• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.85-93
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• 2005

평택항은 2001년 ‘평택항 종합개발 기간계획 정비용역’ 에서 선박의 내항 이용 방법이 갑문식에서 감조식으로 변경됨에 따라 기 건설된 서해대교 입구의 남측호안을 철거하여 선박이 상시 내항을 이용할 수 있도록 계획중이다. 이에 이 연구에서는 남측호안이 철거된 후 평택항을 고려하여 서해대교 하부를 통항하여 내항에 안전하게 입출항이 가능한지를 이론적 고찰 및 풀미션시뮬레이터를 이용하여 평가하고 문제점 발생시 대안을 제시한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.577-584
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• 2000

Seismic refraction survey was peformed for 10 lines along NE-SW and NW-SE directions above Nampoong gallery at Makyo-ri, Dogye, Samcheok, Kangwon-do. 48 geophones were laid in line with the interval of 1m, and a 5Kg hammer was used as a source at 5 points for each line. Data processing was done using reciprocal time method, GRM, and traveltime tomography which utilizes wavefront expansion method for forward process and SIRT for inversion. The result shows that the first layer has its lower boundary between 3.49m and 8.88m. The P-wave velocity of the first and the second layer were estimated as 270 360m/s and 1550 1940m/s respectively. When the boundary of the first and second layer is smooth enough and the velocity difference is large enough, GRM has little advantage over reciprocal time method. The result of reciprocal method and traveltime tomography shows consistency. The northeast part of the boundary has syncline structure, which is similar to the topography above. This implies that the collapse of the cavities of Nampoong gallery result in the subsidence of the ground surface. The subsidence is in progress across the Youngdong railroad, therefore a proper reinforcement work is required.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.125-130
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• 2008

The present study numerically simulates the flow and heat transfer characteristics of rib-induced secondary flow in a cooling channel with staggered V-shaped ribs, extruded on both walls. The rib pitch-to-height ratio (p/h) varies from 2.8 to 10 with the rib-height-to-hydraulic diameter ration ($h/D_h$) of 0.07 and the Reynolds number of 50,000. Shear stress transport (SST) turbulence model is used as a turbulence model. Computational results show that complex secondary flow patterns are generated in the duct due to the snaking flow in the streamwise direction for all tested cases. In the range of p/h=5 to 10 the staggered V-shaped rib gives about 3 times higher heat transfer augmentation than the reference smooth channel with high heat transfer on both front side and the area around the leading edge of the ribs, while the former cases give about 2.5 times higher streamwise pressure drop than the latter ones. Consequently, for the thermal performances, based on the equal pumping power condition, the staggered ones give about 2 times higher values than the latter ones with more uniform heat transfer distribution.

• 대한기계학회논문집A
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• 제25권3호
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• pp.461-469
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• 2001

Existing area-based stereo algorithms rely heavily on rectangular windows for computing correspondence. While the algorithms with the rectangular windows are efficient, they generate relatively large matching errors due to variations of disparity profiles near depth discontinuities and doesnt take into account local deformations of the windows due to projective distortion. In this paper, in order to deal with these problems, a new correlation function with 4 directional line masks, based on robust estimator, is proposed for the selection of potential matching points. These points is selected to consider depth discontinuities and reduce effects on outliers. The proposed matching method finds an arbitrarily-shaped variable window around a pixel in the 3d array which is constructed with the selected matching points. In addition, the method take into account the local deformation of the variable window with a constant disparity, and perform the estimation of sub-pixel disparities. Experiments with various synthetic images show that the proposed technique significantly reduces matching errors both in the vicinity of depth discontinuities and in continuously smooth areas, and also does not be affected drastically due to outlier and noise.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1999년도 제38차 춘계학술대회
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• pp.228-241
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• 1999

Percutaneous coronary angioplasty is well established therapeutic modality in the management of coronary artery disease. However, the high restenosis rate of 30 to 50% limits its usefulness. The principal mechanism of restenosis, intimal hyperplasia, is the proliferative response of vessel wall to injury, which consists largely of smooth muscle cells. A large body of animal investigations and a limited number of clinical studies have established the ability of ionizing radiation to reduce neointimal proliferation and restenosis rate significantly. Human studies have been reported that intravascular radiation after first restenosis inhibits a second restenosis. Encouraged by these reports, we are also conducting a double blind, placebo-controlled, randomized trial to evaluate this new therapeutic modality in patients with coronary artery stenosis. The objective of our trial is to determine the safety and efficacy of catheter-based solutional beta emitting radioisotope system in preventing restenosis after angioplasty. This review describes the vascular brachytherapy systems and isotopes that have been utilized in the initial clinical trials performed in this area of post PTCA coronary restenosis. The results of many worldwide ongoing clinical trials will determine whether this new technology will change the future practice of vascular intervention.

