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Modern coding of speech signals using overcomplete models
Zapletal, Ondřej ; Průša, Zdeněk (referee) ; Rajmic, Pavel (advisor)
The theoretical contents of this thesis are studies of overcomplete models. Those are the models of signals, on which is set for their parametrization more variables, than it's necessary and consequently there's computed so-called sparse solution via iteration algorithms. A goal of this analysis is a selection just of the considerable (sparse) parameters. The theory is based on a linear algebra, vector spaces, bases and so-called frames. The task of the individual project of this thesis is a description and simulation of two speech coders: a classical coder based on linear predictive speech coding and a coder, that's making use of overcomplete stochastic ARMA processes models. A part of their realization is to simulate their decoders and a analyze their reconstruction quality. For their realization there is used MATLAB and an overcomplete models' library (toolbox frames).
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Spectram power distribution of radiant flux depending on supply voltage
Novotný, Tomáš ; Baxant, Petr (referee) ; Drápela, Jiří (advisor)
The master’s thesis consists of two parts. The first part describes base quantities of lighting engineering, basics of the electrical energy transformation to the light energy, laws of the thermal radiation and characteristics of incandescence and discharge light sources used for general illumination. This part concludes with a theoretical analysis of influence of power supply on the parameters of light source’s luminous flux. The second part of the thesis deals with the draft and configuration of a workplace for measuring spectral radiation of light sources depending on power supply. The last part of the thesis is created by the evaluation of spectral radiation and other light parameters changes according to the light source’s power supply changes.
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Methods for Quality of Service measurement in Wi-Fi networks
Bachan, Jiří ; Kolka, Zdeněk (referee) ; Prokopec, Jan (advisor)
This work deals with the wireless Wi-Fi networks, that used unlicenced ISM frequency band 2,4 GHz. These wireless networks are very extended in these days and used mainly for the Internet connection. With the multimedia data transfers expanding it’s necessary to ensure the specific quality of service QoS in wireless networks mainly for applications, which are sensitive to delay or packets lost. The main aim of this work is to describe Wi-Fi networks based on IEEE 802.11b/g/n standards, description of QoS techniques according to IEEE 802.11e standard and description of parameters describing QoS for the VoIP services. The practical part is divided on a two parts. The problems of measuring the radio link quality and the creation of simple program for quality of wireless connection analysis are solved in the first part. The second part incluledes measuring of the lost packets number in Wi-Fi network with the commercial application AirMagnet Laptop Wireless LAN Analyzer and measuring of the signal noise influence with the help of spectrum analyzer and vector signal generator.
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Automatic / Automated recogniton of emotional states based on utterance analysis
Pfeifer, Leon ; Atassi, Hicham (referee) ; Smékal, Zdeněk (advisor)
The diploma thesis deals with the analysis of human emotional states. The thesis consists of three parts. The first part is charcterize, the process of speech generating, from phonetic and psychological poin of view. In the second part there are proccesed metods and contextual things.(preprocessing of signal, voice activity detector). For calculation fundamental Frequency it was used metod of central clipping, another used metod is formant frequency analyse and the last is metod of determinatin of nuber of thorns and planes. In the thirt part there are proccesesed results of measurements performed by particural metods. It was scorred five different emotional states: neutral, anger, happiness, sadness and surprise. At the end of this part there are discussed results for each metod.
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Electromyography, measurement of muscle electric activity
Kořínek, Peter ; Provazník, Ivo (referee) ; Kolářová, Jana (advisor)
The task of this thesis was to become acquainted with the issue of measuring of muscle electric activity.In the theoretical part we became familiar with the computer measuringsystem BIOPAC and its options to measure monitored magnitudes. This continue with practical part, in which we watch the problematic according to a theory in a group of people. We learned data with BIOPAC according to protocol of the result of physicaleffort influence on EMG. In the end the results were statistically analysed. The data as a product offallowing research were verified by hypothesis. In thelast step, the data are presented in graphical user interface development environment. After loading of the EMG of measured person, the process are displayed-without, with and after the power with onus. It is possible to choose from different analyses.
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Measurements of nonlinear optical phenomena generated by femtosecond laser pulses. Autocorrelator
PAVLÍČEK, Martin
Ultrashort intensity optical pulses are often used in science, physic or med. Therefore I will be make work, which examine these pulses. In this work I measuring width of ultrashort laser pulses. Load of this work is a make experimental measuring system, which can measure these pulses. The light is propagating as electromagnetic waves. This waves contains electric and magnetic particles. I using light characterized by electric particle. In this case, light is propagating as femtosecond laser pulse. This laser pulses are generating in modelocking lasers, they are based on phase synchronization of longitudinal modes. If pulses are propagating through anisotropic medium (nonlinear crystal), can arrive phenomenon called frequency doubling (second harmonic generating). Further in this work I explore expansion of pulse, propagating through the medium. This phenomenon called group velocity dispersion. I´m measuring the pulse width by two methods. Both of these methods are compare. Addition measure is pulse spectrum measure. From these results are calculated quality of laser source INTEGRA-i. From theoretical formulas are calculated possibility values. Theoretical and practical results are compare on end of this work.
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Pseudospectra and non-stationary excitation
Kozánek, Jan ; Berthelot, F.
The behaviour of linear (and non-linear) dynamical systems is characterized with the help of the spectral properties. The pseudospectrum is in this situation better instrument, giving the estimation about the resolvent. The formal substitution (using a regression method) of the non-stationary excitation of rotating machines during start up and run down regimes by the exponencial function corresponding to the resolvent solution is proposed and discussed.
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