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The issue of VFR flights at high altitudes
Vrána, Jiří ; Chlebek, Jiří (referee) ; Hammer, Jaromír (advisor)
This bachelor thesis deals with procedures of VFR flight at high altitudes. It describes the division of airspace including the limitations applied and significant international organizations in relation to its management and organization. It also focuses on the rules for the execution of VFR flights, non-standard flights, and comparison of non-standard flights with adjacent states.
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Use of the dynamic damper in hydrodynamics
Vrána, Jiří ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The master thesis deals with the possibility of using dynamic damper in hydrodynamics. Specifically, the assessment of the impact of dynamic damper on the dynamic stability of the fluid system when the system exhibited unstable behaviour prior to damper installation due to self-excited vibration. In the thesis is presented the algorithm for the calculation of pressure and flow pulsations based on the transfer matrix method, the transition matrices for different damper designs variants are derived. Using the algorithm, the effect of a damper placed in a stable and unstable fluid system is solved. The output of this work is software for solution of pressure and flow pulsations in the system with serially arranged hydrodynamic elements created in the MATLAB program.
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Pendulum excitation
Vrána, Jiří ; Březina, Lukáš (referee) ; Hadaš, Zdeněk (advisor)
This thesis is focused on creating a model situation of excited pendulum with one degree of freedom that oscillates in both linear and nonlinear condition. The theoretical part describes several basic concepts of oscillation theory and states some examples of pendulum applicability. The practical part consists assembling of motion equations of model situations, based on which simulations programs are created. The thesis contains also concept of practical use of the nonlinear pendulum model.
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Evaluation of patient radiation load due to radiodiagnostic examinations
Drobílková, Daniela ; Daneš, Jan (advisor) ; Vrána, Jiří (referee)
The aim of this study is to determination of local diagnostic reference levels for radiodiagnostic examination in the General Teaching Hospital in Prague. Local diagnostic reference levels are used for an evaluation of radiation load which patients receive during medical examinations of specific parts of the human body. The evaluation can be on the level of a hospital and its department or on the level of concrete X-ray machine. The theoretical part describes a ionizing radiation, including its interaction with matter, creating, formation of radiodiagnostic image, legislation during optimization of radiodiagnostic examination, radiological protection and determination of values for radiation dose. The practical part describes the determination of local diagnostic reference levels with the help of entrance surface kerma and the median dose in the mammary gland. Both of these variables are relevant for determination of the risk of adverse effects of ionizing radiation which is applied during radiographic examination. Data for this study was collected with the help of operating diaries and PACS system. It has been rated twenty-six kinds of examinations from twelve mobile and nine stationary (including two mammographs) X-ray machines. All resulting values were statistically processed and compared with...
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Somatomotor and somatosensory modulation of pain in the EEG and fMR image
Vrána, Jiří ; Stančák, Andrej (advisor) ; Vymazal, Josef (referee) ; Jech, Robert (referee) ; Hájek, Milan (referee)
Pain processing is modulated at different levels of the central nervous system by concurrent sensory and motor processes. From previous studies with innocuous somatosensory evoked potentials we know of the phenomenon of gating by movement. The classical explanation [Melzack R, Wall PD. Pain mechanisms: a new theory. Science 1965;150(699):971-979.] of the mechanism of gating in the posterior horn of spinal cord is complemented by other, lesser understood data, suggesting supraspinal mechanisms. A similar lack of understanding of the cortical mechanisms is seen in pain modulating methods using concurrent electrical nerve stimulation. This work is intended to further our understanding of the cortical mechanisms of pain modulation in the specific cases of (a) isometric muscle contraction of the right or left hand during painful electrical intraepidermal stimulation of the right index finger and (b) during observation of the acute effects of concurrent innocuous median nerve stimulation on painful tonic thermal stimulation of the thenar eminence.
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|
Use of the dynamic damper in hydrodynamics
Vrána, Jiří ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The master thesis deals with the possibility of using dynamic damper in hydrodynamics. Specifically, the assessment of the impact of dynamic damper on the dynamic stability of the fluid system when the system exhibited unstable behaviour prior to damper installation due to self-excited vibration. In the thesis is presented the algorithm for the calculation of pressure and flow pulsations based on the transfer matrix method, the transition matrices for different damper designs variants are derived. Using the algorithm, the effect of a damper placed in a stable and unstable fluid system is solved. The output of this work is software for solution of pressure and flow pulsations in the system with serially arranged hydrodynamic elements created in the MATLAB program.
|
|
|
The issue of VFR flights at high altitudes
Vrána, Jiří ; Chlebek, Jiří (referee) ; Hammer, Jaromír (advisor)
This bachelor thesis deals with procedures of VFR flight at high altitudes. It describes the division of airspace including the limitations applied and significant international organizations in relation to its management and organization. It also focuses on the rules for the execution of VFR flights, non-standard flights, and comparison of non-standard flights with adjacent states.
|
|
|
Pendulum excitation
Vrána, Jiří ; Březina, Lukáš (referee) ; Hadaš, Zdeněk (advisor)
This thesis is focused on creating a model situation of excited pendulum with one degree of freedom that oscillates in both linear and nonlinear condition. The theoretical part describes several basic concepts of oscillation theory and states some examples of pendulum applicability. The practical part consists assembling of motion equations of model situations, based on which simulations programs are created. The thesis contains also concept of practical use of the nonlinear pendulum model.
|
|
|
Evaluation of patient radiation load due to radiodiagnostic examinations
Drobílková, Daniela ; Daneš, Jan (advisor) ; Vrána, Jiří (referee)
The aim of this study is to determination of local diagnostic reference levels for radiodiagnostic examination in the General Teaching Hospital in Prague. Local diagnostic reference levels are used for an evaluation of radiation load which patients receive during medical examinations of specific parts of the human body. The evaluation can be on the level of a hospital and its department or on the level of concrete X-ray machine. The theoretical part describes a ionizing radiation, including its interaction with matter, creating, formation of radiodiagnostic image, legislation during optimization of radiodiagnostic examination, radiological protection and determination of values for radiation dose. The practical part describes the determination of local diagnostic reference levels with the help of entrance surface kerma and the median dose in the mammary gland. Both of these variables are relevant for determination of the risk of adverse effects of ionizing radiation which is applied during radiographic examination. Data for this study was collected with the help of operating diaries and PACS system. It has been rated twenty-six kinds of examinations from twelve mobile and nine stationary (including two mammographs) X-ray machines. All resulting values were statistically processed and compared with...
|
|
|
Somatomotor and somatosensory modulation of pain in the EEG and fMR image
Vrána, Jiří ; Stančák, Andrej (advisor) ; Vymazal, Josef (referee) ; Jech, Robert (referee) ; Hájek, Milan (referee)
Pain processing is modulated at different levels of the central nervous system by concurrent sensory and motor processes. From previous studies with innocuous somatosensory evoked potentials we know of the phenomenon of gating by movement. The classical explanation [Melzack R, Wall PD. Pain mechanisms: a new theory. Science 1965;150(699):971-979.] of the mechanism of gating in the posterior horn of spinal cord is complemented by other, lesser understood data, suggesting supraspinal mechanisms. A similar lack of understanding of the cortical mechanisms is seen in pain modulating methods using concurrent electrical nerve stimulation. This work is intended to further our understanding of the cortical mechanisms of pain modulation in the specific cases of (a) isometric muscle contraction of the right or left hand during painful electrical intraepidermal stimulation of the right index finger and (b) during observation of the acute effects of concurrent innocuous median nerve stimulation on painful tonic thermal stimulation of the thenar eminence.
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