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Linear system stability analysis
Jelen, Michal ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This bachelor’s thesis will be dealing with stability analysis of linear systems. In theoretical part will be mentioned stability and its conditions, stability criteria, their partition to groups and description of each criterion. In practical part will be chosen one stability criterion which will be working with afterwards. As examined circuit will be a filter with current conveyors as active elements which will be obtained a characteristic multinomial from. There will be working with transmittion functions of single and double pole model in examples. It will be created a computer programme which will enable an automatization of Routh’s stability criterion and plot graphical outputs in dependence on input parameters and their values.
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Detection of mutations associated with increased incidence of breast and ovarian tumors using modern molecular biology methods
RÁJOVÁ, Kristýna
Breast cancer and ovarian cancer is one of the most common malignancies what women have in the Czech Republic and the incidence of new diagnoses has a tendency to increase. It is estimated that 5-10 per cent of these tumours is cause by pathogenic mutations in highly penetrance tumour suppressor genes BRCA1 or BRCA2. The main function of these genes are repair of double strand DNA breaks and another function is control of cell division and participate on regulation of transcription and chromatin remodeling. The aim of this bachelors thesis is to summarize current knowledge of the "Gene mutations" topic, the function of the genes BRCA1 and BRCA 2 and their link with hereditary breast and ovarian cancer, an overview of possible detection methods and particularly also the summary of the Czech studies of detection mutations in the Czech Republic. It pointed out to the strong effect of the founder mutation. Among the most frequently found mutations are mutations as c.5266dupC, c.181T> G and c.3700_3704del5 in the gene BRCA1 and c.7913_7917del5 and c.8537_8538del2 in the BRCA2 gene. In the experimental part of the work I have tried to optimize ARMS PCR method for point mutation c.5266dupC. This mutation has proved to be one of the most common mutations not only in the Czech Republic but also in Europe. The objective was to optimize the PCR ARMS in the conditions of the GENLABS Ltd. laboratory. The main goal of the optimization was the selection of appropriate PCR mix and optimal temperature of PCR profile at which the quality and quantity of the yield was visualized on gel electrophoresis as specific and highest as it is possible. The aim of this part is also practically to do the DNA isolation from peripheral blood and buccal swab, preparation and execution of the PCR reaction and detection of PCR products by gel electrophoresis. Eventually, we managed to optimize a method for the two different matrices for the DNA isolates, and peripheral blood. Unfortunately the method for the buccal swab was not successful. During gradually temperature increasing, we started the process of annealing at 55°C, the best results were achieved at a temperature of 65.5 ° C using gb Basic PCR Master Mix from the Generi Biotech firm. In the future this optimization might allow the using of method for mutation in the gene BRCA1 c.5266dupC for the routine practise in the laboratory.
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Wavelet-based Realized Variation and Covariation Theory
Baruník, Jozef ; Vošvrda, Miloslav (advisor) ; Kočenda, Evžen (referee) ; Di Matteo, Tiziana (referee) ; Veredas, David (referee)
English Abstract The study of volatility and covariation has become one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. This dissertation contains a complete theory for realized variation and covariation estima- tion, generalizing current knowledge and taking the estimation into the time-frequency domain for the first time. The first part of the theory presents a wavelet-based realized variation theory, while the second part introduces its multivariate counterpart, a wavelet- based realized covariation theory. The results generalize the popular realized volatility framework by bringing robustness to noise as well as jumps and the ability to measure realized variation and covariation not only in the time domain, but also in the frequency domain. The theory is also tested in a numerical study of the small sample performance of the estimators and compared to other popular realized variation estimators under dif- ferent simulation settings with changing noise as well as jump level. The results reveal that our wavelet-based theory is able to estimate the realized measures with the greatest precision. Another notable contribution lies in the application of the presented theory. Our time-frequency estimators not only produce more efficient...
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Frequency filters with tunable current amplifier
Jemelík, Lukáš ; Lattenberg, Ivo (referee) ; Jeřábek, Jan (advisor)
The bachelor thesis deals with the designing of active frequency filters of the second – order which are make use of active elements. These filters were designed by means of autonomous circuits. Digitally Controlled Current Amplifier DCCA and Multiple Output Current Follower MO-CF were used as active elements. Designed filters works in current mode. The bachelor thesis is divided into five chapters. In the introductory part there are described general characters of frequency filters, the second part contains the description of the active elements, the third part includes the method of construction high – order filters. In fourth part there are described particular circuitry, their transmission functions and confirmation of their functionality in computer software.
