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Electromigration of defects in (CdZn)Te single crystals.
Pekárek, Jakub ; Belas, Eduard (advisor) ; Grill, Roman (referee)
In the present work we study effect of electromigration of defects in CdTe material in external electric field at various temperatures and biases. The aim was to verify this effect using a set of electric contacts arranged linearly along the sample. These contacts as a potential probes was used for the detection of the drift of the local resistance modulation. We try to determine under what conditions and why it happens and then decide how this effect can be used for purification of semi-conducting samples and for preparation of semi-insulating material.
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Precise voltage references
Budáč, Peter ; Ing. Miroslav Horáček, Ph.D., ÚPT AVČR Brno (referee) ; Zobač,, Martin (advisor)
The aim of this thesis is the realization of the workplace to measure long-term stability and temperature coefficient of precision voltage references. It analyses individual solutions precision voltage references and their important parameters for the stability of the reference voltage. It deals with the influence of thermoelectric voltages and methods how to minizme their effect on measurement error . In conclusion it proposes a solution of this measuring workplace, and evaluate the results measuring of long-term stability and temperature coefficient on selected precision voltage references.
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Narrow Band Filtering of ECG Signals
Němeček, Tomáš ; Walek, Petr (referee) ; Kozumplík, Jiří (advisor)
Main objective of this bachelors thesis, was to learn about issues and possibilities of ECG filtration. This thesis is focused on narrowband filtration by Lynn’s filters. The objective for this thesis was to design filters for filtration of interferences called drift and brum. Both of them should not affect the relevant part of signal.
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Simulation of charged particles motion in electrical and magnetic fields
Zavřel, Marek ; Kloc, Petr (referee) ; Aubrecht, Vladimír (advisor)
In the first part of this bachelor thesis has been explained a basic idea of plasma state. In the second part have been described charged particle motions in various configurations of electric and magnetic fields. These motions are: accelerating and deflection of charged particle by electric field, gyration in magnetic field and drift motion in crossed electric and magnetic fields. Principles of magnetic mirror and magnetic trap were described as well. In the third part have been described operating principles and manipulation with simulation program, which is the main outcome of this thesis. Simulation program draws trajectories of mentioned charged particle motions in homogenous electric and magnetic fields.
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An Extended Model of a MEMS Gyroscope: Design and Identification
Vágner, Martin ; Sopata,, Milan (referee) ; Tůma, Jiří (referee) ; Beneš, Petr (advisor)
The thesis is aimed on measurement and modeling of MEMS gyroscopes based on input-output characteristics. The first part briefs the state of the art. The second part is dedicated to measurement methodology. Critical points and sources of uncertainty are discussed and evaluated using measurements or simulations. The last part shows key characteristics of MEMS gyroscopes based on the survey of a group of different sensor types. The results have revealed significant influence of supply voltage that causes bias drift of the gyroscope and bias drift of the internal temperature sensor. The error can be comparable to temperature drift; however, this effect is not addressed in the literature. The second observed effect is temperature dependency of angle random walk. In the last part, a general model of a MEMS gyroscope is rewritten to reflect observed effects. Moreover, the structure is selected to be easily extendable and the coefficients are expressed to allow a comparison of nominal parameters of different sensors.
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ECG noise generator
Mikuláš, Karol ; Kozumplík, Jiří (referee) ; Hrubeš, Jan (advisor)
Real ECG signal contains undesirable artifacts arising from its capture. Due to loss of diagnostically useful information in the noise signal and followed by the filtering the signal is important to know the characteristics, the most common symptoms and causes, to avoid or minimize the noise ECG signal. ECG noise generator is an educational program designed to serve the learning methods of filtering the noise signal. The user program can verify the effectiveness of the chosen method and the extent of deformation of the useful signal. The program includes basic types of artifacts, such as powerline interference, baseline wander, drift, impulse noise, myopotentials and change of baseline wander of ECG signal, which can be prepared noise signal from a database or other signal selected by the user.
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Time Varying Filters for ECG Signals
Peterek, Jan ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
The aim of this master’s thesis is to create a multiband stop derived from Lynn filters for suppressing mains hum and baseline variation (drift). The first part of the thesis is focused on brief theoretical introduction to the distortion types affecting ECG signal and twelve lead connection. The following practical part describes free realizations of ECG filter and ECG signal filtration. The filter has been tested both on distorted and on non-distorted signal. Finally filters’ error rate was computed from CSE database signals.
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Computer modeling of MOSFET transistor
Major, Jan ; Harwot, Ondřej (referee) ; Pokorný, Michal (advisor)
Work is focused on computer modeling of PN junction and MOSFET transistor in the program COMSOL Multiphysics and in program TiberCAD. The text is discussed on the drift and diffusion in semiconductors. Also shown is a method of modeling the PN junction and MOSFET transistor in the programs and compare models.
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Monitoring of the bullhead (\kur{Cottus gobio}) in the upper reaches of the river Elbe.
GUČÍK, Michal
Bullhead is common fish of our trout zones of streams and small rivers. It lives in mountain streams or small rivers. It needs clear water with high oxygen saturation. Therefor bullhead is used as a bioindicatorof clear waters. The aim of our experiment was compare the influence of artificial and natural flood on bullhead population in river Labe. Artificial flood was caused by wild water race competition in 2011. There was drained the water reservoir Labská during this event. The observed stretch of river Labe was fished out before and after this competition using electric generator. The fish obtained before the artificial flood were branded and released back to the river. New out fishing was done immediately after the flood. There were counted and measured the fish with or without brands. The same manner was used for obtaining of dates before and after natural flood in 2012. The main result of this experiment is showing the artificial flood is more destructive and dangerous than natural flood. The reason is faster increase and decrease of flow in river during the artificial flood.
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Effect of electrofishing on macrozoobenthos
PAVLÍČEK, Michal
Experiment has been addicted for observing effect of electrofishing on macrozoobenthos including mechanical stimulus (passing of trawling squad). Reaction on electrofishing and fading has been rebound by drift increment. Sample taking had been done by use of Surber and drift nets. Evaluation has been made both quantitative (standing crop in drift in particular methods), and qualitative (substitution of taxons in particular methods).
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