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Study of thin transparent films properties
Schmiedová, Veronika ; Veselý, Michal (referee) ; Zmeškal, Oldřich (advisor)
The main aim of this bachelor´s thesis is a study of thin transparent layers of organic materials (PPV, P3HT, TiO2, DPP). The theoretical part describe the methods of quality examinations of their surface, mostly the use of optical and interference microscopy. For elaboration of data was used the image analysis via HarFA program. Thickness of layer and the index of refraction was provided by interference microscope. From the interference images was identified the amplitude of groove for various values of treshold, but mainly the interface inhomogenity of groove, which proofs the surface inhomogenity of samples. For the images taken by the optical microscope were allocated the average errors (but also errors of superior sorts) defining the surface inhomogenities of samples. The conlusion of this study compare the results of both methods.
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Entropy for heart rate variability analysis
Zemánek, Ladislav ; Čmiel, Vratislav (referee) ; Janoušek, Oto (advisor)
The analysis of HRV is an advanced and noninvasive method which is used to investigate the involuntary nervous system. It is also one of the important parameters of its proper function. Heart rate variability can also be analyzed by entropy, which studies the discrepancy of the RR intervals of the HRV signal and thus can be used to diagnose cardiac diseases
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Classification of high frequency oscillations in intracranial EEG
Kozlovská, Magda ; Vítek, Martin (referee) ; Ronzhina, Marina (advisor)
This Master’s thesis deals with investigation of high-frequency oscillations in intracranial electroencephalography in patients with pharmacoresistant epilepsy. It describes individual types of oscillations with respect to their frequency definition, examines their physiological differences and occurrence. In addition to conventional high-frequency oscillations (up to about 600 Hz), it also focuses on oscillations with a frequency component above 1kHz. According to recent studies, these oscillations could have higherspecificity for the determination of pathological tissue in the epileptic brain. The data for this work was obtained by manual labeling and categorization of approximately 1500 sections of the stereoencephalographic record signals of patients undergoing surgical removal of the epileptic foci and subsequently monitored for success in the operation. Differences between individual groups of oscillations and resected or unresected tissues are investigated in this work by methods using calculations of entropy signals or cross frequency coupling. The most significant results were achieved for the classification group (FR + vFR) vs. uFR, methods frequency-amplitude coupling and sample entropy 1. When categorizing according to information about channel resection, the Shannon entropy is the most successful classification parameter.
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Software for entropy resource evaluation
Šelinga, Martin ; Zeman, Václav (referee) ; Burda, Karel (advisor)
This thesis is focused on exploring the sources of entropy. It includes a description of random number generators and tests used to evaluate entropy quality. Random number generator for Windows and Linux OS was created together with software for entropy evaluation. Subsequently, measurement of entropy was performed on physical workstations and Cloud environments.
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Analysis of Entropy Levels in the Entropy Pool of Random Number Generator
Krempa, Peter ; Hanáček, Petr (referee) ; Barabas, Maroš (advisor)
V informatice je pojem entropie obvykle znám jako nahodný proud dat. Tato práce krátce shrnuje metody generovaní nahodných dat a popisuje generátor náhodnych čísel, jež je obsažen v jádře operačního systému Linux. Dále se práce zabývá určením bitové rychlosti generování nahodných dat tímto generátorem ve virtualizovaném prosředí, které poskytují různé hypervizory. Práce popíše problémy nízkého výkonu generátory nahodných dat ve virtualním prostředí a navrhne postup pro jejich řešení. Poté je nastíňena implementace navržených postupů, které je podrobena testům a její vysledky jsou porovnány s původním systémem. Systém pro distribuci entropie může dále vylepšit množství entropie v sytémovém jádře o několik řádu, pokud je připojen k vykonému generátoru nahodných dat.
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Entity
Jindra, Jakub ; Turek, Filip (referee) ; Hájek, Václav (advisor)
Informace může vytvářet určité entropické krajiny. Entropická krajina je složená ze zdrojů informace. Zdroj může být informačně přínosný nebo úplně zbytečný. Dobrý zdroj vytváří nízkou entropii, vysoký náboj, a špatný zdroj entropii vysokou s nízkým informačním nábojem. Touto optikou pak můžeme vidět fiktivní krajinu, která se kolem nás nalézá. Entita je její vizualizací, vytváří útesy, tam kde byly roviny, hory zkoncentrované informace a měsíční údolí s nulovou hodnotou.
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Lossless Video Compression
Kafka, Jan ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis is about the lossless video compression using 3D prediction. At first is introduced the necessary theory about image data modification. This part serves to define important terms, which are needed to start the creative work itself. Then several variants of codec's structure proposals follow, as well as the choice of methods and description of expected characteristics. Here we can get the first idea how the codec works. Then there is a description of some implementation's details, which could give a detailed insight into the codec's inner architecture. In the last part of the work, the implemented codec is tested and its characteristics are compared to another lossless codecs. The result is that the own codec, using the 3D prediction, can defeat all other tested codecs with its compression ratio.
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Lossless Image Compression
Němec, Jaroslav ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis deals with lossless image compression. You can nd all the process of assembling lossless image coder/decoder. There are described many predictors, color models and two entropy coders in this thesis. The results of thesis are compared and disscused with current lossless image format PNG at the end of thesis.
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