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Modelling of parametric arterial input function in perfusion imaging
Černý, Štěpán ; Jiřík, Radovan (referee) ; Kratochvíla, Jiří (advisor)
The task of this bachelor’s tesis is to study the subject in the area of perfusion imaging based on dynamic imaging with T1 contrast. Aims is primarily on the role of the arterial input function. Principles phenomenon of dynamic magnetic resonance measurements are discribed. The role of contrast media and their influence on the relaxation time T1 are described. It is also described problems perfusion analysis, measurement and mathematical modeling of arterial input function and perfusion acquisition parameters. In the experimental part, there is modeled several models of arterial input function and their evaluation. Further the creation program for the approximation real measurement of arterial input function created models and the integration of this program into a graphical interface created for work with models. Was also verified the functionality of the program and evaluate the success of approximations for individual models.
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SLM process parameters optimization for processing of AW2618 aluminum alloy
Těšický, Lukáš ; Dočekalová, Kateřina (referee) ; Koutný, Daniel (advisor)
The diploma thesis deals with possibilities for processing aluminium alloy EN AW 2618 using Selective laser melting (SLM). The theoretical part contains basic knowledge about production by this technology and possibilities of evaluation of relative density of samples. It also contains an overview of the current state of knowledge about the processing of aluminium alloys by SLM technology. Above all, aluminium alloys of the series 2000, where the main alloying element is copper. In the experimental part testing samples were designed based on the research. These samples can be divided into three areas: single-track specimens, volume samples and samples for tensile testing. Single-track and volume samples were used to find appropriate processing parameters to achieve a relative density close to full volume of material. For this purpose, the effect of the different scanning strategies on the relative density of the sample were examined. The limiting factor has been the occurrence of small cracks in the broad range of parameters studied. Mechanical properties of samples produced by SLM were compared with extruded material. It was found that the material processed by SLM achieves only half the yield strength and tensile strength of extruded material. This is mainly due to the occurrence of small cracks and other defects in the structure of the material.
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Classification of Music Files Using Machine Learning
Sládek, Matyáš ; Smrčka, Aleš (referee) ; Janoušek, Vladimír (advisor)
This thesis is focused on classification of music files using machine learning algorithms. Seven classifiers were compared in this thesis, based on classification accuracy and speed. Two feature extraction methods, two feature selection methods and two parameter optimization methods were used. The best classifier proved to be XGBClassifier, which had reached accuracy of 87.56 % on dataset Extended Ballroom Dataset, 64.56 % on dataset FMA: A Dataset For Music Analysis and 83.50 % on dataset GTZAN. This model could be used for playlist creation or music database categorization.
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Classification of Music Files Using Machine Learning
Sládek, Matyáš ; Smrčka, Aleš (referee) ; Janoušek, Vladimír (advisor)
This thesis is focused on classification of music files using machine learning algorithms. Seven classifiers were compared in this thesis, based on classification accuracy and speed. Two feature extraction methods, two feature selection methods and two parameter optimization methods were used. The best classifier proved to be XGBClassifier, which had reached accuracy of 87.56 % on dataset Extended Ballroom Dataset, 64.56 % on dataset FMA: A Dataset For Music Analysis and 83.50 % on dataset GTZAN. This model could be used for playlist creation or music database categorization.
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Optimization of assembly line parameters
HODIÁNEK, Pavel
The introductory part of this thesis is theoretical. Here I deal with the standards that the automotive must follow. I describe also basic concepts, division of production, assembly lines and layout of single work positions. In the next part I deal with modifications of the workplace, its release for production and the SMED method. In the practical part I analyze the current process of re-assembly of the assembly line and then I create suggestions for its optimization.
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SLM process parameters optimization for processing of AW2618 aluminum alloy
Těšický, Lukáš ; Dočekalová, Kateřina (referee) ; Koutný, Daniel (advisor)
The diploma thesis deals with possibilities for processing aluminium alloy EN AW 2618 using Selective laser melting (SLM). The theoretical part contains basic knowledge about production by this technology and possibilities of evaluation of relative density of samples. It also contains an overview of the current state of knowledge about the processing of aluminium alloys by SLM technology. Above all, aluminium alloys of the series 2000, where the main alloying element is copper. In the experimental part testing samples were designed based on the research. These samples can be divided into three areas: single-track specimens, volume samples and samples for tensile testing. Single-track and volume samples were used to find appropriate processing parameters to achieve a relative density close to full volume of material. For this purpose, the effect of the different scanning strategies on the relative density of the sample were examined. The limiting factor has been the occurrence of small cracks in the broad range of parameters studied. Mechanical properties of samples produced by SLM were compared with extruded material. It was found that the material processed by SLM achieves only half the yield strength and tensile strength of extruded material. This is mainly due to the occurrence of small cracks and other defects in the structure of the material.
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Modelling of parametric arterial input function in perfusion imaging
Černý, Štěpán ; Jiřík, Radovan (referee) ; Kratochvíla, Jiří (advisor)
The task of this bachelor’s tesis is to study the subject in the area of perfusion imaging based on dynamic imaging with T1 contrast. Aims is primarily on the role of the arterial input function. Principles phenomenon of dynamic magnetic resonance measurements are discribed. The role of contrast media and their influence on the relaxation time T1 are described. It is also described problems perfusion analysis, measurement and mathematical modeling of arterial input function and perfusion acquisition parameters. In the experimental part, there is modeled several models of arterial input function and their evaluation. Further the creation program for the approximation real measurement of arterial input function created models and the integration of this program into a graphical interface created for work with models. Was also verified the functionality of the program and evaluate the success of approximations for individual models.
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