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Automatic Analysis of Heart Rate Variability Signals
Kubičková, Alena ; Halámek, Josef (referee) ; Lhotská, Lenka (referee) ; Kozumplík, Jiří (advisor)
This dissertation thesis is dedicated to the heart rate variability and methods of its evaluation. It mainly focuses on nonlinear methods and especially on the Poincaré plot. First it deals with the principle and nature of the heart rate variability, then the ways of its representation, linear and also nonlinear methods of its analysis and physiological and pathophysiological influence on heart rate variability changes. In particular, there is emphasis on the metabolic syndrome. In the next section of the thesis there are compared and evaluated different ways of representation of the heart rate variability and further are tested selected methods of heart rate variability analysis on unique data from patients with the metabolic syndrome and healthy subjects provided by the Institute of Scientific Instruments, Academy of Sciences of Czech Republic. In particular, they are used the Poincaré plot and its parameters SD1 and SD2, commonly used time domain and frequency domain parameters, parameters evaluating signal entropy and the Lyapunov exponent. SD1 and SD2 combining the advantages of time and frequency domain methods of heart rate variability analysis distinguish successfully between patients with the metabolic syndrome and healthy subjects.
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Random number generator
Križan, Viliam ; Burda, Karel (referee) ; Ležák, Petr (advisor)
This master thesis deals with a generation of random numbers and Fortuna generator implementation in Java language. In the first part the theoretical familiarization to the issues is introduced. Various entropy sources like mouse movement, keyboard typing, microphone and web camera noise are described and analysed. The analysis focuses on randomness, usability and volume of gathered data. Also the Fortuna random number generator is described from the theoretical view. Object analysis and implementation details are described in the last chapter of the document.
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Asymmetric-Key Cryptography in Embedded Systems
Záhorský, Matej ; Kula, Michal (referee) ; Nosko, Svetozár (advisor)
Účelom tejto práce je prieskum a implementácia existujúceho asymetrického kryptografického algoritmu v FPGA a vyhodnotenie jeho výkonu. Prvá kapitola sa zameriava na vstavané systémy a FPGA, pričom popisuje ich štruktúru a použitie. V druhej kapitole je porovnanie kryptografických algoritmov a ich vlastností, ktoré umožňujú ich použitie vo vstavaných systémoch. Fázy návrhu a implementácie v tomto projekte popisujú a implementujú riešenie, ktoré zahŕňa výber a integráciu podpisovacieho algorithmu v FPGA. Dodatočné optimalizácie na zvýšenie výkonu sú taktiež naimplementované vo forme hardvérovej akcelerácie, ktoré sú zároveň porovnané s pôvodným algoritmom v kapitole vyhodnotenia.
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Random number generators evaluation
Svoboda, Martin ; Sikora, Marek (referee) ; Zeman, Václav (advisor)
The topic of the thesis is random numbers and the problem of their testing. The thesis presents methods of generating random numbers and many statistical tests of randomness. Part of the work is a description of an application created for testing random numbers, which contains a set of 23 statistical tests of randomness and 5 integrated generators. In the last chapter, various types of generators and keys created by quantum key distribution are tested using the application.
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In the process
Volková, Markéta ; Velická, Erika (referee) ; Korbička, Pavel (advisor)
My bachelor's thesis is an object responding to the space that surrounds it. It points out the contradiction between organic and austere form. In my work, I materialize abstract experiences through metonymically selected building elements related to the places in which I have these experiences. As an extraction of elements appearing in the architecture of the Southern Mediterranean, a form of ornament appears in the work, which is understood by a figurative comparison to the experience of travelling on holiday. Another element, representing a figurative experience of returning "to reality", are the lux spheres. Their character is linked to the architecture of Central Europe. I explore the relationship between the different types of buildings, which I then freely develop. My perception of reality enhances the recognition of the new with the already known. I let the objects represent and capture these two opposing perceptions with implications and emphasis on their differences. In this way, I come to find in my work a similarity between geometric austerity, which signifies perfectionism, and the intuitive unfolding of ornament, which inserts the theme of organicity into the object. An important aspect of the thesis is processuality. I understand my work as a border between conceptual and intuitive process.
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Compressing Pseudorandom sequences
Vald, Denis ; Holub, Štěpán (advisor) ; Růžička, Pavel (referee)
Generators of pseudorandom sequences are widely used objects, not in the least place because of their application in stream ciphers. One of the ways to improve resistance to different types of attack is to use compression on the generated sequence in order to remove redundant information, that might lead to an attack against the generator. In this work we try to explore from a wider perspective the theoretical foundations for compressing pseudorandom sequences created thus far. Using this general view we will examine some known attacks against the PRN generators and look for a way to resist such attacks.
