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991.
992.
Han Kyun Choi Hyun Soo Kim Kwan Heng Lee 《The International Journal of Advanced Manufacturing Technology》2010,50(1-4):235-252
The use of highly detailed models is continuously increasing in computer-aided design (CAD) design and computer graphics field as the technology of range scanners advances. Real-time rendering and manipulating applications are also increasing to support applications in various areas such as collaborative design and scientific visualization. Although graphics hardware technology has been improved rapidly, more attributes such as color, material property, texture coordinate, and curvature are added to CAD models, and it becomes a challenge to handle and render such heavy models. Consequently, the models with complex mesh need to be approximated to improve the efficiency of rendering and manipulation and to reduce computation time. A considerable amount of work has been done regarding geometry preservation, but relatively little research has been performed to preserve both geometry and additional attributes. We present a feature sensitive simplification method using curvature color as an additional attribute. We also use curvature color filtering and optimal positioning methods after edge collapse to preserve feature more sensitively. Our method is applied to several models, and the performance is demonstrated by comparing it with other methods. 相似文献
993.
Dong-Kil Lee Won-Sub Chung Yong-Hwan Kim Inwon Lee Ho-Hwan Chun Hyun Park 《Metals and Materials International》2010,16(5):833-836
The pH variations of Mg, Zn and Al solutions to which had been added the rare earth metals Nd, Pr and Y were observed in 3.5
wt.% NaCl with respect to high energy mechanical ball milling effects. Mg was directly dissolved and exhibited a pH value
of 10.5. On the other hand, Zn and Al needed to be saturated for a certain amount of time. The addition of rare earth metals
played a role in increasing the pH with low reduction potentials. Additionally, mechanical ball milling provided high energy
to Mg + x wt.% Zn + 0.5 wt.% Nd mixture by fracturing fragmentation of metals, which led to an increase in the pH when the
mixture was immersed in 3.5 wt.% NaCl. The addition of Zn to Mg + 0.5 wt.% Nd caused a higher pH than when Mg + 0.5 wt.% Nd
alone was added. 相似文献
994.
Seon Yang Youngjoong Ko 《Pattern recognition letters》2011,32(2):293-296
In this paper, we study how to extract comparative sentences from Korean text documents. We decompose our task into three steps: (1) collecting comparative keywords; (2) extracting comparative-sentence candidates by keyword searching; and (3) eliminating non-comparative sentences from these candidates using machine learning techniques. We perform various experiments to find relevant features. As a result, our experiments show significant performance, an F1-score of 90.23%. 相似文献
995.
Asemi-empirical atomic potential, the second nearest-neighbor MEAM, has been applied to obtain an atomic potential for the Fe-Cr system, based on the previously developed potentials for pure Fe and Cr. The procedure for the determination of potential parameter values and the performance of the assessed alloy potential were also presented. It was shown that the potential describes the basic thermodynamic property and alloy behavior in the bcc solid solution successfully, as well as many physical properties of pure Fe and Cr. The limit in the applicability of the present potential is also discussed. 相似文献
996.
Kyu-Sung Kim Hyun Seok Lee Young-Min Jeon Joon-Woo Kim Chil-Won Lee Myoung-Seon Gong 《Dyes and Pigments》2009,81(3):174-179
A novel, spiro-type host material 2-(10-naphthylanthracene)-spiro[fluorene-7,9′-benzofluorene] was prepared by reacting 2-bromo-spiro[fluorene-7,9′-benzofluorene] with 9-(2-naphthylanthracene)-10-boronic acid via the Suzuki reaction. 2-4′-(Phenyl-4-vinylbenzeneamine)phenyl-spiro[fluorene-7,9′-benzofluorene], 4-[2-naphthyl-4′(phenyl-4-vinylbenzeneamine)]phenyl and diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]-amine were used as dopant materials. Devices with the configuration of ITO/N,N′-bis[4-(di-m-tolylamino)phenyl]-N,N′-diphenylbiphenyl-4,4′-diamine)/bis[N-(1-naphthyl)-N-phenyl]benzidine/2-(10-naphthylanthracene)-spiro[fluorene-7,9-benzofluorene]:5% dopant/aluminum tris(8-hydroxyquinoline)/Al-LiF showed a maximum power efficiency of 3.7 cd/A at 17.93 mA/cm2 and a maximum luminance of 5018 cd/m2 at 10 V with a turn-on voltage of 4.5 V. 相似文献
997.
