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Active Frequency Filters for Higher Frequencies
Fröhlich, Lubomír ; Dostál, Tomáš (referee) ; Biolek, Dalibor (referee) ; Sedláček, Jiří (advisor)
This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.
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Economics Efficiency of Thermodynamic Heating
Balga, František ; Dostál, Tomáš (referee) ; Luňáček, Jiří (advisor)
This master thesis intents on analysing of economic efficiency of the investment project. Theoretical part of the thesis describes particular periods of the investment decision, what compromise a definition of more types of investments, investment projects and their classification. At the practical part of this thesis is applied the theoretical knowledge to evaluation of the planned investment, then is analysed the most profitable of the evaluated alternates and the last step is to propound next measure for the succesful realization of the project.
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Construction RNAV instrument departures for runway 03C at the Kunovice airport
Dostál, Tomáš ; Vosecký, Slavomír (referee) ; Veselý, Petr (advisor)
This master´s thesis deals with RNAV-1 departure routes for runway 03C at the Kunovice airport. Suggested routes are linked to the new RNAV-1 routes in TMA Brno. RNAV SID maps and construction of one of the departure track are also done and described in this master´s thesis. Beyond design of RNAV-1 routes are also analyzed influences and factors in the master´s thesis that affect the construction of these routes. Construction of RNAV SID routes are based on the knowledge and shortcomings conventional routes that are resulted from the analysis of the current departure routes at the Kunovice airport. In the second part of the thesis is submitted 3 variants of departure routes for Kunovice airport.
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Class D stereo audio power amplifier
Kazelle, Kamil ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
The content of this project is design of stereo audio amlifier working in class D with output power 2x20W. Project includes also a design of preamplifier and power supply. This project is divided into the four parts. In first part the theory and problems of amplifiers working in class D is resumed, in the second the designed circuits are dicussed, in the third the results of simulations in the program PSpice are presented and the last part of project describes the realization and presents the results of measurements.
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Active electrical filters based on switched-capacitor circuits
Třeček, Stanislav ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
This thesis deals with concept of universal frequency filter by application of a switched-capacitor functional block. The concept is based on the theory of switched-capacitor circuits and the theory of a design of classical frequency filters. The printed circuit board was designed based on the filter connection developed by using a software Eagle. The filter was implemented as a laboratory product. This product has been revitalized and the frequency response of all types of filters has been measured. The measured parameters were compared with the parameters set out in the technical documentation of functional block.
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Carbon dynamics in the chernozem region after half a century of intensive cultivation
Juřicová, Anna ; Chuman, Tomáš (advisor) ; Dostál, Tomáš (referee) ; Maerker, Michael (referee)
Soils are vital for global food security and recently they have also received attention as a tool potentially mitigating climate change due to their ability to store large amounts of carbon (C) and provide other vital non-productive functions. However, several forms of degradation threat these functions. In agricultural soils, the decline of soil organic carbon (SOC) and soil erosion are two of the degradation processes. Soil erosion laterally redistributes large amounts of SOC in hilly agricultural landscapes. Lateral fluxes further impact the SOC storage in soils and indirectly modulate the vertical C fluxes between the terrestrial sphere and the atmosphere. The aim of this thesis is to investigate the long-term (> 50 years) regional SOC changes and analyze the impacts of soil redistribution in C dynamics in a hilly agricultural landscape. We consider soil redistribution via water and tillage as the main erosion agents. The study uses a comparison of recently resampled and legacy data from historical monitoring (the 1960s) together with coupled erosion and C dynamics modelling using the SPEROC-C model. The study is conducted in the chernozem region, south Moravia, the Czech Republic. Our results showed that the change in SOC content tends to be positive after more than 50 years. Moreover,...
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Spatial interpolation and soil erosion modeling
Bek, Stanislav ; Ježek, Josef (advisor) ; Segeth, Karel (referee) ; Dostál, Tomáš (referee)
The doctoral thesis deals with selected methods of spatial interpolation and their applications to numerical modeling of the earth's surface, in particular soil erosion. The first part contains the description of the studied methods. Firstly and foremost, the method called regularized spline with tension (RST) is introduced. It has proven to be useful in interpolating elevation data. In the thesis, RST is presented in depth with the derivation of its radial basis function and its links to kriging. Further on the mathematics of digital terrain models and the tools for terrain geometric analysis are covered. The following chapter deals with the description of the soil erosion process and of the selected erosion models. The second part of the thesis summarizes five of the author's research articles which include applications of the described mathematical methods. The first two articles are devoted to the problem of elevation data interpolation and the building of digital elevation models. They deal with the optimization of the RST method for particular input data and target erosion models. The third article analysis the spatial structure of the soil data and the pedogenesis of the Žofínský prales natural forest. The last two articles deal with the spatial properties of heavy rainfalls and the mapping of...
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Development of monitoring application for a production cell workspace with SICK scanners
Dostál, Tomáš ; Kovář, Jiří (referee) ; Andrš, Ondřej (advisor)
This thesis is about scanners of SICK company and monitoring methods in workspaces. Next in this thesis is described implementation of monitoring methods in robotic industry. Objective of practical part was design, implementation and to test application created in LabVIEW for monitoring workspaces. Created application contains choice of use serial communication with scanner SICK PLS 101-312 or possibility to create simulation of monitoring workspace. In conclusion both choices are tested and evaluated.
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Vliv dusíkato-sirných hnojiv s humáty na výnos a kvalitu pšenice ozimé
Dostal, Tadeáš
The aim of diploma thesis was to examined the effect of humate addition to nitrogen fertilizers with sulfur on yield and qualitative parameters of the winter wheat. The ex-periment was established as a two-years small-plot field experiment. The experiment was established on two experimentation locations – Žabčice and Vatín. Because of the high number of factors, two multifactor analyzes were performed in the statistical evaluation. The variant of fertilization included in the experiment are: DASA (amonnium sul-phate nitrate), DASAMAG (amonnium sulphate nitrate and magnesite) and MAGNI-SUL (amonnium suplhate nitrate and magnesite) with their analogies DASA H, DASAMAG H a MAGNISUL H with the humate addition in form of lignite. Ferti-lizers were applied in two terms either regenerative or productive. The highest statistical differences were achieved for the factors of the locality and the year. The average yileds achieved in Žabčice were higher in comparison with Vatín (the difference was 0,45 t/ha respectively 5,7 %). There were observed higher average yields in the year 2017 beside the year 2016 (the difference was 1,86 t/ha respectively 26,1 %). There were also recorded higher values of qualitative parameters in Žabčice in 2017. Based on the results, it can be stated that the best average yields and the other monitored parameters were in Žabčice 2017. There were no statistical differences between variants with and without humate. The highest average yield achieved variant fertilization with DASA. Only variant MAGNI-SUL H achieved higher yield than variant MAGNISUL (the difference was minimal, 0,2 %). MAGNISUL H was the only variant that achieved higher average volume weight and sediment values compared to the fertilizers without the humate addition. The term of application did not prove to be statistically significant.
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