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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.
61

Politika nulové tolerance v Duchcově a Litvínově jako (společnost polarizující) politika disciplinace / Zero Tolerance policy in Duchcov and Litvínov: A Case of Polarizing Politics of Disciplination

Matysová, Barbora January 2016 (has links)
In this thesis, I deal with the Zero tolerance policy in its perspective of theory, records and application. I regard it as a disciplining policy, which leads to polarization and consequent deepening of problems in absence in of indications of social issues by their proper names. Answer to the issue of work is evidence of a practical example in a foreign surrounding and subsequent in-depth qualitative analysis of the two urban cases of region Ústí nad Labem - Duchcov and Litvínov. The data were processed by qualitative methods and techniques of sociological research in support partial statistics and hard data. This combined methodology aims to grasp the topic in the field of urban sociology and on that basis try for plasticity research based on interdisciplinarity. Based on research confirmed that the Zero tolerance policy in Duchcov and Litvínov is not recommendable manual for dealing with long-term social and deteriorating security situation. found that the appointment of politicians do not address the causes of incurred to shape the long-term problems. Furthemore been found the named policy do not address the causes of incurred to shape the long-term problems. Vice versa, reverses the logic of cause and effect - the cause of the decline in the quality of life in cities. In thus considered the...
62

Měření parametrů polarizovaného světla na výstupu optovláknového senzoru / Measurement of polarized lightparametrs measurement on the optical-fiber sensor output

Drábek, Jakub January 2018 (has links)
This master's thesis deals with the analysis of the optical power measurement using an optical fiber sensor. The thesis contains the theoretical background to understand the origin of polarization and its representation in space using Poincaré’s sphere and Stokes vectors. There is also a part describing optical performance measurement and the preview of analog measurements from various researches. Practical part focuses on verification of changes of fiber sensor parameters at temperature change in its surroundings and this part includes also additional suggestions for various types of measurements and verification of the function of the photodiode as an optical power transducer. Most measurements are based on the comparison of results obtained with the polarimeter. The results were plotted and discussed.
63

Měření elektrických parametrů vysokonapěťových komponentů pomocí elektronického můstku / Measurement of HV equipments by electronic bridge.

Kumičák, Ivan January 2019 (has links)
The main idea of this thesis is measurements of dielectric materials by using a device Tettex. The thesis is about basic physic properties of dielectric materials. The determination of a dielectric material is considered. The behavior of these materials in electrical fields and reasons, those can have an influence on it, are considered as well. In the text are described measuring methods of chosen parameters of dielectric materials by device Tettex and its functional principles. There are an evaluation of measurements, which were done, and a discussion about achieved results.
64

Využití a potlačování dvojlomných jevů v optovláknových senzorických aplikacích / Utilization and Suppression of Birefringence Phenomena in Optical Fiber Sensory Applications

Motúz, Rastislav January 2019 (has links)
The thesis deals with integral and distributed optical fiber sensors of electric current. In the area of integral sensors the analysis is performed by Jones matrix calculus and the simultaneous influence of induced circular and undesired linear birefringence using an ortho-conjugation retroreflector. Furthermore, the proposed conjugation loop variant using half-wave phase retarders is analyzed. The theoretical conclusions are confirmed by simulation and experimental measurement. In the field of distributed fiber optic sensors, analysis and simulation for the detection of plasma currents in thermonuclear fusion reactors, based on the POTDR technique, is performed. An improvement procedure is proposed for circular-shaped vacuum vessel reactors. Plasma current detection procedure in divertor-type reactors have been newly designed and simulated to investigate the effect of the OTDR detector noise on plasma current detection accuracy.
65

Minimalizace vlivu rušení na bezdrátovou síť / Minimizing the effect of interference on wireless network

Doležal, Jan January 2008 (has links)
This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
66

Vlastnosti kapalin na bázi organických esterů / Properties of liquids based on organic esters

Toulová, Jana January 2012 (has links)
This master's thesis deals with the electrical insulation fluids used in electronics industry. The analysis of the current state of research and innovations in modern, biodegradable fluids in terms of their use as diagnostics. It is described by the physical nature of polarization and conductivity mechanisms, which are applied in liquids. It was compiled automated workstation for monitoring components of the complex permittivity over a wide temperature range. In the experimental part we analyzed the behavior of liquids selected alternative based on natural esters when exposed to an alternating electric field at various temperatures. Evaluated results are compared with values for conventional mineral oil.
67

