• Journal of Advanced Marine Engineering and Technology
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• v.23 no.5
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• pp.711-718
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• 1999

Current turbulence models including modified $K-{\varepsilon}-{\tau}$ turbulence model do not predict compression effect on turbulence accurately in an internal combustion engine. The $K-{\varepsilon}-{\tau}$ turbulence model was suggested to improve the predictability of compression effect by We et al. In this paper a numeri-cal study was performed to clarify the applicability of the $K-{\varepsilon}-{\tau}$ turbulenc model to the calculation of the in-cylinder flow of an axisymmetric engine. THe results using $K-{\varepsilon}-{\tau}$ turbulence model are compared to those from the modified $K-{\varepsilon}-{\tau}$ turbulence model and experimental data. The mean veloc-ity and rms velocity profiles using $K-{\varepsilon}-{\tau}$ turbulence model showed a better agreement with an experimental data than those of modifid $K-{\varepsilon}-e$ turbulence model.

• Journal of Ginseng Research
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• v.24 no.2
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• pp.94-98
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• 2000

Tetracycline hydrochloride (TC) caused 100%, 50% and 20% mortality rates among rats injected with 40 mg, 30 mg and 20 mg/100g. b.w. respectively; while the morta]ity rates were decreased to 50%, 20% and 10% when Panax ginseng (2 mg/100g. b.w.) injected with TC during 72 hrs. post-injection. Subacute-toxicity study demonstrated that TC caused severe hepato-nephrotoxicity (demonstrated by biochemical analysis of serum including: transferases , alkaline phosphatase, total protein, glucose, cholesterol urea and creatinine) in rats injected i.p. with 10 mg and 5 mg/100g. b.w. for 7 days of daily injection . These signes of toxicity were greatly diminished by P. ginseng addition to TC doses.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.241-248
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• 2001

The ductility of circular hollow reinforced concrete columns with one layer of longitudinal and spiral reinforcement placed near the outside face of the section and the steel tube placed on the inside face of the section is investigated. Such hollow sections are confined through the wall thickness since the steel tube is placed. The results of analytical moment-curvature analyses for such hollow sections are compared with those for the circular section with the sane diameter. In this study, moment-curvature analyses are conducted with Mandel's confined concrete stress-strain relationship in which the effect of confinement is to increase the compression strength and ultimate strain of concrete. The moment-curvature analyses confirmed that the ductility is primarily influenced on the ultimate strain. The variables influenced on the ultimate strain is the ratio and yield strength of confining reinforcement and the compression strength for confined concrete. From this ultimate strain - the transverse reinforcement ratio relationship, the transverse reinforcement ratio for circular hollow reinforced columns with confinement is proposed. The proposed transverse reinforcement ratio is confirmed by experimental results.

• The Korean Journal of Ecology
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• v.26 no.2
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• pp.53-58
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• 2003

Ever-growing recreation, tourism and ecotourism worldwide have become a significant factor of resource degradation in many protected areas. Managers of these areas are increasingly challenged to implement policies, strategies and actions that would protect the resource base while providing quality visitor experience. One major issue in managing protected area visitations is that of carrying capacity, or the question of "how much use is too much\ulcorner". Scientific studies of visitor impacts, often known as recreation ecology, has generated a knowledge base that provides valuable input to the visitor carrying capacity management process adopted by the U.S. National Park Service. This paper aims at (a) providing an overview of recreation ecology research and its application in managing visitor carrying capacity, and (b) examining the relevance of recreation ecology to East Asian protected areas with special reference to the visitor capacity issue.ity issue.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.444-450
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• 1999

Hydroxyapatite(HA) was spray-coated to alloy substrate(Ti-6Al-4V) using plasma-spray process for bioceramic application The coating morphology composition and crystallinity were influenced by following process parameters ; stand-off distance spray power level and auxiliary gas pressure. These parameters have been systematically varied in the present study to evaluate their relative influence on the coating qual-ity and to seek an optimum spraying condition. Amorphicity and decomposition of HA increased with stand-off distance and the imperfect coating layer was obtained at the short stant-off distance (55mm). The cry-stallinity of HA coating decreased with spray power level and auxiliary gas pressure but the bond strength between the HA coated layer and Ti alloy substrate increased with the spray power level.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1071-1074
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• 2002

최근 차세대 인터넷 환경의 표준 데이터 포맷으로 각광받고 있는 XML(eXtensible Markup Language)을 사용한 전자상거래 규격에 대한 국 내외적 표준화 작업이 가속화 되고있으며, 아울러 기업간 전자문서 교환시의 인증 및 보안문제 또한 필수적인 사항이 되어가고 있다. 본 논문에서는 XML표준화 기구에서 정의한 명세서 기반의 XSS(XML Secu.ity Suite) 라이브러리를 이용하여 기업간 전자문서 교환시 발생하는 보안문제를 해결하기 위한 전자서명 관리 시스템을 연구하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.1-6
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• 2001

High-quality sumdard lamps of total luminous flux were developed to be used as a reference source for measuring light output of qJtical sources using an integrating sphere in the Iigbting industry. These standard lamps have the uniform spatial intensIty distribuuons and the stability better than 0.5 % for the bmning tirre of 100[h].100[h].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.488-491
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• 2000

Bi-2223/Ag superconducting wires have been mainly prepared by a powder-in-tube method. The drawing and the rolling are main processes to increase the core density and wire length. In the fabrication of long wire, especially, the drawing should be precisely controlled to assure the filament homogeneity. In this paper, the influences of drawing die angle, bearing length and reduction ratio on the sausaging and the critical current density of the wire are investigated. Single cored and multi-filamentary wires are fabricated by PIT method with different conditions. The core densities and sausaging in the wires are investigated and are discussed regarding their relationship to the I$_{c}$. It was made clear that the geometry of drawing die is sensitively dependent on the sausaging. The improvement of I$_{c}$ was achieved by reducing the die angle and high core density.ity.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.85-90
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• 2000

The image quality of CRT displays is descnbed by the physical characteristics such as luminance, contrast, address ability, viewing distance, and so on. However, the final evaluation of rmage quality is deteITIlllled by not phYSICal data, but subjective perceived Image quality. Therefore the correlation is compared the score of subjective image qualIty accompli~hed by several persons with calculated SQRI (SQuate Root Integral) value uSlllg 4 kInds of CRT monitors. And the influence of tile physical chatac1eristics for subjective Image quality is analyzed on the basis of the validity of SQRI method as a metric for the evaluation of subjective image quality. ality.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.6
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• pp.498-505
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• 2001

This study was conducted to investigate the characteristics of dough and bread prepared by a Korean pigmented rice(KPR). The fermentation of the dough was promoted with a lower pH. Though the springiness and gumminess of the dough were low, but It was more tender and moist than that of control. Color of the bread showed red wine and the acceptabi]ity of the bread was higher than control evaluated by sensory test. The tissue of the bread has more small particles of starch than that of control and It was densely populated. The distribution tendency of the starch particles in the tissue of the bread was the more apparent in the KPR. And big starch particles like lens were observed in the dough with 10% of KPR. Mouse feeling of the bread was more sticky but, it was little clogging.