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Analýza výpočtu největšího společného dělitele polynomů
Kuřátko, Jan ; Zítko, Jan (advisor) ; Janovský, Vladimír (referee)
In this work, the analysis of the computation of the greatest common divisor of univariate and bivariate polynomials is presented. The whole process is split into three stages. In the first stage, data preprocessing is explained and the resulting better numerical behavior is demonstrated. Next stage is concerned with the problem of the computation of the numerical rank of the Sylvester matrix, from which the degree of the greatest common divisor is obtained. The last stage is the actual algorithm for calculating the greatest common divisor of two polynomials. Furthermore, the underlying theory behind the computation of the greatest common divisor is explained and illustrated on many examples. 1
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Numerické metody zpracování obrazu
Tóthová, Katarína ; Hnětynková, Iveta (advisor) ; Zítko, Jan (referee)
The aim of this thesis is to provide a concise overview of the numerical techniques in digital image processing, specifically to discuss the construction, properties and methods of solving of the image deblurring problems modelled by a linear system Ax = b. Often, these problems fall within a group of the ill-posed problems with severely ill-conditioned matrix A and hence require special numerical treatment. We provide a brief overview of selected regularization methods that can be used in this situation, including direct (TSVD, Tikhonov regularization) and iterative ones (CGLS, LSQR), together with the pertinent parameter-choice methods - L-curve, GCV and the discrepancy principle. The theoretical discussion is supplemented by the numerical experiments with real-life image data.
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Od problému momentů k moderním iteračním metodám - historické souvislosti a inspirace
Tůma, Martin ; Strakoš, Zdeněk (advisor) ; Zítko, Jan (referee)
In the present work we study the connections between the moment problem and the modern iterative methods. A short historical review of the study of the moment problem is given. Some different definitions of the moment problem are shown. Motivation and results of some mathematicians, who used the moment problem in their work are discussed. Connections between different definitions of the moment problem, Gauss-Christoffel quadrature, orthogonal polynomials, continued fractions, Sturm-Liouville problem, reduction of the model in linear dynamical systems and some of the iterative methods like Lanczos and Conjugate gradients method are explained.
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Teoretické otázky popisu chování krylovovských metod
Strnad, Otto ; Strakoš, Zdeněk (advisor) ; Zítko, Jan (referee)
The presented thesis is focused on the GMRES convergence analysis. The basic principles of CG, MINRES and GMRES are briefly explained. The thesis summarizes some known convergence results of these methods. The known characterizations of the matrices and the right hand sides gen- erating the same Krylov residual spaces are summarized. Connections and the differences between the different points of view on GMRES convergence analysis are shown. We expect that if the convergence curve of GMRES applied to the nonnormal matrix and the right hand side seems to be de- termined by the eigenvalues of the matrix then exists a matrix that is close to normal and has the same spectrum as the matrix and for the right hand side has the same GMRES convergence curve (We assume that the initial approximation 0 = 0). Several numerical experiments are done to examine this assumption. This thesis describes an unpublished result of Gérard Meu- rant which is the formula for the norm of the -th error of GMRES applied to the matrix and right hand side and its derivation. The upper estimate of the -th GMRES error is derived. This estimate is minimized via spectrum.
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Intracellular trafficking of an anti - Amyloid Protein Precursor antibody.
Zitko, Jan ; Doležal, Martin (advisor) ; Trejtnar, František (referee)
Intracellular trafficking of an anti-Amyloid Protein Precursor antibody Alzheimer's disease is characterized by over-accumulation of beta-amyloid peptide (Aβ) in the brain. Aβ is produced by proteolytic cleavage of beta-amyloid precursor protein (APP) by β- and γ-secretases. Novel monoclonal antibody, 2B12, has been shown to bind to β-secretase cleavage site of APP, reducing the production of APP, presumably by preventing the cleavage by steric hindrance. 2B12 is hypothesized to bind to APP molecules exposed on the cell surface and to be internalized in the form of complex with APP via natural endocytic pathway. This hypothesis was confirmed by San Pei Ho's (2007), who followed the internalization of 2B12 in living astrocytoma MOG-G-UVW, cells in time-course experiment. This project is focused on intracellular trafficking of 2B12 and its localization within specific cellular compartments. Experiments were performed with fixed astrocytoma MOG- G-UVW cells (constitutively expressing APP). Originally planned experiments with live cells could not be performed due to decreased stability of 2B12 (causes remain unknown). 2B12 was tested for colocalization with polyclonal affinity purified antibodies labelling subcellular markers (proteins) associated with compartments known to participate in APP...
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Peano kernel of the quadrature formula
Valešová, Petra ; Zítko, Jan (referee) ; Kofroň, Josef (advisor)
Nazev prace: Poanovo jadro kvadraturni formula Autor: Pctra Valcsova Katedra (ustav): Katedra numcricke matciriatiky Vcdouci bakalarskc pracc: Doc. RNDr. Josef Kofroii, CSc. c-inail vcdouciho: Josef.Kohxm^.tinff.cuni.cz Abstrakt: V pfedlozcnc praci studujcme vyjadfcni chyb kvadraturnich for- rnuli pomoci Peanova jadra. Nejprve je definovano Peanovo jadro kvadra- turni fornmlc. dale jsou uvcdcny a dokazany ricktcrc jcho vlastnosti a na dvou pfikladoch jc ukazan vypocct Peanovych jadcr. Kaslcdneje vyuzito Peanova jadra k nalezeni optimalni kvadraturni for mule. Potc jc popsana kon.strukce Rombergovy kvadraturni formulc a pfislusncho Peanova jadra. Jc uvcdcno a dokazano nekolik vlastnosti Peanovych jadcr Rombergova kvadraturniho vzorce. Dale jc na nekolika pfikladcch srovnan odhad chyby kvadraturnich formuli. Na /,;iver jc definovano Sardovo jadro kubatumi for mule a na pfi- kladc je ukazan vypocet Saixlova jadra. Klicova slova: kvadraturni vzorcc, Pcanovo jadro, chyba kvadraturni fonnule Title: Pcario kernel of the quadrature formula Author: Pctra Valesova Department: Department of Numerical Mathematics Supervisor: Doc. RNDr. Josef Kofroil, CSc. Supervisor's e-mail address: .loscf.Kofrori'il'mff.cuni.r/, Abstract: In the present work we study the expressing of errors of a qua- drature formula by Pcano kernel....
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Solving bordered linear systems
Štrausová, Jitka ; Janovský, Vladimír (advisor) ; Zítko, Jan (referee)
The comparison of two algorithms for solving bordered linear systems is considered. The matrix of this system consists of four blocks (matrices A,B,C,D), the upper left one is a sparse matrix A, which is ill-conditioned and structured. The other blocks (B,C,D) are dense. We say that the matrix A is bordered with the matrices B,C,D. It is desirable to preserve the block structure of the matrix and take advantage of sparsity and structure of the matrix A. The literature suggests to use two different algorithms: The first one is the method BEM for matrices with the borders of width equal to one. The recursive alternative for matrices with wider borders is called BEMW. The second algorithm is an iterative method. Both techniques are based on different variants of the block LU-decomposition.
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