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Analysis of boundary conditions of ground heat exchangers
Floreková, Skarleta ; Horák, Petr (oponent) ; Hirš, Jiří (vedoucí práce)
Master thesis ,,Analysis of boundary conditions of ground heat exchangers,, is primarily focused on analysis of boundary conditions and major factors affecting a reliable design and heat transfer of horizontal ground heat exchanger in the area of geothermal activities at Spa Island in Piešťany. Assessments of its possible environmental impacts such as an origin of subsoil thermal alterations due to the heat extraction including a soil freezing around the pipelines and potentially contamination of groundwater are discussed too. As a part of this final thesis, three numerical analyses were processed using finite element method software COMSOL Multiphysics 5.6., which may occur in this specific area. The first numerical analysis is subjected on study of dynamic processes of horizontal ground heat exchanger and saturated subsoil under the constant boundary temperature condition of the ground. Dynamic process of ground heat exchanger and saturated subsoil under the inconstant temperature boundary condition is examined in the second numerical analysis. The last analysis is carried out to assessments the horizontal ground heat exchanger operation with possibility of groundwater flow in the same strata. Thanks to these numerical studies and dynamic thermal models results, each study case contains soil temperature distributions, outlet temperatures from the exchanger and its own partial conclusion.
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Analysis of boundary conditions of ground heat exchangers
Floreková, Skarleta ; Horák, Petr (oponent) ; Hirš, Jiří (vedoucí práce)
Master thesis ,,Analysis of boundary conditions of ground heat exchangers,, is primarily focused on analysis of boundary conditions and major factors affecting a reliable design and heat transfer of horizontal ground heat exchanger in the area of geothermal activities at Spa Island in Piešťany. Assessments of its possible environmental impacts such as an origin of subsoil thermal alterations due to the heat extraction including a soil freezing around the pipelines and potentially contamination of groundwater are discussed too. As a part of this final thesis, three numerical analyses were processed using finite element method software COMSOL Multiphysics 5.6., which may occur in this specific area. The first numerical analysis is subjected on study of dynamic processes of horizontal ground heat exchanger and saturated subsoil under the constant boundary temperature condition of the ground. Dynamic process of ground heat exchanger and saturated subsoil under the inconstant temperature boundary condition is examined in the second numerical analysis. The last analysis is carried out to assessments the horizontal ground heat exchanger operation with possibility of groundwater flow in the same strata. Thanks to these numerical studies and dynamic thermal models results, each study case contains soil temperature distributions, outlet temperatures from the exchanger and its own partial conclusion.
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Various change point estimation methods
Šimonová, Soňa ; Pešta, Michal (vedoucí práce) ; Hušková, Marie (oponent)
Cieľom tejto práce je podať zrozumiteľný výklad niektorých najnovších metód odha- dovania bodu zmeny. V literatúre môžeme nájsť rôzne prístupy k riešeniu tejto problema- tiky. Medzi ne patria testy založené na procese CUSUM, testy pomerom vierohodností, metóda WBS a metódy pre odhadovanie bodu zmeny v panelových dátach. Okrem spo- mínaných prístupov je v práci vysvetlený aj prípad závislých panelov. Praktická časť štúdie je zameraná na aplikáciu metódy WBS na týždenné logaritmické výnosy akcio- vého indexu Dow Jones. Najskôr na analyzovaný časový rad aplikujeme GARCH model. Metódu WBS následne použijeme na detekciu štrukturálnych zmien v pôvodnom rade, ako aj v rezíduách z modelu GARCH. Analyzujeme niekoľko typov penalizačných krité- rií a skúmame ich vplyv na odhadnutý počet a polohy bodov zmeny v danom dátovom súbore. 1
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