Implementace telematiky při přepravě nebezpečných věcí
Uhříček Vladimír; Pichl Martin
2014 - Available at various departments of the ČVUT. Implementace telematiky při přepravě nebezpečných věcí

Uhříček Vladimír; Pichl Martin
České vysoké učení technické v Praze, 2014

Design of Experiments in Scheduling Scenarios for Workload Distribution and Qualitative Usage of Time
Kavan Michal; Gruia George Cristian
2014 - Available at various departments of the ČVUT. Design of Experiments in Scheduling Scenarios for Workload Distribution and Qualitative Usage of Time

Kavan Michal; Gruia George Cristian
České vysoké učení technické v Praze, 2014

Studium vzniku trhlin LMAC při žárovém zinkování
Kreibich Viktor; Kuklík Vlastimil
2014 - Available at various departments of the ČVUT. Studium vzniku trhlin LMAC při žárovém zinkování

Kreibich Viktor; Kuklík Vlastimil
České vysoké učení technické v Praze, 2014

Hodnocení lidského činitele v řízení letového provozu
Voštová Věra; Štecha Richard
2014 - Available at various departments of the ČVUT. Hodnocení lidského činitele v řízení letového provozu

Voštová Věra; Štecha Richard
České vysoké učení technické v Praze, 2014

Numerical modeling of laminated glass structures
Šejnoha Michal; Zemanová Alena; Šejnoha Jiří
2014 - English Laminated glass structures are formed by stiff layers of glass connected with a compliant polymer foil. Due to their slenderness, heterogeneity, and time- and temperature-dependent properties of the interlayer, they exhibit a complex mechanical response that is difficult to capture by single-layer models. The main aim of this work is to develop a finite element model that can describe the behavior of laminated glass units without the need for fully resolved three-dimensional simulations, which lead to unnecessarily expensive calculations. For a geometrically nonlinear description of the behavior of units, each layer is considered to behave according to the Reissner finite-strain beam theory or the Reissner-Mindlin plate theory, complemented with membrane effects and the von Kármán assumptions. The compatibility of independent layers is enforced by the Lagrange multipliers, which proceeds from a refined plate theory due to Mau. The time- and temperature-dependent behavior of the interlayer is accounted for by the generalized Maxwell model and by the time-temperature superposition principle due to the Williams-Landel-Ferry equation. The resulting system is solved by the Newton method with consistent linearization and the viscoelastic response is determined incrementally by the exponential algorithm. By comparing the model predictions against available experimental data, analytical methods and two-dimensional finite element simulations, it is demonstrated that the proposed formulation is reliable and accurately reproduces the behavior of the laminated glass units. As such, it offers a convenient basis to incorporate additional phenomena, such as delamination of glass layers.Laminated glass structures are formed by stiff layers of glass connected with a compliant polymer foil. Due to their slenderness, heterogeneity, and time- and temperature-dependent properties of the interlayer, they exhibit a complex mechanical response that is difficult to capture by single-layer models. The main aim of this work is to develop a finite element model that can describe the behavior of laminated glass units without the need for fully resolved three-dimensional simulations, which lead to unnecessarily expensive calculations. For a geometrically nonlinear description of the behavior of units, each layer is considered to behave according to the Reissner finite-strain beam theory or the Reissner-Mindlin plate theory, complemented with membrane effects and the von Kármán assumptions. The compatibility of independent layers is enforced by the Lagrange multipliers, which proceeds from a refined plate theory due to Mau. The time- and temperature-dependent behavior of the interlayer is accounted for by the generalized Maxwell model and by the time-temperature superposition principle due to the Williams-Landel-Ferry equation. The resulting system is solved by the Newton method with consistent linearization and the viscoelastic response is determined incrementally by the exponential algorithm. By comparing the model predictions against available experimental data, analytical methods and two-dimensional finite element simulations, it is demonstrated that the proposed formulation is reliable and accurately reproduces the behavior of the laminated glass units. As such, it offers a convenient basis to incorporate additional phenomena, such as delamination of glass layers. Keywords: laminated glass; finite-strain Reissner beam theory; Reissner-Mindlin plate theory; von Kármán plate theory; finite element method; Lagrange multipliers; time- and temperature-dependent behavior Available at various departments of the ČVUT. Numerical modeling of laminated glass structures

Laminated glass structures are formed by stiff layers of glass connected with a compliant polymer foil. Due to their slenderness, heterogeneity, and time- and temperature-dependent properties of the ...

