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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.
1

Modelování přenosových kanálů pro příjem digitální televize DVB-T/H / Simulation of the Transmission Channels for the Digital Television DVB-T/H

Kučera, Jan January 2010 (has links)
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.
2

Simulace RF přenosového kanálu pro DVB-T2 / Simulation of the RF transmission channel for the DVB-T2

Strouhal, Adam January 2011 (has links)
This Master thesis is focused on detailed description of the DVB-T2 system. This work deals with the description of the particular parts of models and with typical RF transmission channels for fixed and mobile reception. In order to simulate the impact of the fading transmission channels on the transmitted signal there was developed an appropriate application in MATLAB. The graphic user interface of this application allows set the transmission parameters of DVB-T2 and the parameters of the transmission channels. Results of simulations with various settings are evaluated and compared with the results, obtained from the DVB-T measurements.
3

Simulace RF přenosového kanálu pro DVB-H a DVB-SH / Simulation of the RF Transmission Channel for the DVB-H and DVB-SH

Hrach, Petr January 2011 (has links)
Project is focused on description DVB broadcasting for hand-held’s. It describes standard DVB-H that is founded on DVB-T and uses its transmission infrastructure. Standard DVB-SH is a hybrid system that adds to terrestrial broadcasting satellite connection. Signal can extend by various environments, therefore it are defined models transmission channel with defined parameters. Simulation of the transmission in both channel are realized in user application created in MATLAB. Finally, obtained results are evaluated and discussed.
4

Automatický posuv pro digitální zapisovač dat / Automatic shift for digital data recorder

Šuta, Václav January 2010 (has links)
Master theses of Automatic Shift Control of the Digital Data Recorder is primarily concerned to design and construction of equipment used for measuring the half-width of the laser beam. The introductory part is devoted to the related theoretical basics and serves for better orientation in the following chapters. The second part is devoted to construction, completion and basic setting of product.
5

Stanovení optimálních experimentálních parametrů pro laserovou spektroskopii (LIBS) vybraných vzorků rostlin / Optimization of the experimental parameters for laser induced breakdown spectroscopy (LIBS) of selected plant samples

Prochazka, David January 2008 (has links)
This diploma thesis describes optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples. First part deals with the theoretical method of LIBS and explains the principles and terms. In the next part there is described device which was used for measurements. Main part of diploma thesis describes creation of program for measurement-automation. Main task of program was to solve the connection of autofocus on the sample with the sample automatic movement. Furthermore are described and elaborated specific measurements for optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples.
6

Návrh zásobníku s posuvem a orientací gumové ucpávky / Suggestion of case feeder for orientation gum plug

Laurenc, Filip January 2012 (has links)
The main target of this diploma thesis was to make suggestion orientation and movement product, this solution describe, make calculation and draw drawings documentation.
7

Konstrukční úpravy koherencí řízeného holografického mikroskopu / Modifications in mechanical design of the coherence controlled holographic microscope

Matela, Milan January 2013 (has links)
The aim of diploma thesis are modifications in mechanical design of the coherence controlled holographic microscope which will lead to reduction of some deficiencies. In this thesis there is a brief description of the history interference microscopy and differences between each types of interference microscopes. In this work there are stated some design deficiencies of actual condition of the microscope and also several solutions are suggested and shortly described. Then the best solution is chosen which is adjusted to a final form. It is described in detail and then realized. There is a summary included in the conclusion whether the new solution is suitable and if it fulfills the required condition.
8

Pokročilé metody vyhodnocování topografie povrchu / Advanced methods of surface topography evaluation

Hroděj, Daniel January 2020 (has links)
This paper deals with the analysis of data obtained from the surface of aluminum alloy 7475-T7351 after face milling with a tool inclination of 1°. The theoretical part explains the basic principles of measuring the topography of the surface and instruments that are able to provide relevant data directly from the scanned part. The following part contains the methods of evaluating the information, especially using various types of parameters acquired from ČSN EN ISO standards. The practical part focuses on the data obtained from the sample surface using the Alicona IF-G5. This information determines the character of the surface texture with the tool inclination and the difference between the profile and surface parameters. There is also described surface texture in the tool path and on the edge of the tool path. In the final economic evaluation, the connection between the feed per tooth and the machining price is found.
9

Softwarový přijímač pro dálkový průzkum Země v pásmu X / X-band Earth Observation Satellite Software Defined Receiver

Zedka, Radim January 2019 (has links)
Práce se zabývá procesem návrhu digitálního přijímače pro signály družic dálkového průzkumu Země v pásmu X. V první části je uveden seznam družic které umožnují příjem vědeckých dat pomocí amatérských neautorizovaných stanic. Jsou zde vypsány základní signálové parametry některých družic, z nichž EOS-PM-1 je zvolena jako hlavní objekt pro návrh přijímače. Ve druhé části je použit software MATLAB pro simulaci družicového O-QPSK signálu v základním pásmu, mechanizmu kompenzace kmitočtového ofsetu, synchronizaci nosné, symbolové synchronizaci, rámcové synchronizaci a odstranění fázové dvojznačnosti vlivem modulace. Třetí část práce pojednává detailněji o implementaci jednotlivých bloků přijímače do FPGA při použití aritmetky s pevnou řádovou čárkou. Je zde popsána metoda pro verifikaci celého designu v reálném čase a závěrem je zde uvedeno porovnání výsledků měření touto metodou a výsledků simulace.
10

Metody přesného měření nízkých impedancí / Methods of Accurate Measurement of Low Impedances

Mašláň, Stanislav January 2021 (has links)
Overall topic of presented thesis is development of methods of measurement of low impedances below 10 Ohm in a frequency range up to 1 MHz. The thesis comprises of three main parts. First part of thesis describes design of unique and simple calculable standards of resistance that are used for calibration of the bridge and as the reference standards for the calibrations. Next part of theses is focused on design of digital sampling bridge in various topologies suitable for measurement of various types of impedance standards up to frequency of 1 MHz. The thesis describes the HW components, data processing and corrections scheme allowing the designed bridge to reach expanded uncertainties (k=2) below 0.005% and 250 µrad at 1 MHz. One of the key points of the proposed corrections scheme is unique automatic linearity calibration method requiring minimal operator's effort. The theses also describes integration of Spice model of the bridge the bridge SW that allowed validation of functionality of the bridge and also analysis of uncertainty contributions related to interferences between the bridge components. The last part of the thesis shows selection of measurements of known impedances and international comparisons that proofs performance of the bridge.

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