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71.
An Interactive Deformation System for Granular Material 总被引:2,自引:0,他引:2
Computer Graphics (CG) animations of natural phenomena are currently widely used for movies and in video games. Granular materials occur widely in nature, and therefore it is necessary that CG animations represent ground surfaces composed of a granular material as well as model deformations when the granular material comes into contact with other physical rigid objects (called solid objects). In this paper, we propose a deformation algorithm for ground surfaces composed of granular material. The deformation algorithm is divided into three steps: (1) detection of the collision between a solid object and the ground surface, (2) displacement of the granular material and (3) erosion of the material at steep slopes. The proposed algorithm can handle solid objects of various shapes, including concave polyhedra by additionally using a layered data structure called the Height Span Map. Furthermore, a texture sliding technique is presented to render the motion of granular materials. In addition, our implementation of the deformation algorithm can be used at interactive frame rates. 相似文献
72.
We are developing an agent and server library referred to as X-Economy, by which we can execute multiagent simulations and network games for financial and economic systems. To this end, we analyzed the characteristics of network games in a financial context and compared them with traditional ones. X-Economy has also provided a new research direction in market micro-structure analysis. We executed several kinds of multiagent simulations for technical traders (indices) and obtained non-trivial suggestions regarding the relationship between the market randomness and the effectiveness of technical indices. For instance, the performance of complex technical indices seemed to deeply depend on the characteristics and nature of a market when a market became complex, i.e. it moved far from the Wiener process. 相似文献
73.
Heat and mass transfer during crystal growth 总被引:2,自引:0,他引:2
Quality of semiconductor and oxide crystals which are grown from the melts plays an important role for electronic and/or optical devices. The crystal quality is significantly affected by the heat and mass transfer in the melts during crystal growth in a growth furnace such as Czochralski or horizontal Bridgman methods. This paper reviews the present understanding of phenomena of the heat and mass transfer of the melts, especially instability of melt convection from the detailed numerical calculation, which helps to understand the melt convection visualized using X-ray radiography. Large scale simulation of melt convection during crystal growth is also reviewed.
Characteristics of flow instabilities of melt convection with a low Prandtl number (ratio between momentum and thermal diffusivities) are also reviewed by focusing on the instabilities of baroclinic, the Rayleigh-Benard and the Marangoni-Benard, from the points of view of temperature, rotating and/or magnetic field effects during crystal growth. Oxygen concentration in grown crystals is also discussed how melt convection affects. 相似文献
74.
Asymmetric addition of thiol to diene polymer in the presence of optically active amines as catalyst
The asymmetric addition reaction of thiolacetic acid or benzylmercaptan to diene polymer (natural rubber, cis- and trans-1,4-polyisoprene, cis-1,4-polybutadiene, various styrenebutadiene copolymers and alternating acrylonitrile-butadiene copolymer) by optically active catalysts such as d-bornylamine ([α]d?45.2°), l-aspartic diethyl ester (?11.2°), l-aspartic dibutyl ester (?5.3°) were carried out in benzene at room temperature to 90°C. The optically active polymers were obtained from natural rubber and cis-1,4- and trans-1,4-polyisoprene, but were not obtained from cis-1,4-polybutadiene, styrene-butadiene copolymers, and butadiene-acrylonitrile copolymer. The [α]25D value of optically active derivatives was ?0.1° ~ ?1.0° (in benzene), and the optical rotatory dispersion curves were found to fit the simple Drude equation. 相似文献
75.
Wataru Sakamoto Mio Yamada Naoya Iizawa Yu-Ki Mizutani Daichi Togawa Koichi Kikuta Toshinobu Yogo Takashi Hayashi Shin-Ichi Hirano 《Journal of Electroceramics》2004,13(1-3):339-343
Neodymium-modified Bi4Ti3O12, (Bi, Nd)4Ti3O12 (BNT) ferroelectric thin films have been prepared on Pt/TiOx/SiO2/Si substrates using metal-organic precursor solutions by the chemical solution deposition method. The BNT precursor films crystallized into the Bi layered perovskite Bi4Ti3O12 (BIT) as a single-phase above 600C. The synthesized BNT films revealed a random orientation having a strong 117 reflection, whereas non-substituted BIT thin films exhibited a random orientation with strong 00l diffractions. Among Bi4 – xNdxTi3O12 [x = 0.0, 0.5, 0.75, 1.0] thin films, Bi3.25Nd0.75Ti3O12 thin films showed a well-saturated P-E hysteresis loop with the highest Pr (22 C/cm2) and a low Ec (69 kV/cm) at an applied voltage of 5 V. The Nd-substitution with the optimum amount for the Bi site in the BIT structure was effective not only for promoting the 117 preferred orientation but also for improving the microstructure and ferroelectric properties of the resultant films. 相似文献
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78.
Elisa Barney Smith David Monn Harsha Veeramachaneni Koichi Kise Alessio Malizia Leon Todoran Adnan El-Nasan Rolf Ingold 《International Journal on Document Analysis and Recognition》2003,6(3):200-206
This document is a collection of four working group reports in the areas of digital libraries, document image retrieval, layout analysis, and Web document analysis. These reports were the outcome of discussions by participants at the Fifth IAPR International Workshop on Document Analysis Systems held in Princeton, NJ on 19-21 August 2002.Published online: 16 March 2004 相似文献
79.
Fourier transform near-infrared (FT-NIR) spectra have been measured for bovine serum albumin (BSA) in an aqueous solution (pH 6.8) with a concentration of 5.0 wt% over a temperature range of 45-85 degrees C. Not only conventional spectral analysis methods, such as second-derivative spectra and difference spectra, but also chemometrics, such as principal component analysis (PCA) and evolving factor analysis (EFA), have been employed to analyze the temperature-dependent NIR spectra in the 7500-5500 and 4900-4200 cm-1 regions of the BSA aqueous solution. Intensity changes of bands in the 7200-6600 cm-1 and 4650-4500 cm-1 regions in the difference spectra indicate variations of the hydration and secondary structure of BSA in the aqueous solution, respectively. The plot of a band intensity at 7080 cm-1 in the different spectra shows a clear turning point at 63 degrees C, revealing that a significant change in the hydration occurs at about 63 degrees C. The forward and backward eigenvalues (EVs) from EFA suggest that marked changes in the hydration and secondary structure of BSA take place in the temperature ranges of 61-65 degrees C and 59-63 degrees C, respectively. In addition, the temperature of 71 degrees C marked in the EFA plots may correspond to the onset temperature of increase in the intermolecular beta-sheet structure. 相似文献