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Optimisation of Flow Rates in Lubrication Systems with Progressive Distributors by means of Genetic Algorithms
Vepřek, Jiří ; Pavlok, Bohuslav (referee) ; Bauer, František (referee) ; Habán, Vladimír (referee) ; Nevrlý, Josef (advisor)
This doctoral thesis presents the results of the development of two software programs for the design of progressive distributors and progressive lubrication systems. One of these programs implements a genetic algorithm and the other, which is used to design progressive lubrication systems, implements a parallel genetic algorithm of the island model. The program for the design of progressive distributors was implemented in Java using the NetBeans development environment and the other program was created in Matlab. The thesis further focuses on analytical and computational solutions of the flow of compressible greases seen as viscoplastic fluids. Equations for the numerical solution of the non-steady flow of compressible viscoplastic Bingham fluids were derived and solved by the Lax-Wendroff method in Matlab. As several constants had to be set in the equations, experiments were conducted with the ecological grease Plantogel 2S in the laboratory of the Kaplan Department of Hydraulic Machines, mainly to determine the sound velocity in this grease. The sound velocity was calculated based on the experimental results by applying Fourier transformation and the transition matrix method. In addition to this, the rheological measurements of greases were used. As seen from the results, the ecological greases are actually thixotropic viscoplastic fluids with a significant elastic element. Since a Newton fluid was assumed when calculating the sound velocity, the possibilities of using the transition matrix method for viscoplastic fluids were then considered. No analytical solution of the flow of viscoplastic fluids in a frequency spectrum has been published so far. Because it emerged that greases had a significant elastic stress factor, the problem of the non-steady flow of elastic-viscoplastic fluids was solved numerically between two infinite parallel plates by applying the finite difference method (FDM). The computation was done in Matlab. This doctoral thesis makes a contribution to solving problems related to the design of progressive distributors and progressive lubrication systems used to distribute compressible greases. Considering the complex approach to this field and the achieved results, the thesis also represents a significant contribution to design work.
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Optimalization of Constructional Teams Creation by Genetic Algorithms
Špaček, Jiří ; Zelinka, Ivan (referee) ; Šeda, Miloš (referee) ; Ošmera, Pavel (advisor)
The thesis pertains to optimisation of workgroups in companies. It is based on the work of Dr. Meredith Belbin from the Henley Management College, who is the author of the so-called Belbin’s team role theory. The theory defines fundamental roles within a team including specifications of the behavioural patterns while stipulating that in order to ensure proper functionality of a team, it is essential for all the roles to be represented in it. However, in practice it is necessary for specific people to comply not only with certain personal and psychological requirements but also professional expertise and other requirements. Nevertheless, by the means of adding these parameters to specific people, an enormous number of possible alternatives of the resulting team, which may not be evaluated (easily and in the real time) using traditional methods, proves to come to existence. Therefore, the so-called genetic algorithms inspired by natural development processes originally described by J. G. Mendel and Ch. Darwin were selected for evaluation purposes. The genetic algorithms feature good solutions to the task to be resolved in a very short time while the task does not have to be based on exact specifications and therefore several solutions might exist. A Java application was created within the scope of the thesis; its core comprises a genetic algorithm and it was used for the purpose of modelling of specific teams. The results provided by the application were subsequently verified by the means of creation of teams used for completion of new tasks and monitoring their activities in practice. Furthermore, the model verification of teams previously created solely on the basis of experience of executives was performed and the respective results were compared.
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Optimisation of experimental parameters for double-pulse LIBS
Roščák, Michal ; Novotný, Karel (referee) ; Kaiser, Jozef (advisor)
Diploma thesis presents the description of laser induced breakdown spectroscopy (LIBS) analytical method. The possibility to decrease LIBS detection limits using double pulse LIBS (DP-LIBS) is also detailed. Properties of laser induced plasma (LIP) are discussed. Thesis describes the optimisation process of DP-LIBS setup at laser spectroscopy laboratory of Faculty of Mechanical Engineering, Brno University of Technology. Optimisation was carried out for detection of chrome in steel with respect to detection limits and ablation crater size. Optimised DP-LIBS setup is appropriate for mapping chrome distribution in steel samples.
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Measuring centre process optimization
Benda, Ondřej ; Hanžlík, Pavel (referee) ; Fiala, Alois (advisor)
This master's thesis is engaged in optimisation processes of PUQ (as for Purchasing Quality) department, Robert Bosch České Budějovice. This department is responsible for input control of parts for manufacture as well as check of new parts including their documentation and documentation updates. By optimisation we understand selection of the best variant from group of possibilities.
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Design of Trading Strategy for Managing of Free Financial Capital of the Company
Jiřík, Leoš ; Dufek, Ladislav (referee) ; Budík, Jan (advisor)
This thesis deals with the design of trading strategies suitable for trading the currency markets. Design is carried out by means of artificial intelligence, the proposed strategies are then optimized and evaluated using previously unknown data. The partial objective is to implant this process in an existing company with the aim to broaden its capital. The consequences arising from this trading approach to the development of the company’s capital are subsequently studied from several perspectives – a schedule is outlined for the introduction into the company that has been chosen earlier, then the expected costs and revenues are compared in the scope of medium-term and in the last part the above procedure is analyzed so its risks can be pointed out and therefore procedures for their restrictions can be proposed as well.
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Evaluation and Improvement of the Internet Marketing Strategy of an Existing E-commerce Business
Marcely, Peter ; Goga, Martin (referee) ; Chlebovský, Vít (advisor)
Úspech spoločnosti venujúcej sa elektronickému predaju je hlboko prepojený s nástrojmi internetového marketingu. Široká škála týchto produktov je zložitá na zoptimalizovanie a nastavenie celého procesu tak, aby pracoval efektívne. Efektívnosť v tomto prípade značí pozitívny návrat investície, ktorú do nástrojov vkladáme. Orientácia na zákazníka je dôležitý faktor pre všetky e-business spoločnosti. Zákazníci vyžadujú veľké množstvo doručovacích a platobných možností ako aj rýchlu zákaznícku podporu cez chat alebo telefón. Táto diplomová práca ukazuje všetky tieto aspekty a zároveň demonštruje praktické možnosti použitia internetového marketingu ako aj vylepšenú zákaznícku podporu.
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Image analysis for correction of electron microscopes
Smital, Petr ; Schwarz, Daniel (referee) ; Kolář, Radim (advisor)
This thesis describes the physical nature of corrections of an electron microscope and mathematical methods of image processing required for their complete automation. The corrections include different types of focusing, astigmatism correction, electron beam centring, and image stabilisation. The mathematical methods described in this thesis include various methods of measuring focus and astigmatism, with and without using the Fourier transform, edge detection, histogram operations, and image registration, i.e. detection of spatial transformations in images. This thesis includes detailed descriptions of the mathematical methods, their evaluation using an “offline” application, descriptions of the algorithms of their implementation into an actual electron microscope and results of their testing on the actual electron microscope, in the form of a video footage grabbed from its control computer’s screen.
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Automotive antenna for mobile communications
Porč, Jan ; Láčík, Jaroslav (referee) ; Pokorný, Michal (advisor)
This thesis deals with design of flush–mounted planar disc antenna suitable for use in vehicles. For each of the bands GSM900 and GSM1800, which are used in Czech republic, an independent antenna has been created. As a simulator of the electromagnetic field the program IE3D has been used. For the improvement of theoretical results an optimisation in the program MATLAB has been developed. As the optimisation method the genetic algorithms have been selected.
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