ROC křivka

This bachelor's thesis firstly defines the basic terms and then describes the ROC curve. Thesis deals with meaning of the ROC curve, its properties and construction with a graphic representation. Subsequently, the expression of the ROC curve and its area for normal, exponential and uniform distribution is derived in the work, also with a graphical representation. Then, it is related to statistical testing. At the end, there are described the empirical expression of the ROC curve and its application to real data processed in the Python programming language. 1Táto bakalárska práca na úvod zadefinuje základné pojmy a potom sa zaoberá ROC krivkou. Popisuje jej význam, vlastnosti a konštrukciu aj s gra- fickým znázornením. Následne je v práci odvodené vyjadrenie ROC krivky a jej plochy pre normálne, expo- nenciálne a rovnomerné rozdelenie, taktiež aj s grafic- kým znázornením. Ďalej je daná do súvisu so štatistickým testovaním. Na záver je opísané empirické vyjadrenie ROC krivky a jej aplikácia na reálnych dátach, ktoré sú spracované v programovacom jazyku Python. 1Katedra pravděpodobnosti a matematické statistikyDepartment of Probability and Mathematical StatisticsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

PITTING CORROSION OF AISI 316Ti STAINLESS STEEL WITH POLISHED SURFACE

AISI 316Ti is Cr–Ni–Mo austenitic stainless steel with the high Pitting Resistance Equivalent Number (PREN). The effect of the surface finishing by polishing on the pitting corrosion resistance was tested in aggressive 5% FeCl3 solution. The immersion tests were curried out at the temperature 30, 50, 80 °C. The electrochemical cyclic potentiodynamic tests were carried out in the same solution at temperature 30 and 50 °C. The evaluation of the corrosion resistance arose from the comparison of the results of the immersion and the cyclic potentiodynamic tests

The Visco-Elastic Behavior of PA+PAI Composites with Fiber Glass after UV Degradation

The polymeric composites on the base of the PA+PAI filled by glass fibres are usually used in automotive industry and also exposed to natural atmosphere. The research is focused on resistance study of the mentioned composites in simulated atmospheric conditions. The tested specimens contented 10, 20 and 30 % of the glass fibres and they were exposed in UV box with defined time and intensity of UV radiation and temperature. The mentioned factors have a considerable influence on utility and lifetime of product made of the polymeric composite. The effect of the exposition on the composites behaviour was evaluated microscopically, by rheological measurements and impact tests. By the rheological measurements the changes of visco-elastic parameters (complex viscosity, moduli of elasticity and plasticity) were studied after different times of exposition in the UV box as well as chosen mechanical properties

The Effect of Surface Treatment on Corrosion Resistance of Austenitic Biomaterial

This paper focuses on the effect of surface treatment (grinding, electrochemical polishing) on the corrosion resistance of AISI 316L, a Cr-Ni-Mo low-carbon austenitic surgical stainless steel, in a physiological solution at the temperature of 37 °C. The influence of a surface defect and of sensitization by heat treatment on the corrosion behaviour of electrochemically polished surface is also studied. The evaluation is based on the results of cyclic potentiodynamic polarization tests and on the microscopic observation of specimen surfaces after performed tests. The analysis of cyclic potentiodynamic curves showed the highest pitting corrosion resistance of electrochemically polished specimens regardless of the previous sensitization. The as-received specimen showed the highest susceptibility to pitting, which was microscopically confirmed. Based on the performed experiments we can conclude that electrochemical polishing is an efficient chemical surface treatment to increase the resistance of AISI 316L to pitting corrosion; the resistance to pitting corrosion of electrochemically polished surface can by markedly decreased by the presence of mechanical defects; the as-received surface and the ground surface showed lower resistance to pitting corrosion than electrochemically polished ones; sensitization induced by heat treatment (700 °C/10 hours) does not decrease resistance to pitting corrosion

Influence of the surface finishing on the corrosion behaviour of AISI 316L stainless steel

The influence of the surface preparation of AISI 316L stainless steel by mechanical grinding, polishing and following passivation was examined by immersion corrosion tests in solution simulating body fluids. Decreasing of the surface roughness by finer preparation resulted in decrease of corrosion rates of AISI 316L stainless steel. Passivation of specimens resulted in decreasing of the corrosion rates and in decreasing of the corrosion process speed independently on the roughness of specimens before passivations. Lowest corrosion rates were observed in the case of polished and passivated specimens. However no significant difference in corrosion rates between polished and ground specimens with following passivation was observed

