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Fraunhofer diffraction by identical objects of the same orientation
Prokop, David ; Bouchal, Petr (referee) ; Komrska, Jiří (advisor)
The bachelor's thesis deals with Fraunhofer diffraction by identical objects of the same orientation. Main objective of my thesis is description of Fraunhofer diffraction for three different arrangements of holes along a straight line. In next part, the problem of random distribution of holes along straight line is set into plane. The outcome of my thesis is determination of deviations from regular array of holes. Next part of my thesis includes a description of Fraunhofer diffraction experiment. In final part of my thesis are pictures of diffraction phenomena, to illustrate results obtained from model of random distribution of holes.
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Measurements by sampling computer card - laboratory task
Tomaštík, Roman ; Havránek, Zdeněk (referee) ; Dřínovský, Jiří (advisor)
This thesis focuses on the measurement with the help of sampling cards and determination of the basic parameters of the measured signal. There will be described basic characteristics of the used card Alazartech ATS860- 256M and brief description of the programming languages which will control the cards. In these environments there were the created driving programs for the operation of these cards. Main measuring program was created in the language C\C++, that shall work as oscilloscope and the same time as spectral analyzer. This programme will determine basic characteristics of the measured signal. Further there will be created simple preparation for memasuring with this card. In the conclusion of this thesis will create instrutions for laboratory exercise.
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Analysis of dynamic effects acting on crossings
Vukušičová, Daniela ; Vukušič, Ivan (referee) ; Smutný, Jaroslav (advisor)
This thesis is focused on measurement and analysis of dynamic effects on railway turnouts. Two turnouts with different wear condition were chosen. My attention was focused mainly on the crossing part of the turnout, where the highest dynamic impacts occur. The point of the thesis is comparison of the crossing part of turnouts in term of dynamic behaviour and assessment of influence of the wearing depth on dynamic effects. A part of the thesis is proposal of methodology of the measurement and convenient mathematical apparatus for analysing of dynamic effects on crossings.
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Verification of the Vdip method on the physical model of the MV network
Krčál, Vít ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This Master's thesis is focused on creating of an algorithm which calculates changes of negative-sequence voltages and currents from their instantaneous values. That allows to conduct localization of asymmetrical faults in MV network in line with the Vdip method, which is based on monitoring the changes of negative-sequence components at distribution substations and at a sub-transmission station. The algorithm is being developed in Matlab environment with continuous implementation of partial procedures which are being assessed and compared with each other. A study of phasor estimating methods is carried out with pointing out related problems which are mainly caused by Ripple control and deviation of system frequency from its nominal value. Optimization precautions are designed to mitigate these problems. For elimination of the Ripple control effects a method based on averaging is presented. The deviation of system frequency is dealt with by resampling the original data recordings. The analysis processes are tested by both simulation signals and real measured data. The optimized algorithm enables precise calculation of negative-sequence components changes which is the main contribution of this thesis. The constructed algorithm is used in verification of the Vdip method on physical model of MV network. For these purposes a simple distribution network is created within which ground faults on different places and with different resistances are realised. The results of localization are not convincing which is mainly caused by specific features of laboratory power line models which are constructed with heterogenous parameters.
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Image analysis for correction of electron microscopes
Smital, Petr ; Schwarz, Daniel (referee) ; Kolář, Radim (advisor)
This thesis describes the physical nature of corrections of an electron microscope and mathematical methods of image processing required for their complete automation. The corrections include different types of focusing, astigmatism correction, electron beam centring, and image stabilisation. The mathematical methods described in this thesis include various methods of measuring focus and astigmatism, with and without using the Fourier transform, edge detection, histogram operations, and image registration, i.e. detection of spatial transformations in images. This thesis includes detailed descriptions of the mathematical methods, their evaluation using an “offline” application, descriptions of the algorithms of their implementation into an actual electron microscope and results of their testing on the actual electron microscope, in the form of a video footage grabbed from its control computer’s screen.
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Testing images creation program with defined sub-pixel shift and resize precision
Málková, Eliška ; Martišek, Dalibor (referee) ; Hoderová, Jana (advisor)
Tato práce se zabývá generování testovacích sub-pixelově posunutých obrazu se známým posuvem. Ty umožní najít vhodné parametry váhové funkce, díky nimž se zpřesní hledání posuvu dvou obrazu. Dále je využito konvoluce s proměnným jádrem ke generování obrazu se změněným měřítkem. K definici konvoluce pro obraz využíváme Fourierovu transformaci. Práce zahrnuje všechnu potřebnou teorii a je přiložen program, který slouží ke generování posunutých obrazů a obrazů se změněným měřítkem.
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Semianalytical Computation of Fourier Series Coeficients
Hégr, Tomáš ; Kunovský, Jiří (referee) ; Šátek, Václav (advisor)
This bachelor thesis deals with semianalytical computation of the coefficients of the Fourier series. The aim of this work is to create a graphical user interface for program TKSL/C. The work contains the theory of Fourier series and Fourier transforms. The state of the art software is described in the following chapter. In the next parts the thesis describes the concept of the implementation of the user interface, some tutorial examples which were used and the summary of user testing.
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Automatic Generation of Steps for DDR
Skála, František ; Glembek, Ondřej (referee) ; Černocký, Jan (advisor)
The goal of this work is to draft methods suitable for automatic creation of step-files from music files for a DDR computer dance game. This problem is divided into two main parts - beat detection, thus determining the song tempo, and determination of steps itselves. Beat detection is based on detection of energy growths in particual frequency subbands and following statistical alignment of results. Step creation works similarly, but it focuses on detection of all intense moments of music and contains a logic for placing steps into different directions. Testing by users showed that application has the potential to address players seeking set of simple steps for their favourite songs. The quality of beat detection gives field for application of these methods even beyond scope of example application. This document also suggest a few possible improvements of used methods.
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Bandlimited signals, their properties and extrapolation capabilities
Mihálik, Ondrej ; Havránek, Zdeněk (referee) ; Jura, Pavel (advisor)
The work is concerned with the band-limited signal extrapolation using truncated series of prolate spheroidal wave function. Our aim is to investigate the extent to which it is possible to extrapolate signal from its samples taken in a finite interval. It is often believed that this extrapolation method depends on computing definite integrals. We show an alternative approach by using the least squares method and we compare it with the methods of numerical integration. We also consider their performance in the presence of noise and the possibility of using these algorithms for real-time data processing. Finally all proposed algorithms are tested using real data from a microphone array, so that their performance can be compared.
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