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A Contribution to Optimal Synthesis of Filters
Szabó, Zoltán ; Hájek, Karel (referee) ; Král, Bohumil (referee) ; Sedláček, Jiří (advisor)
The presented dissertation thesis is focused on the optimization of filtering circuit synthesis. In the five main sections of this work, the author analyzes partial problems related to several areas within the synthesis of modern filtering circuits. The first chapter constitutes an examination of elementary aspects which characterize present-day integrated circuits in voltage feedback operational amplifiers, and this main content is further complemented with a view on possible application of these circuits for the designing of filtering circuits as proposed within subsequent parts of the thesis. In this context, the second chapter contains a description of the design and optimization of digitally controlled universal filters tunable by means of digital potentiometers originally produced for audio technology. These digitally controlled circuits are increasingly utilized as analog preprocessing blocks in digital signal processing systems. The most extensive portion of the dissertation is dedicated to a complex analysis of individual configurations of economical, purposely lossy active function blocks and modern voltage operational amplifiers. This part of the thesis aims at providing a detailed insight into the characteristics of individual configurations of examined circuits; furthermore, in this respect, the author proposes a comparison of various application possibilities relating to these circuits and their wider use in the field of active frequency filters optimization. The described section of the work also includes a definition and examples of application of the designed and realized program, which facilitates significant simplification of purposely lossy ARC filters. In the penultimate part of the dissertation thesis, the design, development, and verification of a suitable synthesis procedure are presented together with the optimization of data and (in particular) power models of EMC filters. Based on the verification of characteristics inherent with the designed models of EMC filters, the suggested measuring procedure related to these filters is described, including the design of a station for measuring elementary parameters of line anti-interference devices up to very high frequencies. In the last section of the thesis, the author discusses the procedure of air ions concentration measurement through an aspiration condenser and analyzes the systematic and random errors as well as the optimization of filtration characteristics of the applied measurement method. This part includes the description of the design and characteristics of the realized fully automated measurement system with an aspiration condenser.
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Design and construction of dual Crawford chamber
Haloda, Jiří ; Hadinec, Michal (referee) ; Szabó, Zoltán (advisor)
Dual Crawford cell is also known as dual TEM-cell (Transversal Electromagnetic Mode cell). It is device used for electromagnetic compatibility measurement (emission and immunity) and for biological application. This papers is focused on usage and design dual Crawford chamber and measuring of their electromagnetic compatibility. There are shown their advantages and disadvantages. This type of cell is simple for design and for the construction too. Construction of dual Crawford chamber with characteristic impedance of 50? for measure in 1GHz range was calculated.
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Voltage amplifier for Electrical field generation
Nedbal, Jan ; Szabó, Zoltán (referee) ; Kubásek, Radek (advisor)
This bachelor’s thesis is about design and practical realization of the voltage amplifier for generating an electric field defined trace. First part is introduced design of function generator and a DC power supply symmetric. In the second part is the design and simulation of power amplifier in class A and high voltage DC source. The last part is consists of measurements on a function generator, power amplifier and high voltage DC source.
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Alarm device
Demjanics, Ferenc ; Drexler, Petr (referee) ; Szabó, Zoltán (advisor)
Timer is an equipment that allows us to provide time measure. There are in all-day use a plenty of timers, but their use is ussually limited for one purpose only. Because of this I decided to compile a timer which allows to apply it for an individual needs. This granted a wider spectre of use in real life. We used a microcontroller from Atmel, and also a DCF77 signal (atomic time signal)receiver and decoder. Further, we required a real-time circuit, DC/DC converter, and a powerswitch from manufacturers STmicroelectronics, and Linear Technology,respectively.For the imaging unit we used a graphic LCD connected via an I2C bus, which is commercially available spare part for mobile phones. Following the design we compiled and revived a hardware part of the device. After a succesfull revive, we gradually compiled a program for microcontroller. The program defines a processes for run of the device. It was written in programming language C, with use of compiling enviroment avr studio 4
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Binocular vision
Jemelka, Ondřej ; Szabó, Zoltán (referee) ; Fedra, Petr (advisor)
This thesis concern physiology of binocular vision, tools for recording, processing and reproduction of stereoscopic dynamic records. The thesis describes design and realization of recording tool which uses couple of digital still video cameras as stereoscopic video recorders. The thesis deals with the software capabilities of image processing in Matlab and presents possible solutions in the form of a program for creating stereoscopic video in various formats. In the thesis is presented in detail passive projection techniques O anaglyph and polarization method. Has been designed and constructed projection tool uses the light polarization to obtain stereoscopic vision and then has been objectively and subjectively evaluated qualities of both methods in survey with group of observers.
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Ion fields measurement
Svozil, Radek ; Szabó, Zoltán (referee) ; Steinbauer, Miloslav (advisor)
The aim of this semester project is the introduction to the problematic of ion fields, where and under what circumstances they originate and extinct and the techniques of measurement. The project will deal with the atmosphere and the electrical field of the Earth. I will consider the composition of the atmosphere and the principles of origin and extinction of ions. I am going to mention the division of ions and their influence on the living organisms. Another topic to be dealt with is the methods for measuring the air ions and the small currents. Gradually we are going to learn the known methods of the measuring of air ions. We are going to get a closer look at the method of measuring with the cylindrical aspiration capacitor. We are also going to deal with the problem of measuring very low currents, where they originate and how it is possible to compensate them. The outcome of the project should be the concept and later the creation of the sonde for the measuring of the ion fields itself.
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Detection of the retinal nerve fibre layer
Kunc, Martin ; Szabó, Zoltán (referee) ; Kolář, Radim (advisor)
This thesis is deals with the nerve fibre layer in the colour ophthalmology images of retina. The thesis describes how can we use finding of nerve fibre layer and how was it solved in the past. In the thesis are proposed the methods that are based on processing and scoring frequency spectrums of individual sample of retina. At first here are described the methods of detection on the artificial generated samples that just simulate the nerve fibre layer. Then the thesis concentrates on processing of real images of retina. Because of the bloodstream, that depreciates processing at real images, are all surveyed samples are chosen manually. Except detection the nerve fibre layer itself, the thesis also deals with determination of direction their dissemination.
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The suppresion of mechanical stress impacts in fiber optic transmission systems
Pavlů, Michal ; Szabó, Zoltán (referee) ; Drexler, Petr (advisor)
This bachelors project deals with the suppresion of mechanical stress impacts in fiber optic transmission systems. Factors that have major influence on the polarization state distortion in optical fiber are discussed. It has been propřed the utilization of orthoconjugate retroreflector (OKR) for the compensation of polarization state degeneration. The theoretical analysis of this method is performed. The OKR method has been experimentally verified in the fiber optic current sensor. On the basis of results which were obtained by experimental verification the experimental results show evidence konvenience of the designed method.
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Methods for texture analysis in ophthalmologic images
Hanyášová, Lucie ; Szabó, Zoltán (referee) ; Kolář, Radim (advisor)
This thesis is focused on texture analysis methods. The project contains an overview of widely used methods. The main aim of the thesis is to develop a method for texture analysis of retinal images, which will be used for distinction of two patient groups, one with glaucoma eyes and one healthy. It is observed that glaucoma patients don´t have a texture on the eye ground. Preprocessing of the images is found by transfer of the image to different color spaces to achieve the best emphasis of the eye ground texture. Co-occurrence matrix is chosen for texture analysis of this data. The thesis contains detail description of the chosen solutions and feature discussion and the result is a list of features, which can be used for distinction between glaucoma and healthy eyes. The method is implemented in Matlab environment.
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