Teen audience in a digital era

Bakalárska práca sa bude venovať analýze súčasnej filmovej tvorby určenej pre publikum 12-17 rokov, na volené marketingové stratégie producentov a úspešnosť distribúcie v českých kinách. Nakoľko v Českej republike vzniká len veľmi málo filmov pre túto cieľovú skupinu, môj záujem sa sústredí na príčiny tohto faktu, akými môžu byť nedostatok námetov, nízka atraktivita tohto žánru pre režisérov a producentov, či slabá divácka odozva. Ďalej sa v práci zameriam na príčiny nezáujmu publika a s tým súvisiacu nízku návštevnosť v kinách. Jej príčiny budem hľadať predovšetkým v neohybných reklamných kampaniach k filmom, ktorým sa nedarí zasiahnuť svoju cieľovú skupinu. Ďalej zmene diváckych návykov teenagerského publika a presunu jeho záujmu k obsahu na internete. Taktiež porovnám výsledky domácich filmov s výsledkami zahraničných filmov pre teenagerov a ich podiel v českých kinách a pokúsim sa tak odhaliť rozdiely medzi nimi

Calculation of the economic costs of Covid-19 in the Czech Republic using the CBA method

The thesis was written with the aim to analyse the economic costs and consequences of the Covid-19 pandemic in the Czech Republic for the year 2020. The analysis was carried out using a specific method of Cost-Benefit Analysis (CBA), used for economic evaluation of (not only) healthcare programmes. The main research question was whether the costs of protective measures to prevent the spread of the virus were proportional to their benefits. Relevant data for the analysis came from publicly available sources, mainly from the Czech Statistical Office and the Institute of Health Information and Statistics of the Czech Republic. The basis for the methodological processing of the analysis were academic sources dealing with Cost-Benefit Analysis and analyses of various authors, most often published in scientific journals. The results of the analysis provide answers to the research questions, which are summarized and interpreted in the conclusion of the thesis.Diplomová práca vznikla s cieľom vykonať analýzu ekonomických nákladov a následkov pandémie Covid-19 v Českej republike za rok 2020. Analýza bola spracovaná špecifickou metódou Cost-Benefit Analysis (CBA), používanou na ekonomické hodnotenie (nielen) zdravotníckych programov. Hlavná výskumná otázka znela, či náklady ochranných opatrení na zamedzenie šírenia vírusu boli úmerné ich prínosom. Relevantné dáta na spracovanie analýzy pochádzajú z verejne dostupných zdrojov, a to predovšetkým z dát Českého statistického úřadu a Ústavu zdravotnických informací a statistiky ČR. Základom pre metodické spracovanie analýzy boli akademické zdroje venujúce se Cost-Benefit Analysis a analýzy rôznych autorov, najčastejšie publikované v odborných periodikách. Z výsledkov analýzy plynú odpovede na stanovené výskumné otázky, ktoré sú zhrnuté a interpretované v závere práce.Cílem práce bylo analyzovat ekonomické náklady a důsledky pandemie Covid-19 v České republice za rok 2020. Analýza byla provedena specifickou metodou Cost-Benefit Analysis (CBA), která se používá pro ekonomické hodnocení (nejen) zdravotnických programů. Hlavní výzkumnou otázkou bylo, zda byly náklady na ochranná opatření k zabránění šíření viru úměrné jejich přínosům. Relevantní data pro analýzu pocházela z veřejně dostupných zdrojů, především z Českého statistického úřadu a Ústavu zdravotnických informací a statistiky ČR. Podkladem pro metodické zpracování analýzy byly akademické zdroje zabývající se Cost-Benefit Analysis a analýzy různých autorů, nejčastěji publikované v odborných časopisech. Výsledky analýzy poskytují odpovědi na výzkumné otázky, které jsou shrnuty a interpretovány v závěru práce

Influence of temperature on corrosion resistance of austenitic stainless steel in cl¯ containing solutions

Temperature is considered a complicated external factor of the susceptibility of stainless steels to the pitting. This paper deals with the corrosion behaviour of AISI 316Ti stainless steel in temperature range 22 - 80°C in aggressive chloride environments (3 and 5% FeCl3 solutions). The corrosion resistance of tested steel is evaluated on the base of results of exposure immersion tests and cyclic potentiodynamic tests. According to the obtained results the resistance of AISI 316Ti to the pitting is markedly affected by temperature changes in the range 22 - 80°C. Intensity of corrosion attack increases with the rise of Cl¯ concentration. Gentle changes of temperature and Cl¯ concentration cause significant differences in character of local damage. The appearance of pitted surfaces changes with the rise of the temperature (a density of pitting increases, a size of pits decreases). The strongest change in appearance is observed between 40 and 50ºC

ROC curve

This bachelor's thesis firstly defines the basic terms and then describes the ROC curve. Thesis deals with meaning of the ROC curve, its properties and construction with a graphic representation. Subsequently, the expression of the ROC curve and its area for normal, exponential and uniform distribution is derived in the work, also with a graphical representation. Then, it is related to statistical testing. At the end, there are described the empirical expression of the ROC curve and its application to real data processed in the Python programming language.