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Fully-differential current mode frequency filters
Kubík, Milan ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
The bachelor thesis focuses on design of fully-differential frequency filters in current mode. First part informs about problems concerning frequency filters and creating differential structures in current mode. Second part deals with used active components - Digitally Controlled Current Amplifier (DCCA) and Multiple Output Current Follower (MO-CF). Key point is own design of differential filters, which is divided into three parts. In the first part of design results there are filters obtained with help of models from FilterPro software. There are presented circuit structures implementing low pass, high pass and band pass frequency filters. At the next part two filters derived from autonomous circuits. These circuits are working as low pass and high pass frequency filters. In the last part are designed two types of integrator type components – loss integrator and lossless integrator. These circuits were used to realize cascade connection achieving three filtering function – band pass 1, band pass 2 and low pass. Final part summarises the thesis and features of designed structures.
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Novel active function blocks and their applications in frequency filters and quadrature oscillators
Herencsár, Norbert ; Zahradník, Pavel (referee) ; Kolka, Zdeněk (referee) ; Lattenberg, Ivo (advisor)
Kmitočtové filtry a sinusoidní oscilátory jsou lineární elektronické obvody, které jsou používány v široké oblasti elektroniky a jsou základními stavebními bloky v analogovém zpracování signálu. V poslední dekádě pro tento účel bylo prezentováno velké množství stavebních funkčních bloků. V letech 2000 a 2006 na Ústavu telekomunikací, VUT v Brně byly definovány univerzální proudový konvejor (UCC) a univerzální napět'ový konvejor (UVC) a vyrobeny ve spolupráci s firmou AMI Semiconductor Czech, Ltd. Ovšem, stále existuje požadavek na vývoj nových aktivních prvků, které nabízejí nové výhody. Hlavní přínos práce proto spočívá v definici dalších původních aktivních stavebních bloků jako jsou differential-input buffered and transconductance amplifier (DBTA), current follower transconductance amplifier (CFTA), z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), generalized current follower differential input transconductance amplifier (GCFDITA), voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), a minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). Pomocí navržených aktivních stavebních bloků byly prezentovány původní zapojení fázovacích článků prvního řádu, univerzální filtry druhého řádu, ekvivalenty obvodu typu KHN, inverzní filtry, aktivní simulátory uzemněného induktoru a kvadraturní sinusoidní oscilátory pracující v proudovém, napět'ovém a smíšeném módu. Chování navržených obvodů byla ověřena simulací v prostředí SPICE a ve vybraných případech experimentálním měřením.
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Retinal blood vessel segmentation in fundus images via statistical-based methods
Šolc, Radek ; Walek, Petr (referee) ; Odstrčilík, Jan (advisor)
This diploma thesis deals with segmentation of blood vessel from images acquired by fundus camera. The characteristic of fundus images and current methods of segmentation are described in theoretical part. The reach of the practical part is method using statistical model. The model using Student´s distribution for automatic segmentation is gradually drafted. Firstly EM- algorithm has been incorporated and model drafted on Markov random fields for improving robustness to noise after that. Contrast of thin blood vessel is improved in image preprocessing part by discrete wave transformation. The output image is used as mask for grayscale intensity decrease of thinnest blood-vessel and intensity increase of background. Whole model was programed in Matlab. The model was tested on whole HRF database. The quantitative evaluation of binary images were compared with golden standard images.
