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Identification of the parameters of an electroencephalographic recording system
Svozilová, Veronika ; Sekora, Jiří (referee) ; Mézl, Martin (advisor)
Elektroencefalografický záznamový systém slouží k vyšetření mozkové aktivity. Na základě tohoto vyšetření lze stanovit diagnózu některých nemocí, například epilepsie. Účelem této práce bylo zpracování signálu z toho systému a vytvoření modelového signálu, který bude s reálným signálem porovnán. Uměle vytvořený signál vychází z Jansenova matematického modelu, který byl dále implementován v prostředí MATLAB a rozšířen ze základního modelu na komplexnější zahrnující nelinearity a model rozhraní elektroda – elektrolyt. Dále bylo provedeno měření signálů na EEG fantomu a následná identifikace parametrů naměřených signálu. V první fázi byly testovány jednoduché signály. Identifikace parametrů těchto signálů sloužila k validaci daného EEG fantomu. V druhé fázi bylo přistoupeno k testování EEG signálů navržených podle matematického Jansenova modelu. Analýza veškerých signálů zahrnuje mimo jiné časově frekvenční analýzu či ověření platnosti principu superpozice.
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Statistic Characteristic Function and its Usage for Digital Signal Processing
Mžourek, Zdeněk ; Mekyska, Jiří (referee) ; Smékal, Zdeněk (advisor)
Aim of this thesis is provide basic information about characteristic function used in statistic and compare its properties with the Fourier transform used in engineering applications. First part of this thesis is theoretical, there are discussed basic concepts, their properties and mutual relations. The second part is devoted to some possible applications, for example normality testing of data or utilization of the characteristic function in independent component analysis. The first chapter describes the introduction to probability theory for the unification of terminology and mentioned concepts will be used to demonstrate the interesting properties of characteristic function. The second chapter describes the Fourier transform, definition of characteristic function and their comparison. The second part of this text is devoted to applications the empirical characteristic function is analyzed as an estimate of the characteristic function of examined data. As an example of application is describe a simple test of normality. The last part deals with more advanced applications of characteristic function for methods such as independent component analysis.
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EEG Analysis During Anaesthesia
Hodulíková, Tereza ; Kolářová, Jana (referee) ; Sadovský, Petr (advisor)
This master's thesis deals with the method of functional examination of brain electric activity. In the first part is description of central nervous system, method of electroencephalography and possible connections. Furthermor the project involves characteristic of EEG signal and its artifacts. It also includes signal processing and list of symptoms, which will be used for an analysis of the EEG during anesthesia. The second part of thesis involves development of application, which allow viewing and proccesing of EEG signal. In conclusion of thesis is carried out unequal segmentation and statistical processing.
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Comparison of methods for RGB spectrogram construction of DNA
Postránecká, Tereza ; Provazník, Ivo (referee) ; Kubicová, Vladimíra (advisor)
This thesis discusses about possibilities of construction colour DNA spectrograms and about patterns which can be detected there. Spectrograms as tools of spectral analysis give us a simultaneous view of the local frequency throughout the nucleotide sequence. They are suitable for gene identification or gene regions identification, determination of global character about whole chromosomes and also give us a chance for the discovery of yet unknown regions of potential significance. For purpose of this kind of DNA analysis is possible to use digital signal processing methods. We can apply them on only after conversion of DNA sequence to numerical representation. Selection of correct numerical representation affects how well will be reflected biological features in numerical record which we need for another use in digital signal analysis.
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Measurement of cardiovascular parameters
Kratochvíla, Jiří ; Čmiel, Vratislav (referee) ; Kolářová, Jana (advisor)
The aim of the bachelor’s thesis is to get acquainted with the measurement of cardiovascular parameters, to realize the measurment of these parameters, to analyze them, show the statistic procedure of verifying hypotheses in this spere and finally the presentation of measured data including automatical detection of the heart rate from ECG signal in created program in Guide of Matlab system. On the basis of the theory was done the measurment on own suggestion with the Biopac system and with the quicksilver tonomether. The parameters, that were measured on the group of five people: ECG, blood pressure and the pulse frequency before and after the load. After the data processing was done the statistic analysis, the aim of this analysis was to show the procedure of verifying hypothesis, if and how are these measured parameters of cardiovascular system changing. After that the measured data were transported into Matlab system. The presentation of measured data (created program) contains the time domain and spectral analyses (using Fourier transform) of ECG signal, automatical detection of the heart rate from ECG signal, analysis of the heart rate variability (HRV) – tachogram together with detailed analysis of HRV spectra (spectra of heart rate variability – relating with parasympathetic and sympathetic activity), that are using in clinical practice too, just as the other measured parametres of the cardiovascular system.
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Spectral impuls signal analyzis
Měcháček, Radek ; Kubásek, Radek (referee) ; Fiala, Pavel (advisor)
Analysis signals, especially then pulsed signals and their next processing, today alreadyquaere to many different technological line. From communication engineering over telecommunication and acoustics, after as much as field - club application or multimedia. This work is introduction to the problems methods processing pulsed signals. Is distributive how from the standpoint of theory, so from look future application usage, by the help of programmatic analyses basic signals. Work bears basic description, notions, routes and method for work and analysis with widthspectral and ultraswidthspectral signals. Further be created tool for generation, filtration and near processing of several basic pseudo - random signals.
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Mathematical transformation in dielectric relaxation spectroscopy
Brida, Marek ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This labor treats the problem of dielectric relaxation spectroscopy in time domain, measurement of the absorption characteristics and their conversion to the frequency domain by creating a frequency depends of loss factor. Paper reports an overview of the most common mathematical transformation and approximation, which are used for this conversion and they also compare some of them. Mathematical methods used in this paper are Fourier transformation and Hamon approximation. Measured dielectric insulation is slot insulation type Isonom NKN 2039 and Isonom NMN 0967.
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Fourier transformation and spectrogram analysis of DNA sequences
Krejčí, Michal ; Provazník, Ivo (referee) ; Maděránková, Denisa (advisor)
Various methods of DNA sequences modifications for frequency analysis and basic characteristics of DNA are described in the theoretical part of this thesis. Tricolor spectrograms, created by short time Fourier transform help us to recognize some characteristic patterns in DNA sequences. Practical part of this work deals with developed programme which generates spectrograms and analyse them. Last part deals with the analysis of selected sequences of C. elegans genome. Some patterns are related to data of public databases such as NCBI. Various patterns are explained from the biological nature, which relates to chromosome structure and protein coding regions. Another well recognised patterns, tandem repetitions composed of satellites, microsatellites and minisatelites are described by spectrograms as well.
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Biosignal processing - clusetr analysis
Příhodová, Petra ; Maděránková, Denisa (referee) ; Kolářová, Jana (advisor)
This thesis deals with the problem with cluster analysis and biosignal classification options. The principle of cluster analysis, methods for calculating distances between objects and the standard process in the implementation of clustering are described in the first part. For biosignals processing,it is necessary to get familiar with the primary parameters of these signals in the following sections of thesis, process biosignals and methods for recording of action potentials described. Based on studying different clustering methods is presented a program with the applied method kmedoid in the next section of this thesis. The steps of this program are described in detail and in the end of thesis functionality is tested on a database of signals ÚBMI.
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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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