Analýza elektromagnetické vlny na rozhraní heterogenního prostředí / Analysis of an Electromagnetic Wave on the Boundary between Electromagnetic Materials

Kadlec, Radim January 2014 (has links)
The proposed dissertation thesis contains an analysis of conditions on the boundary between layers having varied electromagnetic properties. The research is performed using consistent theoretical derivation of analytical formulas, and the underlying problem is considered also in view of multiple boundaries including the effect of the propagation of electromagnetic waves having different instantaneous speed. The author presents a survey and formulation of the basic characteristics of methods used for electromagnetic wave propagation analysis; in this respect, special emphasis is placed on radial models. The processing of the topic involved the designing and verification (using a set of different, layered planar materials) of algorithms to analyze the electromagnetic field components. The algorithm was assembled to enable simple evaluation of all components of the electromagnetic field in relation to the speed of the wave propagation in a heterogeneous environment. The proposed algorithms are compared by means of different numerical methods for the modelling of electromagnetic waves on the boundary between materials; moreover, electromagnetic field components in common points of the model were also subject to comparison. When in conjunction with tools facilitating the analysis of material response to the source of a continuous signal, the algorithms constitute a supplementary instrument for the design of a layered material. Such design enables the realization of, for example, recoilless plane, recoilless transition between different types of environment, and filters for both optical and radio frequencies.
68

Rekonfigurovatelná štěrbinová anténní řada / Reconfigurable slot antenna array

Weigel, Filip January 2016 (has links)
This master's thesis deals with the basic principles of slot antennas. Models of antennas were simulated in a selected electromagnetic simulator CST MICROWAVE STUDIO (CST MWS). There are several models of slot antennas which are optimized for communication in the car at a frequency 8 GHz.
69

Vliv hlubokých hladin na transport náboje v CdTe a CdZnTe / Influence of Deep Levels on Charge Transport in CdTe and CdZnTe

Dědič, Václav January 2014 (has links)
CdTe and CdZnTe are promising materials for room temperature semiconductor X-ray and gamma ray detectors. The accumulation of a space charge at deep energy levels due to a band bending at contacts with Schottky barriers and due to trapped photogenerated charge may result in time dependent change of charge collection efficiency in CdTe and CdZnTe detectors known as polarization effect. This thesis is mainly focused on a study of electric field profiles in detectors under dark and high photon flux conditions simulating detector operation using crossed polarizers technique exploiting the electro-optic (Pockels) effect. It also deals with a study of deep levels responsible for the polarization and influence of contact metals on charge accumulation. Several experimental results are supported by theoretical simulations. The measurements were performed on three sets of samples equipped with different contact metals (Au, In) cut from three different n-type CdTe and CdZnTe materials. Energy levels were detected using methods based on the Pockels effect and discharge current measurements. Detailed study of internal electric field profiles has revealed a fundamental influence of near midgap energy levels related to crystal defects and contact metals on the polarization in semiconductor detectors under high radiation...
70

Polarizace USA v Kongresu: Role stranických členských sdružení ve Sněmovně reprezentantů / U.S. Polarization in Congress: The role of Congressional Member Organizations in the House of Representatives

Hodboď, Dominik January 2018 (has links)
This thesis aims to contribute to the current academic debate on contemporary polarization in the U.S. Congress. The paper provides a brief overview of the relevenat existing literature and schools of thought on the issue. As part of the thought direction which steers away from definining roots and causes of polarization among the general public but rather sees them as issues of the political elite, this thesis highlights the need to focus on individual Congressional Member Organizations (CMOs) in the House of Representatives and their connection to polarization. By applying an existing dataset accepted among political science scholars as the key tool for measuring polarization, the thesis seeks to affirm the presumed ideological differences among the individual CMOs (or caucuses). The main part of this thesis which adds value to further discussion is the case study of all roll call votes of the 114th House of Representatives examining voting cohesion of the studied caucuses. The aim of this study is to show to what extent the CMOs are in fact consistent voting blocs and how influential they can potentially be within the political elites in the House of Representatives and to what level they may be contributing to the contemporary polarization.

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