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Parallelisation of Ultrasound Simulations on Multi-GPU Clusters
Dujíček, Aleš ; Kula, Michal (referee) ; Jaroš, Jiří (advisor)
This work is part of the k-Wave project, which is a toolbox designed for time ultrasound simulations in complex and heterogeneous media. The simulation functions are based on the k-space pseudospectral method. The goal of this work is to compute these simulations on graphics cards using local domain decompostion. Thanks to decomposition we could compute these simulations faster, and on larger data grids. The main goal of this work is to achieve efficiency and scalability.
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Parallelisation of Ultrasound Simulations on Intel Xeon Phi Accelerator
Vrbenský, Andrej ; Hrbáček, Radek (referee) ; Jaroš, Jiří (advisor)
Nowadays, the simulation of ultrasound acoustic waves has a wide range of practical usage. As one of them we can name the simulation in realistic tissue media, which is successfully used in medicine. There are several software applications dedicated to perform such simulations. k-Wave is one of them. The computational difficulty of the simulation itself is very high, and this leaves a space to explore new speed-up methods. In this master's thesis, we proposed a way to speed-up the simulation based on parallelization using Intel Xeon Phi accelerator. The accelerator contains large amount of cores and an extra-wide vector unit, and therefore, is ideal for purpose of parallelization and vectorization. The implementation is using OpenMP version 4.0, which brings some new options such as explicit vectorization. Results were measured during extensive experiments.
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Portfólio Value at Risk a Expected Shortfall s použitím vysoko frekvenčních dat
Zváč, Marek ; Fičura, Milan (advisor) ; Janda, Karel (referee)
The main objective of this thesis is to investigate whether multivariate models using Highfrequency data provide significantly more accurate forecasts of Value at Risk and Expected Shortfall than multivariate models using only daily data. Our objective is very topical since the Basel Committee announced in 2013 that is going to change the risk measure used for calculation of capital requirement from Value at Risk to Expected Shortfall. The further improvement of accuracy of both risk measures can be also achieved by incorporation of high-frequency data that are rapidly more available due to significant technological progress. Therefore, we employed parsimonious Heterogeneous Autoregression and its asymmetric version that uses high-frequency data for the modeling of realized covariance matrix. The benchmark models are chosen well established DCC-GARCH and EWMA. The computation of Value at Risk (VaR) and Expected Shortfall (ES) is done through parametric, semi-parametric and Monte Carlo simulations. The loss distributions are represented by multivariate Gaussian, Student t, multivariate distributions simulated by Copula functions and multivariate filtered historical simulations. There are used univariate loss distributions: Generalized Pareto Distribution from EVT, empirical and standard parametric distributions. The main finding is that Heterogeneous Autoregression model using high-frequency data delivered superior or at least the same accuracy of forecasts of VaR to benchmark models based on daily data. Finally, the backtesting of ES remains still very challenging and applied Test I. and II. did not provide credible validation of the forecasts.
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Model of controllable current amplifier based on diamond transistors and voltage amplifiers
Kos, David ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
This thesis is focused on modelling of controllable current amplifier based on voltage controllable amplifiers and diamond transistors. In a first part of the thesis, principle of modelling of diamond transistor and features of diamond transistor OPA860 are discussed. Furthermore, there are discussed features of amplifiers with controllable voltage gain (VCA810 and LMH6505) with main focus on their gain. These amplifiers are used for modelling the current amplifiers. In the next parts there are analyzed of the proposed models and verification of the simulations. The functionality of the models is verified by practical measurements and results are compared with the simulations. In conclusion of the thesis, there are examples of simple applications.
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Napěťová analýza radiální náhrady vřetenní kosti v loketním kloubu
Hlavoň, Pavel ; Florian, Z.
The paper is focused on computational modeling of elbow articulation with radial head replacement. The main part of the project is aimed towards the creation of computational model of suitable partial endoprothesis of proximal part of the radial bone tissue which would keep the function of the elbow articulation while replacing the distance created by resection. The geometrical and computational model of particular radial head replacement and elbow joint were created and analyzed. Computational model with that implant was compared with given physiological state of elbow articulation. The influence of friction and material characteristics of bone tissue and cartilage on changes in contact pressure (and therefore to the abrasion) were analyzed using this model.
