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O vybraných modelech pro částečnou obnovu
Ševčík, Jaroslav ; Volf, Petr
Models of imperfect repairs are based on the reduction of cumulated hazard rate, either directly or indirectly. Other set of models connects the repair with the change of time scale. Further, repair degree can be connected with the reduction of the deterioration. We discuss mainly the question of repair schemes, their consequences, and possibilities of an 'optimal' repair policy leading to the hazard rate stabilization.
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Stochastical inference in the model of extreme events
Dienstbier, Jan ; Picek, Jan (advisor) ; Jurečková, Jana (referee) ; Jarušková, Daniela (referee)
Title: Stochastical inference in the model of extreme events Author: Jan Dienstbier Department/Institute: Department of probability and mathematical statistics Supervisor of the doctoral thesis: Doc. RNDr. Jan Picek, CSc. Abstract: The thesis deals with extremal aspects of linear models. We provide a brief explanation of extreme value theory. The attention is then turned to linear models Yn×1 = Xn×pβp×1 + En×1 with the errors Ei ∼ F, i = 1, . . . , n fulfilling the do- main of attraction condition. We examine the properties of the regression quantiles of Koenker and Basset (1978) under this setting we develop theory dealing with extremal characteristics of linear models. Our methods are based on an approximation of the regression quantile process for α ∈ [0, 1] expanding older results of Gutenbrunner et al. (1993). Our result holds in [α∗ n, 1 − α∗ n] with a better rate of α∗ n → 0 than the other approximations described previously in the literature. Consecutively we provide an ap- proximation of the tails of regression quantile. The approximations of the tails enable to develop theory of the smooth functionals, which are used to establish a new class of estimates of extreme value index. We prove T(F−1 n (1 − knt/n)) is consistent and asymp- totically normal estimate of extreme for any T member of the class....
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GSM-EDGE and UMTS Systems Coexistence
Gleissner, Filip ; Hanus, Stanislav (advisor)
The dissertation thesis deals with the investigation of the coexistence of GSM–EDGE and UMTS systems with focus on the physical layer of the systems. The aim is to provide a set of recommendations for practical cooperation while the systems operate in both the separated and the common radio bands. A detailed description of signal processing of both the systems on the physical layer is presented. On the basis of this description, models of both systems were created and implemented in the MATLAB environment. The simulations are focused on the physical layer quality parameters, especially the bit error ratio evaluation for various ratios of useful signal power to noise power during the transmission over the radio channel. Simulation is also used to examine the quality of received useful signal while it is interfered by signals from the same and adjacent channels. The purpose is to determine the isolation between these adjacent channels, when the bit error ratio of the useful signal does not exceed a certain reference value. The simulation results are subsequently subjected to comparison with the results of the experimental measurements in laboratory conditions. Before the measurements are carried out, a study of possible interference types is performed. Consequently, the crucial parameters of the measuring equipment used are verified. From the results of simulations and measurements, the proposal of a minimum and recommended carrier separation between both the systems is presented in order to efficiently utilize the assigned frequency spectrum. Furthermore, for the cooperation in both the separated and the common radio bands, the necessary precautions are given for reaching the required isolation and thereby inter-system interference minimization.
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Evaluating and modeling of fouling process in heat exchanger
Čirka, Martin ; Kilkovský, Bohuslav (referee) ; Jegla, Zdeněk (advisor)
This diploma thesis discusses fouling processes and mechanisms of industrial heat exchangers, with focus on shell side fouling of heat transfer area by flue gases, and eventually taking fouling into account, or more precisely its modeling and predicting by calculation. Thermal-hydraulic design of heat exchanger is focused mainly on shell side, as flue gases are dominant process medium in terms of fouling and heat transfer. Based on available operational data of evaluated industrial heat exchanger, specific process has been developed to determine by calculation, or more precisely predict change of fouling factor throughout operational period of heat exchanger. Usage and various options of this specific calculation technique are being discussed in conclusion, whether there is a potential to use this technique regarding more complex operational inputs or prediction of fouling process for different operational regime of heat exchanger.