• 전자공학회논문지D
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• 제35D권7호
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• pp.72-78
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• 1998

This paper is focused on the fabrication of reliable novel antifuse, which could operate at low voltage along with the improvement in OFF and ON-state properties. The fabricated antifuse consists of Al/BaTi$_{2}$O$_{3}$/SiO$_{2}$/TiW-silicide structure. Through the systematic analyses for bottom metal and the intermetallic insulator, material and electri cproperties were investiaged. TiW-silicide as the bottom electrode had smooth surface with average roughness of 11.angs. at 10X10.mu.m$^{2}$ and was bing kept as-deposited SiO$_{2}$ film stable. Amorphous BaTi$_{2}$O$_{3}$ film as the another insulator was chosen because of its low breakdown strength (2.5MV/cm). breakdown voltage of antifuse is remarkably reduced by using BaTi$_{2}$O$_{3}$ film, and leakage current of that maintained low level due to the SiO$_{2}$ film. Low ON-resistance (46.ohm./.mu.m$^{2}$) and low programming voltage(9.1V) can be obtained in theses antifuses with 220.angs. double insulator layer and 19.6X10$^{-6}$ cm$^{2}$ area, while keeping sufficient OFF-state reliability (less than 1nA).

• 한국임상약학회지
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• 제10권3호
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• pp.120-124
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• 2000

Diltiazem inhibits calcium channels and leads to vascular smooth muscle relaxation and negative inotroic and chronotropic effects in the heart. Diltiazem (DTZ) is almost completely absorbed after oral administration, but its bioavailability is reduced because of considerable hepatic first-pass metabolism. The main metabolite of DTZ is deacetyldiltiazem. The purpose of this study was to report the pharmacokinetic changes of DTZ and its metabolite, deacetyldiltiazem (DAD) after intravenous administration of diltiazem to control rabbits and rabbits with mild and medium folate-induced renal failure (FIRRs). The area under the plasma concentration-time curves (AUC) of DTZ were significantly increased in mild and medium FIRRs. The metabolite ratio of the DAD to DTZ were significantly decreased in mild and medium FIRRs. The elimination rate constant $(\beta)$ and total body clearances (CLt) of DTZ were significantly decreased in mild and medium FIRRS. These findings suggest that the hepatic metabolism of diltiazem was inhibited and CLt and ${\beta}$ of DTZ were significantly decreased in mild and in rabbits with medium folate-induced renal failure.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.165-171
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• 1992

The developmental process of the epididymis was investigated in Meishan boars from 1 to 364 days of age. Epididymal weight increased rapidly between 45 and 150-180 days of age. The diameter and epithelial area of the epididymal ducts greatly increased up to 105-120 days of age. At 1 day of age, the central and distal cauda already had a pseudostratified epithelium surrounded by smooth muscle. At 60-75 days of age, the central and distal caput, corpus, and proximal cauda revealed a well-developed structure of the epithelium. The proximal caput showed a tall, irregular and vacuolar epithelium at 105-120 days of age. PAS-positive contents in the lumen of the caput, corpus and cauda epididymides were first detected at 60-75, 45-60 and 1-30 days of age, respectively. Moreover, in the central and distal caput, PAS-positive granules appeared at 60-75 days of age, and increased until 105-120 days. These results suggest that the epididymis develops completely by approximately 120 days of age, though its weight increases rapidly up to 150-180 days. Thus, it appears that development of the epididymis occurs at an earlier age in Meishan boars than in European and American breeds.

• 한국항행학회논문지
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• 제22권3호
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• pp.189-197
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• 2018

우리나라는 국토 면적의 대부분이 산악 지역으로 이루어져 공항을 운영할 만한 지역, 즉 공항이나 비행장을 운영할 수 있는 개활지가 부족하여 공항 개발이 활발하지 못하였다. 하지만 현재와 같은 항공운송산업의 발달, 항공수요의 급증에 따른 환경 속에서, 안전하고 원활한 비행훈련을 위해 훈련용 비행장 인프라 구축은 더욱 적극 검토되어야 할 것으로 본다. 본 연구에서는 적정한 수준의 훈련 인프라 구축을 위해 국내 훈련비행장 운영실태 분석과 해외 훈련전용 비행장 사례를 검토하여 우리에게 필요한 훈련전용 비행인프라 구축시 적합한 표준 모델을 제시하고자 한다. 그리고 이를 통해 훈련비행 인프라의 적정 규모와 운영 효율성 부분에 대한 시사점을 제시하고자 한다.

• 대한의생명과학회지
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• 제9권3호
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• pp.123-131
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• 2003

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study hypothesized that a vascular infection with cytomegalovirus (CMV) may induce a chronic inflammatory reaction and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases-9 (MMP-9). To confirm the hypothesis, the immunohistochemical stains for CMV late antigen, COX-2, MMP-9, macrophage, and T-lymphocyte were performed on CMV-infected atherosclerotic lesions. The immunoreactivity for COX-2 and MMP-9 was evident in all cases of atherosclerosis along with plaques, mainly in macrophages/foamy cells, intimal and medial smooth muscle cells, and endothelial cells of the intima. Within the intima, the increased immunoreactivity for COX-2 and MMP-9 was colocalized to the area stained with CMV late antigen. Sections from control specimens showed no immunoreactivity for CMV late antigen, COX-2 and MMP-9. These data seem to support the hypothesis that CMV may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis.