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Browser and User Fingerprinting for Practical Deployment
Vondráček, Tomáš ; Malinka, Kamil (referee) ; Polčák, Libor (advisor)
The aim of the diploma thesis is to map the information provided by web browsers, which can be used in practice to identify users on websites. The work focuses on obtaining and subsequent analysis of information about devices, browsers and side effects caused by web extensions that mask the identity of users. The acquisition of information is realized by a designed and implemented library in the TypeScript language, which was deployed on 4 commercial websites. The analysis of the obtained information is carried out after a month of operation of the library and focuses on the degree of information obtained, the speed of obtaining information and the stability of information. The dataset shows that up to 94 % of potentially different users have a unique combination of information. The main contribution of this work lies in the created library, design of new methods of obtaining information, optimization of existing methods and the determination of quality and poor quality information based on their level of information, speed of acquisition and stability over time.
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Analysis of interaction between cardiovascular signals using non-linear methods
Lokaj, Jiří ; Ronzhina, Marina (referee) ; Kolářová, Jana (advisor)
The short-term regulation of blood pressure is influenced by many influences, some being represented by cardiovascular signals and their changes. Because of the complexity of this system, the linear methods for its analysis are not sufficient. Non-linear methods for time series analysis have been devised quite a lot. In the course of this work, the analysis of the relations of several signals was evaluated as the most suitable conditional entropy and the resulting indexes of affinity and directionality. This method was applied to a set of heart-rate signals and systolic and diastolic pressure signals measured on eight adults and nine children. Relationships were analyzed but unfortunately after the statistical test was held the expected information links between the individual signals were not established. The indices were very small - in the hundredths of bits. Finally, optimization of the algorithm of the whole method has been performed and the newly modified function already shows significantly better results, for example strong information binding from the time-series of systolic pressure to a series of diastolic pressures.
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Quality assessment of retinal images
Tvarůžek, Marek ; Jiřík, Radovan (referee) ; Kolář, Radim (advisor)
This thesis deals with the properties of retinal images, which are taken with a digital fundus camera. The basic image processing operations are described and applied on biomedical images. Based on these operations, the algorithm for image quality assessment is designed and implemented in Matlab. The quality metrics quantify the focusing. The proposed methods are tested on two datasets and the results are presented and discussed.
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Generation of Cryptographic Key from Eye Biometric Features
Semerád, Lukáš ; Hájek, Josef (referee) ; Drahanský, Martin (advisor)
The main topic of the thesis is creation of formulas for the amount of information entropy in biometric characteristics of iris and retina. This field of science in biometrics named above is unstudied yet, so the thesis tries to initiate research in this direction. The thesis also discusses the historical context of security and identification fields according to biometric characteristics of a human being with an overlap for potential usage in biometrics of iris and retina. The Daugman’s algorithm for converting iris image into the binary code which can be used as a cryptographic key is discussed in detail. An application implementing this conversion is also a part of the thesis.
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Analysis of interaction between cardiovascular signals using non-linear methods
Lokaj, Jiří ; Ronzhina, Marina (referee) ; Svačinová, Jana (advisor)
The short-term regulation of blood pressure is influenced by many influences, some being represented by cardiovascular signals and their changes. Because of the complexity of this system, the linear methods for its analysis are not sufficient. Non-linear methods for time series analysis have been devised quite a lot. In the course of this work, the analysis of the relations of several signals was evaluated as the most suitable conditional entropy and the resulting indexes of affinity and directionality. This method was applied to a set of heart-rate signals and systolic and diastolic pressure signals measured on eight adults and sixteen children. Relationships were analyzed and after the statistical test was held some information links between the individual signals were not established.
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Entropic generator of random numbers
Kolář, Michal ; Číž, Radim (referee) ; Burda, Karel (advisor)
This paper is focused on generating random number via entropy generators. There are described sources of entropy on personal computer and described methods of detecting their entropy. There are also described basic operations used for construction and for concept solution this generator under NIST recommendation for personal computer and methods of their testing.
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A tool for assessing the quality of multiple sequence alignments
Pelikánová, Veronika ; Maděránková, Denisa (referee) ; Škutková, Helena (advisor)
This thesis is dealing with quality assessment of multiple sequence alignments. It contains literature review of public available tools of multiple sequence alignments. The main part of this thesis focuses on the program on quality assessment of multiple sequence alignments (created with the help of various tools, using different settings, etc.). The program has a graphical user interface created in Matlab and is enclosed together with a set of nucleotide and protein sequences compiled for program testing and aplication. Last but not least, the thesis contains the assessment of public available tools resulting from program outputs.
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Texture Analysis of Ophthalmologic Images
Kaňka, Jan ; Odstrčilík, Jan (referee) ; Jan, Jiří (advisor)
This thesis is concerned with creating of software for textural analysis of retinal images by statistic method called co-occurrence matrices as possible alternative method to detection of lesion of retina by the glaucoma diseases. The Glaucoma diseases without well-timed diagnostics and consequential treatment leads to blindness. The retinal images captured by fundus camera are common, easily processable and modern devices are able to make images of 10 Mpix resolution and bigger, what specifies outputs of analytic software. Method of co-occurrence analysis is simple and effective statistic. But computing demandingness, showing up with growing objective quality, comming up as disadvantage.
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Network Anomaly Detection
Bartoš, Václav ; Kořenek, Jan (referee) ; Žádník, Martin (advisor)
This work studies systems and methods for anomaly detection in computer networks. At first, basic categories of network security systems and number of methods used for anomaly detection are briefly described. The core of the work is an optimization of the method based on detection of changes in distributions of packet features originally proposed by Lakhina et al. This method is described in detail and two optimizations of it are proposed -- first is focused to speed and memory efficiency, second improves its detection capabilities. Next, a software created to test these optimizations is briefly described and results of experiments on real data with artificially generated and also real anomalies are presented.
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