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Non-destructive Detection Methods of Biological Activities Wood-destroying Insects
Kintr, Jindřich ; Král, Bohumil (referee) ; Fiala, Pavel (advisor)
The subject of this thesis is to study a non destructive methods and methodologies of detection biological wood pests. Analyzed method of detection in this thesis is non destructive acoustic detection. For scanning the activity of wood pests a sensor with piezoelectric converter is used and for scanning the ambient sound a sensor with an electret microphone is used. The signals from these sensors are subtracted in a differential amplifier. In this thesis we can find a method determine the similarity of two signals and a laboratory measuring of detection of activity of a wood pests (Hylotrupes bajulus).
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Low-level magnetic measurements ULF frequency 0-30 Hz
Štefánek, Martin ; Král, Bohumil (referee) ; Fiala, Pavel (advisor)
The work assesses progress in the design of measuring workplace for measuring low level magnetic fields of low frequencies. The thesis describes the basic method of spreading of electromagnetic waves in free losslees ambience. Further is described effect with low level of ultra-low-frequency magnetic fields in the frequency band from 0.01 to 30 Hz for an individual or group of people and also the draft measuring methods for indicating or measuring changes in magnetic fields. Thesis deals with individual blocks of measuring workstation.
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New Optimization Algorithms for a Digital Image Reconstruction in EIT
Kříž, Tomáš ; Koňas, Petr (referee) ; Král, Bohumil (referee) ; Dědková, Jarmila (advisor)
This doctoral thesis proposes a new algorithm for the reconstruction of impedance images in monitored objects. The algorithm eliminates the spatial resolution problems present in existing reconstruction methods, and, with respect to the monitored objects, it exploits both the partial knowledge of configuration and the material composition. The discussed novel method is designed to recognize certain significant fields of interest, such as material defects or blood clots and tumors in biological images. The actual reconstruction process comprises two phases; while the former stage is focused on industry-related images, with the aim to detect defects in conductive materials, the latter one concentrates on biomedical applications. The thesis also presents a description of the numerical model used to test the algorithm. The testing procedure was centred on the resulting impedivity value, influence of the regularization parameter, initial value of the numerical model impedivity, and effect exerted by noise on the voltage electrodes upon the overall reconstruction results. Another issue analyzed herein is the possibility of reconstructing impedance images from components of the magnetic flux density measured outside the investigated object. The given magnetic field is generated by a current passing through the object. The created algorithm for the reconstruction of impedance images is modeled on the proposed algorithm for EIT-based reconstruction of impedance images from voltage. The algoritm was tested for stability, influence of the regularization parameter, and initial conductivity. From the general perspective, the thesis describes the methodology for both magnetic field measurement via NMR and processing of the obtained data.
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The Specifics of Financial Management of Holdings Companies
Ficbauer, David ; Bartoš, Vojtěch (referee) ; Hrvolová, Božena (referee) ; Král, Bohumil (referee) ; Režňáková, Mária (advisor)
The main purpose of the thesis is to explore the specifics of the financial management of holdings companies in the Czech Republic with an emphasis on the area of financial management. However, the author assumes that persistent reasons for holding creation is using of synergy effects consisting mainly of centralized management of cash flows to minimize the cost of capital and minimizing the risk of an individual investor who actively makes managerial functions in view guarantees of individual companies. It was found the lack of a comprehensive and systematic approach for a qualitative research. A total of 15 holding companies was use for the qualitative research. The outcome gives many answers concerning the specifics of the financial management of the holdings companies. It seems guarantee, minimizing cost of capital and cash management are key points. The synergistic effect of the holding companies can be used when transferring financial means between companies holding. The impact of the transfer of available financial means was simulated for holding No. 13. It was clearly shown to decrease WACC at one of the companies within the holding. It was found that the subsidiaries, which effectively control the cash flow, maintain a low level of Cash Ratio and Net Working Capital. It was also found that the subsidiaries that manage cash flow effectively, achieve higher ROA. The same assumption was not found in the parent companies. The research question that subsidiaries, which effectively control the cash flow, use financing through bank loans to a lesser extent, was partially confirmed.
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The Specifics of Financial Management of Holdings Companies
Ficbauer, David ; Kočenda, Evžen (referee) ; Král, Bohumil (referee) ; Zinecker, Marek (referee) ; Režňáková, Mária (advisor)
The main purpose of the thesis is to explore the specifics of the financial management of holdings companies in the Czech Republic with an emphasis on the area of financial management. However, the author assumes that persistent reasons for holding creation is using of synergy effects consisting mainly of centralized management of cash flows to minimize the cost of capital and minimizing the risk of an individual investor who actively makes managerial functions in view guarantees of individual companies. It was found the lack of a comprehensive and systematic approach for a qualitative research. A total of 15 holding companies was use for the qualitative research. The outcome gives many answers concerning the specifics of the financial management of the holdings companies. It seems guarantee and minimizing cost of capital are key points. The synergistic effect of the holding companies can be used when transferring financial means between companies holding. The impact of the transfer of available financial means was simulated for holding No. 13. It was clearly shown to decrease WACC at one of the companies within the holding.