Šejnoha Michal; Zemanová Alena; Šejnoha Jiří
České vysoké učení technické v Praze, 2014

Vyšetřování únavy betonu s přihlédnutím k vlivu prostředí
Štemberk Petr; Sýkorová Jana; Podolka Luboš
2014 - Czech Inženýrské konstrukce jako jsou betonové mosty, bývají během své životnosti vystaveny cyklickému zatěžování od dopravy, které vyvolává únavové poškození. Během zimních měsíců jsou mosty též vystaveny střídání zmrazovacích a rozmrazovacích cyklů. U silničních mostů se v zimě ještě přidává další efekt a to je chemické ošetřování povrchů vozovek rozmrazovacími solemi na bázi chloridů, které se na most dostávají na kolech projíždějících vozidel. Všechny tyto tři efekty mají negativní vliv na životnost betonu. Poškození betonu v tlaku cyklickým zatěžováním se dá vyjádřit poklesem modulu pružnosti betonu v závislosti na počtu zatěžovacích cyklů. Snížení tuhosti betonu z důvodu vystavení konstrukce zmrazovacím a rozmrazovacím cyklům se vyjadřuje jako pokles modulu pružnosti v závislosti na počtu zmrazovacích a rozmrazovacích cyklů, kterými konstrukce prošla. Efekt chloridů ve struktuře betonu je závislý na době vystavení konstrukce tomuto účinku. Proto se u působení chloridů vyjadřuje jejich vliv na beton jako změna modulu pružnosti v závislosti na době jejich působení ve struktuře betonu. V této práci jsou detailně popsány tyto tři efekty a jsou navrženy metody pro jejich vzájemnou kombinaci. Navržené metody kombinací jsou předvedeny na názorných příkladech odhadu životnosti betonových konstrukcí.Concrete bridges are structures which are subjected to cyclic loading caused by transportation during their service life. Cyclic loading causes fatigue damage. During the winter season bridges are also subjected to freeze-thaw cycles. Road bridges often suffer from exposure of their surface to the effect of chlorides during the winter road maintenance. All of these three effects have a negative impact on the service life of concrete structures.Damage of concrete in compression induced by cyclic loading can be expressed by decreasing of modulus of elasticity depending on the number of load cycles. Reduction of stiffness due to exposure of concrete structure to freeze-thaw cycles can be expressed by decreasing of modulus of elasticity depending on the number of freeze-thaw cycles. The effect of chlorides inside the concrete microstructure depends on exposure time. Therefore, the impact of chloride ingress can be expressed by decreasing of modulus of elasticity depending on the exposure time.In this work, all these three effects are described in detail and methods for their combinations are proposed. The proposed methods are demonstrated in illustrative examples. Keywords: Beton; cyklické zatěžování; střídání zmrazovacích a rozmrazovacích cyklů; chloridy; únava betonu; degradace betonu; vývoj modulu pružnosti; stupeň zatížení; stupeň nasycení; difúze. Available at various departments of the ČVUT. Vyšetřování únavy betonu s přihlédnutím k vlivu prostředí

Inženýrské konstrukce jako jsou betonové mosty, bývají během své životnosti vystaveny cyklickému zatěžování od dopravy, které vyvolává únavové poškození. Během zimních měsíců jsou mosty též vystaveny ...

Štemberk Petr; Sýkorová Jana; Podolka Luboš
České vysoké učení technické v Praze, 2014

Aplikace Ginzburg-Landauova modelu na inhomogenní feroelektrika
Hlinka Jiri; Stepkova Vilgelmina; Mokrý Pavel
2014 - English Theoretical study of ferroelectric domain nanostructures Available at various departments of the ČVUT. Aplikace Ginzburg-Landauova modelu na inhomogenní feroelektrika

Theoretical study of ferroelectric domain nanostructures

Hlinka Jiri; Stepkova Vilgelmina; Mokrý Pavel
České vysoké učení technické v Praze, 2014

Senzory plynů s filtry na bázi zeolitů
Sopko Bruno; Vlk Josef
2014 - Available at various departments of the ČVUT. Senzory plynů s filtry na bázi zeolitů

