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Mobile internet principles
Jehličková, Lenka ; Fencl, Josef (referee) ; Hanus, Stanislav (advisor)
Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.
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Antennas for milimeter-wave bands
Pítra, Kamil ; Svoboda, Petr (referee) ; Raida, Zbyněk (advisor)
This thesis describes design and experimental verification of three types of the wideband antenna Bow-tie antenna, Vivaldi antenna and Spiral antenna. The tracked parameters are bandwidth, input impedance, gain and directivity patterns. Next step is design of millimeter-wave horn antennas. Attention is turned to the proper construction of a wideband feeder of the horn. For the final antenna structure, a bow-tie dipole and a Vivaldi antenna were chosen. The antenna construction is aimed to provide a wide bandwidth on one hand and a high gain on the other hand.
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Low bit rate voice encoders
Leitner, Jakub ; Mačák, Jaromír (referee) ; Pust, Radim (advisor)
The final thesis deals with coders and voice coders used in speech signal processing. The aim is to create an integral overview of coders and voice coders including a description of their properties, in the second part of the thesis a simulation of algorithms and methods of speech processing is performed in Matlab Simulink program.The basic methods of speech processing and a parametric LPC voice coder were simulated in time domain. In the LPC voice coder model there are implemented the algorithms for obtaining speech segment parameters. These are the algorithm for classification of voiced and unvoiced speech segment, LPC analysis and pitch detection. The output is a parametric signal that enables a receiver to synthesize a speech signal. The appendix 1 contains a list of names of coders or standard numbers of coders and their properties, the appendix 2 includes an overview of speech processing methods.
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Upgrade of testing workplace for solar cells
Řezníček, Martin ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The master‘s thesis is focused on the modification of measurement workplace for solar cells. In the first part of the thesis are introduced general problems of the solar energy and possible use in the international power supply, the details about the photovoltaic effect, processing of solar cells and their subsequent parameters. More further in the text the autor is concerned with causes of solar cells defects formation and representation of the most important defects. For defects detection are known the detection methods of solar cells, which are generally described in the text. The second part of the thesis includes detailed description of the LBIC method and workplace both the VUT Brno, and in Solartec, Ltd. The most important point of this part is project and description of innovated workplace from hardware and software realization. There is out of print the function and the description of the user interface and subsequently there are mentioned results gained from original and innovated workplace. In the conclusion are summarized whole activities of the master’s thesis, described and evaluated achieved results and outlined the direction, where would the other development of the LBIC workplace on VUT Brno be proceeding.
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Measuring of data communication parameters in computer networks
Šeda, Pavel ; Hošek, Jiří (referee) ; Skořepa, Michal (advisor)
Master‘s thesis is focused on basic characteristics of data transmissions in computer networks. In forepart I digestedly described basic characteristics computer networks, metods of their measurement and valuation. Computer networks type LAN as well as wireless computer networks Wifi, are mentioned. In second part I realized my own proposition of basic characteristics measurement. This proposition is used for SW applications development. Main goal of these applications is measurement of packet delay, packet jitter, paket loss and available bandwidth. I described details of SW applications and realized measurement of real computer networks in the end.
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Crawler chassis for a forwarder
Plichta, Zbyněk ; Kašpárek, Jaroslav (referee) ; Škopán, Miroslav (advisor)
The first part of the bachelor´s thesis introduces crawler chassis used in forwarders and harvesters, its second part includes a concept design of a crawler chassis for a forwarder based on the given parameters. The design concentrates on the arrangement of the undercarriage and the choice of suitable track and idlers. Another intention of the design is to find an appropriate solution for suspension of bottom rollers with a sufficient travel, while observing small dimensions of the undercarriage. The outcome of the thesis is a drawing of the designed crawler chassis.
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Lathe machines
Vidlák, Marek ; Tůma, Jiří (referee) ; Blecha, Petr (advisor)
Bachelor’s thesis deals with distribution of turning machines and describes the basic parts. It is divided into free parts. The first part deals with the history and definition of treatment. It is focused on building a lathe and description of basic parts, especially the description of the spindle which I chose for computational design which I chose for computational design. In the second part I will the distribution of the modern lathe machines and I give a several examples of current production machines. In the last part I will propose construction of spindle to fit the specified parameters.
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Transmission of Linear Pneumatic Cylinder
Bedeč, Csaba ; Mazal, Pavel (referee) ; Nevrlý, Josef (advisor)
The main subject of this bachelor's thesis is analysis and design of a mechanism for converting linear motion to rotary swinging motion used as door drive in the buses. The first part contains analysis and application of the applicable types of mechanisms. The work contains analysis and design of a cam-type mechanism in the second part. The analysis of the designed variants and selection of optimal parameters of the proposed mechanism is the last part.
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Design of a upright drilling machine
Matoušek, Kamil ; Bilík, Martin (referee) ; Blecha, Petr (advisor)
The subject of this thesis is to propose a design of an upright drilling machine. The upright drilling machine is described in the first part. Research about machines available on the market nowadays is accomplished in the second part of the thesis. Based on this research the parameters of machine are selected in the final part and proposal of the engineering design of an upright drilling machine. Basic construction calculations are made too. The result of this thesis is an assembly drawing and a 3D model of an upright drilling machine.
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Solar collectors of Viessmann Company – technical and economical assessment
Kábele, Pavel ; Bělka, Miloslav (referee) ; Jaroš, Michal (advisor)
This work is about technical and economical asessment of solar collectors by Viessmann company. In the first part there are general distribution, description each parts of collectors and parameters which affect a function of collectors. In the second part there are Viessmann company, description of present production. Suitability of use and technical parameters. The last part deals the effect of Viessmann, including basic energetic and economic calculation.
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