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Application of metallic materials for selective growth
Němeček, Tomáš ; Rezek, Bohuslav (referee) ; Čechal, Jan (advisor)
The Si(100) surface and Ga surface phases up to 1 ML on their oxidation have been studied by XPS and LEED. The selective growth of Ga on the SiO2/Si structures fabricated by EBL has been analyzed using SEM and AFM methods. It was proved that Ga clusters grow in structures beside the oxide. The structure of alumina on Ni3Al(111) and NiAl(110) substrates was fully determined by combining the results of STM measurements and DFT simulations. It was determined the alumina/NiAl(110) does not form a suitable template for ordered Fe and Co clusters growth. However, the next research confirmed the alumina/Ni3Al(111) forms template appropriate to clusters growth purpose.
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Detection of poorly differentiated cardiac arrhythmias
Kantor, Marek ; Ronzhina, Marina (referee) ; Novotná, Petra (advisor)
This thesis focusses on the detection methods of atrial fibrilation, atrial flutter and sinus rhythm from ECG. Thesis also concentrate on the description of this arrhythmias and the learning algorithms used. In this thesis are implemented several classification approaches. For extraction of features is used convolution neural network and classification artifitial neural network. Selected 1D CNN method achived classification accuracy global F1 - score is 91 %. Moreover, the proposed CNN optimized with GA appears to be fast shallow network with better accuracy than the deep network. Created model are used for classification other type of arrhythmias too.
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Nonlinear Control of Complex Systems by Utilization of Evolutionary Approaches
Minář, Petr ; Ošmera, Pavel (referee) ; Oplatková,, Zuzana Komínková (referee) ; Matoušek, Radomil (advisor)
Control theory of complex systems by utilization of artificial intelligent algorithms is relatively new science field and it can be used in many areas of technical practise. Best known algorithms to solved similar tasks are genetic algorithm, differential evolution, HC12 Nelder-Mead method, fuzzy logic and grammatical evolution. Complex solution is presented at selected examples from mathematical nonlinear systems to examples of anthems design and stabilization of deterministic chaos. The goal of this thesis is present examples of implementation and utilization of artificial algorithms by multi-objective optimization. To achieve optimal results is used designed software solution by multi-platform application, which used Matlab and Java interfaces. The software solution integrate every algorithms of this thesis to complex solution and it extends possible application of those approaches to real systems and practical world.
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Deposition of Ga nanostructures on graphene membranes
Severa, Jiří ; Mikulík, Petr (referee) ; Mach, Jindřich (advisor)
This diploma thesis deals with the preparation of the graphene membranes for depo-sition of gallium atoms by the molecular beam epitaxy. In the first part properties ofgraphene and methods of its production are described. Second part focuses on the gra-phene membranes, their specific properties, applications and methods of production. Thirdpart describes growth theory of the thin films. Practical part is focused on preparationof graphene membranes, which consists of covering the holes in the silicon substrate bygraphene layer. For that mechanical exfoliated and chemical vapor deposited graphenewere used. Subsequently, gallium atoms were deposited on these membranes by molecularbeam epitaxy and in situ observed by scanning electron microscopy.
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Traveling Salesman Problem
Šůstek, Martin ; Snášelová, Petra (referee) ; Zbořil, František (advisor)
This thesis is focused on modification of known principles ACO and GA to increase their performance. Thesis includes two new principles to solve TSP. One of them can be used as an initial population generator. The appendix contains the implementation of the application in Java. The description of this application is also part of the thesis. One part is devoted to optimization in order to make methods more efficient and produce shorter paths. In the end of the thesis are described experiments and their results with different number of places from 101 up to 3891.
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Assistant systems in car and aircraft control
Novotný, Timotej ; Horpatzká, Michaela (referee) ; Zikmund, Pavel (advisor)
The bachelor thesis deals with assistance systems in cars and aircraft. The aviation sector is focused on GA aircraft. This thesis describes assistance systems used in cars and aircraft, their contribution to traffic safety and limitations of these systems. The comparison of assisting systems in the automotive and aviation industries shows the difference in the speed of development in individual areas, which is caused mainly due to strict requirements for safety and reliability of aviation systems. Furthermore, we can see the difference in implementation of systems monitoring the condition of a driver/pilot. Although the work of a pilot is more demanding than the work of a driver, today’s aircraft do not have a system for monitoring the condition of a pilot or an emergency landing system. Part of the thesis concerning future assistance systems in aviation is devoted to the system monitoring the pilot’s condition and the automatic landing system. Both systems are still under development. However, experiments have shown that these systems could be implemented in future aircraft and increase aviation safety. The last part of the thesis mentions the future of assistance systems, which create a path to autonomous vehicles.
