|
|
Stability of stationary flows of non-Newtonian heat conducting fluid in 2D
Wintrová, Lucie ; Kaplický, Petr (advisor) ; Pokorný, Milan (referee)
This thesis aims to study the Navier-Stokes-Fourier problem with the entropy equa- tion. In particular, we want to define the notion of a solution and prove its existence. We approach this problem by modifying techniques used in several papers studying the generalized NSF system and the entropy equality and we want to conclude similar results. We are treating the two-dimensional case as opposed to the more frequent 3D case, hence we were able to relax conditions on the initial data. Firstly, we formulate the definition of a weak solution and impose sufficient conditions to prove its existence. In particular, we will require a bound p ≥ 2 for the power-law index of the Cauchy stress tensor. Next, we show that there exists a solution to Navier- Stokes-Fourier system (u, ϑ) fulfilling our definition. Lastly, we show that this solution additionally fulfills the entropy equality for η = log ϑ. 1
|
|
|
Spectral analysis of historical pianos
Pokorný, Marek ; Indrák, Michal (referee) ; Jirásek, Ondřej (advisor)
This bachelor thesis focuses on the spectral analysis of historical pianos in aim to identify and compare their acoustic and spectral characteristics. Three examples of pianos were analysed, including a significant piano owned by the composer Leoš Janáček. The analysis was performed on measured piano samples using Fourier transformation in MATLAB, with an emphasis on spectral parameters such as spectral centroid, flatness, skewness, sharpness and roughness, and on the visual representation of a spectrum over time -- the spectrogram. The results of the spectral analysis were used to interpret and evaluate differences in timbre of the pianos and their probable causes. The theoretical part of the thesis provides a brief overview of the history and design of the piano, explains the spectral descriptors used, and examines the properties of musical tones and the influence of psychoacoustics on the perception of pitch and timbre.
|
|
|
Measuring RLC on the components of electrical circuits
Pokorný, Marek ; Vítek, Ondřej (referee) ; Veselka, František (advisor)
Aim those work is inform numerator about possibilities and features gauging apparatus 7600 Precision LCR undergrounds and further then about metering paramers R,L,C on components electric standing ,especially then on sliding contacts,with which this work acquaint and how are their characteristics important for correct functionality electrical machine whereof are site rated power.Warp work largely start from manual to apparatus 7600 Precision LCR undergrounds and further then out publication sliding contact in electrical machine - doc. Veselka, doc. Chmelik.
|
|
|
Antennas for GSM bands
Rousek, Jiří ; Pokorný, Michal (referee) ; Pítra, Kamil (advisor)
Bachelor thesis deals with miniaturization techniques of the planar inverted-F antenna (PIFA). In bachelor thesis were simulated antennas for the GSM bands using meandering of the radiating patch, capacitive load and U-slolts. Influence of parameters of each miniaturization techniques on the antenna size and parameters were studied. The process of designing the antennas is described in detail. Selected models of antennas were adapted to given dielectric substrate and constructed. The measured results are presented and compared with simulations.
|
|
|
Design and realization of ADSR filter
Pokorný, Martin ; Kratochvíl, Tomáš (referee) ; Slezák, Josef (advisor)
The master´s thesis is focused on design of ADSR filter and voltage controlled amplifier (VCA). Three additional circuits performing analog signal processing are added. Functionality of designed circuits is verified in simulation program. All designed circuits are practically realized. Thesis includes complete design of the mentioned circuits and all necessary informations for its practical realization. All designed circuits are measured and the results are presented.
|
|
| |
|
|
Modeling of log-periodic planar antenna
Martiš, Vítězslav ; Pokorný, Michal (referee) ; Láčík, Jaroslav (advisor)
The content of this work is a analysis of the project method and a simulation of planar logarithmically-periodic antenna. The simulation verified effects of main antenna-dimensions on her function. Through the use of results was designed acceptable antenna, inclusive of supply circuit. This was remitted to simulation
|
|
|
Dielectric resonator antenna
Štarha, Michal ; Pokorný, Michal (referee) ; Láčík, Jaroslav (advisor)
This project deals with using of dielectric resonators as antennas. There are discussed possibilities feed of these antennas, as feed probe, feed of microstrip line, aperture coupling, or coplanar waveguide. Then there is a simple example design dielectric resonator antenna and its modeling in CST Microwave Studio. The designed antenna is fabricated and measured.
|
|
|
Vertically polarized Yagi antenna with magnetic dipole
Weigel, Filip ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
This bachelor’s thesis deals with the principles of operation and simulation of planar Yagi antennas with a magnetic dipole. Simulation of electromagnetic field was performed in the simulator CST MICROWAVE STUDIO (CST MWS). The project compares results of simulations of several types of Yagi antennas. These antennas can be used for the communication along the living tissue (on-body communication).
|
|
|
Optimization Algorithm with Probability Direction Vector
Pohl, Jan ; Pokorný, Miroslav (referee) ; Matoušek, Radomil (referee) ; Jirsík, Václav (advisor)
This disertation presents optimization algorithm with probability direction vector. This algorithm, in its basic form, belongs to category of stochastic optimization algorithms. It uses statistically effected perturbation of individual through state space. This work also represents modification of basic idea to the form of swarm optimization algoritm. This approach contains form of stochastic cooperation. This is one of the new ideas of this algorithm. Population of individuals cooperates only through modification of probability direction vector and not directly. Statistical tests are used to compare resultes of designed algorithms with commonly used algorithms Simulated Annealing and SOMA. This part of disertation also presents experimental data from other optimization problems. Disertation ends with chapter which seeks optimal set of control variables for each designed algorithm.
|
guest ::
RSS feed.