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Hardware MISO Emulator for Fading Channels
Rez, Jan ; Pítra,, Kamil (referee) ; Šebesta, Jiří (advisor)
This thesis is devoted to study the possibility of solving a hardware MISO emulator for fading channels and design of experimental device. The theoretical part starts with the theory of propagation of electromagnetic waves in a different types of environment, follows the principles and phenomena describing the radiocommunication channels and gradually gets up to specific channel models used for planning radio links. The actual design study of emulator is based on theoretical knowledge mentioned in this thesis. The basic principle of each channel model and thus so the emulator for fading channels is Tapped Delay Line model. From the point of view of the peripheral emulator solutions are designed with two topology circuits, parallel and serial-parallel. Emulator control method, mechanical arrangement, selection of topology circuit, components selection, desing of the PCB and software design is also analyzed. The results of this thesis is prototype production of experimental device and final discussion about achieved requirements and tasks.
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Modelling of PLC system to ensure the reliability of communication
Procházka, Vít ; Mišurec, Jiří (referee) ; Mlýnek, Petr (advisor)
The master´s thesis is focussed on principles and characteristics of Powerline Communications (PLC), practical usage possibilities and advantages and disadvantage of it. There are described mudulations and a channel encoding which are in PLC used. The main part of the thesis deals with a design of a channel as transfer function through the use of two methods, an echo model and the ABCD matrix. After finishing of the design of transfer function the model of communication was created in the Matlab-Simulink program. There were used the narrowband modulations in the model and analyzed the bit error rate of the tranfer data. In the end all results were treated graphically and evaluated.
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Simulation of the Transmission Channels for the Digital Television DVB-T/H
Kučera, Jan ; Ulovec,, Karel (referee) ; Kratochvíl, Tomáš (advisor)
This thesis focuses on analysis, classification, simulation and assessment of the signal fading in the scope of terrestrial digital television reception. This is a phenomenon associated with signal multipath propagation caused by the reflection, dispersion and diffraction of electromagnetic waves in interaction with relief and artificial obstacles. Wave propagation issues in a specific landscape are not the central theme of this project. Signal transmission between the transmitter and receiver is defined by channel profile models. Attention is directed not only to static reception but also to portable and mobile reception. Simulation of this phenomenon takes place in the software environment of MATLAB. In the framework of this project program fundament was created which allows simulate the signal processing across the entire communication chain of television broadcasting, including its transmitting and receiving parts.
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Properties of the physical layer of ZigBee
Humpolík, Tomáš ; Frýza, Tomáš (referee) ; Prokopec, Jan (advisor)
The ZigBee standart works on using physical and data link layer of IEEE 802.15.4 standart. Three bands were defined (2.4GHz, 915MHz and 868MHz). There was also number of physical layers defined, each of them using one of the three bands and number of modulation and spreading functions. This thesis is focused first of all on specification 2,4GHz physical layer, which is world-wide used because this band can be used (with observace of the local rules) without license. Thesis is in its first part focused on modulation function, as well on used spreading functions and number of channels for each physical layer. In the second part is paid attention to demonstration kit by ATMEL Corporation, which enables associate a simple network in star topology and using the network for demonstration of simple functions of associated devices, and kit by Radiocrafts corporation, which is used in laboratory work. Laboratory work is focused on characteristics measurement during data transfer.
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Assemblying effect on cable lines quality
Dočkal, Martin ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
In the first part is explained what actually a structured cabling is. Its beginning, from what and why it was created. Its history when at the beginning were applied unbalanced coaxial cables, those were later replaced by balanced cables. In cabling for TVs are still used coaxial cables. Balanced cables are according to type named UTP, STP, FTP, and so on. Whit growing popularity of this type of cabling and its wide spread application was necessary to set some rules, standards, specifications and demands, how to build up the cabling from project to realization. According to these rules is the system built so there are strict rules for length of subsystems and interfaces and the whole appearance of the structure cabling. Next important point is projecting of cabling that is related to the previous points and when it’s finished, we should strictly follow it. With the project is closely connected characteristic of this cabling as attenuations, cross-talks and other transmission parameters which are measured in the practical part. In the second part is spoken about all the parts of which the structured cabling consists - metallic and optical connecting elements and cables. There are also mentioned their mechanical, electrical and transmission features. In the third part is described influence of man on the quality of structured cabling and the most common causes of lower quality and the ways how to prevent this from happening and how to manipulate with cabling not to destroy it. The final (fourth) part considers the measurement. There are measured qualities of metallic wires as the attenuations, delay, cross-talks on the near- and far-end, impedance and resistance. To all the features are mentioned schemes of the measurement on the twisted pairs. The measurement is divided into two parts. In the first part are measured five types of balanced cables of different length, category and damage influencing quality of these cables. In the second part is measured one balanced cable if it’s corresponding with category 5 for that t was made and if it would be possible to use it also for higher category 6. Values are tabularly sorted in tables.
