• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.112-118
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• 2008

In the present study, the dependence of ultrasonic phase velocity on porosity and frequency in cancellous bone was predicted using the Biot model and the modified Biot-Attenborough (MBA) model for propagation in fluid-saturated porous media. It was also compared with previously published measurements in human and bovine cancellous bones in vitro. It was shown that the phase velocity in cancellous bone decreased with increasing porosity and frequency The dependence of phase velocity on propagation angle in cancellous bone as predicted using the Schoenberg model together with the Biot model and tile MBA model which were modified to include the effect of angle. The theoretical models used in the present study advance our understanding of the interaction between ultrasound and cancellous bone and can be expected to be usefully employed for the diagnosis of osteoporosis.

• Bulletin of the Society of Naval Architects of Korea
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• v.32 no.5
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• pp.19-26
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• 1995

표면효과익선(WIG : Wing-In-Ground Effect Ship)은 해면 위를 낮게 비행함으로써 표면효과에 의한 양력 증가를 얻게 되어 초고속으로 운행할 수 있는 선박과 항공기의 중간형태의 차세대 해상운송 수단이다. 해면 위에 직접 이.착륙이 가능하기 때문에 별도의 활주로가 필요 없으며 수륙양용으로 사용 가능하다. 연근해 도서지방 관광 및 신선도 유지가 필수적인 신속화물의 수 송에도 사용될 수 있으며 해난사고 구난 및 해양 경비용으로도 사용가능한 해상 운송수단이다. 본 고에서는 표면효과익선의 특징을 간략히 살펴보고 21세기 고속해상운송수단으로 사용될 가 능성에 대한 경제성 검토 및 핵심애로기술을 살펴보았으며 러시아 표면효과익선의 발달과정과 개발된 선종의 특징을 조사하였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.193-202
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• 1991

Antimicrobial substances were screened by paper disk plate method in marine sponges, Halichondria okadai, Halichendria sp., H iaponica and Haliclona Pemollis, collected from the south coast of Korea. Antibacterial components were detected in two species, H okadai and Halichondria sp.. Three components such as benzoic acid, okadaic acid(OA) and dinophysistoxin-1(DTX1) were identified from these sponges as the antimicrobial compounds by MS and NMR spectral data. OA$(550{\~}600{\mu}g/kg)$ and $(400{\~}490{\mu}g/kg)$ were determined from the wet H okadai and Halichondria sp., respectively, by using fluorometric HPLC analysis with 9-anthryldiazomethane(ADAM) as fluorescent labelling reagent.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.4
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• pp.243-249
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• 2023

This case study showed improvement both in pain and gait disturbance caused by SCH. KM can be a positive treatment for reducing pain or improving gait disturbance caused by SCH, and it can be considered a treatment option for SCH. Future studies with a larger number of cases and longer period of follow-up in SCH with gait disturbance and rigidity are needed.

• Proceedings of the Ginseng society Conference
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• 2004.05a
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• pp.50-52
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• 2004

• Journal of Ocean Engineering and Technology
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• v.9 no.2
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• pp.71-74
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• 1995

A numerical model capable of simulating a 2-D airfoil flying over in the vicinity of the waves is discussed. Instead of treating the problem as a heaving oscillation one above the rigid flat wall, sources are distributed on the prescribed wave profile. The wave deformation due to the airfoil is assumed to be negligible and treated as a rigid undulated wall. The source and vortex are distributed on the surface of the foil. It is found that the variation of $C_L$ with wave steepness in severe and that the lift variation due to waves decreases as the wing height above the water surface increases.