Sopko Bruno; Vlk Josef
České vysoké učení technické v Praze, 2014

Chosen economic and environmental aspects of material resources in construction in the view of sustainability - Tools to assess capability to reduce primary energy demand in housing
Dlask Petr; Anisimova Nataliya; Karásek Jiří
2014 - English Energy use in European housing comprises the greatest part of total energy consumption and is above industry and transport figures. The growing trend in building energy use has made energy efficiency strategy the main concern for energy policies which then involve developing new building regulations and certification processes. The main objectives of the thesis is the estimation of financial funds required to motivate the efficient energy use in housing construction in each EU state, and the definition of the most efficient ways of the investment into energy demand reduction in housing. The objectives were reached by means of the following methods: generalization of existing knowledge, experience and requirements, analysis of foreign practice, mathematical-statistical methods of data evaluation, comparative analysis, value engineering. First of all, the required amount of funds for support programs which would motivate the energy efficiency increase in dwelling houses was estimated on a national scale for different EU countries. After that different direction of the required investment into energy efficiency increasing steps were chosen and assessed within the research taking into account not only environmental but also economic aspect. In the thesis were described the following tools to assess the capability to reduce energy demand of buildings: certification systems, thermal energy balance, embodied energy assessment, quantification of energy savings. None of these tools involves both economic and environmental assessment of energy performance of building. The developed tool (total efficiency assessment) is based on the thermal energy balance, discriminant analysis, and the required investment evaluation. The tool was demonstrated on the basis of fifteen case studies with the following approach: the input data (decrease in final energy demand, in primary energy demand and in CO2 emissions) were derived from each option's energy balance of the building; the options were evaluated in accordance with the ratio between the gained utility and required investment; after that the total efficiency of the options was assessed in a short time period.Energy use in European housing comprises the greatest part of total energy consumption and is above industry and transport figures. The growing trend in building energy use has made energy efficiency strategy the main concern for energy policies which then involve developing new building regulations and certification processes. The main objectives of the thesis is the estimation of financial funds required to motivate the efficient energy use in housing construction in each EU state, and the definition of the most efficient ways of the investment into energy demand reduction in housing. The objectives were reached by means of the following methods: generalization of existing knowledge, experience and requirements, analysis of foreign practice, mathematical-statistical methods of data evaluation, comparative analysis, value engineering. First of all, the required amount of funds for support programs which would motivate the energy efficiency increase in dwelling houses was estimated on a national scale for different EU countries. After that different direction of the required investment into energy efficiency increasing steps were chosen and assessed within the research taking into account not only environmental but also economic aspect. In the thesis were described the following tools to assess the capability to reduce energy demand of buildings: certification systems, thermal energy balance, embodied energy assessment, quantification of energy savings. None of these tools involves both economic and environmental assessment of energy performance of building. The developed tool (total efficiency assessment) is based on the thermal energy balance, discriminant analysis, and the required investment evaluation. The tool was demonstrated on the basis of fifteen case studies with the following approach: the input data (decrease in final energy demand, in primary energy demand and in CO2 emissions) were derived from each option's energy balance of the building; the options were evaluated in accordance with the ratio between the gained utility and required investment; after that the total efficiency of the options was assessed in a short time period. Keywords: assessment; tool; housing; energy demand; economic aspect; environmental aspect; total efficiency. Available at various departments of the ČVUT. Chosen economic and environmental aspects of material resources in construction in the view of sustainability - Tools to assess capability to reduce primary energy demand in housing

Energy use in European housing comprises the greatest part of total energy consumption and is above industry and transport figures. The growing trend in building energy use has made energy efficiency ...

Dlask Petr; Anisimova Nataliya; Karásek Jiří
České vysoké učení technické v Praze, 2014

Patterns in URL
Vaníček Tomáš; Hujer Roman; Molnár Zdeněk
2014 - English This text describes the research on patterns in URL, URL classification and their respective relation. Firstly, motives for the URL classification and patterns in URL are explained. The motives come from topicality of the search engines and the webometrics. The webometrics and the search engines later turn out to be an application of the work results. It is be explained which questions the research should answer, what is the hypothesis and for whom could be the research beneficial.Related technologies such as deep web, semantic web, microformats and search engine optimization are mentioned in a chapter about the current state of scientific knowledge and it is explained how these topics influence the research. More space is dedicated to webometrics as it is a science closely related to the work's topic.The core of the work describes traversing as an alternative of following hyperlinks. Then introduces classification as a generalization of the patterns concept, followed by two experiments. The first experiment confirms the numeric pattern. The second experiment demonstrates way of finding another patterns. The chapter is concluded by a formal description of the concept of pattern in URL.In the end is concluded the scientific contribution of the work and outline possible future work.This text describes the research on patterns in URL, URL classification and their respective relation. Firstly, motives for the URL classification and patterns in URL are explained. The motives come from topicality of the search engines and the webometrics. The webometrics and the search engines later turn out to be an application of the work results. It is be explained which questions the research should answer, what is the hypothesis and for whom could be the research beneficial.Related technologies such as deep web, semantic web, microformats and search engine optimization are mentioned in a chapter about the current state of scientific knowledge and it is explained how these topics influence the research. More space is dedicated to webometrics as it is a science closely related to the work's topic.The core of the work describes traversing as an alternative of following hyperlinks. Then introduces classification as a generalization of the patterns concept, followed by two experiments. The first experiment confirms the numeric pattern. The second experiment demonstrates way of finding another patterns. The chapter is concluded by a formal description of the concept of pattern in URL.In the end is concluded the scientific contribution of the work and outline possible future work. Keywords: hyperlink; URL; pattern; resource; hyperlink classification Available at various departments of the ČVUT. Patterns in URL

This text describes the research on patterns in URL, URL classification and their respective relation. Firstly, motives for the URL classification and patterns in URL are explained. The motives come ...

Vaníček Tomáš; Hujer Roman; Molnár Zdeněk
České vysoké učení technické v Praze, 2014