National Repository of Grey Literature 8 records found  Search took 0.00 seconds. 
Numerical solution of traffic flow models
Vacek, Lukáš ; Kučera, Václav (advisor) ; Janovský, Vladimír (referee)
Our work describes the simulation of traffic flows on networks. These are described by partial differential equations. For the numerical solution of our models, we use the discontinuous Galerkin method in space and a multistep method in time. This combination of the two methods on networks is unique and leads to a robust numerical scheme. We use several different approaches to model the traffic flow. Thus, our program must solve both scalar problems as well as systems of equations described by first and second order partial differential equations. The output of our programs is, among other things, the evolution of traffic density in time and 1D space. Since this is a physical quantity, we introduce limiters which keep the density in an admissible interval. Moreover, limiters prevent spurious oscillations in the numerical solution. All the above is performed on networks. Thus, we must deal with the situation at the junctions, which is not standard. The main task is to ensure that the law of conservation of the total amount of cars passing through the junction is still satisfied. This is achieved by modifying the numerical flux for junctions. The result of this work is the comparison of all the models, the demonstration of the benefits of the discontinuous Galerkin method and the influence of limiters.
Optimal portfolios
Vacek, Lukáš ; Hurt, Jan (advisor) ; Večeř, Jan (referee)
In this diploma thesis, selected techniques for construction of optimal portfo- lios are presented. Risk measures and other criteria (Markowitz approach, Value at risk, Conditional value at risk, Mean absolute deviation, Spectral risk measure and Kelly criterion) are defined in the first part. We derived analytical solution for some cases of optimization problems, in some other cases there exists numeri- cal solution only however. Advantages and disadvantages, theoretical properties and practical aspects of software implementation in Wolfram Mathematica are also mentioned. Simulation methods suitable for portfolio optimization are brie- fly presented with their motivation in the second part. Multivariate distributions: normal, t-distribution and skewed t-distribution are presented in the third part with connection to optimization of portfolio with assumption of multivariate dis- tribution of financial losses. Optimization methods are illustrated on real data in the fourth part of this thesis. Analytical methods are compared with numerical ones. 1
Field of values of a matrix: Theory and computation
Vacek, Lukáš ; Tichý, Petr (advisor) ; Tůma, Miroslav (referee)
The field of values of a matrix A is a convex set in the complex plane assigned to A. It is important in matrix analysis, especially in invetigation of properties of nonnormal matrices and matrix polynomials, in study of the con- vergence of iterative methods applied to these matrices, in the estimation of ma- trix function norms, etc. This thesis summarizes theory about the field of values of a matrix, formulates open problems and explaines the main idea of the basic numerical method for its computation. In numerical experiments the standart algorithmic realization of method is compared with alternative approaches that use power method, Lanczos algorithm and Chebfun.
Probability distributions of financial losses
Vacek, Lukáš ; Hurt, Jan (advisor) ; Zichová, Jitka (referee)
In this bachelor thesis, selected probability distributions which might appear useful for financial losses modelling are presented. Losses, risk measures and an example with a normality assumption are defined in the first part. Among others, the following distributions are presented in the second part: asymmetric Laplace distribution, skew normal distribution and generalized hyperbolic distribution. We present selected theoretical properties of these distributions. Procedures of a derivation of two asymmetric distributions from their symmetric cases are discribed. The asymmetric Laplace distribution is described more in detail, we also listed the maximum likelihood estimation with its implementation in software Wolfram Mathematica 10. The third part is a short numerical study, where an application of selected distributions is presented on real market data. Test of randomness and goodness of fit tests are performed. Powered by TCPDF (www.tcpdf.org)
Ma Zhiyuan - Huangliangmeng (analysis and translation)
Vacek, Lukáš ; Andrš, Dušan (referee) ; Lomová, Olga (advisor)
V této práci se budu zabývat čínským dramatikem z přelomu 13. a 14. století Ma Zhiyuanem (Jl; ft.iit.) a především jeho divadelní hrou Huangliang meng1 (~ :W:. ~). Pokusím se ukázat problematiku překladu čínského literárního útvaru a zjistit, zda se překladatelské teorie, které zde zastoupí práce a názory J. Levého, založené na zkušenosti z překládání literárních děl v rámci evropského kulturního kontextu, dají použít jako teoretické východisko i při překládání takto jazykově i kulturně odlišného útvaru. Mým záměrem je především podat ucelený pohled na problematiku a charakter hry Huangliang meng, zasadit ji do kontextu žánrových konvencí a doby, kdy vznikala, a ukázat, v čem spočívají její specifika. Na rozboru hry budu chtít ukázat zásadní problémy překladu a na několika příkladech se zároveň pokusím postihnout výrazné literární prostředky a autorský styl Ma Zhiyuana. Poté přistoupím k literárnímu překladu prvního jednání, abychom si jednotlivé přístupy, problémy a charakteristické motivy představili z celkového pohledu překladatele i čtenáře. Powered by TCPDF (www.tcpdf.org)
Adventure Game with Intelligent Cooperating Actors
Vacek, Lukáš ; Samek, Jan (referee) ; Zbořil, František (advisor)
The goal of this master's thesis is to design and implement framework that can be used for development of agent systems. Framework is implemented in Java and encapsulates JADE library. Framework is used for implementation of adventure game. There are several characters (agents) with specific roles who cooperate and try to achieve their goals.
A Tool for Automated Testing of GUI
Vacek, Lukáš ; Charvát, Lukáš (referee) ; Smrčka, Aleš (advisor)
Despite of GUI usability and availability is GUI testing quite new specialization technique. Manual testing is often used for verifying of GUI functionality. The aim of this work is to create a tool for testing and controling GUI. By tool is meant library for automated testing of GUI using object recognization method. Library detects basic GUI elements and controls them according to their standard behavior. Object detection depends on image processing and tracing graphic changes while mouse and key events are incoming.
Design of core shooting machine with a fixed head
Vacek, Lukáš ; Pavlík, Jan (referee) ; Bradáč, František (advisor)
This work deals with shooting machines with fixed head engineering design. The first part follows up purpose of cores using in the foundry industry and its development. Marginally addresses problems arising in the foundry industry related to the environment and then comparing shooting machines used for the cores production. The work includes a three-dimensional structural model of shooting machine describing the various parts, strength calculations and detailed design of machine worktable.

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1 Vacek, Lubomír
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