• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.8-17
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• 2019

In this study, a model reduction technique was used to develop a precise noise and vibration prediction model for the individual components of a driveline system. The dynamic reduced-order model generated by the Craig-Bampton method was applied to perform dynamic analysis of an electric agricultural power cart. The natural frequency and acceleration response results were analyzed according to the different number of dominant sub-structural modes contained in the reduced-order models. Through the analysis results, it was confirmed that a sufficient number of dominant sub-structures to satisfy the operating conditions should be selected to construct an optimal reduced-order model.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.722-725
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• 1999

Background: To secure a rapid and safe approach which is at the same time cosmetically appealing, we employed the right anterolateral thoracotomy incision for repair of atrial septal defects and valvular heart diseases in the adult. Material and method: Between October 1989 and June 1998, 44 adult patients underwent open heart surgery through right anterolateral thoracotomy at our institution. Operative time, cardiopulmonary bypass time, aortic cross clamp time, blood loss until chest tube removal, length of ICU stay, days to discharge, and survival were compared with those that received cardiac surgery via conventional sternotomy. Result: No significant differences were observed between the two groups. There was no death and no additional morbidity directly related to this approach. Cosmetically satisfying results were obtained with safety using the right anterolateral thoracotomy approach. Conclusion: Our data show that the right anterolateral thoracotomy approach is a safe alternative to conventional median sternotomy as it offers excellent exposure and aesthetically more acceptable wounds while not adding on to the operative risks.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.138-143
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• 1999

Background: The endothelium-dependent vasorelaxation has been largely accounted for by the release of nitric oxide (NO). Three distinct isoforms of NO synthases (NOS) have been characterized, i.e., brain(bNOS), inducible (iNOS), and endothelial constitutive (ecNOS). Although hypertension hasbeen associated with a vascular endothelial dysfunction, changes in the vascular expression of NOS isoforms have not been established. The present study was aimed at exploring the vascular expression of NOS isozymes in hypertension. Material and Method: Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were induced in rats. The expression of different NOS isozymes in the thoracic aorta was determined by Western blot analysis. The vascular tissue contents of nitrites were measured by colorimetric assay. Result: Arterial blood pressure was significantly higher in experimental groups of 2K1C and DOCA-salt rats compared with their corresponding control rats. The vascular expression of bNOS as well as that of ecNOS was decreased in both models of hypertension. iNOS was not changed in DOCA-salt hypertension, but was also decreased in 2K1C hypertension. The vascular contents of nitrites were significantly decreased in DOCA-salt as well as in 2K1C hypertension. Conclusion: These results suggest that 2K1C and DOCA-salt hypertension are associated with decreases in the vascular expression of NOS isozymes and nitrite contents.

• Journal of Life Science
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• v.26 no.1
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• pp.91-100
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• 2016

Angiogenesis is essential for the pathophysiological processes of embryogenesis, tissue growth, diabetic retinopathy, psoriasis, wound healing, rheumatoid arthritis, cardiovascular diseases, and tumor growth. Inhibition of angiogenesis represents an attractive therapeutic approach for the treatment of angiogenic diseases such as cancer. However, uncontrolled angiogenesis is also necessary for tumor development and metastasis. Inhibition of vascular endothelial growth factor (VEGF) signaling, a critical factor in the induction of angiogenesis, cause robust and rapid changes in blood vessels of tumors and therefore VEGF constitutes a target for such anti-angiogenic therapy. Recently, since natural compounds pose significantly less risk of deleterious side effects than synthetic compounds, a great many natural resources have been assessed for useful substance for anti-angiogenic treatment. Here we evaluated the anti-angiogenic effects of a hot water extract of Scutellaria baicalensis (SBHWE) using in vitro assays and ex vivo animal experiments. Our results show that SBHWE dose-dependently abrogated vascular endothelial responses by inhibiting VEGF-stimulated migration and invasion as well as tube formation in a human umbilical vein endothelial cell (HUVEC) model, without cytotoxicity, as determined by a cell viability assay. Further study revealed that SBHWE prevented VEGF-induced neo-vascularization in a rat aortic ring sprouting model. Taken together, our findings reveal an anti-angiogenic activity of Scutellaria baicalensis and suggest that SBHWE is a novel candidate inhibitor of VEGF-induced angiogenesis.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.53-53
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• 2003

