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Changes of microclimate in a sedge-grass marsh within the last 40 years
Dušek, Jiří ; Stellner, Stanislav ; Hudecová, S.
The average, maximum and minimum air temperatures have been gradually increasing since 1977 to 2017. The air temperature rise was not the same in all periods of the year. We found different increases for individual months. The daily mean air temperature rose significantly in the growing period (April-August). The precipitation characteristics have been changing in the sedge-grass marsh too. The observed trends differ among months in sign as well as in the magnitude, and they are consistent with the air temperature changes. We found that extreme precipitation seems to occur significantly more frequently in recent years compared to the period before 2000. Awareness of these changes is important for possible positive human intervention when a desirable wetland ekosystem function is threatened.\n
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Magnetic field measurement
Dušek, Jiří ; Máca, Josef (referee) ; Vyroubal, Petr (advisor)
Bachelor thesis describes ways and technology for measuring of the magnetic field. Furthermore it deals with comparing sensors for magnetic fields measuring and creating a basic conception of the meter. For design of conception was selected sensor HMC2003 from Honeywell company. Design of conception describes two units, which meter contains. Conception include power, compensation and reset circuits. After that is detailed describe layout of both printed circuit boards, setting up and soldering components. Output of this meter is signal of the three axis of sensor. Meter was subjected to trial run, which verified functionality of the whole device.
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Analysis of high concentrations of total phosphorus incidence in small agricultural subcatchments
DUŠEK, Jiří
This thesis focuses on analysis of the peak values of phosphorus concentration in small agriculturally used subcatchments. The cycle of phosphorus in nature, in water and issue of the eutrophication is described in this thesis as well as basic characteristics of three monitored subcatchments. The concentration of phosphorus, flow rate and precipitation was measured in these three monitored subcatchments. Peak values of phosphorus concentration and possible impact of rainfall-runoff occurrences on these peak values are as well analyzed in this thesis. This research uses statistical methods. The final part of this thesis assesses the impact of rainfall-runoff occurrences on the peak values of phosphorus concentration. Other possible factors which could cause these peak values are also discussed.
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Online conference system based on HTML5
DUŠEK, Jiří
HTML5 technologies allow access to data provided by a webcam or microphone within a web browser. This thesis deals with the use of such technical means for their transmission through the Internet in a web browser environment in real time. The base of bachelor thesis is analysis of current web-based conference systems. In this analysis, their parameters will be ascertained as well as the technologies used for the transmission of multimedia data. Obtained information will be used to create a design of conference system. In connection with this issue follows a detailed analysis of the possibilities of HTML5 technologies for transmitting audio and video between client devices in real time. In the practical part of the thesis will be created on the basis of the analysis a prototype online conference system based on HTML5 technologies. The system will allow the creation of conference rooms that will provide audiovisual communication and an online chat between participants of the room. Creating the system includes the design, implementation, subsequent deployment and testing. It will be created with regard to the accessibility of mobile devices.
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Classification of asynchronous motors
Čala, Václav ; Dušek, Jiří (referee) ; Singule, Vladislav (advisor)
This diploma thesis deals with a creation of a “Classification Document” of asynchronous motors with a short-circuit armature with axial heights of 355, 400, 450, 500, and 560 mm. Furthermore, it is concerned with a creation of an integral design documentation for the production and assembly of these motors at the company TES VSETÍN, s.r.o. By writing this diploma thesis I would like to achieve a simplification of communication with the customers during the processing of asynchronous motors orders and to speed up the processing of asynchronous motors orders not only in the design department but also the complete technologic preparation of the production which will surely be provided by this integrated documentation.
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Design of laboratory model of Inverse Pendulum
Dušek, Jiří ; Grepl, Robert (referee) ; Šolc, František (advisor)
Purpose of this Bachelor’s thesis was to set matemathic laboratory model fixture of „Inverted penduluem“ togther, to verify it and on this base to create simulating model. Furthermore for this simulating model system to create way its controling in „stabilisation in upper instable location“ mode and in „crane during moving with the load“ mode. For operation in both modes was state-feedback regulator chosen and projected by method LQR, which was applied after that to real model of laboratory fixture. Realization of exsisting system was described and during using incremental rotary encoder and I/O card of new type was modernized. Further possibility of operation of carriage travel of pendulum by voltage supply was examined. Rotation version of laboratory model fixture was projected and alternative driving facilities were selected.
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Special induction machine as source of electric energy
Dušek, Jiří ; Janda, Marcel (referee) ; Skalka, Miroslav (advisor)
This work deals with description of an induction machine principles for both of motor and generator operations. Then is been described a special kind of an induction generator working into an isolated system. The construction of an induction generator was designed with two stator winding connection due to possibility of the variable number of pole pairs. Also there is an excitation capacity design for self-excitation. Last part of this work contains the measurement of an induction generator with different values of excitation capacity and both terminal clamps connection.
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Electronic throttle
Dušek, Jiří ; Beran, Martin (referee) ; Havlíková, Marie (advisor)
The aim of this master’s thesis was to analyze the contemporary electronic throttles and the requirements imposed on them. Then to build the mathematical model, identify parameters of the given electronic throttle, proceed the verification and on its basis to build the simulation model. There were selected suitable control and high power components to control the electronic throttle. Due to the knowledge of these parameters the simulation model was extended. For this extended simulation model was designed the position cascade controller with speed and current control loop. Using the designed controller the implementation of the electronic throttle control and the available high power and control module was realized.
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Control of salient PM machine using d-q frame machine model and Matlab Simulink
Dušek, Jiří ; Huták, Petr (referee) ; Ondrůšek, Čestmír (advisor)
Tato práce se zabývá synchronním motorem s permanentními magnety na rotoru (PMSM), jeho modelováním a návrhu regulační struktury. V práci jsou uvedeny způsoby a výhody použití permanentních magnetů v elektrických motorech. Dále se práce zabývá transformací třífázové soustavy do dq0. Pomocí Parkovy transformace jsou v práci odvozeny rovnice stroje v dq0 souřadnicovém systému a vytvořeny náhradní schémata stroje v dq osách. Rovnice i schémata zahrnují jak ztráty v mědi, tak ztráty v železe. Náhradní schémata jsou popsány elektrickými a mechanickými rovnicemi a následně překresleny do grafické podoby v programu Matlab Simulink. Vytvořeny jsou dva modely PMSM, jeden s uvažováním ztrát v železe a druhý bez těchto ztrát. Pro oba dva modely je zde popsán postup návrhu regulátorů proudu a otáček. Pro model, u kterého jsou uvažovány ztráty v železe je navíc použito více druhů řídicích strategií a tyto strategie jsou mezi sebou navzájem porovnány.
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Solution drilling technologies and clamping units.
Dušek, Jiří ; Zemčík, Oskar (referee) ; Kalivoda, Milan (advisor)
Bachelor thesis rotary drilling technology and clamping units. The beginning of the work deals with a general description of the drilling. Subsequent mentions of the necessary information for choosing the appropriate clamping units for the drill hole. In conclusion, the custom design solutions for clamping units Guliwer Electronics Company Ltd.
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