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Modelling 3D Forest Structure for Improved Retrieval of Forest Biophysical Properties
Janoutová, Růžena ; Albrechtová,, Jana (referee) ; Štarha, Pavel (referee) ; Martišek, Dalibor (advisor)
Hlavním cílem práce bylo zlepšení kvantitativních odhadů vegetačních parametrů smrkových porostů pomocí spektrálních simulací trojrozměrného modelu přenosu záření. Prvně bylo potřeba vytvořit přesný 3D model smrku. Implementace přesného 3D modelu smrku pro parametrizaci celých lesních porostů je v současné době výpočetně nemožné, bylo tedy nutné tento 3D model smrku zjednodušit. Přesný 3D model smrku společně s dostupnými leteckými daty sloužil pro nalezení optimálního zjednodušení. Optimální model vedl ke kompromisu mezi výpočetní náročností a přesností výsledné odrazivosti z modelu přenosu záření. Následně byl optimální model smrku využit pro odhady vegetačních parametrů ze satelitních snímků. Přesnost odhadů byla ověřena oproti pozemním měřením odhadovaných parametrů. Na závěr byly porovnány výsledky z odhadů vegetačních parametrů pomocí optimálního 3D modelu smrku s výsledky z tradičního přístupu pomocí modelů stromu s geometricky jednodušími tvary korun.
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New Approaches in Airborne Thermal Image Processing for Landscape Assessment
Pivovarník, Marek ; Pokorný,, Jan (referee) ; Štarha, Pavel (referee) ; Zemek, František (advisor)
Letecká termální hyperspektrální data přinášejí řadu informací o teplotě a emisivitě zemského povrchu. Při odhadování těchto parametrů z dálkového snímání tepelného záření je třeba řešit nedourčený systém rovnic. Bylo navrhnuto několik přístupů jak tento problém vyřešit, přičemž nejrozšířenější je algoritmus označovaný jako Temperature and Emissivity Separation (TES). Tato práce má dva hlavní cíle: 1) zlepšení algoritmu TES a 2) jeho implementaci do procesingového řetězce pro zpracování obrazových dat získaných senzorem TASI. Zlepšení algoritmu TES je možné dosáhnout nahrazením používaného modulu normalizování emisivity (tzv. Normalized Emissivity Module) částí, která je založena na vyhlazení spektrálních charakteristik nasnímané radiance. Nový modul je pak označen jako Optimized Smoothing for Temperature Emissivity Separation (OSTES). Algoritmus OSTES je připojen k procesingovému řetězci pro zpracování obrazových dat ze senzoru TASI. Testování na simulovaných datech ukázalo, že použití algoritmu OSTES vede k přesnějším odhadům teploty a emisivity. OSTES byl dále testován na datech získaných ze senzorů ASTER a TASI. V těchto případech však není možné pozorovat výrazné zlepšení z důvodu nedokonalých atmosférických korekcí. Nicméně hodnoty emisivity získané algoritmem OSTES vykazují více homogenní vlastnosti než hodnoty ze standardního produktu senzoru ASTER.
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A classic experiment and computer simulation in physics teaching
PELC, Vít
The thesis discusses the use of the classical experiment and computer simulation in teaching physics at the elementary school. Paper defines the term experiment focuses on specific types of classic experiment and computer simulation options. A classic experiment and computer simulation in the research section gives associated with motivation for learning in physics classes. In the didactic analysis in teaching physics at inclusion classical experiment and computer simulation evaluates the effectiveness of the selected type of experiment.
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The appraisal of development of tax proportion of budgetary incomes of municipalities and regions in the Czech Republic
Poláková, Tereza ; Peková, Jitka (advisor) ; Krbová, Jana (referee)
The aim of this diploma thesis is a detailed analysis of tax incomes of municipalities and regions with focus on four particular municipalities and one region in a practical part. From the year 2001 to 2015 the share of tax incomes and their development are evaluated as a part of total incomes. The theme is highly topical due to ongoing discussions among lawmakers on the subject of budgetary allocation of taxes. The law determining the budgetary allocation of taxes is modified frequently, that is why knowing the impact of changes on particular municipalities or regions is helpful. This knowledge can be useful base for planning new adjustments of budgetary allocation of taxes. In the theoretical part there are mentioned expert opinions on financial management of municipalities and regions that arise from their functions and positions. The emphasis is put on incomes of municipalities and regions, especially on tax incomes. Particular changes from 2001 to 2015 in law regulating budgetary allocation of taxes are described here with their impacts on municipalities and regions. Incomes and management of selected municipalities representing various size categories and Liberec region are analysed in the practical part. Financial self-sufficiency is evaluated here. In general municipalities are more financial self-sufficient than regions. This thesis is further dealing with individual tax incomes and impacts of changes in budgetary allocation of taxes on their size. Making models of theoretical incomes is used to simulate effects of diverse law adjustments. Results of the analysis show that tax incomes of municipalities and regions are generally increasing. During the observed period there was tendency to lower the growth of tax incomes of large cities, to increase the growth of tax incomes of small municipalities and to straighten the level of tax incomes of medium municipalities thanks to changes in budgetary allocation of taxes. Tax incomes of regions were increased thanks to changes in budgetary allocation of taxes despite of partial decrease in particular segments of tax incomes after 2012.
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