|
|
Tilt sensors
Hájek, Tomáš ; Caha, Luděk (referee) ; Beneš, Petr (advisor)
The topic of the Bachelor's thesis are MEMS sensors of inclination, which find their use inside integrated circuits, equipment of aerospace and automobile industry, but also in ordinary electrical appliance. The work serves the reader to build a grasp over production, usage, basic principles. Finally, it offers an overview of sensors to ease the orientation on the market. The design of the physical model, which can be used to prevent the sensor from apperance of mathematical errors, is tested in the practical part.
|
|
|
Properties of ultrasound probes
Rusina, Michal ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.
|
|
|
Sensitivity analysis of frequency filters with current active elements
Kupčík, Petr ; Koton, Jaroslav (referee) ; Kubánek, David (advisor)
This bachelor´s thesis is about sensitivity analysis of frequency filters with current active elements. Includes theory of sensitivity analysis and sensitivity function. There are two second order multifunction frequency filters analysed. The first one is filter with Current Mirrors and Inverters (CMI). The second one is filter with Current Operational Amplifiers (COA). Conclusion is description how tolerances of passive and active elements affects frequency characteristics of filters and comparison of these filters in light of sensitivity. Next chapters are occupied by another two analyses: Parametric Sweep and Monte-Carlo. These analyses are applied on two fourth order frequency filters with Differential Input / Output Current Followers (DIOCF) and also on two previous second order filters (only low-pass filters). Parametric Sweep is applied on internal parameters of active filter elements (not in case COA). During Monte-Carlo analysis passive elements have tolerance 5% and active elements are considered ideal. Conclusion is description how tolerances of passive elements (Monte-Carlo) and parametres of active elements (Parametric Sweep) affects frequency characteristics of filters.
|
|
|
MRI Acquisition and Preprocessing of Image Sequences for Clinical Perfusion Imaging
Krchňavý, Jan ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
This thesis describes the theory for static and dynamic magnetic-resonance imaging using contrast agents affecting T1 relaxation time. The available acquisition methods in the specified facility of Masaryk Oncological Institute in Brno are described. The sequences for subsequent experimental measurements are selected. The used phantoms are described. Acquisition protocol for measuring is described briefly and the evaluation method for the measured data is suggested. The best acquisition sequence and a method of measurements is chosen influenced by estimation of relaxation time T1, sensitivity and signal to noise ratio. Perfusion analysis is executed and perfusion parameters are calculated. The work was supported by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101).
|
|
|
Substituting circuit of an induction machine
Běloušek, Radim ; Cipín, Radoslav (referee) ; Patočka, Miroslav (advisor)
Although induction motors are the simplest and most working reliability machines, is the identification of the parameters of their substituting circuit very difficult. There is solved the identification of the parameters of the substituting circuit in the T-network and ? –network in this work. The work also includes the proposal of magnetic circuit of the induction motor, the calculation of magnetizing and leakage inductances and resistances of the machine. The conclusion of the work is devoted to the sensitivity analysis of current and torque characteristics of induction motor upon the change of the single parameters of the substituting circuit.
|
|
|
Influence of breathe to baroreceptor reflex
Humpolík, Tomáš ; Janoušek, Oto (referee) ; Kolářová, Jana (advisor)
This Master's thesis deals with the influence of breathe to baroreceptor reflex. The first chapter is focused on measuring of blood pressure, in reference to later used method. In the second part is detailed analysis and explanation of term baroreflex, relationship between frequency spectra of systolic blood pressure, heart rate and breathing, mechanisms of regulation of blood pressure and heart rate variability. Third chapter deals with possible ways, how to analyze data, which are needed for estimation of baroreflex sensitivity, analyze of heart rate variability and estimation of power spectral density. Next parts of this thesis is paid attention to technical equipment and methods of acqusition of data, using this equipmnent. Part of this work is also software application, which makes possible from the recorded data estimate baroreflex sensitivity.
|
|
|
Sensitivity analysis in distributed-parameter systems
Kapusta, Ján ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
The aim of this bachelor’s thesis was to familiarize with calculation of modified nodal analysis and its application in distributed-parameter systems. Realize evaluation of sensitivities with respect to a primary parameters R0,L0,C0,G0 and length l of transmission line. Then apply this technique on example in Matlab language using graphical user interface GUIDE. Selected technique is accelerated method based on efficient computation of matrix exponential function. The results are sensitivities of circuit values with respect to a primary parameters R0,L0,C0,G0 and length l of transmission line.
|
|
| |
|
|
Study of influence of input parameters for the numerical modeling of the compression test
Polách, Marek ; Keršner, Zbyněk (referee) ; Lehký, David (advisor)
The thesis analyses influence of input parametres of the 3D Non Linear Cementitious 2 material model for the numerical modeling of compression test performed in ATENA 2D and ATENA 3D software. The aim is to identify parametres with considerable influence and subsequently replicate the load-deflection curve obtained from laboratory compression test by numerical modeling. The effects of selected model and material model settings are studied on three kind of models in total. As tools for analyzing the effects, deterministic and statistic sensitivity analyses were chosen. Parametres with significant influence will be highlighted and added to the group of parametres obtained from numerical modeling of three-point bending test. This will create a set of parametres of considerable influence when it comes to modeling advanced structures with different types of stresses.
|
|
|
Hydrogen-terminated diamond surface as gas sensing layer working at room temperature
Davydova, Marina ; Kulha, P. ; Babchenko, Oleg ; Kromka, Alexander
Effect of fluorine- and hydrogen-terminated diamond surface on the gas sensing properties at room temperature was investigated. The gas sensing properties diamond-based sensor were measured by the changes of electrical resistance to various volatile organic compounds (C6H6, C3H6O, isopropylalcohol) and relative humidity. The comparative sensing performance of hydrogenated diamond surface shows improvement in sensitivity toward benzene, acetone, isopropylalcohol and humid air in contrast to fluorinated diamond surface, where the surface conductivity was suppressed.
|
guest ::
