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Holographic antenna
Klečka, Tomáš ; Polívka,, Milan (referee) ; Pokorný, Michal (advisor)
This master’s thesis deals with principle of microwave holography, methods of microwave hologram recording and analyzes some types of holographic antennas from structural and functional point of view. It also includes simulations of selected holographic antennas and their modi?cations, applies optimization on three types of antennas. Finally it reviews measured results of three costructed antennas.
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Multiplatform communication in access networks
Novotný, Bohumil ; Sýkora, Jiří (referee) ; Křepelka, Václav (referee) ; Škorpil, Vladislav (advisor)
Doctoral thesis deals with failure detection methods in wireless access network using distributed stochastic algorithms. A new method of detecting a fault based on the push-sum algorithm has been designed and simulated. Within the scope of the work objectives, the statistical credibility of the average push-sum protocol convergence rate representative and the effect of message loss during the calculation on the robustness of the system using this protocol were compared. Based on the acquired knowledge, the ability of the protocol to mathematically derive deviations from the real average of the values in the specified topology was demonstrated and thereby the existence of an abnormality in the network has been proved or refuted.
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Interference modelling for xDSL
Čermák, Josef ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
This work is focused on the subject of the interference modelling for xDSL technologies. First, the xDSL technologies are explained. Following is the presentation and description of the different kinds of the xDSL technologies. The next part deals with the basic parameters of metallic cable lines – especially the primary and secondary parameters. Nowadays wider bandwidths are used for the achievement of higher data transmission rates. During a higher frequency signal transmission a more intensive line attenuation appears. To identify the transfer characteristics of the lines while using an xDSL system, mathematic models of transmission lines are applied. That is why these mathematic models are dealt with in the next chapter. At the end of this section the mathematic models are compared using the modular and phase characteristics. The main aim of the work is to describe the different impacts which influence the efficiency of the xDSL systems. First, the causes interfering from the inside of the cable are deeply explained: Near End Crosstalk (NEXT), Far End Crosstalk (FEXT), Additive White Gaussian Noise (AWGN). Following is the explanation of the external interfering impacts: Radio Frequency Interference (RFI) and Impulse Noise. The next goal of this thesis is a design of a workstation for the tests of spectral features and the efficiency of the xDSL systems. The work also presents a designed GUI application and its description. The GUI application is an instrument for the choice or data entry of the final interference. The last chapter describes a realization of a measurement and shows the measured characteristics which were recorded on the ADSL tester and oscilloscope.
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Data transmission over the distribution network
Mucha, Martin ; Mrákava, Petr (referee) ; Mlýnek, Petr (advisor)
his paper describes the principle of data communication through high-tension lines.Preliminary work examines the transmission system, the types of high-tensionn lines and then disassembling the possibility to transmit data through this system. Then there is interference with the types of data and analysis. It includes the PLC technology, which include types of modulation and error correction methods. The paper deals with the possibilities of PLC modems and their use. The following chapter defines the ways of modeling the high-tensionn lines through which is possible to deduce the transfer function of lines. The work includes practical examples of setting the PLC modems and data transmission from one modem to another. It shall also include practical demonstration of spectrum communication signal during the data transfer.
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The influence of mother tongue on learning foreign languages
Kimličková, Lenka ; Langerová, Petra (referee) ; Smutný, Milan (advisor)
Tato práce se zabívá tématem přivlastňování si cizího jazyka a vztahem mezi mateřským a cizím jazykem. Objasňuje základní pojmy, například přivlastňování si jazyk, kontrastní analýza a jazykový transfer. Zdůrazňuje význam přivlastňování si mateřského jazyka a vysvětluje teorie přivlastňování si jazyků. Poskytuje čtenáři příklady nejčastějších chyb, které se vyskytují při učení jazyků. Kromě tohohle pojednává také o nejrůznějších faktorech, mezi které patří věk nebo motivace a jejich vliv na učení jazyků.
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Phone line simulator
Vítek, Jiří ; Vařacha, František (referee) ; Prokeš, Aleš (advisor)
This master’s thesis is focused on the problems of designing telephone lines which are 7 km long with a step of 1 km. The thesis contains a detailed description of the basic parameters of metallic transmission lines. There is also briefly mentioned the issue of interfering the transmission lines. The main part is devoted to a system design of artificial lines connection, including printed circuit board design. The next section deals with a design of prototype controlling. The last part verifies the activity of implemented artificial lines.
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Coexistence of LTE and LoRa in the 2.4 GHz ISM band
Potočňak, Martin ; Staněk, Miroslav (referee) ; Polák, Ladislav (advisor)
This diploma thesis deals with the study and measurement of coexistence scenarios that can occur between the LTE and LoRa systems in the unlicensed ISM band 2.4 GHz. A common radio frequency band in which LTE and LoRa systems can coexist is defined. An appropriate laboratory measurement is proposed and realized, allowing automatized measurement of the defined coexistence scenarios. For this purpose, a personal computer, professional measurement equipment and software MATLAB are utilized. Functionality of the proposed concept is verified by extensive measurements. The obtained results are graphically shown and discussed in detail.
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Optical transmission applications in industries
Worbis, Vít ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of the semestral work term use of optical transmission in the industry is to find the right equipment for communication in industrial applications, which would lead to better control and management of these applications. My show almost seamless connection between the device, which is controlled by another device such as a computer. The first chapter shows how inside the core optical fiber and reflected beams are then carried around the skylight. The second section lists the differences between the copper and fiber cabling, there is described why metallic line slowly destroyed and replaced him fully optics. In the third chapter, I focused on the optical fiber, what are its characteristics, from which parts are made and what is distributed. In the fourth part shows the optical transmitters for multimode and singlemode optical fibers, which are differences between them, which are produced and with what characteristics, etc. In the fifth chapter is applied to a network of possible involvement in the industrial zone, is designed only as they could theoretically be industrial zone controlled by the machine. In the sixth part of the thesis I have tried to design a laboratory task that consists of those optical converters. It is only a small sample, as used in the industry far more extensive involvement.
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Optical Field Evaluations for Hologram Synthesis
Fedorko, Matúš ; Polok, Lukáš (referee) ; Zemčík, Pavel (advisor)
The primary concern of this work is computer generated holography, in particular accelerating computation of synthetic holograms by means of modern-day massively parallel graphics chips. It starts by introducing fundamental holography principles together with mathematical and physical concepts behind it. Following discussion then deals with OpenCL, which is a relatively new, but well recognized standard for GP-GPU programming. Finally, the last two chapters of this work give an overview of problem analysis and its implementation in C++.
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