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Influence of injection dose and body parameters on PET image quality by means of Monte Carlo simulations
Dvořák, Jiří ; Boldyš, Jiří (advisor) ; Prokešová, Michaela (referee)
Positron emission tomography (PET) is an imaging technique allowing to determine radiotracer distribution in a patient's body. This work reviews basic principles of PET imaging. It also uses the random field theory to detect locations with increased radiotracer uptake. This procedure is tested on a collection of simulated PET images. The aim of this work is to describe the quality of simulated PET images in terms of both the patient's physical parameters and the amount of applied radiopharmaceutical. The relations are used to provide curves of constant quality determining the amount of radiopharmaceutical needed to achieve desired quality of the resulting images. The resulting curves are compared with the formula currently used in medical practice.
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Analýza výsledků modelování částicových jevů v počítačových hrách
Novotný, Jiří ; Boldyš, Jiří (advisor) ; Beneš, Jan (referee)
The main subject of this thesis is to design a method that is able to compare the outputs of a manually set up particle system with a video template of a simulated particle phenomenon. For the sake of simplicity, this work is focused exclusively to smoke effects and its comparisons. Specifically, descriptors depicting the color scheme of the examined input videos are proposed as well as the shape descriptors and time variability descriptors, which are based on the image segmentation method called Alpha Matting. This method is able to distinguish foreground objects from the background, while the foreground objects are described together with their transparency. Video template recordings captured specially for the purpose of this work are included. At the end, the resulting method is supported by an example of the gradually improving smoke effect simulation. Powered by TCPDF (www.tcpdf.org)
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Visually realistic modeling of dynamic objects deformations
Bulušek, Petr ; Boldyš, Jiří (advisor) ; Šír, Zbyněk (referee)
The present work deals with simulation methods for rigid bodies and deformable bodies. In the first chapter you can find research of some methods for simulation of rigid body physics with emphasis on method used in open source physics engine Bullet. In second chapter you can find methods for simulation of deformable bodies, again with emphasis on Bullet physics engine. In last chapter model order reduction technique is presented. This method enables to reduce system of ordinary differential equations. These equations come for example from applying finite element method to partial differential equations describing motion of elastic body. The technique is studied on bar truss systems. Powered by TCPDF (www.tcpdf.org)
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Signal complexity evaluation in the processing of functional magnetic resonance imaging
Vyhnánek, Jan ; Boldyš, Jiří (advisor) ; Dvořák, Jiří (referee)
Functional magnetic resonance imaging has been recently the most common tool for examining the neural activity in human and animals. The goal of a typical data-mining challenge is the localisation of brain areas activated during a cognitive task which is usually performed using a linear model or correlation methods. For this purpose several authors have proposed the use of methods evaluating signal complexity which could possibly overcome some of the shortcomings of the standards methods due to their independence on a priori knowledge of data characteristics. This work explains possibilities of using such methods including aspects of their configuration and it proposes an evaluation of performance of the methods applied on simulated data following expected biological characteristics. The results of the evaluation of performance showed little advantage of these methods over the standard ones in cases when the standard methods were possible to apply. However, some of the methods evaluating signal complexity were found useful for determining the regularity of signals which is a feature that cannot be assessed by the standard methods. Optimal parameters of the methods evaluating signal regularity were determined on simulated data and finally the methods were applied on the data examining emotional processing of...
