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Neural networks in audio signal watermarking algorithms
Kaňa, Ondřej ; Smékal, Zdeněk (referee) ; Zezula, Radek (advisor)
Digital watermarking is a technique for digital multimedia copyright protection. The robustness and the imperceptibility are the main requirements of the watermark. This thesis deals with watermarking audio signals using artificial neural networks. There is described audio watermarking method in the DCT domain. Method is based on human psychoacoustic model and the techniques of neural networks.
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Anti-Error Coding Systems with Block Codes
Pacher, Jakub ; Zezula, Radek (referee) ; Němec, Karel (advisor)
This work deals with selection and proven suitable error-correcting code securing aggregating errors. First we give analysis anti-error coding system and requirements rapid/fire at them. The next text is focusing on survey and characteristics often used codes, mainly Fire, Hamming and two BCHs codes. After an explanation of Hamming code use, the text describes verification of proper function anti-error system in the MathCad enviroment.
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Analysis of distributed control protocols for indistrial applications
Horych, Vladimír ; Zezula, Radek (referee) ; Koutný, Martin (advisor)
This master's thesis deals with distributed control protocols for industrial applications. It explains term distributed control system, control protocol and it is dealing with properties, frame structures and ways of communication within CAN, Modbus, IEC60870-5-101 and DLMS protocols. This thesis includes informations, which are in most cases difficult to find. Second part of the thesis is dedicated to education system. This part is contained by information about protocols and their layers based on ISO/OSI model, pictures of structure of messages, knowledge test and an application based on JavaScript language. This JavaScript application emulates behavior of workstations, which are using communication based on IEC 60870-5-101 protocol. This application can set various conditions for influence of message transfer. These conditions are setting way of message transfer, data availability, filling of workstation’s buffer or intentional damage of message's content. It also contains a large amount of context help, activated after moving mouse cursor over most of application's elements. Even visitor without great knowledge of distributed control systems should understand how this protocol works, thanks to these context help and messages printed in lower part of the application. The conclusion of this work is aimed to positive and negative features and comparison of mentioned control protocols.
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Realization and implemention of RDS message management software
Heralt, Jiří ; Zezula, Radek (referee) ; Koutný, Martin (advisor)
The purpose of this work was realization and implementation of two applications for the management of Radio Data System (RDS) messages. These applications will be subsequently used in the Czech Radio Ostrava to support two RDS services, namely the Traffic - Announcement Identification and Radiotext. Both applications are secured against unauthorized use by incompetent users through a password - protected access, access rights and encryption of passwords in initialization files. The text of this work is divided into three parts. The first describes the system RDS and services provided by it and implementation of RDS in the Czech Radio Ostrava. The second part deals with the realization of both applications and the last part describes the implementation itself. The work shows all applications windows. Work also includes all the flow charts. The list of all broken down by subroutines is given in the appendix.
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Image watermarking
Štágl, Luboš ; Zezula, Radek (referee) ; Číka, Petr (advisor)
This diploma thesis is concerned in static pictures Security problems. That means, additional informations (watermark) are embedded to the original picture in a specific way. This complex picture structure (watermark) should be unremoval by different attacks runing processes. The main goal of this diploma thesis is realize two separated methods digital data watermarking in MATLAB program. For reason of a quite large scale of different watermarking methods are chosen at this time only two of take were choosen. First of the methods is Watermark injection in the spatial domain and the second in the freuquency domain. Both methods are set up in a special way and finish goals of the process. Expected result are, that digital picture user doesn't know about the watermarking technique was aplied on this picture and the watermarking data are the most resistant as possible as can be. These attacks were simulated in Checkmark program.
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Comparison of success rate of multi-channel methods of speech signal separation
Přikryl, Petr ; Zezula, Radek (referee) ; Míča, Ivan (advisor)
The separation of independent sources from mixed observed data is a fundamental problem in many practical situations. A typical example is speech recordings made in an acoustic environment in the presence of background noise or other speakers. Problems of signal separation are explored by a group of methods called Blind Source Separation. Blind Source Separation (BSS) consists on estimating a set of N unknown sources from P observations resulting from the mixture of these sources and unknown background. Some existing solutions for instantaneous mixtures are reviewed and in Matlab implemented , i.e Independent Componnent Analysis (ICA) and Time-Frequency Analysis (TF). The acoustic signals recorded in real environment are not instantaneous, but convolutive mixtures. In this case, an ICA algorithm for separation of convolutive mixtures in frequency domain is introduced and in Matlab implemented. This diploma thesis examines the useability and comparisn of proposed separation algorithms.
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VST Plug-IN for audio signal watermarking
Henzl, David ; Schimmel, Jiří (referee) ; Zezula, Radek (advisor)
This thesis deal with digital signal proccessing methods, possibilities their processing and especially audio signal watermarking like possibility safeguard author's rights of audio content. In this thesis are foreshadoweds basic audio watermarking methods and possibilities of watermark detection. To idea generation about watermarking there is described audio watermarking method known as Echo Hiding. This method embed watermarks to audio content in time-domain while watermark detection is made in kepstral-domain by using Fast Fourier Transform and correlation function. Method is implemented like VST plug - in and along with ASIO drivers that minimize signal latency provides audio signal watermarking in real - time. Aim of the first volume of this thesis is introduction of VST technology, ASIO driver and creating VST plug – in‘s. Alternative volume of thesis deal with implementation watermarking methods in conjunction with VST technology.
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Using masking effects for audio data watermarking
Kabourek, Jiří ; Schimmel, Jiří (referee) ; Zezula, Radek (advisor)
In this work is presented technique for embedding digital watermark in digital audio signals. Digital watermark must be imperceptible and should be robust against attacks and other types of distortion. Algorithm is implemented for embedding digital watermark using technique spread-spectrum and psychoacoustic model ISO-MPEG I layer I. Robustness was tested for filtering signal, MP3 compression and resample method.
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Simulation and analysis of the block cipher mode with statistical self-synchronization
Kopčan, Marek ; Zezula, Radek (referee) ; Burda, Karel (advisor)
There is a enormous rise in importance of cryptography. In age of hi-technologies, where information are the most valuable asset, is need to protect this value. But we need to transport information between us and keep information confidental. In this case we use special modes of block cipher because of defect in communication canal. Not all modes are able to deal with this problem. For this purpose, there are special modes. This work deal with self-synchronization modes of block cipher. It is protection of tranfered information in communication canal against different types of defects. We will exam two self-synchronization modes - OCFB (Optimized Cipher FeedBack) and SCFB (Statistical Cipher FeedBack). Both have their advantages and disadvantages. The goal of this work is to provide analyse of both modes and to create simulation model. This model should help with further research of self-synchronization modes.
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