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Vágní informace na konečných abecedách a její monotónní charakteristiky
Kovářová, Lenka ; Beneš, Viktor (advisor) ; Kupsa, Michal (referee)
Title: Vague information on finite alphabets and its monotonous characteristics Author: Mgr. Lenka Kovářová Department: Department of Probability and Mathematical Statistics Supervisor: prof. RNDr. Viktor Beneš, DrSc. Abstract: The bachelor thesis is focused on information-theoretic source of messages with vague recognition from a final general alphabet. The aim of this work is to compile an overview of existing approaches to entropy and information. There were published several approaches how to convert to the fuzzy set theory the concept of entropy, which was originally introduced in physics, mathematically expressed as an additive-probability model and adjusted for Shannon probabilistic information source. Most of these approaches maintains the additive-probability model, while the emphasis in the theory of fuzzy sets is laid on the characteristics of minimum and maximum. Keywords: Entropy, Information, Fuzzy sets, Vague Entropy, Vague Information 1
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Generating random data from biometric samples
Sachová, Romana ; Říha, Zdeněk (advisor) ; Vondruška, Pavel (referee)
Title: Generating random data from biometric samples Author: Bc. Romana Sachová Department: Department of Algebra Supervisor: Ing. Mgr. Zdeněk Říha, Ph.D. Supervisor's e-mail address: zriha@fi.muni.cz Abstract: This thesis aims to achieve the generation of random data from the bio- metric samples. Studying the biometric characteristics, randomness and generation of random data suitable for cryptography as well the variability of fingerprint, iris, face and human voice. In the practical part has been tested the variability of 200 prints from the same finger, using three factors: 1) The coordinates of fingerprints cores. Due to the repeatability of coordinates the obtained entropy was low. 2) Fingerprint area approximation. It was able to verify the diversity of all areas. The maximum available entropy remains around 15 bits. 3) Ridge lines distortion. From the core to the top of the fingerprint has been taken boxes containing part of the ridge line. For all boxes was calculated the average phase angle of the gradient which represents the change of intensity in the box. Vector of phase angles describes the ridge line distortion. Maximum estimated entropy of this vectors was estimated at 71,586 bits. Keywords: biometry, randomness, entropy 1
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Signal complexity evaluation in the processing of functional magnetic resonance imaging
Vyhnánek, Jan ; Boldyš, Jiří (advisor) ; Dvořák, Jiří (referee)
Functional magnetic resonance imaging has been recently the most common tool for examining the neural activity in human and animals. The goal of a typical data-mining challenge is the localisation of brain areas activated during a cognitive task which is usually performed using a linear model or correlation methods. For this purpose several authors have proposed the use of methods evaluating signal complexity which could possibly overcome some of the shortcomings of the standards methods due to their independence on a priori knowledge of data characteristics. This work explains possibilities of using such methods including aspects of their configuration and it proposes an evaluation of performance of the methods applied on simulated data following expected biological characteristics. The results of the evaluation of performance showed little advantage of these methods over the standard ones in cases when the standard methods were possible to apply. However, some of the methods evaluating signal complexity were found useful for determining the regularity of signals which is a feature that cannot be assessed by the standard methods. Optimal parameters of the methods evaluating signal regularity were determined on simulated data and finally the methods were applied on the data examining emotional processing of...
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Testing exponentiality
Dvoranová, Romana ; Anděl, Jiří (advisor) ; Hušková, Marie (referee)
This bachelor thesis focuses on detailed review of a selection of tests for exponentiality and their comparison. This text presents classical methods for goodness-of-fit testing for exponentiality, as well as the most recent tests for exponentiality published in the last decades. Based on the characterisation of exponential distribution that is being used, the review includes $\chi^2$ goodness-of-fit tests, tests based on empirical distribution function using Kolmogorov-Smirnov and Cramér-von Misés test statistics, as well as tests based on integral transforms, entropy, mean residual life function, Gini index and others. In particular, this bachelor thesis focuses on tests for exponentiality based on entropy characterisation, e.g. using Shannon, Rényi or cumulative residual entropy. Finally, this thesis includes simulation study comparing power of several more recent tests for exponentiality that have been theoretically described. Powered by TCPDF (www.tcpdf.org)
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