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Identification of pauses in noisy speech signal
Kepák, Petr ; Míča, Ivan (referee) ; Smékal, Zdeněk (advisor)
The basic problem of speech is a complete separation of the natural noise which arise from correct articulation of voiced and unvoiced consonants from noise and disturbance environment. Objective of this master’s thesis is to find an effective method that could identify the pauses without speech activity, which can identify the properties of noise and disturbance. Once the noise is correctly identified, it is already possible to use different methods for its removal. The master’s thesis describes two methods of pauses identification. These methods are programmed in Matlab and tested on nine speech recordings. Methods analysis of the results was performed using the ROC (Receiver Operating Characteristic) curves. In the end are summarized results analysis of created methods.
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Pure tone audiometer
Blahák, Petr ; Rampl, Ivan (referee) ; Chmelař, Milan (advisor)
Human hearing is to collect information from the outside world and is one of the basic human senses. Part of this thesis is devoted to acoustics, properties of the human ear in terms of perception of sounds and methods, which human ears are investigating. Audiometer is an instrument which is most often used in healthcare. The main content of this thesis is to design pure tone audiometer, which is important for the subjective tests of human hearing non-invasive method.
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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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Measuring of Vehicle Instant Velocity
Štencel, Jakub ; Petyovský, Petr (referee) ; Horák, Karel (advisor)
The theoretical part of this paper summarizes the methods for motion analysis in an image. Inspected in detail are the methods used for motion detection in the image sequences. The practical part is focused on finding the significant points in the image (the targeting reticles on the body of the vehicle) which are then used to calculate the speed of the vehicle.
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Broadband Lownoise Amplifier
Varga, Kamil ; Havránek, Zdeněk (referee) ; Beneš, Petr (advisor)
The bachelor thesis describes the problems of broadband low-noise preamplifiers and the conditions of their design, including their printed circuit board. Furthermore, the thesis considers debugging and measuring of the most important parameters of these amplifiers. All of these problems are explained on two practical solutions.
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Acoustic generator for evoked potentials stimulation
Škutková, Helena ; Rampl, Ivan (referee) ; Chmelař, Milan (advisor)
Evoked potentials are electric brain response to external stimulus. They are important diagnostic no visual method in neurology. For their excitation use of different of kinds stimulation, most often: visual, auditory, somatosenzory, olfactory and gustatory. Evoked potentials are objective method for measurement sense perception. This master’s thesis is specialized to auditory evoked potentials and design acoustic generator for their stimulation. Auditory evoked potentials are primary used for objective audiometry, but they have another usage. In the first place, application is specialized on health sector. The aim of this master’s thesis is compact specified medical requirements with available technical resources.
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Multichannel Image Deconvolution
Bradáč, Pavel ; Kolář, Radim (referee) ; Jiřík, Radovan (advisor)
This Master Thesis deals with image restoration using deconvolution. The terms introducing into deconvolution theory like two-dimensional signal, distortion model, noise and convolution are explained in the first part of thesis. The second part deals with deconvolution methods via utilization of the Bayes approach which is based on the probability principle. The third part is focused on the Alternating Minimization Algorithm for Multichannel Blind Deconvolution. At the end this algorithm is written in Matlab with utilization of the NAG C Library. Then comparison of different optimization methods follows (simplex, steepest descent, quasi-Newton), regularization forms (Tichonov, Total Variation) and other parameters used by this deconvolution algorithm.
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Wireless transmission interference modeling (AWGN, Rayleigh, Rice fading channels)
Hloušek, Tomáš ; Gleissner, Filip (referee) ; Mikulka, Jan (advisor)
This thesis describes and models wirelesss transmission intereferences in real communication channels. A signal received on a fading channel is subjected to a multiplicative distortion and to the usual additive noise. Real channel adds to the signal noise and fadings. Gaussian noise is a result of channel awgn. Fadings is implicated by multipath propagation of signal in Rayleigh and Rician channels. Main goal of this project is to program BERsolve, which is created in tool GUIDE in Matlab. User program BERsolve makes it possible to analyse bit error rate and symbol error rate for some types of channel models, which are defined by standard COST207. BERsolve offers some other functions i.e. display time behaviour, constellation diagram and spectrum. This program provides us with an overview representation of problem by multipath interferences in communication channels.
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Noise diagnostic of solar cells
Krahulec, Martin ; Macků, Robert (referee) ; Sadovský, Petr (advisor)
The thesis deals with detailed theoretical and experimental investigation of noise and transport characteristics of selected photovoltaic cells in both forward and reversed directions focusing on the area of local PN junction instability (within the microplasma regions). It will be studied the correlation among different characteristics.
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Noise diagnostics of rectifier diodes PN junctions
Klimíček, Jaromír ; Macků, Robert (referee) ; Raška, Michal (advisor)
The thesis deals with the design of the measurement installation, which is intended for the microplasma noise measurements. This noise is being generated in the defective parts of the PN junction. The goal of this work is to design the measurement installation and to realize the fully functional workbench for the analogical noise related measurements and to determine the transfer function of the measurement installation. Main part of the work is to choose proper parameters for the measuring devices and to design the software intended for the automated measurements. Consequently, we have to process the measured waveforms of the microplasma noise, to determine the dependency of the noise on the signal magnitude and to calculate the power spectral noise density. Finally, we have to determine the transfer function of the measurement installation and to design the inversion filter.
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