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Some results of simulations of flows with internal permeable walls
Louda, Petr
The work deals with the numerical modelling of compressible flow in a domain containing permeable walls in its interior, i.e. submerged in the fluid. The aim is to exclude direct simulation and find a model approximating the flow through a permeable plate driven by the static pressure difference between the sides of the wall. The numerical experiments so far enable to understand better forming of parasitic wave structures in the measuring section of the wind tunnel. The model of permeable wall needs further verification.
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Advanced Methods for the Solution of Journal Bearing Dynamics
Maršálek, Ondřej ; Louda,, Petr (referee) ; Furch, Jan (referee) ; Novotný, Pavel (advisor)
Náplní této disertační práce je popis komplexní a obecně použitelné strategie výpočetního modelování chování kluzných ložisek, pracujících v režimu smíšeného mazání a uvažujících reálné struktury drsných povrchů obou členů kluzných ložisek – ložiskových pánví a ložiskových čepů. V práci jsou uvedeny a detailně popsány způsoby získání charakteristických popisných dat těchto drsných povrchů a její nedílnou součástí je i popis numerických algoritmů, sloužících k následnému zpracování těchto dat. Dále jsou zde rozebrány implementované výpočetní přístupy k modelování kontaktního tlaku. Ovlivnění hydrodynamické mazací vrstvy kluzných ložisek je dáno velikostí a průběhem faktorů toku, jejichž numerické stanovování je zde detailně popsáno. Alternativní stanovení faktorů toku pomocí analytických funkcí je zde pro úplnost rovněž obsaženo. V závěru práce je uveden popis numerického řešiče modelování chování kluzných ložisek spolu s uvedenými výsledky provedených simulací a jejich diskuzí. Ověření jednotlivých výpočetních modelů, popřípadě porovnání výsledků s výsledky získanými alternativním způsobem, je uvedeno v příslušných kapitolách.
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Incentives leading companies to certification of ISO 14001
Polášek, Petr ; Vejchodská, Eliška (advisor) ; Louda, Jiří (referee)
Aim of the thesis is to define, characterize, structure and analyse incentives that lead firms to undergo and keep certification of the voluntary environmental standard ISO 14001. Following hypothesis was formulated in line with chosen aim: firms certify themselves with ISO 14001 mainly due to necessity of implementation of environmental elements to corporate governance in line with sustainable development. Outcome of the retrievel part of the thesis is to clearly define and well structure incentives that lead firms to certification. Subject matter experts from different certified companies assign to these incentives scales using staistical pairwise comparisons called Fuller's triangle. Based on the scales and order is confirmed or denied formulated hypothesis.
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Analysis bike-sharing usability in the capital city Prague
Steinbachová, Dominika ; Louda, Jiří (advisor) ; Sunega, Petr (referee)
The aim of this thesis is to analyse a bike-sharing in Prague, especially its usability and future potential. The thesis answers questions whether a bike-sharing can prosper in Prague and if so whether it can contribute to the solution of a problematic traffic situation. In a theoretical part of the thesis there are firstly described concepts of economics theories which are closely related with the concept of bike-sharing. The thesis also characterises fields of the collaborative economy, collaborative consumption and the model of sharing economy. There are introduced definitions of basic concepts and principles on which the sharing economy is based. In the beginning of the practical part it is performed a comparison of chosen cities from all around the world in which the bike-sharing is operated. Individual cities are compared based on collected statistical data and by DEA models. In an analysis of the potential of the bike -sharing in Prague it is performed a quantitative comparison of alternative transport options - bike, car and public transport. Using the collected data and several hypotheses, the means and variances (which can also play in significant role when selecting the optimal transport option) are compared. Outputs of these analyses are appropriately confronted with economic costs of alternatives and the result is a complex insight into the problem of choosing a travel option. The analysis shows that the bike-sharing may be more favourable than a public transportation under certain conditions. Analysis shows that we cannot expect such an expansion of bike-sharing, which can be seen lately in some cities abroad. It can be supposed that if Rekola or another subject minimalized current weaknesses, the bike-sharing in Prague may experience a significant popularity and growth. As regards a potential of the bike-sharing to contribute to solve the traffic load in Prague it can be expected almost zero effect. Even in cities where the bike-sharing is fully developed it forms maximally unit's percent of traffic mix. Its influence in Prague will probably never be noticeable.
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Numerical Simulation of Turbulent Flows Through Turbine Cascade With Rough Blades
Fürst, J. ; Louda, Petr ; Příhoda, Jaromír
The article deals with numerical simulation of turbulent compressible flows through 2D model of a turbine with rough blades. The mathematical model is based on the Favre-averaged Navier-Stokes equations combined with several two-equations turbulence models. The wall roughness is modeled using an appropriate boundary condition for specific dissipation rate. The comparison with experimental data shows correct increase of energy losses in the case of increased wall roughness.
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Comparison of .NET and other platforms for developing web applications
Louda, Petr ; Pecinovský, Rudolf (advisor) ; Pavlíčková, Jarmila (referee)
The thesis complements a comparison of two frameworks for Java platform and PHP language by third framework for .NET platform. As the main source of comparison serves thesis by František Odehnal and a sample application developed in ASP.NET MVC framework. Thanks to the detailed description of the application development and application of reasonable complexity thesis can serve as a study material for novice developers. A secondary aim of this thesis is to complete the context of web application development, by analyzing trends in rapid application development (RAD) and through presentation of .NET platform. Following František Odehnal's methodology this thesis complements comparison of Grails and Zend frameworks by ASP.NET MVC framework. The first area comparisons are fundamental differences between the frameworks. A comparison of architecture of frameworks follows and criteria are based on the architectural patterns of Martin Fowler. Working with frameworks is compared by using objective criteria and personal opinions. These areas are complemented by comparison of frameworks support (publications, discussion groups, etc.). Completed comparison allows the reader to get an overview of frameworks for rapid application development on the three major platforms. This can help novice developers in deciding which framework to test or use. Presentation of the platform and the trend analysis provides additional useful information not only for novice developers.
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Analysis of selected factors on the use of public transport
Kašpar, Petr ; Vejchodská, Eliška (advisor) ; Louda, Jiří (referee)
This thesis is aiming on the use of public transport in Europe. Objective of this work is by using correlation analysis determine whether the amount of subsidies to public transport and the ownership structure as the decisive criterion for the number of passengers, as an additional variable to assess the impact of fleet composition. Secondary data obtained from study of the University of Dublin has served to analyze. Calculation of the dependence didn't confirm or disclaim it. This gives space for further exploration. After analyzing the more comprehensive data set should be followed by analyzing the nature of subsidies, the choice of carriers, contractual conditions and other factors affecting the use of public transport.
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