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Acoustic signal classification
Pospíšil, Aleš ; Balík, Miroslav (referee) ; Atassi, Hicham (advisor)
Bachelor's thesis is focused on automatic music genre classication. First part of work evaluates present situation and refer to published studies. Gained knowledge from there is applied in this work. In terms of nding solution for problem the work summarize and describe suitable music features and classication techniques like neural networks and k-nearest neighbor. Four selected classication classes were classical, electro, jazz and rock music. Result of work is user-friendly system that provides automatic music genre recognition. Achieved classication performance is more less comparable to human music genres recognition.
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Fractional-Octave Analysis of Acoustic Signals
Ryšavý, Marek ; Frenštátský, Petr (referee) ; Schimmel, Jiří (advisor)
The diploma thesis is focused on design and optimalization of digital octave and fraction-octave band filters. This thesis describe the behavior of filters in systems with fixed point arithmetics and investigate the impact of quantization coefficients for frequency response of filter. Filters, whitch has been designed, are implemented into simple software in C. Designed filters are in accordance with standard IEC 61260.
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Noise Source Identification Using Beamforming
Kurc, David ; Míča, Ivan (referee) ; Schimmel, Jiří (advisor)
This master's thesis is focused on the noise source identification using microphone arrays and beamforming as the signal processing method. It describes parts of such a system and provides a comparison with other systems that serve a similar purpose (eg. NAH). Various types of microphone arrays are mentioned with their influence on the resulting ability to identify the noise source. We are further focusing on Delay-And-Sum technology, on which we are explaining the basic principles and constraints of beamforming. The practical part describes the implementation of the DAS method in MATLAB and C language, the specific structures of built microphone arrays and assembly of complete systems capable of identifying sources of noise. These systems were tested by performing a practical experiment. Achievements in the form of distribution maps of acoustic energy in the focused space are interpreted in the last chapter.
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Acoustic Signal Recording and Processing Using B-Format Technology
Kurc, David ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
This bachelor’s thesis is focused on the system of recording and processing of acoustics signals called Ambisonics. It describes single sections of this system in the chain of acoustic signal processing. At most it is aimed at the B-format technology as the main ambisonic instrument, its encoding from the signals recorded with the special microphone capsule of the soundfield type or with help of encoding equations and its decoding into single speaker channels of various speaker arrays. The UHJ transmission format is also mentioned. The application B-format Decoder was created in the MATLAB programming environment. It consists of several functions and has friendly user interface, which provides the processing and decoding of B-format components for the speaker array with entered parameters. Among others this interface ensures loading, displaying, analysis and playback of source and resulting acoustic signals.
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Korelace charakteristických signálů laserem buzeného plazmatu
Terschová, Vanda ; Novotný, Karel (referee) ; Pořízka, Pavel (advisor)
Laser-induced breakdown spectroscopy (LIBS) is a fast analytical method, but can also be complicated. This spectroscopic method is used to provide a qualitative and quantitative analysis of a sample. The analysis is carried out by capturing the emission radiation of the generated plasma. The accuracy and stability of the measurement is affected by several parameters, such as stability of the laser, physical and chemical properties of the sample, its homogeneity and others, that can not always be eliminated. For this reason other methods are being added to the LIBS experiment that could improve the quality of this analysis. This diploma thesis is focused on a research of the literature on the standardization of laser-induced plasma signal and the possibility of using an acoustic signal for this purpose. For this reason , it is necessary to perform basic experiments and to verify if the acoustic signal correlates with the emission signal. If these signals correlate together, it would be possible to use the acoustic signal for standardization og the LIBS data, which would improve the accuracy of the analysis. In the theoretical part at the beginning other spectroscopic methods are summarised. Then the work is focused on the description of the LIBS method, possible ways of the analysis, standardization of emission signals and its review in the literature. The experimental part is aimed at the study of the acoustic signal that was performed in the framework of this study. At the beginning, there are introduced results of the basic measurements on steel and brass samples. These results were important for an optimization of the experiment. The following section shows the results obtained from the measurements of the acoustic signal on the samples with the same chemical composition but different hardness. At the end the correlation between the acoustic and emission signals is discussed.
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Analýza průběhu spalování akustickým signálem
Procházka, Jan
The presented diploma thesis monitors and evaluates the combustion process in conventional internal combustion engines according to the measurable and observable parameters, such as acoustic signal specifically. The first part of thesis focuses on the classification and use of internal combustion engines. Moreover, the combustion of the mixtures in cylinders is described as well as individual components of the engine that monitor and measure the combustion process. In the next part, the issue of acoustic emission is specifically addressed followed by the analysis of the combustion process using th acoustic signal. In conclusion, the use of the acoustic signal as an analytical tool for the evaluation of the combustion process is assessed according to the obtained results.
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Korelace charakteristických signálů laserem buzeného plazmatu
Terschová, Vanda ; Novotný, Karel (referee) ; Pořízka, Pavel (advisor)
Laser-induced breakdown spectroscopy (LIBS) is a fast analytical method, but can also be complicated. This spectroscopic method is used to provide a qualitative and quantitative analysis of a sample. The analysis is carried out by capturing the emission radiation of the generated plasma. The accuracy and stability of the measurement is affected by several parameters, such as stability of the laser, physical and chemical properties of the sample, its homogeneity and others, that can not always be eliminated. For this reason other methods are being added to the LIBS experiment that could improve the quality of this analysis. This diploma thesis is focused on a research of the literature on the standardization of laser-induced plasma signal and the possibility of using an acoustic signal for this purpose. For this reason , it is necessary to perform basic experiments and to verify if the acoustic signal correlates with the emission signal. If these signals correlate together, it would be possible to use the acoustic signal for standardization og the LIBS data, which would improve the accuracy of the analysis. In the theoretical part at the beginning other spectroscopic methods are summarised. Then the work is focused on the description of the LIBS method, possible ways of the analysis, standardization of emission signals and its review in the literature. The experimental part is aimed at the study of the acoustic signal that was performed in the framework of this study. At the beginning, there are introduced results of the basic measurements on steel and brass samples. These results were important for an optimization of the experiment. The following section shows the results obtained from the measurements of the acoustic signal on the samples with the same chemical composition but different hardness. At the end the correlation between the acoustic and emission signals is discussed.
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Fractional-Octave Analysis of Acoustic Signals
Ryšavý, Marek ; Frenštátský, Petr (referee) ; Schimmel, Jiří (advisor)
The diploma thesis is focused on design and optimalization of digital octave and fraction-octave band filters. This thesis describe the behavior of filters in systems with fixed point arithmetics and investigate the impact of quantization coefficients for frequency response of filter. Filters, whitch has been designed, are implemented into simple software in C. Designed filters are in accordance with standard IEC 61260.
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Acoustic Signal Recording and Processing Using B-Format Technology
Kurc, David ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
This bachelor’s thesis is focused on the system of recording and processing of acoustics signals called Ambisonics. It describes single sections of this system in the chain of acoustic signal processing. At most it is aimed at the B-format technology as the main ambisonic instrument, its encoding from the signals recorded with the special microphone capsule of the soundfield type or with help of encoding equations and its decoding into single speaker channels of various speaker arrays. The UHJ transmission format is also mentioned. The application B-format Decoder was created in the MATLAB programming environment. It consists of several functions and has friendly user interface, which provides the processing and decoding of B-format components for the speaker array with entered parameters. Among others this interface ensures loading, displaying, analysis and playback of source and resulting acoustic signals.
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