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Minimizing the effect of interference on wireless network
Doležal, Jan ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
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.
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The quality of assembly in data transmission
Šalplachta, Milan ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The content of this work is theoretical and practical an analysis of transmission characteristics of structured cabling and related effect of assembling, which directly affects the characteristics of channel. Individual treshold limits of channel parametres, as technological methods of montages are outgoing from corresponding european specifications.
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A method of programming the TV channel ČT1 in connection with its focus groups
Kindlová, Pavlína ; Štoll, Martin (advisor) ; Lokšík, Martin (referee)
This thesis deals with programming of the TV channel ČT1 in connection with its audience. The first part of this thesis is a theoretical explanation of the television programming. It clarifies reasons and methods of the channel structure, then it introduces the research of viewer ratings. It concerns the techniques of the television programming whose goal is to gain sufficient ratings of the stated programme. However, it also determines the Czech Television as a public broadcaster with respect to the Czech law. It tries to explain how this fact affects programming of the Czech Television's channels. The second part of this thesis consists of practical research of programme ČT1. It analyses four weeks in 2015, it clarifies their main features. It takes knowledge from three interviews with the key operatives who are responsible for the programming at the Czech Television. It also devotes to the fact how the target audience forms placing of programmes sociologically. It is known that the association of human life with television broadcasting is necessary and strong. Besides, it identifies the channel ČT1 as it is, it compares its target audience with other channels of Czech television. A significant part of the thesis is dedicated to its prime time and the comparison with competitive channels....
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Molecular mechanisms of polymodal regulation of TRPA1 receptor
Sinica, Viktor ; Vlachová, Viktorie (advisor) ; Vondrášek, Jiří (referee) ; Holendová, Blanka (referee)
The TRPA1 channel is a universal, nociception-mediating cellular sensor activated by various environmental irritants, potentially harmful physical modalities and endogenous mediators of pathophysiological processes. The polymodality of TRPA1 channel allows the activation stimuli to further enhance or suppress each other's effect. While this modulation effect has its physiological importance in promoting the protective cellular and behavioral mechanisms, it may result into the unpleasant pain-related effects accompanying the chronical pain caused by aberrant TRPA1 channel activity. In order to effectively and selectively target the synergic properties of TRPA1 modulators, while preserving the sensitivity to the environmental threads, the knowledge of the mechanisms of polymodal regulation at the molecular level are required. This doctoral thesis aims at the elucidation of three main mechanisms of TRPA1 regulation: 1) the regulation via intracellular signaling cascades and phosphorylation, 2) the interaction with membrane phospholipids and 3) the temperature-driven gating. The results presented in the thesis show that the effects of the inflammatory mediator bradykinin are decreased by the low-frequency high-induction electromagnetic field used in magnetotherapy. We have identified a residue S602...
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Environmental education on children's channel ČT:D Ty Brďo! and S Jakubem v přírodě
Maňáková, Anežka ; Wolák, Radim (advisor) ; Römer, Lucie (referee)
This bachelor thesis is focused on the environmental education in the children's shows at the public channel ČT:D. Specifically this is the shows Ty Brďo! and S Jakubem v přírodě. The main intention is the qualitative analysis of these shows and using of them in the education. To find out what these shows can offer to the children from the perspective of the media studies. The thesis is divided into three parts. The first part emphasis the theory. Primarily the channel ČT:D, it's origin and evolution, program scheme, web sites and education. Besides there's summary of the Framework educational program (RPV) and the Recommended expected outputs of the environmental education (DOV). These materials are then compared with information gained by qualitative analysis. The second part of the thesis is dedicated mainly qualitative content analysis of individual parts and comparison of acquired data with the Framework educational program and the Recommended expected outputs. The last part of the thesis is dedicated to the focus group, which was carried out with eight children from the target group of analysed shows, and summary of the obtained information.
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