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Time-Frequency Signal Analysis
Kovačev, Radovan ; Polok, Lukáš (referee) ; Bařina, David (advisor)
The main subject of this work represents the time-frequency signal analysis. Firstly, it intends to provide the most essential theoretical background with focus on the continuous wavelet transform, where also a comparison of the key features with its close relative the short-time Fourier transform is performed. Afterwards, there follows a demonstration of the purpose with a practical example. The particular aim is to create a phase vocoder solution for modifying the length of a sound record duration and pitch shifting. Here, in this place, the functional principles, design, procedure of assembling, outputs and achieved results are well documented.
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Using Hilbert Huang transformation for analysis of non-stationary signals from physical experiments
Tuleja, Peter ; Balík, Miroslav (referee) ; Rášo, Ondřej (advisor)
This paper discusses the possible use of Hilbert-Huang transform to analyze the data obtained from physical experiments. Specifically for the analysis of acoustic emission in the form of acoustic shock. The introductory section explains the concept of acoustic emission and its detection process. Subsequently are discussed methods for signal analysis in time-frequency domain. Specifically, short-term Fourier transform, Wavelet transform, Hilbert transform and Hilbert-Huang transform. The final part contains the proposed method for measuring the performance and accuracy of different approaches.
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Short time Fourier transform for heart rate variability analysis
Osičková, Kristýna ; Slávik, Vladimír (referee) ; Janoušek, Oto (advisor)
The thesis describes the heart rate variability (HRV), its physiological and clinical significance and the means of its analysis. It includes a thorough dissection of the methods applied in the process of HRV evaluation in a time domain and using the short-time Fourier transform. The thesis compare both of the methodologies regarding changes of HRV caused by global ischaemia. The practical part descibes the application created in Matlab for analysis in the time domain and using short-time Fourier transform. The resulsts were calculated from the positions R wave EG signal isolated rabbit hearts.
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Boundary effects in signal processing: From classical problems to new opportunities
Popoola, Seyi James ; Druckmüllerová, Hana (referee) ; Cicone, Antonio (advisor)
Tato práce se zaměřuje na hraniční problémy při rozkladu signálů. Problematika hranic klasických metod byla rozsáhle studována, ale v posledních několika desetiletích byla představena nová generace metod. Implementace těchto nových metod má potenciál produkovat efektivním způsobem přesnější, flexibilnější a interpretovatelné výsledky, které mohou pomoci posunout výzkum v reálných aplikacích v různých oblastech. Hraniční problémy pro tyto techniky byly studovány teprve nedávno. Dosud zveřejněné výsledky ukazují, že tyto metody mají svá omezení a předpoklady, které je třeba pečlivě zvážit, aby se předešlo možnému zneužití. V této studii identifikujeme a řešíme hlavní překážky spojené s používáním těchto nových metod a poskytujeme také doporučení, jak je co nejefektivněji využít. Abychom dále ilustrovali možné důsledky nesprávného použití, provádíme komplexní zkoumání jejich aplikace na skutečná data a provádíme numerické simulace. Nakonec navrhujeme soubor osvědčených postupů pro optimalizaci výkonu těchto technik v kontextu rozkladu signálu. Zásadním návrhem je použít před aplikací jakékoli metody rozkladu techniku rozšíření signálu jako prostředek ke zmírnění hraničních efektů.
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Wavelet transform
Valter, Boris ; Hlávka, Zdeněk (advisor) ; Dvořák, Jiří (referee)
Wavelet transform is a term from signal analysis. It is mostly used in physics, but also in finance, where we can use it to find a trend in different financial data. In the first chapter we will describe two older methods of signal analysis: Fourier transform and short-time Fourier transform. In the second chapter we show, how wavelet transform works, derive frequently used algorithm for calculating discrete wavelet transform and at the end we show several practical examples. This thesis was considered to deepen the knowledge of time-frequency analysis of signals, for better understanding of the principle, how wavelet transform works, and for potential extending its use. Powered by TCPDF (www.tcpdf.org)
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Wavelet transform
Valter, Boris ; Hlávka, Zdeněk (advisor) ; Dvořák, Jiří (referee)
Wavelet transform is a term from signal analysis. It is mostly used in physics, but also in finance, where we can use it to find a trend in different financial data. In the first chapter we will describe two older methods of signal analysis: Fourier transform and short-time Fourier transform. In the second chapter we show, how wavelet transform works, derive frequently used algorithm for calculating discrete wavelet transform and at the end we show several practical examples. This thesis was considered to deepen the knowledge of time-frequency analysis of signals, for better understanding of the principle, how wavelet transform works, and for potential extending its use. Powered by TCPDF (www.tcpdf.org)
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Short time Fourier transform for heart rate variability analysis
Osičková, Kristýna ; Slávik, Vladimír (referee) ; Janoušek, Oto (advisor)
The thesis describes the heart rate variability (HRV), its physiological and clinical significance and the means of its analysis. It includes a thorough dissection of the methods applied in the process of HRV evaluation in a time domain and using the short-time Fourier transform. The thesis compare both of the methodologies regarding changes of HRV caused by global ischaemia. The practical part descibes the application created in Matlab for analysis in the time domain and using short-time Fourier transform. The resulsts were calculated from the positions R wave EG signal isolated rabbit hearts.
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Time-Frequency Signal Analysis
Kovačev, Radovan ; Polok, Lukáš (referee) ; Bařina, David (advisor)
The main subject of this work represents the time-frequency signal analysis. Firstly, it intends to provide the most essential theoretical background with focus on the continuous wavelet transform, where also a comparison of the key features with its close relative the short-time Fourier transform is performed. Afterwards, there follows a demonstration of the purpose with a practical example. The particular aim is to create a phase vocoder solution for modifying the length of a sound record duration and pitch shifting. Here, in this place, the functional principles, design, procedure of assembling, outputs and achieved results are well documented.
|
|
|
Using Hilbert Huang transformation for analysis of non-stationary signals from physical experiments
Tuleja, Peter ; Balík, Miroslav (referee) ; Rášo, Ondřej (advisor)
This paper discusses the possible use of Hilbert-Huang transform to analyze the data obtained from physical experiments. Specifically for the analysis of acoustic emission in the form of acoustic shock. The introductory section explains the concept of acoustic emission and its detection process. Subsequently are discussed methods for signal analysis in time-frequency domain. Specifically, short-term Fourier transform, Wavelet transform, Hilbert transform and Hilbert-Huang transform. The final part contains the proposed method for measuring the performance and accuracy of different approaches.
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