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Analysis of Selected Artefacts in Diffusion-Based Magnetic Resonance Measurements
Marcoň, Petr ; Král, Bohumil (referee) ; Frollo, Ivan (referee) ; Bartušek, Karel (advisor)
The presented dissertation thesis analyses artefacts in diffusion-weighted images. In medical practice, the artefacts can impede the diagnostics of pathological tissues and, therefore, need to be eliminated. As the first step within the thesis, an analysis of the most frequent artefacts in diffusion-weighted images is performed, and the hitherto known approaches to artefact elimination are described. In order to facilitate the reduction of artefacts caused by the inhomogeneity of the static magnetic field and induced by eddy currents, a novel three-measurement method is shown. This technique will find application especially in measuring the diffusion coefficient of isotropic materials. At this point, it is important to note that a significant and commonly found problem is the magnetic susceptibility artefact; different magnetic susceptibility values at the boundary between two materials can cause magnetic field inhomogeneities and even complete loss of the signal. Therefore, we designed a novel method for the measurement of magnetic susceptibility in various samples of magnetically incompatible materials, which do not produce any MR signal. The technique was experimentally verified using a set of differently shaped diamagnetic and paramagnetic samples. In addition to the magnetic susceptibility problem, the thesis presents artefacts such as noise, motion-induced items, hardware limitations, chemical shift, and the dependence of the diffusion coefficient on the temperature. To enable precise measurement of the diffusion coefficient, we proposed a thermal system; in the experiment, it was determined that when the measurement error does not exceed 5%, the temperature change should not be higher than 0,1 °C. In the final sections of the thesis, practical application examples involving the designed methods are shown.
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A Contribution to Optimal Synthesis of Filters
Szabó, Zoltán ; Hájek, Karel (referee) ; Král, Bohumil (referee) ; Sedláček, Jiří (advisor)
The presented dissertation thesis is focused on the optimization of filtering circuit synthesis. In the five main sections of this work, the author analyzes partial problems related to several areas within the synthesis of modern filtering circuits. The first chapter constitutes an examination of elementary aspects which characterize present-day integrated circuits in voltage feedback operational amplifiers, and this main content is further complemented with a view on possible application of these circuits for the designing of filtering circuits as proposed within subsequent parts of the thesis. In this context, the second chapter contains a description of the design and optimization of digitally controlled universal filters tunable by means of digital potentiometers originally produced for audio technology. These digitally controlled circuits are increasingly utilized as analog preprocessing blocks in digital signal processing systems. The most extensive portion of the dissertation is dedicated to a complex analysis of individual configurations of economical, purposely lossy active function blocks and modern voltage operational amplifiers. This part of the thesis aims at providing a detailed insight into the characteristics of individual configurations of examined circuits; furthermore, in this respect, the author proposes a comparison of various application possibilities relating to these circuits and their wider use in the field of active frequency filters optimization. The described section of the work also includes a definition and examples of application of the designed and realized program, which facilitates significant simplification of purposely lossy ARC filters. In the penultimate part of the dissertation thesis, the design, development, and verification of a suitable synthesis procedure are presented together with the optimization of data and (in particular) power models of EMC filters. Based on the verification of characteristics inherent with the designed models of EMC filters, the suggested measuring procedure related to these filters is described, including the design of a station for measuring elementary parameters of line anti-interference devices up to very high frequencies. In the last section of the thesis, the author discusses the procedure of air ions concentration measurement through an aspiration condenser and analyzes the systematic and random errors as well as the optimization of filtration characteristics of the applied measurement method. This part includes the description of the design and characteristics of the realized fully automated measurement system with an aspiration condenser.
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Passive optical detection of moving targets
Hladík, Roman ; Král, Bohumil (referee) ; Fiala, Pavel (advisor)
This master thesis deals with a problem of a small moving object detection - one or few pixels. Relevant mathematical aparats which are usualy used for processing of dynamic pictures are included. There was proposed experimental aparat for standalone locator for real-time operation. It is consisted from two devices - CMOS camera module and development board based on ARM processor. System GNU/Linux is used as operation system on this board. There were also tested methods useful for the essence of this project. On behalf of the tests was developed an algorithm to detect small particle in video sequence. C language routines were build including essence algorithms.
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Incubator with adjustable temperature and humidity
Hikaník, Matúš ; Král, Bohumil (referee) ; Steinbauer, Miloslav (advisor)
This project deals with comparing types and properties of commercial produced incubators for exotic birds. It searches the best solution from these area. In this project are compars individual components and their choice for realization in this project. Then in this project is solution of regulation temperature and humidity in engineered mechanism and discovered parameters of specifically space. Then is developed solution of thermostat and hydrosatat for this prototype. Temperature is changed by Peltier module, who is involved in correct system. Humidity is regulated by resistor humidifier. Complex system is managed by microcontroler. System communicates with PC via USB interface and Ethernet. Solution of this project is maked functional prototyp.
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