|
|
Bird mortality at transparent barriers
Houdová, Monika ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Bird mortality at transparent barriers (noise barriers or common house windows) is undoubtedly very important environmental issue, because of the rapid development of human society and even more rapid growth of very dangerous places for birds. At this time there is no review article yet, that would synthesize each sub-study on the extent to which individuals can die on those obstacles, which factors are critical for the ability of obstacle avoiding, how much collision threaten the vitality of bird populations and if we can prevent such unintended damage. This bachelor thesis handle with these questions as a literary review. From the available information we can suggests that the most important factor is migration behavior of birds, individuals migrating through the night are much more at risk than those migrating during the day, mostly because of light pollution, which can confuse them. The most dangerous time of year in this direction is clearly autumn, and that also relates with migration. Population losses caused by collision to the transparent barriers can be up to 20 % of the total population per year. Thesis in addition to a summary of available information on the issue proposes and evaluates possible preventive aplications, which may further serve to effective conservation for birds among...
|
|
|
Collisional evolution of the Main Asteroid Belt over 4 billion years
Cibulková, Helena ; Brož, Miroslav (advisor) ; Ďurech, Josef (referee)
In this work, we constructed a new model for the collisional evolution of the Main Asteroid Belt. Our goals are to test the scaling law from the work of Benz & Asphaug (1999) and ascertain if it can be used for the whole belt. We want to find initial size-frequency distributions (SFDs) for the considered six parts of the belt, and to verify if the number of asteroid families created during the simulation matches the number of observed families as well. We used new observational data from the WISE satellite (Masiero et al., 2011) to construct the observed SFDs. We simulated mutual collisions of asteroids with a modified Boulder code (Morbidelli et al., 2009), in which the results of hydrodynamic (SPH) simulations from the work of Durda et al. (2007) are included. Because material characteris- tics can affect breakups, we created two models - for monolithic asteroids and for rubble-piles (Benavidez et al., 2012). The results for monolithic and rubble- -pile asteroids are comparable and in both cases the number of created families is, within uncertainties, consistent with the observations. A disagreement of the SFDs for a limited size range D 1 to 5 km a is a good motivation to conduct new SPH simulations with relatively small targets. 1
|
|
|
Properties of near-horizon geometry of spacetimes
Daněk, Jiří ; Žofka, Martin (advisor) ; Svítek, Otakar (referee)
Nowadays, the near-horizon regions of black holes have enjoyed great attention thanks to their role in the popular AdS/CFT correspondence and their specific geometry suitable for formulations of uniqueness theorems in higher dimensions. A strictly general-relativistic point of view reveals also many interesting phenomena taking place near black-hole horizons. Our aim was to investigate how horizon multiplicity affects near-horizon geometry, geodesical distance, radial motion of photons and massive, charged particles, and also the possibility of collision processes leading to unbound collision energies near the horizon. We chose the Reissner-Nordström-de Sitter metric, which, on the one hand, is simple thanks to being static and spherically symmetric but which, on the other hand, is rich enough to enable the existence of up to a doubly degenerate ultra-extreme horizon. After discussing the physical feasibility of the near-horizon limit, we applied it to single, double, and triple horizons, their near-horizon geometries, and local collision processes. We found continuous coordinate systems covering all types of horizons and analytic solutions for motion of radial photons and special or critical, massive, charged particles in their vicinity. We addressed particle collisions in the immediate vicinity of horizons...
|
|
|
Security and usability of standard has hfunctions, in particular MD-5, SHA-1 and SHA-2
Galaczová, Barbora ; Tůma, Jiří (advisor) ; Joščák, Daniel (referee)
Title: Security and usability of standard hash functions, in particular MD-5, SHA-1 and SHA-2 Author: Galaczová Barbora Department: Department of Algebra Supervisor: Doc. RNDr. Tůma Jiří, DrSc., Department of Algebra Consultant: Ing. Budiš Petr, Ph.D. Abstract: In the present work we try to digestedly describe standard hash functions, in particular MD-5, SHA-1 and SHA-2. We describe resume of existing attacks on these hash functions. We closely focused on MD-5 collision attacks, because the other hash function collision attacks result from these. Next we describe posibilities of practical usage of hash function collisions, in particular into the qualified certificates area and possible threats. At the end to the present work we describe new hash functions, which could replace current hash functions. This work also contains software to calculate MD-5 hash and search it`s collisions. The software is based on method invented by Czech cryptoanalytist Vlastimil Klíma. Keywords: hash function, collision, qualified certificate, security.