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Analysis of results of particle phenomena modeling in computer games
Novotný, Jiří ; Boldyš, Jiří (advisor)
The main subject of this thesis is to design a method that is able to compare the outputs of a manually set up particle system with a video template of a simulated particle phenomenon. For the sake of simplicity, this work is focused exclusively to smoke effects and its comparisons. Specifically, descriptors depicting the color scheme of the examined input videos are proposed as well as the shape descriptors and time variability descriptors, which are based on the image segmentation method called Alpha Matting. This method is able to distinguish foreground objects from the background, while the foreground objects are described together with their transparency. Video template recordings captured specially for the purpose of this work are included. At the end, the resulting method is supported by an example of the gradually improving smoke effect simulation. Powered by TCPDF (www.tcpdf.org)
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Analysis of results of particle phenomena modeling in computer games
Novotný, Jiří ; Boldyš, Jiří (advisor)
The main subject of this thesis is to design a method that is able to compare the outputs of a manually set up particle system with a video template of a simulated particle phenomenon. For the sake of simplicity, this work is focused exclusively to smoke effects and its comparisons. Specifically, descriptors depicting the color scheme of the examined input videos are proposed as well as the shape descriptors and time variability descriptors, which are based on the image segmentation method called Alpha Matting. This method is able to distinguish foreground objects from the background, while the foreground objects are described together with their transparency. Video template recordings captured specially for the purpose of this work are included. At the end, the resulting method is supported by an example of the gradually improving smoke effect simulation. Powered by TCPDF (www.tcpdf.org)
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Analýza výsledků modelování částicových jevů v počítačových hrách
Novotný, Jiří ; Boldyš, Jiří (advisor) ; Beneš, Jan (referee)
The main subject of this thesis is to design a method that is able to compare the outputs of a manually set up particle system with a video template of a simulated particle phenomenon. For the sake of simplicity, this work is focused exclusively to smoke effects and its comparisons. Specifically, descriptors depicting the color scheme of the examined input videos are proposed as well as the shape descriptors and time variability descriptors, which are based on the image segmentation method called Alpha Matting. This method is able to distinguish foreground objects from the background, while the foreground objects are described together with their transparency. Video template recordings captured specially for the purpose of this work are included. At the end, the resulting method is supported by an example of the gradually improving smoke effect simulation. Powered by TCPDF (www.tcpdf.org)
|
|
|
Visually realistic modeling of dynamic objects deformations
Bulušek, Petr ; Boldyš, Jiří (advisor) ; Šír, Zbyněk (referee)
The present work deals with simulation methods for rigid bodies and deformable bodies. In the first chapter you can find research of some methods for simulation of rigid body physics with emphasis on method used in open source physics engine Bullet. In second chapter you can find methods for simulation of deformable bodies, again with emphasis on Bullet physics engine. In last chapter model order reduction technique is presented. This method enables to reduce system of ordinary differential equations. These equations come for example from applying finite element method to partial differential equations describing motion of elastic body. The technique is studied on bar truss systems. Powered by TCPDF (www.tcpdf.org)
|
|
|
Signal complexity evaluation in the processing of functional magnetic resonance imaging
Vyhnánek, Jan ; Boldyš, Jiří (advisor) ; Dvořák, Jiří (referee)
Functional magnetic resonance imaging has been recently the most common tool for examining the neural activity in human and animals. The goal of a typical data-mining challenge is the localisation of brain areas activated during a cognitive task which is usually performed using a linear model or correlation methods. For this purpose several authors have proposed the use of methods evaluating signal complexity which could possibly overcome some of the shortcomings of the standards methods due to their independence on a priori knowledge of data characteristics. This work explains possibilities of using such methods including aspects of their configuration and it proposes an evaluation of performance of the methods applied on simulated data following expected biological characteristics. The results of the evaluation of performance showed little advantage of these methods over the standard ones in cases when the standard methods were possible to apply. However, some of the methods evaluating signal complexity were found useful for determining the regularity of signals which is a feature that cannot be assessed by the standard methods. Optimal parameters of the methods evaluating signal regularity were determined on simulated data and finally the methods were applied on the data examining emotional processing of...
|
|
|
Influence of injection dose and body parameters on PET image quality by means of Monte Carlo simulations
Dvořák, Jiří ; Boldyš, Jiří (advisor) ; Prokešová, Michaela (referee)
Positron emission tomography (PET) is an imaging technique allowing to determine radiotracer distribution in a patient's body. This work reviews basic principles of PET imaging. It also uses the random field theory to detect locations with increased radiotracer uptake. This procedure is tested on a collection of simulated PET images. The aim of this work is to describe the quality of simulated PET images in terms of both the patient's physical parameters and the amount of applied radiopharmaceutical. The relations are used to provide curves of constant quality determining the amount of radiopharmaceutical needed to achieve desired quality of the resulting images. The resulting curves are compared with the formula currently used in medical practice.
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