• The Journal of the Korean dental association
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• v.32 no.11 s.306
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• pp.805-814
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• 1994

균질화기법을 적용하여 치과 임플란트 시스템에 대한 미세응력해석을 수행하였다. 균질화기법은 하악골내의 해면골과 같은 비균질 비등방성 구조체에 대한 물질모델을 설정하고 이를 이용하여 수치해석시 작은 계산량으로도 해면골조직의 미세단위까지의 응력해석을 가능케 하여준다. 균질화기법을 적용하여 계산된 해면골의 스트레스레벨은 기존의 방법으로 계산도니 수치보다 열배이상 높게 나타났는데, 이는 치과 임플란트 시스템의 응력상태에 대한 기존의 인식과 큰 차이를 보이고 있어 치과 임플란트 설계에 대한 전반적인 검토가 필요한 것으로 생각된다. 또한 균질화기법을 통하여 임플란트 시스템에 대한 측방력의 효과는 매우 크게 나타남을 확인할 수 있었고, 임플란트 시스템의 응력해석시 지나치게 단순화된 유한요소 모델을 사용함으로서 발생되는 오류가 지적되었다.

• 한국해양학회지
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• v.25 no.4
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• pp.161-181
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• 1990

A numerical model is established in order to simulate the storm surges which were observed in the seas around Korea during typhoon and winter storm periods. The typhoons are Brenda (1985), Vera (1986) and Thelma (1987). the winter storm period is January 1-6, 1986. The simulated surges for the typhoon periods show good agreements with the recorded ones for the periods at the Korean coasts, but those for the winter storm show fair agreements in general tendencies, not in details. The model simulation in open sea shows a positive sea level near the typhoon center and a native sea level behind the typhoon. the positive surge seems to be due to the low pressure near a typhoon center and the negative on due to the wind stresses of the typhoon. The negative sea level is usually in the form of an elongated gyre. In the gyre, there is a cyclonic circulation of sea water, in which the pressure gradient force induced by the circular depression of the sea surface is balanced by the Coriolis force in readjusting stage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.847-852
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• 2006

This study was designed to investigate the effects of KH204 on the relaxation response and reproductive function in male. Strips of rabbit corpus cavernosum were prepared for mounting and isometric tension measurement in an organ bath. On cavernosal strips contracted with $1{\times}10^{-6}$ phenylephrine and KH204 was applied in increasing concentrations from 0, 61, 183 and 549 mg/L, causing dose-dependent relaxation. Male Sprague-Dawley rats were orally administered with 61, 183 and 549 mg/kg/day of KH204 for 10 weeks. We examined organ weights, testicular sperm head counts, epididymal sperm counts, motility and morphology. KH204 relaxed rabbit corpus cavernosal strip contracted by $1{\times}10^{-6}$ phenylephrine in a dose-dependent manner. In the male rat, testicular weight was increased significantly in the KH204 treated groups compared with control group. Also in the testicular sperm head counts, epididymal sperm counts were increased significantly in the KH204-treated rats. In conclusion, the data suggest that KH204 could enhance erectile and reproductive function.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.548-553
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• 2007

This study was designed to investigate effects of KH-305 on erectile dysfunction in hyperlipidemic rat. KH-305 has been evaluated for antihyperlipidemic and antierectile dysfunction effects on experimental hyperlipidemic rats induced by high cholesterol-diet. After oral administration of KH-305 water extract (50, 100, 200, 300 mg/kg) to hyperlipidemic rats for 8 weeks, the variables including body weight, total cholesterol, HDL-, and LDL-cholesterol levels in serum, the expression of eNOS and nNOS in penis were measured. Also, erectile function was determined by the measurements of intracavernosal pressure (ICP) and maximal arterial pressure (MAP) after electrical stimulation of the cavernosal nerve. Oral administration of KH-305 extracts significantly inhibited the increase of serum total cholesterol and LDL-cholesterol levels and the decrease of serum HDL-cholesterol level in hyperlipidemic rats induced by high fat diet. The penile expression level of the two enzymes (eNOS, nNOS) were increased significantly after oral administration of the KH-305 extracts. Erectile function after 10 volts stimulation was significantly decreased in the hyperlipidemic rat compared with the normal rat, but increased in KH-305 group compared with hyperlipidemic group. These results suggest that KH-305 is effective for erectile dysfunction in hyperipidemia.