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Dispraise Diversification in Business Firm
Horák, Jiří ; Moráček, Miroslav (referee) ; Kocmanová, Alena (advisor)
This master´s thesis specifies theoretical and formal procedures used while controlling and limiting risks in a company´s business activities. It covers analysis of external and internal risk factors which affect the analyzed company and analysis of the methods of limiting the mentioned risks. Consecutive suggestions and recommendations result from the performed analyses.
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Periodic structure design for directivity enhancement of dielectric resonator antennas
Slavíček, Radek ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
The thesis deals with linearly polarized dielectric rectangular resonator antenna (DRA) operating in the basic mode TEy11 and higher order mode TEy131 at f0 = 10GHz surrounded by an electromagnetic band gap structure (EBG). The dielectric resonator antennas, the EBG structure were designed and a method of integration of both components was developed. The simulated results show a significant improvement of the radiation pattern in the E-plane radiation pattern (narrower main beam, lower level of side lobes, higher directivity) in comparison to a conventional DRA. This was verified by the TEy11 measurement.
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Heating in lossy waveguide
Tichý, Jakub ; Horák, Jiří (referee) ; Raida, Zbyněk (advisor)
This thesis deals with modeling of a waveguide with the rectangular cross-section in Comsol Multiphysics and optimization with PSO algorithm in MATLAB. The practical section describes electromagnetic wave excitation at different frequencies; and the influence of changes of basic characteristics, proportions and the location of an inserted dielectric slide on passing electromagnetic wave in a single-mode band. In next phase of the project, changes of basic characteristics on heating structure at electromagnetic field excitation by this waveguides are discussed. The last part deals with optimizing waveguide filter with particle swarm optimization and research his new electric and thermal character. Modeled phenomena are illustrated by pictures of a waveguide from the axial upper projection, and on rectangular charts.
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Design of manipulation table for workpiece rotating
Horák, Jiří ; Opl, Miroslav (referee) ; Pavlík, Jan (advisor)
This master’s thesis deals with the design of the manipulator for rotating objects, especially workpieces, semifinished products, or complete products around horizontal axis. It’s the manipulator for objects where is needed change orientation during production process. This thesis describes step by step construction of individual components of the manipulator and calculations of propulsive units. At the beginning the conveyor roller with propulsive unit is designed. The next step is construction of scissor lift table and choice of the propulsive unit. There is also made FEM analysis for the scissor mechanism. The next unit is aimed to the construction and computation of rotating and telescopic jaw. Then hydraulic circuit with computation of the propulsive unit is designed. As the final step the appropriate type of sensors are chosen and the step diagram of the manipulator is made. The manipulator is designed in the 3D model program and there are also made some assembly drawings.
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Planar antennas with special superstrates
Zdráhal, Roman ; Oliva, Lukáš (referee) ; Horák, Jiří (advisor)
This diploma thesis deals with the modeling of planar antennas with special superstrates in the CST Microwave Studio. Attention is given to the electromagnetic bandgap (EBG) substrates. Firstly, the working principle of these special substrates and generally physical phenomena accompanying electromagnetic waves propagation in a periodic medium are analyzed. By modeling of basic EBG structures in CST their dispersion diagrams were obtained and afterwards compared to one another. The object of the second part of this thesis was modeling of a chosen antenna in CST. An Antenna placed first on the conventional and then on the EBG substrate - in both cases with special superstrates - is analyzed and compared to each other. In the third part of this thesis, the particle swarm optimization (PSO) technique was implemented in CST (VBA language), and was applied to the original design of the chosen antenna. In the final part of this thesis, the optimized antenna was modeled and analyzed in ANSOFT HFSS, and the results from both simulation programs are compared to each other.
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Modeling of microwave structures based on SIIG
Teplý, Tomáš ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
Well-known dielectric image guide reach in millimeter-wave interesting results. Compared to a conventional types of lines and waveguides is characterised by low-through loss for frequencies approaching 100 GHz. This work is detail focused to basic characteristics and especially type of perforate highpermitivity substrate for obtain implemented waveguide to dielectric board (SIIG). The work also contains couple suggestions for various transitions from a commonly used lines and waveguides. Simulation results using finite element method is achieved attenuation values below 2 dB, which corresponds to a 2 cm length and include a waveguide itself with a pair of transitions. Finally, this work also designed the production method and SIIG applicatoin in practicle.
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Planar Antennas on Electromagnetic Bandgap Substrates
Horák, Jiří ; Dědková, Jarmila (referee) ; Škvor,, Zbyněk (referee) ; Raida, Zbyněk (advisor)
Planar antennas are used in several technical applications. The family of planar antennas contains microstrip antennas, which are very popular due to the low weight, low profile, simple manufacturing and easy mass production. Lower gain and excitation of surface waves are disadvantages of microstrip antennas. The propagation of surface waves can be efficiently suppressed if the conventional substrate is replaced by an electromagnetic bandgap (EBG) substrate. Microstrip antennas on EBG substrates have been presented in an open literature for several years. Nevertheless, no published work is devoted to the design of EBG substrates, which can suppress surface waves at several frequencies those cannot be covered by a single bandgap. In order to reach optimum parameters of designed antennas, selected global optimization methods are applied (genetic algorithms, particle swarm optimization, ant colony optimization).
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Design of heating by using process Building Information Modeling (BIM)
Horák, Jiří ; Hirš, Jiří (referee) ; Maurerová, Lenka (advisor)
This thesis processes heating of the apartment house in Rožnov pod Radhoštěm, Vsetín district. Revit program was used for the design of the heating. Some calculations were made in Revit too. Then the correctness of the calculations was checked. The Revit families were made in this thesis. These families support the calculations and design automation. Then these procedures were applied to the apartment house. It is five floors building with 1012 m2 of built area. Thesis solves design of heating and technical room equipment. The technical room is placed in first floor. Heat supply is solved as central heat supply system. The ventilation is mechanical, equal pressure. Thesis is in – cooperation with the house planner and the air – conditioning system design.
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Heating the building for youth and free time
Horák, Jiří ; Počinková, Marcela (referee) ; Horák, Petr (advisor)
The content of this thesis is the treatment of heating of a multipurpose building for youth and leisure time in Letovice, Blansko district. The building has three floors with a total built-up area of 1003 m2. Thesis solves a design of the heating system of the first floor including solution to the boiler room for heating the whole building. The boiler room is located on the ground floor. Pellet boilers are designed for heating purpose. Solar system is designed for preheating drinking water. Room ventilation in building is designed as a natural.
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Slot antenna for X band
Buriánek, František ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
This work familiarizes readers with the issues of slot antennas. It presents design and simulation of slot antenna for X band in CST Microwave Studio program. The simulation procedure is described here, including all the settings required for proper operation of the simulation. Then there is the description of the principle of the Half-Mode Substrate Integrated Waveguide - HMSIW. In the end the designed structure of HMSIW and the slot antenna are assembled and measured. The results of the simulation are compared with the results acquired by measurements. The designed antenna at the frequency 10 GHz achieves the impedance bandwidth 255 MHz, and the gain 8,81 dBi (the simulated values in CST Microwave studio).
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