Ju Young Lee Hong Seung Kim Chung-Hyun Lee Hyung Koun Cho Bo Hyun Kong 《Thin solid films》2009,517(17):5157-1130
We report the effects of thermal annealing in air and N2 ambient on the structural, optical, and electrical properties of zinc oxide (ZnO) films deposited on a p-GaN substrate. Also, we report on the fabrication and device characterization of heterojunction light-emitting diodes based on the n-ZnO/p-GaN systems. In the case of N2 ambient, room-temperature electroluminescence (EL) in the violet region with peak wavelength 400 nm was observed under forward bias. In air ambient, EL spectrum consisted of a broad band from 400 nm to 700 nm due to the Ga-O mixed region formed interface between the ZnO and GaN layer. 相似文献
998.
Korea is experiencing an extraordinarily rapid demographic transition. We investigated the short-term association between air pollution and mortality and assessed the impact of improved air quality on mortality in a rapidly aging city, Seoul, Korea.The generalized additive model (GAM) was used to estimate the relative risks (RR) of mortality associated with changes in air pollution. The time trends, seasonal variations, day of the week effects, and weather effects were controlled in the models. To estimate the health benefits, we used the US Environmental Protection Agency's BenMAP.For people 0–64 years of age, elderly people (65+ years), and all age groups, an increase of 10 μg/m3 in PM10 was associated with increases in daily death counts of 0.27% (95% CI: 0.04–0.50), 0.45% (95% CI: 0.27–0.64), and 0.37% (95% CI: 0.23–0.52), respectively. For ages 0–64 years, elderly people, and all age groups, a 10 ppb increase in 1-hour maximum ozone concentration resulted in an increased risk of daily death counts of 0.28% (95% CI: − 0.19–0.74), 0.96% (95% CI: 0.46–1.47), and 0.81% (95% CI: 0.35–1.26), respectively.For elderly people, it was estimated that the health benefits of attaining the World Health Organization's (WHO) air quality guidelines (AQGs) for PM10 (24-hour average 50 μg/m3) would suggest an annual reduction of 964 (95% CI: 564–1366) premature deaths, and 329 (95% CI: 159–500) premature deaths could be prevented annually in 2015 from attaining the WHO's guidelines for ozone (8-hour average 100 μg/m3).The rapid increase of the elderly population has major consequences and implications for society and public health. This study showed that elderly people are at higher risk for the acute mortality effects of air pollution. Therefore, cleaner air will substantially contribute to improved public health in Seoul, given the growing concern about the adverse effects of air pollution for elderly people. 相似文献
999.
Dong Hwan Kim Sang Hyuck Kim Young Min Jhon Seong Yun Ko Jae Cheol Jo Sang Sam Choi 《Photonics Technology Letters, IEEE》1999,11(5):521-523
A 10-Gb/s semiconductor-fiber ring laser is proposed and demonstrated. The performance of a harmonically mode-locked semiconductor-fiber ring laser was described in detail. A long cavity length configuration in semiconductor optical amplifier is found to eliminate the relaxation oscillation, and improved short-term amplitude stability. The laser output has a pulsewidth of 18.4 ps and a spectral width of 0.3 nm 相似文献
1000.
Dae Kyun Baek Tae Jo Ko Seung Han Yang 《Journal of Materials Processing Technology》2013,213(4):553-559
We present a new fabrication method that enables precision hole machining to be achieved by sacrificing the coating on the substrate in ultrasonic machining (USM). A hard wax coating is deposited on the glass substrate, and holes are precisely fabricated in the coated glass using USM. Finally, a wax coating is removed using a cleaning process. The wax coating protects the surface of the glass so that cracks are generated in the wax rather than on the surface. The surface accuracy of the glass substrate is evaluated at the hole entrance using the new tools in USM as a function of the thickness of the coating. The entrance diameters of the machined holes and the machining forces at the beginning of cutting are measured as a function of the thickness of the coating. The entrance cracks and out-of-roundness of the machined holes are generated in the sacrificed coating on the glass substrate; hence, the surface quality of the glass holes is enhanced in USM. 相似文献