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Biodiverzita a cílový management ohrožených a chráněných druhů organismů v nízkých a středních lesích v soustavě Natura 2000: TARMAG 2000
Mendelova zemědělská a lesnická univerzita v Brně, Lesnická a dřevařská fakulta ; Machar, Ivo ; Jankovský, Libor
Cílem projektu je zhodnotit stav biodiverzity populací evropsky významných druhů rostlin a živočichů v biotopech nízkých a středních lesů a lužních lesů v ČR a navrhnout management těchto biotopů v zájmu cílů soustavy Natura 2000. Bude provedena analýza významu lesů výmladkového původu, včetně lesů nízkých, středních a lužních lesů z hlediska biodiverzity a návrh hospodářských postupů v těchto ekosystémech. Cílový management vybraných druhů organismů bude vyjádřen modelem hospodaření v konkrétních ekosystémech. Projekt je členěn na 8 úkolů. Úkoly 1 – 3 shrnují problematiku nízkých a středních lesů z hlediska biodiverzity, jejich současného stavu a významu z pohledu hospodaření v podmínkách střední Evropy. Úkoly 4 – 7 analyticky hodnotí vazby jednotlivých skupin organismů na nízké a střední lesy, hodnotí jejich biodiverzitu a zpracovávají znalosti o biologii, ekologii, rozšíření a ohrožení druhů vybraných pro cílový management a zásad pro aplikaci cílového managementu. Úkol 8 pak syntetizuje získané poznatky v modelech managementu a návrzích pěstebních opatření pro konkrétní nízké a střední lesy. Biogeografické a geobiocenologické rámce zavádění cílového managementu vzácných druhů organismů v lesích výmladkového původu. 2. Zhodnocení stavu a rozšíření biotopů nízkých a středních lesů (včetně lesů lužních) z hlediska ekologické stability a funkcí krajiny a zachování biodiverzity evropsky významných druhů rostlin a živočichů v soustavě Natura 2000. 3. Historický vývoj a zhodnocení významnosti hospodářských postupů obhospodařujících nízké a střední lesy. 4. - 7. Biodiverzita a cílový management biotopů středních a nízkých lesů z hlediska ochrany vybraných druhů rostlin, hub, hmyzu a obratlovců včetně studia jejich biologie, ekologie a rozšíření. 8. Model managementu biotopů středních a nízkých lesů z hlediska soustavy Natura 2000 a návrh pěstebních opatření a metodika převodů vysokého lesa na nízký a střední včetně ekonomických souvislostí z hlediska vlastníky lesa.
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The influence of legally owned firearms on crime in the Czech Republic.
Převrátil, David ; Stroukal, Dominik (advisor) ; Brožová, Dagmar (referee)
The work aims to analyze the influence of the number of legally owned firearms on crime in the Czech Republic. The main hypothesis is chosen on the basis of previous empirical research from the United States. The work assumes that the effect of the number of legally owned firearms held by civilians has a negative impact on the overall crime rate in the Czech Republic. The hypothesis is tested by using the metodology of regression analysis of time series for the whole country between the years 2003 - 2013 and regression analysis of panel data for 14 regions in the Czech Republic between the years 2009 - 2013. Based on the obtained data six models observing the effect of the number of firearms and the number of firearm license owners to overall crime, murder and burglary and theft. The result is the finding of a positive impact on the number of legal guns in overall crime in the country. Unfortunately, the observed variable of legally owned firearms is statistically insignificant in all models. The work opens up new possibilities for further study of the influence of firearms on crime in the Czech Republic.
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Mají kuřáci nižší mzdy?
Nguyen, Nhat Linh ; Brožová, Dagmar (advisor) ; Špecián, Petr (referee)
This study examines relationship between smoking cigarettes and wage. Studies have found statistically significant wage penalty for smoking cigarettes before (from 3 to 10 %). This study works with cross-sectional data consisting of US residents. The source of the data is The Panel Study of Income Dynamics which was found in 1968. The results in this work suggest 6-10% wage penalty for smoking cigarettes using 3 econometric models. The wage penalty can be caused for example by the health impact of smoking which can affect the productivity of worker. It can be also explained by differences in education between smokers and nonsmokers or by the discrimination of smokers on labor market.
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Is import of goods from european countries to Czech republic more or less influenced by changes in nominal and real exchange rates than in non european countries?
Vereš, Jan ; Stroukal, Dominik (advisor) ; Slaný, Martin (referee)
This bachelor thesis analyses the connection between import of goods from foreign countries to Czech Republic and the exchange rate changes. The initial hypothesis of this paper is to prove that the depreciation of domestic currency has positive influence on balance of trade balance. For this purpose there is eight econometric models which were created by using time series from years 2003 to 2016. These models are divided in pairs among four chosen countries. For each country two models were created that follow the development of trade balance between Czech Republic and one of the countries in two different time frames. All the models always use the real effective exchange rate, growth rate of GDP for Czech Republic and growth rate of GDP for one of the countries as explanatory variable. It is connected with the second task of this thesis, which is the analysis of the differences in the behaviour of the models that belong to the countries which are members of the EU and these that are not. The aim is to find out whether the existence of tariffs on imported goods from countries out of the EU causes visible differences in the behaviour of the variables that were included in the models. Based on the outcomes of all eight models the main hypothesis has been proved right for three out of four countries. In the models for Germany, China and France the relation of real exchange rate and trade balance came out as positive in long term, in short term the outcome was ambiguous. The second question of this thesis has been answered, but its added value is questionable. The final models for each state do show some noticeable differences and they can be used to determine if the influence of the change of exchange rates on trade balance is smaller or bigger in the countries where tariffs are used. On the other hand, from the results we can learn that the sample of only four countries is insufficient for the deduction of any conclusions.
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Metallurgy of gamma TiAl based alloys
Zemčík, L. ; Dlouhý, Antonín
The present paper deals with the basic metallurgical processes associated with the investment casting of intermetallic alloys based on gamma TiAl. The analysis focuses on the evaporation of the aluminium from the melt, chemical reactions between the molten intermetallic, the ceramic mould and crucible and also on the reactions between the melt and the residual gases present in the atmosphere of the vacuum furnace. Results of the thermodynamic models are applied to the experimental melts of the Ti-48Al-2Cr-2Nb-1B intermetallic alloy in the vacuum induction furnace.
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