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Power-line network communication
Sláčik, Ján ; Rášo, Ondřej (referee) ; Kolka, Zdeněk (advisor)
The master’s thesis is dealing with PLC technology and its modem realization based on several types of standards by using commercially available integrated circuits. This projects also describes fundamentals and prerequisites for building the PLC network fulfilling the European standard CENELEC. The work further describes designed system concept, which serves as the automated system for the appliances connected to an electrical network. Components are selected for implementation and then is introduced concrete solution and implementation power-line network. Within the work are then other parts, that together form a system concept. Work includes the hardware and software implementation and a description of the options implemented system.
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Programming of processors in 32- or 64-bit operation systems
Rášo, Ondřej ; Kyselý, František (referee) ; Balík, Miroslav (advisor)
Main topic of this thesis is Win32 application programming interface and symbolic instructions programming language. It can be divided into four parts. First part sums the basics of 32-bit programming in symbolic instructions language in Windows. Second part describes the Win32 resources for computer intercommunication. Third part presents, describes and comments selected problems in symbolic instructions language.Last part covers a creation of an example application. This application and its parts will be the content of computer exercises in VUT Brno FEEC subject Počítače a jejich periferie.
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Cryptography protocol with public key
Fujdiak, Radek ; Rášo, Ondřej (referee) ; Mlýnek, Petr (advisor)
The Master thesis is an introduction to cryptology. The Thesis describe cryptosystems and selects one ideal cypher for low-power microcontroler. In thesis provides manual for instal development program COde Composer Studio, basic implementation of selected cryptosystem with small numbers and suggestion for implementation selected cyptosystem with big numbers.
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Hierarchical Coding of Moving Pictures
Špaček, Milan ; Rášo, Ondřej (referee) ; Schimmel, Jiří (advisor)
Bachelor‘s thesis deals with hierarchical coding – scaling – of moving pictures in currently widely used compression algorithms MPEG-2 and MPEG-4. Scaling is the process whereby the encoded data stream is divided into graduated layers, adapted especially to the possibilities of transmission media and capabilities of terminal devices. The content of the base layer is a signal with reduced quality. The content of one or more extension layers is a supplementary picture information, completing the signal to a full quality form. The decoder, depending on its abilities and external circumstances, can decode only the relevant layers from the received bitstream. The thesis focuses in the theoretical part on the detailed description of encoding and decoding video signal according to MPEG standards using three types of scalability. In the concrete, the spatial, qualitative SNR and Fine granular scalability are mentioned. In the practical part of thesis was created an educational application in Matlab environment with its own graphical user interface, which implements the functions performing spatial, qualitative SNR and Fine granular scalability. Based on the user-specified input parameters, it performs scaling the image and then displays the outputs of individual layers after scaling and after the image reconstruction. The input of the programme, in which a hierarchical coding is done, is the image in bitmap format with any size in RGB format.
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Design and Realization of Modification of Acoustic Field in Laboratory
Ješko, Petr ; Rášo, Ondřej (referee) ; Schimmel, Jiří (advisor)
The thesis deals with the problems of closed spaces. It deals with situations where it is necessary to reduce the reverberation time in certain octave bands. It provides procedures comparing conventional method of solving by calculation of the mean sound absorption coefficient of the area and the subsequent experimental addition of acoustic absorbers which occupy different areas and method that uses an acoustic simulation software for the 3D model. It also deals with a concept of Reflection Phase Grating diffuser.
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Modular web interface for Asterisk PBX
Moučka, Martin ; Rášo, Ondřej (referee) ; Krajsa, Ondřej (advisor)
This bachelor thesis is dealing with various ways of configuring Asterisk PBX and creating a modular web interface. This interface’s goal is to simplify the configuration of PBX and allow expanding its functions by adding new modules. Apart from a simple configuration, interface contains a self care zone where user can check his call history and keep his own phone book. As part of this work, there are two modules especially useful in environment of technical support and call centers. Those modules provide an opportunity to create interactive voice response menu, calling automat and queues management. Interface depends on Asterisk in version 13 which is the newest version with long term support. The application is secured by user account management with role assigning. The role can be modified by permitting only specified actions.
