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Meaurement process automatization of deviations and stability of oscilators
Čermák, Jan ; Nováková Zachovalová, Věra (referee) ; Havlíková, Marie (advisor)
This Master´s thesis on a topic ,,Meaurement process automatization of deviations and stability of oscilators‘‘ describes methods for measuring the difference of time scales. Using this method, calculates the parameters of the oscillator, which is also describes in this work. Parameters of the oscillator means inning and stability. Describes is the procedure for calculating the uncertainties and their presentation in the final calibration sheet. This Master´s thesis also describes the practical measurement with this method in the Czech metrology institute in Brno. Measurement of the parameters of oscillator by the method of measurement of the difference of time scales is carried out automatically by computer. This Master´s thesis deals with the creation and development of new software and thus the automation of the entire task.
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Emotional State Recognition Based on Speech Signal Analysis
Čermák, Jan ; Atassi, Hicham (referee) ; Smékal, Zdeněk (advisor)
The thesis is focused on the emotional states classification in the Matlab program, using neural networks and the classifier which is based on a combination of Gaussian density functions. It deals with the speech signal processing; the prosodic and spectral signs and the MFCC coefficients were extracted from the signal. The work also deals with the quality evaluation of individual signs of which the most suitable were chosen in order to provide the correct classification of emotional states. In order to identify the emotional states, two different methods were used. The first method of classification was the use of neural networks with differently selected parameters, and the second method was the use of the Gaussian mixture model (GMM). In both methods, a database of emotional utterances was divided into the training group and the test group. The testing was based on a method independent of the speaker. The work also includes the comparison of individual analyzed methods as well as the representation and comparison of the results. The conclusion comprises a proposition for the best parameters and the best classifier for the recognition of the speaker’s emotional state.
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Interference modelling for xDSL
Čermák, Josef ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
This work is focused on the subject of the interference modelling for xDSL technologies. First, the xDSL technologies are explained. Following is the presentation and description of the different kinds of the xDSL technologies. The next part deals with the basic parameters of metallic cable lines – especially the primary and secondary parameters. Nowadays wider bandwidths are used for the achievement of higher data transmission rates. During a higher frequency signal transmission a more intensive line attenuation appears. To identify the transfer characteristics of the lines while using an xDSL system, mathematic models of transmission lines are applied. That is why these mathematic models are dealt with in the next chapter. At the end of this section the mathematic models are compared using the modular and phase characteristics. The main aim of the work is to describe the different impacts which influence the efficiency of the xDSL systems. First, the causes interfering from the inside of the cable are deeply explained: Near End Crosstalk (NEXT), Far End Crosstalk (FEXT), Additive White Gaussian Noise (AWGN). Following is the explanation of the external interfering impacts: Radio Frequency Interference (RFI) and Impulse Noise. The next goal of this thesis is a design of a workstation for the tests of spectral features and the efficiency of the xDSL systems. The work also presents a designed GUI application and its description. The GUI application is an instrument for the choice or data entry of the final interference. The last chapter describes a realization of a measurement and shows the measured characteristics which were recorded on the ADSL tester and oscilloscope.
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3D scanning methods
Čermák, Jan ; Matyáš, Pavel (referee) ; Marada, Tomáš (advisor)
In the first part of this thesis there is a task of taxonomy of the 3D scanners. It explains some principles of the 3D scanners functioning. Then in the second part there are described two particular technologies of the 3D scanning in the more complex way. In the chapters of both of these methods there is described procedure of scanning and compared several commercially available sensors. In the end there is comparison of these two methods.
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Stability and chaotic behaviour of the Lorenz system
Oborná, Eliška ; Nechvátal, Luděk (referee) ; Čermák, Jan (advisor)
This bachelor's thesis analyzes the behavior of the Lorenz's model of convective flow in the atmosphere depending on the Rayleigh number. It offers several methods when analyzing stability of nonlinear systems of the first order autonomous differential equations. Part of the work also consists of introduction to deterministic chaos which appears in dynamic systems with a parameter. The work is supported by graphic interpretation of a stable and chaotic behavior by using the software Maple.
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Mathematical models in epidemiology
Skopalová, Kristýna ; Štoudková Růžičková, Viera (referee) ; Čermák, Jan (advisor)
This bachelor's thesis deals with the mathematical models which are used in epidemiology. The aim of this thesis is a description and a creation of basic Kermack-McKendrick model and its analysis. The thesis is also dedicated to modification of this model and illustration on the concrete data. Last but not least, the stability of the selected models is checked in the stationary points.
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Planar dynamics of the mathematical pendulum
Rauš, Michal ; Tomášek, Petr (referee) ; Čermák, Jan (advisor)
This bachelor's thesis is focused on the mathematical modeling of a motion of simple and double pendulum with the use of an ordinary differential equations. It's main objectives are a derivation of equations of motion, an assessment of stability as well as periodic behaviour of respective models and graphical interpretation of achieved results.
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Fatigue Evaluation of Aircraft Structure According to FAR Part 23 Airworthiness Standards
Čermák, Jakub ; Koštial, Rostislav (referee) ; Augustin, Petr (advisor)
This bachelor thesis deals with acceptable means of showing compliance with the FAR 23 regulation based on safe-life experimental and analytical evaluation. In the introduction the author focuses on the historical development of the regulation and follows with summarization of current requirements. The subsequent pages describes in detail the certification based on full-scale testing, component testing and structural analysis using the cumulative rule. Appendix includes examples of load spectra approved by the FAA.
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Solution of inverse problems in the area of material and heat exchangers
Kůdelová, Tereza ; Nechvátal, Luděk (referee) ; Čermák, Jan (advisor)
This bachelor's thesis deals with the dynamic behavior of heat exchangers which is described by the system of dierential equations. In this conection it includes a general information about necessary theoretical background especialy concerning heat transfer. Further, it mentions also the basic types of arrangement of heat exchangers that may occur in practice. The main goal is to answer the questions of controllability, observability and identifiability of the parameters obtained by solving corresponding inverse problem.
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Mathematical modeling of population problems in biology
Čampulová, Martina ; Opluštil, Zdeněk (referee) ; Čermák, Jan (advisor)
This bachelor´s thesis deals with the modeling of population problems in biology. The aim of this thesis is to mention some basic models describing dynamics of the evolution of one or two populations. Models mentioned in this thesis are described by first-order ordinary differential equations. Exploring the evolution of the population brings the main question - searching for singular points (and verifying their stability) of differential equations describing the evolution of the population. Therefore the thesis also deals with these problems.
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