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Methods for automated camera focusing
Kičina, Pavol ; Rášo, Ondřej (referee) ; Šmirg, Ondřej (advisor)
This bachelor´s thesis is about methods of focusing with web camera. Edge detection method and Discrete cosine transform method are use in this thesis. In program MatLab I create a program, which take a picture from web camera. With handle focusing this program shows information how much is picture focus. Functional and elementary are subject, which I use to compare. Advantages and disadvantages are in this thesis, with important elements about quality of focus,too.
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Study of electrical properties of thin polymer films
Pospíšil, Jan ; Vala, Martin (referee) ; Zmeškal, Oldřich (advisor)
The thesis is focused on the study of electric and dielectric properties of thin-film organic materials that can be used as an active layer of photovoltaic cells. Primarily were studied the properties of the layers on the PET or glass substrate, which consist of a thin active layer of polymethylphenylsilane (PMPSi) or derivatives of diketopyrrolpyrrole (DPP). On a selected sample were first measured current-voltage characteristics and current dependences on time at constant voltage (relaxation characteristics). Finally were measured frequency dependences (impedance spectra) and their relaxation characteristics too. The measured data were evaluated using the methods of fractal analysis in HarFA. The results will be used to optimize the properties of photovoltaic cells.
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Image Transformations
Novák, Radim ; Juránek, Roman (referee) ; Venera, Jiří (advisor)
The main goal of this thesis is to introduce two fundamental geometric transformations in 2D space - by changing the resolution together with related image resampling and image rotation. Also brightness interpolation, technique of mapping and other problems related to the topic are explained there, i.e. Fourier transformations, problem with aliasing and technique of aliasing suppression.
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Analysis of pulse wave velocity variability
Benešová, Lenka ; Kozumplík, Jiří (referee) ; Svačinová, Jana (advisor)
This diploma thesis deals with the variability of pulse wave velocity. It studies the variability of cardiovascular signals. It presents the research of measurement of pulse wave velocity and its analysis in physiology and pathological physiology. Applies spectral analysis in Matlab to a data set. It evaluates and reviews the results of this analysis
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Venturi nozzle shape influence on hydrodynamic cavitation
Mračko, Patrik ; Balko, Marek (referee) ; Rudolf, Pavel (advisor)
Thesis focuses on the influence of various differently shaped diffusers of Venturi nozzle on the cavitation, which occurs during flow of liquid through said nozzle. Several models with different shapes of diffuser's wall were designed. Cavitation in these models was then investigated with numerical calculation. Two physical nozzles were made according to designed models and tested on experimental circuit. As part of the experiment, the cavitation inside the nozzles was measured with flow of liquid corresponding to a large range of cavitation numbers. Results of this experiment were used to determine which model of the nozzle is more effective in creation of a cavitating flow.
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Sound analyzer
Daniel, Jiří ; Fiala, Jiří (advisor) ; Mareš, Martin (referee)
Title: Sound analyzer Author: Jiří Daniel Department: Department of Applied Mathematics Supervisor: doc. RNDr. Jiří Fiala, Ph.D., Department of Applied Mathematics, Malostranské nám. 25, 118 00 Praha 1 Supervisor's e-mail adress: fiala@kam.mff.cuni.cz Abstract: The goal is to program a utility that would conduct the spectral analysis of the audio signal. Special attention will be given that the analysis was carried out in real time (here it is necessary to optimize data flows depending on the computational power of machines) and to allow the user to specify the width and the density of each frequency band. The work can be extended to the preparation of spectral filters, which would carry out the downstream signal conditioning. Keywords: spectral analysis, Fourier transformation, digital band-pass filter, feedback
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Analysis of pulse wave velocity variability
Benešová, Lenka ; Kozumplík, Jiří (referee) ; Svačinová, Jana (advisor)
This diploma thesis deals with the variability of pulse wave velocity. It studies the variability of cardiovascular signals. It presents the research of measurement of pulse wave velocity and its analysis in physiology and pathological physiology. Applies spectral analysis in Matlab to a data set. It evaluates and reviews the results of this analysis
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Monitoring of hydraulic machines using acoustic emissions
Závorka, Dalibor ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The goal of this diploma thesis is to clarify possibilities of usage of acoustic emission as a hydraulic machinery diagnostics tool. Especially for exposing presence of ruptures or cracks in the parts of machine, assuming changes in acoustic exposure of the part during operation. This clarification is based on series of simple measured experiments, which consist of monitoring the bolt placed in fluid stream inside of a pipe. This bolt was preloaded against inner wall of pipe by appropriate tightening torque. This preload is supposed to simulate effects of the size of rupture. High preload simulates small rupture or none in object and respectively small preload is supposed to simulate big rupture. A group of pressure sensors and accelerometers measures experiments and their evaluations are processed by script created in software MATLAB. Outputs of this script are charts with effective values of respective sensors from the entire record split into individual frequency spectrums. These charts compare spectrums of each configuration to judge effects of parameters changes.
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Methods of analysis of vibration signals
Sivera, David ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The aim of the thesis is to focus on the different methods of analysis of vibration signals. Focusing on the physical fundamentals of vibrations and a description of their origin in an electrical machine. Describe the vibration sources from mechanical across the electromagnetic to the aerodynamic. Defining the current defects of electric machines and sensors suitable for the measurement of vibrations in an electric machines. Introduction to the methods of analysis of vibration signals in the time and frequency domain. Then using some of these methods for the analysis of vibration signals measured asynchronous motors with different manufacturer defined production defect. The conclusion is composed from the comparison between measured and analyzed results.
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Sound analyzer
Daniel, Jiří ; Fiala, Jiří (advisor) ; Mareš, Martin (referee)
Title: Sound analyzer Author: Jiří Daniel Department: Department of Applied Mathematics Supervisor: doc. RNDr. Jiří Fiala, Ph.D., Department of Applied Mathematics, Malostranské nám. 25, 118 00 Praha 1 Supervisor's e-mail adress: fiala@kam.mff.cuni.cz Abstract: The goal is to program a utility that would conduct the spectral analysis of the audio signal. Special attention will be given that the analysis was carried out in real time (here it is necessary to optimize data flows depending on the computational power of machines) and to allow the user to specify the width and the density of each frequency band. The work can be extended to the preparation of spectral filters, which would carry out the downstream signal conditioning. Keywords: spectral analysis, Fourier transformation, digital band-pass filter, feedback
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