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Thermal Desorption Spectroscopy (TDS) and its Application for Research of Surface Processes
Potoček, Michal ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
ermal desorption spectroscopy (TDS) is a common method for surface analysis of adsorbed molecules. In chapter 1 the work deals with the theoretical background of this method and shows the principles of a desorption process influenced by subsurface diffusion. Chapter 2 first shows application of TDS for detection of surface molecules and determination of binding energy.Experiments were mainly focused on ditermination of surface adsorbents and impurities on Si wafers. The second part of chapter 2 describes desorption of atoms of a Ga layer on Si surface and their subsurface diffusion. A Ga diffusion process was also observed by with secondary ion mass spectrometry (SIMS) and numerically simulated.
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Solution of Continuous Systems by Evolutionary Computational Techniques
Lang, Stanislav ; Šeda, Miloš (referee) ; Olehla, Miroslav (referee) ; Matoušek, Radomil (advisor)
The thesis deals the issue of solution of continuous systems by evolutionary computational techniques. Evolutionary computing techniques fall into the field of softcomputing, an advanced metaheuristics optimization that is becoming more and more a method of solving complicated optimization problems with the gradual increase in computing performance of computers. The solution of continuous systems, or the synthesis of continuous control circuits, is one of the areas where these advanced algorithms find their application. When dealing with continuous systems we will focus on regulatory issues. Evolutionary computing can then become a tool not only for optimization of controller parameters but also to design its structure. Various algorithms (genetic algorithm, differential evolution, etc.) can be used to optimize the parameters of the controller, for the design of the controller structurewe usually encounter so called grammatical evolution. However, the use of grammatical evolution is not necessary if appropriate coding is used, as suggested in the presented thesis. The thesis presents a method of designing the structure and parameters of a general linear controller using the genetic algorithm. A general linear regulator is known also as so called polynomial controller, if we encounter the polynomial theory of control. The method of encoding the description of the general linear controller into the genetic chain is crucial, it determines a set of algorithms that are usable for optimization and influence the efficiency of the calculations. Described coding, effective EVT implementation, including multi-criteria optimization, is a key benefit of this work.
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Evolutionary Design of Artificial Neural Network
Jílek, Tomáš ; Šperka, Svatopluk (referee) ; Pospíchal, Petr (advisor)
Focus of this bachelor thesis is on Neural networks, Genetic algorithms and Evolutionary Design. First part of thesis describes Neural networks, their history, training and ways of use and Genetic algorithms, their components, operators and practical application. Next part is devoted to prediction of time series, specifically prediction with use of Neural networks. This is followed by practical part of work, implementation of experiments with Evolutionary design of Neural networks for prediction in which currency exchange rates of several countries are used as a predicted time series. Results and discussion about further development of thesis are described in last chapter.
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The deposition of Ga and GaN nanostructures on silicon and graphene substrate
Novák, Jakub ; Jarý, Vítězslav (referee) ; Mach, Jindřich (advisor)
The thesis is focused on the study of properties of GaN nanocrystals and Ga structures on the surface of silicon and graphene substrate. In the theoretical part of this thesis, the basic properties of Ga/GaN and graphene are described, as well as their applications or connection of both structures together in different devices. The ability of metal nanoparticles to enhance not only photoluminescence, due to the interaction of the material with surface plasmons, is also shown in several examples. The experimental part of the work first deals with the production and characterization of graphene sheets prepared by Chemical Vapor Deposition. Ga/GaN growth on both types of substrates was performed in a UHV chamber using an effusion cell for Ga deposition and an atomic ion source for nitridation. Prepared structures were characterized using various methods (XPS, SEM, AFM, Raman spectroscopy or photoluminescence). In the last step, GaN nanocrystals were coated with Ga islands to study the photoluminescence enhancement.
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