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Stabilization methods for unstable solutions of the discrete logistic equation
Fedorková, Lucie ; Tomášek, Petr (referee) ; Čermák, Jan (advisor)
Diplomová práce pojednává o stabilizaci diskrétního logistického modelu pomocí několika řídících metod. Je zde provedena především stabilizace rovnováh, 2-periodických cyklů a 3-periodických cyklů. Ke stabilizaci systému je využito proporčního zpětně-vazebního řízení, zpětně-vazebního řízení s časovým zpožděním a řízení založeného na predikci. U každé metody je diskutovaná stabilizační množina pro řídící zesilovač spolu s oblastmi stability pro odpovídající kontrolovaná řešení. Všechny teoretické výsledky jsou ilustrovány grafickými interpretacemi v softwaru MATLAB. Podpůrné výpočty jsou provedeny pomocí softwaru Maple.
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Difference calculus and difference equations
Bukotin, Denys ; Opluštil, Zdeněk (referee) ; Řehák, Pavel (advisor)
This thesis deals with application of difference equations for describing real processes. The aim of this work is to show the applicability of this kind of equations for solving some problems. We define some concepts of difference calculus, theory of difference equations and stability theory, also we show some similarities with theory of differential equations. Then we investigate a particular mathematical model and the behavior of its solutions. We examine Nicholson-Bailey model, as an example of population models and we show that difference equations are a useful tool for describing real processes.
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The Z transformation and its application to solutions of difference equations
Hubatová, Michaela ; Opic, Bohumír (advisor) ; Johanis, Michal (referee)
This thesis uses knowledge from the introductory course of complex analysis, especially the theory of Laurent series. It provides basic information about the Z transformation and shows its mathematical applications. The text gives characterizations of exponential type sequences and defines their Z transformation. Presented theorems can be used to determine images of exponential type sequences and to find preimages of functions holomorphic at the point infinity. These theorems are given with proofs and illustrated with examples. Also some methods of the inverse tranformation are mentioned and a list of preimages of chosen rational functions holomorphic at infinity is included. In the last chapter the Z transformation is applied to solve linear difference equations. Powered by TCPDF (www.tcpdf.org)
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Discrete Channel Capacity
Butora, Jan ; Holub, Štěpán (advisor) ; Žemlička, Jan (referee)
Title: Discrete Channel Capacity Author: Jan Butora Department: Department of Algebra Supervisor: doc. Mgr. Štěpán Holub, Ph.D. et Ph.D., Department of Algebra Abstract: This Bachelor thesis introduces and examines C.E. Shannon's discrete channel capacity theory, which was first published in 1948 as one of the founding studies in the field of mathematical information theory. In the first place, possible way of information measurement is presented and communication systems are described. Additionally, emphasis is given to discrete noiseless channel and the theorem on calculating the capacity of such channels is examined and proven. Shannon's proof is examined in detail as it contains several non-trivial results in finite differences. Finally, calculation of channel capacity using the theorem is shown in practice. Keywords: difference equations, generating function, channel capacity
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Continuous and discrete models of population biology
Fedorková, Lucie ; Tomášek, Petr (referee) ; Čermák, Jan (advisor)
This thesis analyzes the continuous and discrete logistic model of a single-species population. For both of these models, there are discussed problems of equilibria, their stability and behaviour of the solutions for different initial conditions. In the case of the discrete model, the periodic behaviour of solutions is discussed in detail with respect to change of a parameter characterizing growth of the investigated population. The chaotic behaviour of solutions is mentioned as well. The graphic interpretations of each of the problems are performed using the software MATLAB. The calculations are checked via the software Maple.
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The Qualitative and Numerical Analysis of Nonlinear Delay Differential Equations
Dvořáková, Stanislava ; Baštinec, Jaromír (referee) ; Šremr,, Jiří (referee) ; Čermák, Jan (advisor)
Disertační práce formuluje asymptotické odhady řešení tzv. sublineárních a superlineárních diferenciálních rovnic se zpožděním. V těchto odhadech vystupuje řešení pomocných funkcionálních rovnic a nerovností. Dále práce pojednává o kvalitativních vlastnostech diferenčních rovnic se zpožděním, které vznikly diskretizací studovaných diferenciálních rovnic. Pozornost je věnována souvislostem asympotického chování řešení rovnic ve spojitém a diskrétním tvaru, a to v obecném i v konkrétních případech. Studována je rovněž stabilita numerické diskretizace vycházející z $\theta$-metody. Práce obsahuje několik příkladů ilustrujících dosažené výsledky.
