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Towards Effective Measurement and Interpolation of Bidirectional Texture Functions
Filip, Jiří
Bidirectional texture function (BTF) is acquired by taking thousands of material surface images for different illumination and viewing directions. This function, provided it is measured accurately, is typically exploited for visualization of material appearance in visual accuracy demanding applications. However, accurate measurement of the BTF is time and resources demanding task. While the sampling of illumination and viewing directions is in all known measurement systems done uniformly, we believe that to be more effective the sampling should be tailored specifically to reflectance properties of materials to be measured. Hence, we introduce a novel method of sparse BTF sampling. The method starts with collecting information about material visual behavior by means of small initial subset of reflectance samples measurement and analysis. This information is fed into our heuristic algorithm producing sparse material dependent sampling that is consequently used for BTF measurement and interpolation.
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Řešení 3D elektrostatických problémů se singulaturou s použitím adaptivní hp-FEM
Kůs, Pavel ; Šolín, Pavel ; Doležel, Ivo
For most numerical methods, accurate resolution of singularities occurring at sharp re-entrant corners or edges of electrically conductive objects is highly problematic. Finite differences are known for their inability to treat complex geometries, and traditional low-order (piecewise-linear or quadratic) finite element methods (FEM) exhibit extremely poor convergence. Nowadays, the best numerical method for the solution of most singular problems is the adaptive hp-version of the FEM (hp-FEM). This method is based on spatial refinements toward the singularities combined with optimal variation of polynomial degrees on the elements. The hp-FEM has mathematically proven exponential convergence, and also in practical computations typically it is by several orders of magnitudes faster than standard FEM.
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The First Decade of the Czechoslovak Republic in the Light of Two Languages of the České Budějovice Press. Czech-German Comparison.
ZEMANOVÁ, Ivana
The purpose of the diploma thesis is to examine the relationship of the Czechs and Germans in the newly established Czechoslovak Republic shown in the local press. Both nations had an extremely difficult task ? to learn how to live together. The euphoria of the Czechs, expressed by a simple motto: ?End to the 300-hundred-years´ subjection?, did not correspond to the worries of the Germans, who after the four years of war hardship, had to face a very uncertain future within the new state. The selected issues: revolution, general difficulties of the Czech-German coexistence, local elections, festivities (especially ?svatováclavské milénium?), and sports phenomenon of football, show gradual, very fragile emancipation of both nations, from open hate to settlement of the relationships, making the Czechs and Germans respecting each other. Only in the second half of the 1920s, the Germans begin to participate in the administration of the Czechoslovak state; they are part of the governmental structures. However, the borderline between yes and no was very inconstant, which can be seen from the then local periodicals. The tense truce, which was typical for the first ten years of the new republic, world economic depression and German fascism, transformed into an open struggle, which is another topic anyway.
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Casting compound and its use in modern ceramic design\nl (practically theoretical work)
DVOŘÁKOVÁ, Zuzana
This work deals with design of products made in limited series production. The typical feature of these products is using a technique of casting compound. The aim of this work is to look into design of applied arts from the beginning of the 20th century up to now. The theoretical part consists of several parts. At the beginning is described formation of artistic movements and schools that deal with ceramic manufacturing. After this part follows description of theory and technique of casting formation of this technology and its usage. There is also described application of casting compound in industry. In the other part of theory I focus on design of tea kettles. My task for the practical part was to design, make and present a tea kettle. This kettle was made by above mentioned technique of casting compound.
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On selections of constraints for the BDDC method
Čertíková, M. ; Šístek, Jakub ; Novotný, J. ; Burda, P.
The Balancing Domain Decomposition by Constraints (BDDC) method is an iterative substructuring domain decomposition method which uses a coarse space. The choice of coarse constraints on continuity has strong influence on convergence of the method. The goal of this paper is to compare the performance of several algorithms for selection of the coarse constraints applied to both test and industrial 3D linear elasticity problems and confront results obtained for typical test problems with results for industrial problems.
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The optical spectra of carbon-based thin films measured by the photothermal deflection spectroscopy (PDS)
Remeš, Zdeněk ; Pham, T.T. ; Varga, Marián ; Kromka, Alexander ; Stuchlík, Jiří ; Mao, H.B.
Our photothermal deflection spectroscopy (PDS) setup allows to measure simultaneously the absolute values of the optical transmittance T, reflectance R and absorptance A spectra of thin layers on glass substrates in the spectral range from ultraviolet to near infrared light with the typical spectral resolution 5 nm in the ultraviolet, 10 nm in visible and 20 nm in the near infrared region. The PDS setup provides the dynamic detection range in the optical absorptance up to 4 orders of magnitude. Here we demonstrate the usability of this setup by comparing the optical absorbance on a series of the carbon layer and nanocrystalline diamond (NCD) thin layers deposited on glass substrates by using the magnetron sputtering and the microwave based surface wave discharge in linear antenna chemical vapor deposition (CVD) processes, respectively. The defect-induced localized states in the energy gap are observed in all carbon layers as well as in NCD.
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Modelling of crack propagation through bi-material interface
Náhlík, Luboš
Under conditions of Linear Elastic Fracture Mechanics is studied crack behaviour in front of circular particle. The typical behaviour of crack approaching the interface between matrix and particle is showen. Results of numerical calculations and applications of earlier suggested tentative fracture criteria for crack terminating at the bi-material interface are presented.
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