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Reverb Digital audio effect based on convolution with impulse response of acoustic room
Tichý, Vladimír ; Rajmic, Pavel (referee) ; Mačák, Jaromír (advisor)
This work deals with a computer simulation of an acoustic room using its impulse response. Two different approaches to the simulation are described with their pros and cons and then the work is focused on the physical approach, which uses room’s impulse response during the simulation. Several methods for the extraction of the impulse response of the acoustic room are mentioned with their conditions of use. The detailed description of various algorithms for a real time convolution computing is followed by the cost analysis of frequency domain block convolution algorithms. Several algorithms are chosen, implemented and tested in Matlab environment. Then the most effective of them is chosen to be implemented in VST technology as the plug in module for real time room simulation.
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Graph theory - implementation of selected problems
Stráník, František ; Rajmic, Pavel (referee) ; Koutný, Martin (advisor)
This work is intended on identification with basic problems from the graphs theory area. There are the basic conceptions as well more complicated problems described. The one part of this work is specialized in working of individual types of graphs. It starts with single linked list through double linked list after as much as trees which represented the simplest graphs textures. The other part of this work devotes to the whole graph and describes more complicated problems and their resolution from the theory graphs area. Among these problems belongs to searching in graphs help by Depth First Search and Breadth First Search methods. Then searching the shortest way help by the specific algorithms as are: Dijkstra´s algorithm, Floyd-Warshall´s algorithm and Bellman-Ford´s algorithm. The last part is devoted to problems with searching minimal frames of graphs with usage Kruskal´s algorithm, Jarnik´s algorithm and Boruvka´s algorithm methods.
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Speech denoising based on wavelet transform and voice recognition in segments
Chrápek, Tomáš ; Sysel, Petr (referee) ; Rajmic, Pavel (advisor)
The wavelet transform is a modern signal processing tool. The wavelet transform earned itself a great success mainly for its unique properties, such as the capability of recognizing very fast changes in processed signal. The theoretical part of this work is introduction to wavelet theory, more specifically wavelet types, a wavelet transform and its application in systems dealing with signal denoising. A main problem connected to speech signals denoising was introduced. The problem is degradation of the speech signal when denoising unvoiced parts. It is because of the fact that unvoiced parts and noise itself have very similar characteristics. The solution would be to apply different attitude to voiced and unvoiced segments of the speech. The main goal of this diploma thesis was to create an application implementing the speech signal denoising using the wavelet transform. The special attention should have been paid to applying different attitude to voiced and unvoiced segments of the speech. The demanded application is programmed as a grafical user interface (GUI) in MATLAB environment. The algorithm implemented in this form allows users to test introduced procedures with a great comfort. This work presents achieved results and discusses them considering general requirements posed on an application of given type. The most important conlusion of this Diploma Thesis is the fact that some kind of trade-off between sufficient signal denoising and keeping the speech understandable has to be made.
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JAVA-based effective implementation of an image compression tool
Průša, Zdeněk ; Rajmic, Pavel (referee) ; Malý, Jan (advisor)
This diploma thesis deals with digital image lossy compression. Lossy compression in general inserts some kind of distorsion to the resulting image. The distorsion should not be interupting or even noticable in the better case. For image analysis there is used process called transformation and for choosing relevant coefficients process called coding. Evaluation of image quallity can be done by objective or subjective method. There is encoder introduced and realized in this work. Encoder utilizes two-dimension wavelet transform and SPIHT algortihm for coefficient coding. It was made use of accelerated method of wavelet transform computation by lifting scheme. Coder can proccess color information of images using modificated original SPIHT algorithm. For implementation the JAVA programming language was employed. The object-oriented design principes was made use of and thus the program is easy to extended. At demonstaration pictures there are shown effectiveness and characteristic way of distorsion of the proposed coder at high compression rates.
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Graphics and Presentation in the TeX and LaTeX Systems
Buňka, Roman ; Sysel, Petr (referee) ; Rajmic, Pavel (advisor)
This bachelor’s thesis deals with the insertion of external graphic files into LaTeX documents and the creation of graphics using internal tools of TeX. It describes the basic properties of the PSTricks additional package and its expansion enabling the creation of 2D and 3D graphs, special mathematical functions and electrical circuits. The work deals also with the method of creating PDF presentations using the Beamer class. This work suggests a structure of a source SVG file displaying electric circuits or flow charts. It also involves the creation of an XSLT conversion template providing for the conversion of these charts from the SVG format to the PSTricks format making it possible to use these graphic files in the LaTeX system.
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System for Bibliography Database Management on the Internet
Daněk, Jiří ; Janovič, Filip (referee) ; Rajmic, Pavel (advisor)
The aim of this master´s thesis was to create a web interface for working with bibliographic quotations. This whole project was created to easy writing bibliographic quotations in author´s piece. The system allows inserting, searching and managing bibliographic quotations. These quotations can also be exported into four types of files : RTF, XML, HTML, a database bib file. The czech norms CSN ISO 690-1 and also CSN ISO 690-2 are fully supported. Whole the system is based on language like PHP which is used for developing dynamic web pages. The system contains graphical user interface, which is simple to use. The web interface is fully functional and it is ready for using by autors of scientific publications or students in schools.
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Modern Speech/pause Detectors
Adamec, Michal ; Smékal, Zdeněk (referee) ; Rajmic, Pavel (advisor)
This masters theses deals with standard detection methods of speech/pause - voice activity detectors are based on the principles of short-time energy, real spectrum, short-time intensity and on a combinations of these three detectors. In the next parts, there are mentioned other voice activity detectors based on hidden Markovov‘s models and a detector described in the ITU-T G.729 standard. All the detectors, mentioned above, were implemented in research environment MATLAB. Further there was created an user interface for testing functions of the implemented detectors. Finally, there was done an evaluation by ROC characteristics according to the results of the testing.
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Detection of speech disorders
Struhař, Michal ; Rajmic, Pavel (referee) ; Sysel, Petr (advisor)
This thesis deals with detection of speech disorders. One of the aims of this thesis is choosing suitable parameterization: short-time energy, zero-crossing rate, linear predictive analysis, perceptual linear predictive analysis, RASTA method, cepstral analysis and mel-frequency cepstral coefficient can be chosed for detections. Next aim is construction of detector of speech disorders based on DTW (Dynamic Time Warping) and artificial neuron network. Single detection proceeds on the base of collected tokens from chosen analysis and phonetic transcription of speech. Analyses, detector and phonetic transcription of Czech language are implemented in simulation environment of MATLAB.
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