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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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Two phase flow of water and air, flat jet above the plate, jet sloping 75° and 90°
Říha, Zdeněk
The report contains CFD results and description of the two phase flow water and air. Water comes into the computational domain through\nsimplified nozzle which creates water flat jet with spraying angle c. 40o. The flat jet falls on the wall surface where flows along the surface plate in all directions (x,y mainly). The aim of the work is to show how the falling water flows on the wall surface with help of advanced CFD model. Two cases had been solved there with various jets sloping to the surface plate. The first case contains results with configuration of the geometry for the jet sloping 75o and second case contains results with configuration of the geometry for the jet sloping 90o, see enclosures 1 and 2. Given calculation had been done as steady state calculations.
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Cryptovirology and Future of Malware
Prchal, Josef ; Říha, Zdeněk (referee) ; Cvrček, Daniel (advisor)
Malware is connected to information technology. They influence each other. The aim of this thesis is to describe various types of this software and give a brief account of its history and development. It also discusses main trends of this area and tries to foretell the future development.
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CDF model of mixture gas flow in the vacuum column 12T-70102, revamp tower
Říha, Zdeněk
The report contains description of fluid flow for case with revamp tower of the column 12T -70102. Vapor flow was mainly calculated in the above mentioned geometry. In last iteration the liquid droplet (diameter 0,3mm) were injected into the geometry through the nozzle 12, see enclosure in the report. Introductory section of the enclosuere contains pictures with geometry and boundary conditions description, See figure G1. Then, slice plan follows, see figure G2. Next pictures show distribution of pressure and velocity on given slices. Pictures at the end of the enclosure show path-lines distribution and droplets particle traces distribution in the solved geometry.
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CFD model of mixture gas flow in the vacuum column 12T-70102, existing state of internals
Říha, Zdeněk
The report contains description of fluid flow for case with existing state of the column 12T -70102. Vapor flow was mainly calculated in the above mentioned geometry. In last iteration the liquid droplet (diameter 0,3mm) were injected into the geometry through the nozzle 12, see enclosure in the report. Introductory section of the enclosuere contains pictures with geometry and boundary conditions description, See figure G1. Then, slice plan follows, see figure G2. Next pictures show distribution of pressure and velocity on given slices. Pictures at the end of the enclosure show path-lines distribution and droplets particle traces distribution in the solved geometry.
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CFD model of mixture gas flow in the vacuum column D-6501
Říha, Zdeněk
The report contains CFD results and description of the gas mixture flow in the vacuum column D-6501. Two rotationally opposite (swirl) input nozzles S1 and S2 (ID 0,835m) create main input of vapour into the vacuum column. There are two enhanced vapour horn (EVH) distributor, for given input nozzle (S1, S2) separately. Enhanced vapour horn makes redistribution of vapour leaded from above mentioned nozzles. There also is next input of vapor given by bottom striping section. The inner diameter of the column is 7,464m and solved domain has height c. 15m. Aim of the calculation is to show distribution of calculated variables (velocity, pressure, density, etc.) on given slices. Mainly, we would like to know if the distribution of velocity is sufficiently uniform at the input into the packing bed SECTION “B”.
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CFD model of mixture gas flow in the vacuum column D-6501, adjusted EVH and tray
Říha, Zdeněk
The report contains CFD results and description of the gas mixture flow in the vacuum column D-6501 with adjusted internals against last calculated case, see [1]. Two rotationally opposite (swirl) input nozzles S1 and S2 (ID 0,835m) create main input of vapour into the vacuum column. There are two enhanced vapour horn (EVH) distributor, for given input nozzle (S1, S2) separately. Enhanced vapour horn makes redistribution of vapour leaded from above mentioned nozzles. There also is next input of vapor given by bottom striping section. The inner diameter of the column is 7,464m and solved domain has height c. 15m. Aim of the calculation is to show distribution of calculated variables (velocity, pressure, density, etc.) on given slices. Mainly, we would like to know if the distribution of velocity is sufficiently uniform at the input into the packing bed SECTION “B”
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CFD model of multiphase flow in the abrasive water jet tool
Říha, Zdeněk
The possibility of using CFD fluid flow modeling in area of tools with abrasive water jet is described in the paper. The correct function of such tool is based on proper setting of multiphase flow of water, air and solid particles in the inner space of the tool. The multiphase fluid flow numerical simulation can provide information which show relation between the geometry and the flow field. Then, this stable CFD model of multiphase flow creates key to design of the tool able to work with higher efficiency.
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The flow of mixture vapors in the athmospheric column, comparison of new distributor and new tray
Říha, Zdeněk
The description of CFD analysis and the description of mixture gas flow in the atmospheric column are listed in the report. This article builds on previous work [1]. There were calculated two cases with original distributor and with GT-OPTIFLOW distributor, see [1]. This article adds next two cases. The case with adjusted GT-OPTIFLOW distributor (enclosure 1) and adjusted GT-OPTIFLOW distributor with newly designed the chimney tray and new layout of the packing bed (enclosure 2). The flow area of the newly designed chimney tray is smaller than for previous design (5,36m2 vs. 6,89m2). New layout of the packing bed has smaller flow area (28,27m2 vs. 29,35m2) and higher pressure drop (129 Pa vs. 80Pa) in comparison with last design of the packing bed also used in [1].
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The description of the fluid flow solution in a nozzle
Říha, Zdeněk
The description of the fluid flow solution in a nozzle with help of ANSYS-Fluent software is listed in this article. Self-oscillations of the main hydraulic parameters are consequence of the fluid flow in the nozzle. Input pressure of the water reaches level 10 MPa. This value evokes high speed fluid flow in the nozzle. Fluid is created with the mixture of water air and vapor. For such conditions, we need to take into account the effect of compressibility in the calculation. The aim of the calculations was to find a principal of the flow in the nozzle for given conditions, if we know, that in fact a pulsating fluid jet was at the output form the nozzle
Fulltext: content.csg -  PDF
Plný tet: UGN_0426588 - PDF
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