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Representation of Solutions of Linear Discrete Systems with Delay
Morávková, Blanka ; Růžičková, Miroslava (referee) ; Khusainov, Denys (referee) ; Diblík, Josef (advisor)
Disertační práce se zabývá lineárními diskrétními systémy s konstantními maticemi a s jedním nebo dvěma zpožděními. Hlavním cílem je odvodit vzorce analyticky popisující řešení počátečních úloh. K tomu jsou definovány speciální maticové funkce zvané diskrétní maticové zpožděné exponenciály a je dokázána jejich základní vlastnost. Tyto speciální maticové funkce jsou základem analytických vzorců reprezentujících řešení počáteční úlohy. Nejprve je uvažována počáteční úloha s impulsy, které působí na řešení v některých předepsaných bodech, a jsou odvozeny vzorce popisující řešení této úlohy. V další části disertační práce jsou definovány dvě různé diskrétní maticové zpožděné exponenciály pro dvě zpoždění a jsou dokázány jejich základní vlastnosti. Tyto diskrétní maticové zpožděné exponenciály nám dávají možnost najít reprezentaci řešení lineárních systémů se dvěma zpožděními. Tato řešení jsou konstruována v poslední kapitole disertační práce, kde je řešení tohoto problému dáno pomocí dvou různých vzorců.
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Solution of difference equations and relation with Z-transform
Klimek, Jaroslav ; Smékal, Zdeněk (referee) ; Růžičková,, Miroslava (referee) ; Diblík, Josef (advisor)
This dissertation presents the solution of difference equations and focuses on a method of difference equations solution with the aid of eigenvectors. The first part reminds the basic terms from area of difference equations such as dynamic of difference equations and linear difference equations of first order and higher order. Then the second section recalls also the system of difference equations including the fundamental matrix and general solution description. Afterthat, the method of solving the difference equations with a variation of constants and transform of scalar equations to the system are shown. The second part of the dissertation analyses some known algorithms and methods for the solution of linear difference equations. The Z-transform, its importance and usage for finding the solution of difference equation is recalled. Then the discrete analogue of Putzer's algorithm is mentioned because this algorithm was often used to check the results obtained by the newly described algorithm in further parts of this thesis. Also some ways of the system matrix power are stated. The next section then describes the principle of Weyr's method which is the basic point for further development of the theory including the presentation of the research results gained by Jiří Čermák in this area. The third part describes own solution of the difference equations system via eigenvectors based on the principle of Weyr's method for differential equations. The solution of system of linear homogeneous difference equtions with constant coefficients including the proof is presented and this solution is then extended to nonhomogeneous systems. Consequently to the theory, the influence of a nulity and the multiplicity of roots on the form of the solution is discussed. The last section of this part shows the implementation of the algorithm in Matlab program (for basic simpler cases) and its application to some cases of difference equations and systems with these equations. The final part of the thesis is more practical and it presents the usage of the designed algorithm and theory. Firstly, the algorithm is compared with Z-transform and the method of variation of constants and it is illustrated how to obtain the same results by using these three approaches. Then an example of current response solution in RLC circuit is demonstrated. The continuous case is solved and then the problem is transferred to discrete case and solved with the Z-transform and the method of eigenvectors. The obtained results are compared with the result of the continuous case.
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Linear difference equations: stability analysis
Tesař, Lukáš ; Dosoudilová, Monika (referee) ; Tomášek, Petr (advisor)
This thesis deals with asymptotic stability investigation of linear difference equation. The Schur-Cohn criterion and discrete Routh-Schur criterion are introduced and demonstrated on several examples. Both criterions are implemented in Maple programming enviroment. Boundary locus technique is illustrated on a stability analysis of the Adams-Bashforth method for numerical solving of an initial value problem of first order ordinary differential equation.
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