|
|
|
Game 128kB Using OpenGL
Kačur, Vladimír ; Kučiš, Michal (referee) ; Milet, Tomáš (advisor)
Bachelor thesis deal with creation of the game with limited memory space. It describes methods for reducing the size of the final application. Main part of the thesis describes methods for generating graphic content, as well as movement and interactions within it. It also deals with making of textures and terrain.
|
|
|
Retrospective Arcade Game
Trčka, Martin ; Jaroš, Jiří (referee) ; Pospíchal, Petr (advisor)
This bachelor's thesis describes the evolution of computer, which is inspired of historical game called Arkanoid. The first part of the thesis describes history of computer games and conputer graphics. Next section details the graphics libraries as DirectX and OpenGL.The second part of the thesis describes the plan of the game and collisional system. Then the thesis includes description of implementation, where are used object oriented design, library OpenGL and library SDL in C++. The end of thesis is devoted to testing of game.
|
|
|
Retrospective Space Game for Two Players
Kimer, Tomáš ; Kaštil, Jan (referee) ; Pospíchal, Petr (advisor)
This bachelor's thesis describes the development of a computer game inspired by one of the first computer games ever - Spacewar!. The first part describes computer games and associated history, current status, their genres and retrospective games. The second part deals with hardware-accelerated computer graphics, focused on its history and discusses the graphics libraries, especially OpenGL. Next part is devoted to design of the developed game, addressing the movement of objects, collisions between them, effects using particle systems, controls for two players on one computer and a basic graphics user interface. Next chapter covers implementation in C++ language using OpenGL and SDL libraries and object oriented design. The final section is devoted to testing the resulting application, including analysis of user ratings.
|
|
|
Application for Demonstration of Hash Algorithms SHA-1 and SHA-2
Siska, Josef ; Petrlík, Jiří (referee) ; Novotňák, Jiří (advisor)
In this thesis, the theory related to the hash algorithms SHA-1 and SHA-2 is presented, along with a description of possible implementation of an application that demonstrates how these algorithms work. The first part of this thesis describes the principles of construction of hash functions, their use and history of selected hash functions. The two following chapters present conventions and algorithms of the SHA-1 and SHA-2. The next chapter describes the general concepts related to the attacks on the hash functions and selected attacks are presented in more detail. The last two chapters outline the design and implementation of an application that was created as part of this work. In the end the evaluation of results of this thesis and proposals for its possible continuation are presented.
|
|
|
Physical Simulation in Graphics Scene
Javorka, Marián ; Herout, Adam (referee) ; Pečiva, Jan (advisor)
This master's thesis deals with physical simulation of cars. Program is implemented in C++ using OpenSceneGraph and Bullet libraries, which are shortly introduced. The application is implemented as simple racing game for one or two players. Using a simple menu, the user can select a car and the weather, which dramatically affects the handling characteristics of vehicles. Setting weather to random is one of the options leading to a dynamic weather changes during the game. The application takes into account collisions among cars and collisions with the terrain and bars on a racing circuit.
|
|
|
Anti-Collision System Based on GPS
Varga, Marek ; Drahanský, Martin (referee) ; Orság, Filip (advisor)
Aircraft industry is constantly facing the need to increase security not only in the case of large machines, but also in the small aircraft. Many systems were established in order to inform the pilot of the impending hazard, where appropriate, about the location of the other aircraft. The main objective is to establish a facility which uses global position system for determining the position and imparts coordinates using wireless networks for subsequent determination of collision. The functions of satellites and GPS receivers, sending wireless data and collision calculation and synchronization of individual modules is described in detail.
|
guest ::