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Conversion of monophonic melody from the audio signal into the MIDI protocol stream
Krupička, Jan ; Rášo, Ondřej (referee) ; Mačák, Jaromír (advisor)
The aim of this thesis is to compare possibilities of the pitch extraction methods in the monophonic melody. There is presented the overview of the methods based on the speech pitch extraction techniques in the thesis. These methods uses frequency, time and „cepstral“ domain. They are compared in the term of success of the detection of various test signals. The part of the thesis specification is the implementation of these methods in Matlab. There are described basics of sound features at the beginning of this work. The overview of the musical tuning systems is mentioned and there is described a problem of the determination of the pitch from the detected frequency. There is considered an issue of MIDI protocol in the next part of the work. There are described the brief history and the essential structure of MIDI protocol. The last task of the work was the creation of the program in C language. The purpose of the program is to analyze the monophonic melody in audio signal form and assign note numbers to the detected sounds according to MIDI specification. After that the numbers are written into the standard MIDI file (SMF). There was implemented a correlation pitch detection algorithm in this program. It had the best results as compared to the others. There was used the fast correlation based on Fast Fourier transformation to accelerate computing of the correlation. The program was created in the form of MEX function, which provides various possibilities to be used in Matlab. There was also attached the description of the FFTW library, which was used to compute FFT.
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Secure access to web interface
Kazik, Milan ; Hajný, Jan (referee) ; Rášo, Ondřej (advisor)
This document contains basic principles and processes regarding secure access to web information system. It consists of theoretic and applied part. These are mainly written together in thesis’s chapters. Theoretic informations were tested on simple web application created in PHP computer language on Apache web server using MySQL database. In the beginning, there is an analysis of used programming environment, especially it’s advantages and disadvantages. The main part of this document is simple characterization of many security problems which can be found on many websites all around the world. In the first place it’s a handling problem of inputs and outputs in the web applications. Password disputableness is solving separatelly. Theory of a problem is analysed first of all. Then a couple of solving methods are suggested and the one which is practically realized is described in detail. There is a notification system created which is used to inform user about errors appeared in web application. In the last section there is a client and server certificates described. This document contains fully characterization of used scripts and connection between them. They are supplemented with many pictures and screenshots which are used to better understanding the disputableness of web security.
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Restoration of analog sound records form magnetic tapes
Spiššák, Filip ; Vrba, Kamil (referee) ; Rášo, Ondřej (advisor)
The aim of this bachelor thesis is a theoretical analysis of noises that often occur in magnetic audio tape recordings both from objective and subjective point of view. Furthermore, listening test is designed and carried out. In this test, the task of the listener is to evaluate the subjective variable „disturbance rate of unwanted sound in audio recording“ via specific software that was designed for this purpose. From the described noises, unwanted sounds represent the three most frequently occuring ones. It is a so-called „Hiss“ and two variations of „Hum“ noises. Hum is investigated in two dimensions so that the differences in the perception of even and odd harmonics can be analysed. Through a statistical analysis of the collected data, these noises can be classified according to the subjective perception of the specific recordings, which was also the primary purpose of this work. The findings of this thesis indicate that for instance Hiss is the most disturbing noise and that there is not a significant difference in the perception of even and odd harmonics. This information could be useful for the purposes of old record’s restorations, for example when an effort is made to remove specific types of noise. The measurement performed in this work may also help with the planning of other time-consuming and money-consuming listening tests.
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Objective methods for evaluation of the audio signal quality
Granát, Michal ; Rajmic, Pavel (referee) ; Rášo, Ondřej (advisor)
This diploma thesis deals with the objective methods of audio-signal qualification. In detail have been described algorithms to the reader which are used in individual methods. Individual methods are analyzed from computational intensity, ability to predict precisely subjective quality of audio-signals, point of view. There have been described basic variables by which audio-signals are described in further parts of this thesis. Second part has been dedicated to theoretical description of individual methods – their advantages and disadvantages and practical forms of usage. Third part has been dedicated to implementation of two chosen methods in graphical interface of MATLAB program. All the functions are described in detail which these applications offer. In the last part of the thesis there are in detail described results obtained by practical testing of audio-signals with different character in created applications and evaluated quality of reached results as an outcome.
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