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Industrial building
Michálek, Vojtěch ; Pilgr, Milan (referee) ; Sýkora, Karel (advisor)
In the bachelor thesis a project for steel construction of an industrial hall in Brno area is developed. The extent of the ground plan of the hall is 30x63m with maximum height of 17,300m. The main load-bearing structural elements such as suspended purlin, truss bond timber, noggin pieces, solid-poles forming a cross linking with the bond timber, base and crane runway, are designed and considered in the static calculation. The statement of material and design documentation consisting of the design, cross-section, production drawing of a bond timber and selected details are part of the thesis.
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VLBI receiver chain monitoring
Michálek, V. ; Kodet, J. ; Schreiber, U. ; Ploetz, Ch. ; Procházka, I. ; Pánek, Petr
he most demanding goal of the Global Geodetic Observing System initiative is the definition of station positions to an accuracy of 1mm and the corresponding velocities to 0.1 mm/year. The main remaining sources of error are caused by systematics, leading to intra- and inter- technique biases. In this work, we have focused on Very Long Base Interferometry (VLBI) and phase calibration generator currently in operation. This unit is injecting calibration tones into the detection chain through an input coupler located near the input of the antenna. The tones propagate further through entire detection chain and are recorded with the observed signal. Then they are extracted in post processing. These tones are generated out of an atomic frequency standard. The supplied frequency is significantly influenced by temperature and mechanical changes since usually a long cable is employed to bring the frequency to the calibration unit. To monitor the electrical length of the cable, calibration with a picosecond precision is essential. We have redesigned a phase calibration unit so that it enables the implementation of the Two Way Time Transfer (TWTT) method on single coaxial cable using two event timers to monitor the electrical length of the critical cable. Such a system has been installed in parallel to the unit currently in operation. The comparison of the TWTT method with previous measurement method is presented
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