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Simulation of two-dimensional flow past obstacles using lattice-gas cellular automata
Tomášik, Miroslav ; Scholtz, Martin (advisor) ; Pavelka, Michal (referee)
Cellular automata constitutes a unique approach to the modeling of complex systems. The major phase of their development in continuum mechanics came in the late 80s, but the closer inspection of their macroscopic limit revealed that it does not accurately correspond to hydrodynamic equations. Besides the Lattice-Boltzmann model, various other approaches to improve LGCA have emerged. The main focus of our research is on the Pair-interaction cellular automaton. In this thesis, we propose the non-deterministic variant of this automaton, and we compare it with its predecessor on the simulations of the "exploding cube", Taylor- Green vortex and fully developed turbulence. The results for the non-deterministic automaton seem quiet reasonable, but derivation of the hydrodynamic equations is necessary to conclude in what extent it solves the problem with anisotropic viscosity.
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Spatial modeling of brain tissue
John, Pavel ; Neruda, Roman (advisor) ; Brom, Cyril (referee)
Neural connections in the human brain are known to be modified by experiences. Yet, little is known about the mechanism of the modification and its implications on the brain function. The aim of this thesis is to investigate what impact the spatial properties of brain tissue can have on learning and memory. In particular, we focus on the dendritic plasticity. We present a model where the tissue is represented by a two-dimensional grid and its structure is characterized by various connections between the grid cells. We provide a formal definition of the model and we prove it to be computational as strong as the Turing machine. An adaptation algorithm proposed enables the model to reflect the environmental feedback, while evolutionary algorithms are employed to search for a satisfactory architecture of the model. Implementation is provided and several experiments are driven to demonstrate the key properties of the model. Powered by TCPDF (www.tcpdf.org)
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Simulace dvojrozměrného toku kolem překážek za použití "lattice-gas" celulárních automatů
Tomášik, Miroslav ; Scholtz, Martin (advisor) ; Pavelka, Michal (referee)
Cellular automata constitues original computational methods, that found its application in many disciplines. The special class of cellular automata, so called lattice gas automata were succesfull in dealing with many challenges in hydrodynamic simulations, and they bootstrap one of the most perspective CFD methods, the Lattice Boltzmann models. In the theoretical part, we follow the evolution of the lattice gas automata, explore the theory behind them, and from their microdynamics, we derive the macroscopic equations. In the practical part, we implemented two distincet types of LGCA, the pair-interaction automata and FCHC. We applied them on the flow around obstacles of various shapes. The scientifically most relevant part concerns statistical properties of the turbulent flow simmulated by LGCA, but requires further research to conclude it. Powered by TCPDF (www.tcpdf.org)
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Using Cellular Automata for Data Encryption
Dvořák, Martin ; Trunda, Otakar (advisor) ; Mráz, František (referee)
Cellular automata are discrete systems with very simple rules but very diverse behaviour. Some cellular automata can generate high-quality pseudorandom bit sequences. This leads us to the question of whether cellular automata could be used in cryptography, as a replacement for stream ciphers for instance. We will create and compare various methods for generating long one-time-pads from short keys, where our methods will utilize cellular automata. Besides direct design of cryptographical algorithms, we will also create an evolutionary algorithm, which will try to connect our building blocks in the best possible way. The outcome of our work will be a Windows desktop application for file encryption. Powered by TCPDF (www.tcpdf.org)
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Tool for Designing Procedural Textures
Číž, Miloslav ; Polok, Lukáš (referee) ; Milet, Tomáš (advisor)
This thesis deals with implementation of a program library for designing and generating two-dimensional procedural textures and its GUI supportive tool. Attention was paid to common methods as well as to other computer graphics areas with effort for modifying the algorithms in order to achieve unique results. An effective way of texture representation and its concrete implementation is also presented.
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An Implementation of CellMatrix in FPGA
Martinák, Jan ; Bidlo, Michal (referee) ; Sekanina, Lukáš (advisor)
Reconfigurable hardware architecture represents a modern trend in development of the new curcuits. Rising demands on such architecture lead in efforts to create curcuit, that is able to reconfigure itself in parallel and locally. One of such technologies is the Cell Matrix which is based on principles of cellular automata. The purpose of this thesis is to inform the reader about Cell Matrix architecture and to show its advantages, functions and potentialities by implementation in FPGA on FITkit development kit.
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Pseudorandom Number Generation in FPGA
Korček, Pavol ; Vašíček, Zdeněk (referee) ; Sekanina, Lukáš (advisor)
This bachelor thesis analyzes various implementations of pseudorandom number generators. In particular, two most-widely used mechanisms in generating the pseudorandom numbers in digital systems based on linear feedback shift register (LFSR) and cellular automata (CA) are described. Two models which are also widely used in practice were chosen from each group and implemented in C language. Additionally, another interesting combinatorial scheme of LFSR which is also sometimes used was implemented. Evaluation of the generators using Diehard set of statistical test was performed as well. Another part of this work dealt with implementing the chosen generators in a hardware description language. The choice was made for VHDL and several models, including the serial and parallel type of LFSR, were described in this language. Finally, a serial type of LFSR was implemented on the educational platform FITKit. The demands for area consumption of implemented generators were also investigated.
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Self-Replication in Cellular Automata
Mikeš, Martin ; Bidlo, Michal (referee) ; Žaloudek, Luděk (advisor)
This thesis introduces cellular automata as an environment suitable for simulating complex and massively parallel systems, built from a large number of simple cooperating units. The thesis explores self-replication and self-replicating loops - structures operating within the cellular space, particularly those capable of carrying out useful tasks. The thesis provides a description of implementation of three such loops, executing following tasks: coloring of the space within a loop, construction of letters "MM" and binary addition. A practical usability is discussed at the end.
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Traffic Modelling Based on Cellular Automata
Hodaňová, Andrea ; Martinek, David (referee) ; Peringer, Petr (advisor)
Among many other fields of science, cellular automata play an important role also in the microsimulations of traffic. In this thesis, we analyze the characteristics of a wide range of cellular automata traffic models from the most simple deterministic ones to complex stochastic automata derived from the pivotal Nagel-Schreckenberg model, which is thoroughly described. As a result of this analysis, a generally usable traffic simulator is designed and implemented in the Java programming language. Its graphical user interface can visualise the state of a road CA to display the key features of the implemented traffic models to the user.
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Cellular Automata Simulation Library
Bocko, Dávid ; Křivánek, Jan (referee) ; Korček, Pavol (advisor)
This work describes concept and description of library for the cellular automata (CA) simulator. In the introduction is described brief history, types of CA and formal definition of CA. In the library implementation section is described the design of object-oriented model (classes, methods) and usage. Library of CA is created with regard to reusability, which allows to simply define any type of CA simulator. The Library was created in purpose to fill user's needs, because of lack of general CA simulator.
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