
The present thesis attempts at an overview of DC methods used for diagnosing electrical isolation systems. It investigates the problem of small currents and how to measure them. Part of the thesis deals with building a workstation designed for long-term monitoring of absorbing characteristics of dielectric materials and it also presents a layout of a workstation used for measuring recovery voltage. Both workplaces are computer-automated using the VEE Pro application provided by Hewlett-Packard. Tests were performed on both workstations and the obtained results were processed in a test report as specified under ČSN IEC 93. During the experiment, every effort was made to ensure and monitor the atmospheric conditions of the measuring process.
12

Bikónická dipólová anténa s kruhovou polarizací / Biconical dipole antenna with circular polarisation

Urbaník, Jaroslav January 2013 (has links)
Tato diplomová práce se zabývá teoretickými poznatky a návrhem bikónické antény pracující v kmitočtovém rozsahu 4 až 8 GHz. V rámci práce jsou také popsány způsoby impedančního přizpůsobení a vybrané typy polarizátorů elektromagnetických vln a radioprůzračných krytů. Na základě teoretických poznatků je určena koncepce návrhu bikónické antény a vybrán vhodný polarizátor pro zajištění kruhové polarizace vyzařovaných elektromagnetických vln.
13

Antény integrované do helmy / Antennas integrated into the helmet

Elfmark, Zdeněk January 2013 (has links)
The work is focused on antennas integrated into the helmet. They preferred planar antennas with different polarization and different feed. They consider possible positions on the helmet, or into helmet.
14

Automatizované měření polarizačních vlastností optického svazku / Automated measurement of polarisation properties of an optical beam

Březina, Vojtěch January 2014 (has links)
Diploma thesis deals with polarization properties of an optical beam and the determination of its polarization state by means of the proposed automatic measurement method. Furthermore the influence of an environment on the polarization state of the optical wave is studied. At the beginning of this thesis the fundamental terms with respect to the wave polarization including the description of the polarization devices are presented. In conclusion a method for an automated experimental workplace for the measurement of the polarization properties using Poincare sphere and Stokes parameters is designed and verified.
15

Kvalita služeb v optických přístupových sítích / Quality of Services in Optical Access Networks

Šifta, Radim January 2015 (has links)
The thesis focuses on the optical access networks and deals with the issue of transmission parameters of the physical layer, their negative impact on the quality of the services parameters and the possibilities of reducing their effect using the polarization multiplexing. The first and second chapter describe the theoretical background necessary for understanding the subsequent parts. The third chapter contains the practical part of the thesis. At first the optical routes in the Czech Republic in terms of polarization mode dispersion, which is together with insertion loss the main limiting parameter of high-speed optical networks, are evaluated. In the following part the measuring of the temperature changes effects on the polarization mode dispersion of the passive components and the effect of temperature changes to the polarization multiplexed signal are evaluated. To double the bandwidth and reduce the influence of polarization mode dispersion on the quality of services, the two simulation models of optical access networks using polarization multiplexing were carried out. These theoretical outputs were verified by the practical measurements in the laboratory and subsequently on the real optical route. Finally, a draft of the broadband optical access network based on wavelength and polarization multiplexing was designed based on obtained knowledge.
16

Analýza polarizace prostoru a možnosti rozvoje periferních území: příklad Trutnovska / Analysis of Space Polarisation and Possibilities of Development of Periphery Areas: Case Study the Trutnov Region

Turek, Karel January 2010 (has links)
This diploma thesis discusses the analysis of space polarisation in the Trutnov region and consequently it tries to suggest possibilities of development for peripheral areas. The first part is devoted to the theoretical concepts of the spatial polarization and the methodological analysis of this thesis. In the second part, the selected theoretical and methodological concepts are applied to area of the Trutnov region. The analysis of space polarisation in the Trutnov region was realised on the basis of using quantitative methods. Development of the peripheral areas between two time periods (around a year 1991 and present) was evaluated too. The final part of this thesis is aimed to the analysis of the peripheral areas in the Trutnov region and proposition of their possible development strategy.
17

Komparativní analýza regionálního vývoje Chorvatska a Slovinska - tendence, problémy a rizika polarizace / Comparative analysis of regional developemnt of Croatia and Slovenia - trends, challenges and risks of the polarization

Pessr, František January 2021 (has links)
The submitted diploma thesis deals with the issue of regional development of Slovenia and Croatia. The theme of regional differences and territorial differentiation is one of the classic themes of social and political geography. The main goal of the diploma thesis is - a comparative analysis of the regional development of Croatia and Slovenia at several scale levels. At the same time, the aim is to map the change in the regional image of Slovenia and Croatia over a longer period of time, especially since the end of the war in the Balkans, which took place here in the early 1990s. At the same time, the work aims to find out what general and specific factors play the most important role in regional development. A data set covering a wide range of socio-economic and demographic variables serves to achieve the proposed objectives. With the help of quantitative methods, the trends of regional disparities of the monitored countries, the influence of the most developed areas and the monitoring of regional variability of both countries are examined. Data comparing the regional development of both countries confirm that Slovenia is becoming a stronger dimension of social and regional policy than Croatia, where a significantly higher deepening of regional disparities and the concentration of production in...
18

Návrh antény s kruhovou polarizací pro kmitočtové pásmo 2,4 GHz / Design of circular polarized antenna for 2.4 GHz

Hase, Michal January 2008 (has links)
In this thesis, I introduce two types of circularly polarized rectangular microstrip antennas at 2.44 GHz. First type has direct fed and the second has two inputs for fed. In first case is used a stub to make the frequency with minimum return loss and equal to the frequency with minimum axial ratio. In second case is use the power splitter to divide the wave in to two lines with phase shift 90° for feeding the patch. In this thesis is described, how to get the best results of Axial Ratio.
19

Textilní štěrbinová anténa / Textile slot antenna

Špůrek, Jan January 2016 (has links)
This diploma thesis is focused on design of various antenna structures, based on slot antennas, created in the wider wall of a rectangular-shaped waveguide. As the substrate, it is used a 3D textile material, while its properties are examined. They were designed structures, that operate with linear and circular polarization, and other related structures, that are used for feeding and power division. Structures are designed to operate at central frequency of 8 GHz and its vicinity.
20

Studium procesu Drell-Yan na experimentu Compass / Studies of Drell-Yan process at Compass experiment

Matoušek, Jan January 2013 (has links)
Hadron structure is not fully understood yet. While the spin-averaged Parton Dis- tribution Functions (PDFs) and the helicity-dependent PDFs are well determined, little is known about the transverzity and some other transverse-momentum de- pendent PDFs (TMDs). The COMPASS experiment at CERN is preparing for studying the TMDs using a Drell-Yan process on transversely polarized target hit by pion beam in 2014-2015. An outline of the parton model of hadrons and of the TMDs is given. The COMPASS spectrometer is described, with emphasis on the modifications for the Drell-Yan program, and its capabilities to measure the TMDs is briefly discussed. A special attention is paid to the polarized target. The dilution refrigerator, the DNP system for polarizing the nuclei and the NMR for polarization measurement are described. The new monitoring system of the refrigerator is described, including the author's contribution to it. Issues of the new NMR coils design are discussed. 1

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