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Analysis of Thick Film Amperometrical Sensors Signal and Its Usage for Measurement and Characterization of Enzymes
Ondruch, Vít ; Kizek, René (referee) ; Masojídek,, Jiří (referee) ; Vrba, Radimír (advisor)
V práci je popsán princip synchronní detekce (SD), který byl uplatněn při měření s biosenzory. Metoda SD umožňuje dosažení výrazně lepšího poměru signálu k šumu, vyššího limitu detekce a celkové zlepšení robustnosti měření. Uplatnění SD při měření s biosenzory umožní zlepšit analýzu jeho odezvy a umožní odstranění nežádoucích interferencí nebo šumů, které mohou být způsobeny například mícháním roztoku, elektromagnetickými vlivy nebo parazitními proudy. SD také umožňuje rozložit získaný signál na odezvu stimulace a na dlouhodobý signál jiného procesu, a dále také identifikovat jevy druhého řádu. Pro identifikaci stimulačního signálu ve výstupním signálu měření byl na základě lineárního statistického modelu vyvinut specializovaný software. SD byla ověřena na modelovém případu výstupního signálu biosenzoru s aplikovaným komplexem fotosystému II (PSII) a jeho odezvě na stimulaci světlem. Odezva PSII se řídí kinetikou prvního řádu a může být také ovlivněna inhibitory. Kinetické konstanty vazby herbicidu na PSII závisí lineárně na koncentraci herbicidu. To umožňuje jejich měření také při nízkých koncentracích herbicidu.
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A study of binary stars with accretion disks
Chadima, Pavel ; Harmanec, Petr (advisor) ; Krtička, Jiří (referee) ; Mourard, Denis (referee)
This thesis contains spectroscopic analyses of two unusual binaries with circum- stellar disks - β Lyr and ǫ Aur. Several hundred optical spectra were processed and analyzed for both binaries which led to several original findings. For β Lyr, it was a discovery of a weak shell spectrum originating in a disk pseudophotosphere and a hidden satellite spectrum, present only during eclipses, which arise from additional absorption of the primary light passing through the gaseous envelope around the secondary. For ǫ Aur, it led to the discovery of the apparent multiperiodic line vari- ability occuring during the current eclipse with a dominant and common period of 66d .21 and to an explanation of complex Hα line profiles during the eclipse which is again caused by an additional absorption of a primary light in an atmosphere of a dark disk around a secondary. Also rich series of radial velocity measurements and photometric observations were collected and used to determine a new precise orbital solution for ǫ Aur. Further, a hydrodynamical and a radiative modeling of a discontinuous mass transfer in a close binary system was carried out which resulted in a formation of an elongated disk with a slow prograde revolution, demonstrated itself by double emission Hα line profiles that exhibit V/R variations.
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Time-domain Dielectric Spectroscopy of Carboxymethylcellulose
Palai-Dany, Tomáš ; Lelák, Jaroslav (referee) ; Mentlík, Václav (referee) ; Liedermann, Karel (advisor)
The dissertation deals with the time-domain dielectric relaxation spectroscopy of carboxymethylcellulose. The main attention was paid to the experimental part of research, mainly to the design and subsequent development of an experimental setup for the measurement of discharge currents and for their processing and analysis. The subject of the measurement is carboxymethylcellulose (CMC), which is a simple polysaccharide used in wide range of applications, among else also in biomedical engineering. The study of CMC properties has required the development of a new experimental set-up of original design, which includes the equilibration (short-circuiting) of a sample before the measurement, charging and discharging at defined time intervals, switching between these two modes, recording of measurement, adjustments and processing of measured signals up to Fourier transformation into the frequency domain and, finally, calculation of complex permittivity of the sample. The frequency dependence of complex permittivity or its imaginary part, obtained by Fourier transformation of discharge current in time domain, is then referred to as the dielectric spectrum. In view of the fact that current measurements were done at very low levels of measured signal (below 10-12 A) the whole measurement was no easy matter. The framework of the work also necessitated studies and subsequent resolution of problems associated with shielding, grounding, presence of noise and sensitivity to various ambient influences. The research work focused on a reliable and trustworthy measurement of very low discharge currents and, subsequently, mathematical processing of noise present in them, i.e., operations with the original, experimentally established signal in time domain, leading in principle to a digital filtration of measured dielectric data. A further pursued objective is the explanation of dielectric parameters of tested carboxymethylcellulose sample in the widest possible frequency spectrum. The integral part of the research was the selection and application of the method for the transformation of the adjusted signal to the frequency domain. The experimental works, including data processing, were carried out in the Department of Physics, Brno FEEC BUT. Measurements were done with Keithley 617 Electrometer, HP4284A Frequency Analyzer and Janis CCS-400-204 cryogenic system. The results were completed with results obtained at the V Department of Experimental Physics, Centre for Electronic Correlations and Magnetism, University of Augsburg, Germany.
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