National Repository of Grey Literature 18 records found  1 - 10next  jump to record: Search took 0.02 seconds. 
Modern coding of speech signals using overcomplete models
Zapletal, Ondřej ; Průša, Zdeněk (referee) ; Rajmic, Pavel (advisor)
The theoretical contents of this thesis are studies of overcomplete models. Those are the models of signals, on which is set for their parametrization more variables, than it's necessary and consequently there's computed so-called sparse solution via iteration algorithms. A goal of this analysis is a selection just of the considerable (sparse) parameters. The theory is based on a linear algebra, vector spaces, bases and so-called frames. The task of the individual project of this thesis is a description and simulation of two speech coders: a classical coder based on linear predictive speech coding and a coder, that's making use of overcomplete stochastic ARMA processes models. A part of their realization is to simulate their decoders and a analyze their reconstruction quality. For their realization there is used MATLAB and an overcomplete models' library (toolbox frames).
Power side channel
Zapletal, Ondřej ; Mácha, Tomáš (referee) ; Martinásek, Zdeněk (advisor)
This thesis deals with side-channel cryptoanalysis. It is focused on power side-channel attack on cryptographic device. The microcontroller PIC is used as the cryptographic device. This microcontroller performs encryption through the symmetrical algorithm AES. For the purpose of simple and differential power analysis, we designed and constructed an experimental printed circuit board. The power consumption of the microcontroller PIC working with instruction AddRoundKey and SubBytes was scanned by a Tektronix CT-6 current probe. Data obtained by measuring were processed on the computer with relevant software and provided important information about the encryption key that was used.
LPC Speech Coding
Zapletal, Ondřej ; Kyselý, František (referee) ; Rajmic, Pavel (advisor)
The contents of the thesis "LPC speech coding" are studies of this method of a parametric source coding, explanation of mathematical procedures that are used in it (linear prediction, autocorrelation, Levinson-Durbin algorithm, transfer to a form suitable for transmission, Chebyshev root searching polynomial method) and acquaintance with the signification and application of that method in real speech encoders. The task of the original project of this thesis is a description and simulation of a simple speech encoder based on LPC, which transforms a real speech signal into a bit flow, which contains all of the significant parameters for its backward reconstruction (LSF coefficients, pitch period, excitation level, voice detection - AMDF method). One part of this thesis is a discussion about currently used speech encoders.
Comparison of accuracy achieved by traditional models and ensemble methods
Zapletal, Ondřej ; Klusáček, Jan (referee) ; Honzík, Petr (advisor)
This thesis deals with empirical comparison of traditional and meta-learning models in classification tasks. Accuracy of 12 RapidMiner models was statistically compared on 20 data sets. Second part of this thesis consists of description of self-programed application in programing language C#, which implements 6 different models. Four of those are compared with equivalent models of program RapidMiner.
Wearable Antennas Operating in the ISM Band
Zapletal, Ondřej ; Hebelka,, Vladimír (referee) ; Vašina, Petr (advisor)
Presented thesis is oriented on wearable antennas. The main aim of this thesis is to introduce the basic properties, measurement of textile’s electric properties and several manufacturing methods. The antenna design for the ISM 5.8 GHz bandwidth is also included and further observed by numerical model in CST Microwave Studio. The impact of flexibility and the influence of human tissue are evaluated in the case of designed equipment. According to the optimized design was made several samples by various technologies and samples were measured. Achieved results are further compared to equivalent results listed in actual available references.
Image Recognition by Convolutional Neural Networks - Basic Concepts
Zapletal, Ondřej ; Jirsík, Václav (referee) ; Horák, Karel (advisor)
This thesis is studying basic concepts of Convolutional Neural Networks. Influence of structural elements on ability of the network to train is investigated. Result of this thesis is comparisons of designed model of Convolutional Neural Network with results from ILSVRC competition.
Classifiers of power patterns
Zapletal, Ondřej ; Člupek, Vlastimil (referee) ; Martinásek, Zdeněk (advisor)
Over the last several years side-channel analysis has emerged as a major threat to securing sensitive information in cryptographic devices. Several side-channels have been discovered and used to break implementations of all major cryptographic algorithms (AES, DES, RSA). This thesis is focused on power analysis attacks. A variety of power analysis methods has been developed to perform these attacks. These methods include simple power analysis (SPA), differential power analysis (DPA), template attacks, etc. This work provides comprehensive survey of mentioned methods and also investigates the application of a machine learning techniques in power analysis. The considered learning techniques are neural networks and support vector machines. The final part of this thesis is dedicated to implemenation of the attack against protected software AES implementation which is used in the DPA Contest.
Analog Guitar Multieffect
Zapletal, Ondřej ; Petržela, Jiří (referee) ; Staněk, Miroslav (advisor)
Presented thesis is focused on guitar effects used for sound modification produced by an electric guitar. The main aim of this thesis is an introduction into guitar effects topic and the design of selected types chosen as follows: overdrive, noise gate and delay. Final multieffect is created by these mentioned components. Another part of presented thesis is the design of source feeding the whole final multieffect. Furthermore, the design of chosen components is presented in this thesis as well as the including of control simulations and PCBs.
Image Recognition by Convolutional Neural Networks - Basic Concepts
Zapletal, Ondřej ; Jirsík, Václav (referee) ; Horák, Karel (advisor)
This thesis is studying basic concepts of Convolutional Neural Networks. Influence of structural elements on ability of the network to train is investigated. Result of this thesis is comparisons of designed model of Convolutional Neural Network with results from ILSVRC competition.
Comparison of accuracy achieved by traditional models and ensemble methods
Zapletal, Ondřej ; Klusáček, Jan (referee) ; Honzík, Petr (advisor)
This thesis deals with empirical comparison of traditional and meta-learning models in classification tasks. Accuracy of 12 RapidMiner models was statistically compared on 20 data sets. Second part of this thesis consists of description of self-programed application in programing language C#, which implements 6 different models. Four of those are compared with equivalent models of program RapidMiner.

National Repository of Grey Literature : 18 records found   1 - 10next  jump to record:
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1 Zapletal, Otto
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