남한에 분포하는 현생 화강암류는 트라이아스기-쥬라기의 소위 대보화강암과 백악기-제3기의 불국사화강암으로 분류되어 왔다. 대보조산운동은 대동누층군의 퇴적이후에 일어난 조구조운동을 지칭하므로 트라이아스기의 화강암을 포함하는 대보화강암이라는 명칭은 그와 사실상 직접적인 관계는 없다. 트라이아스기-쥬라기의 화강암은 영덕, 청송 암체 외에는 경상분지 밖에 위치하고 백악기-제3기의 화강암은 속리산, 월악산 암체 외에는 경상분지 안쪽에 주로 분포한다. 트라이아스기-쥬라기의 화강암 중 영광-대전-청주-충주-원주-강릉 방면에 걸쳐 북동-남서 방향으로 분포하는 화강암질 저반은 남한에서 가장 넓은 면적을 차지하는 화강암체지만 신뢰할만한 연대측정 자료가 매우 부족한 실정이다. 이 화강암질 저반에 대해서는 Rb-Sr, K-Ar법이 해답을 주기 어렵다. 예를 들어 청주-음성-증평 지역의 화강암류에 대한 Rb-Sr 전암 자료는 분산이 심하며 약 380 Ma에 해당되는 초시선을 보여 기원물질의 불균질성 내지 불완전한 혼합 효과를 반영하고 있다. 옥천대와 영남육괴에 분포하는 일부 화강암체에 대해 잘못 보고된 Rb-Sr 전암연대 역시 모두 중광물의 U-Pb 연대보다 오래된 값을 보이는 것으로 보아 이들은 생성 당시부터 일정한 $^{87}$ Sr/$^{86}$Sr 초기치를 가지지 않고 Rb/Sr 비에 따른 양(+)의 기울기를 가졌음이 확실하다. 과잉의 방사기원 Ar을 가지거나 폐쇄온도가 낮은 광물들을 대상으로 한 K-Ar 자료 역시 화강암체의 관입편대를 정확하게 지시할 수는 없다. 우리는 이에 대한 연구의 일환으로 충청남도 청원군의 물류센터에서 채취한 중립질의 흑운모화강암 한 시료에 대한 U-Pb 스핀연대측정 결과를 다음과 같이 보고한다. $^{206}$ Pb$^{*}$ /$^{238}$ U age = 174.6$\pm$2.7 Ma $^{207}$ Pb$^{*}$ /$^{235}$ U age = 170.3$\pm$14.6 Ma $^{207}$ Pb$^{*}$ /$^{206}$ Pb sup */ age = 111$\pm$187 Ma 위에서 볼 수 있듯이 청주화강암의 스핀에 대해 콘코던트(concordant)한 연대가 얻어졌으며 자료의 오차, 스핀의 U-Pb계에 대한 폐쇄온도 및 화강암의 솔리더스(solidus)를 고려할 때 $^{206}$ Pb$^{*}$ /$^{238}$ U 연대인 174.6$\pm$2.7 Ma를 관입정치시기로 해석한다. 동일 시료의 흑운모에 대해서는 145 Ma의 Rb-Sr 연대가 얻어졌으며 따라서 관입이후 약 35$0^{\circ}C$까지 대략 1$0^{\circ}C$/Ma의 냉각속도를 구할 수 있었다. 청주화강암의 쥬라기 중기 연대는 영광-대전-청주-충주-원주-강릉 지역의 화강암질 저반이 대동누층군 퇴적 이후에 일어난 지구조 사건과 연관되었을 가능성을 지시하지만 이를 확인하기 위해서는 더 많은 자료가 요구된다. 우리는 현재 충주, 괴산 지역의 화강암체에 대해서도 스핀 연대측정을 수행중에 있으며 이들 자료를 암상을 구분하여 해석한다면 우리나라 중생대 지구조운동에 대한 새로운 사실이 밝혀질 수 있을 것으로 믿는다.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.351-368
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• 2024

Purpose: In general, traffic accidents occur sporadically, so there are various limitations in terms of time and cost when conducting field investigations to prepare prevention and prevention measures. In particular, with the transition to a non-face-to-face society after the COVID-19, there is a greater need to prepare a replacement for field surveys. Therefore, in this study, Roadview provided by various websites was used as an alternative to field surveys in Sasang-gu, Busan City. The possibility was evaluated. Method: The research method was to extract vulnerable points for traffic accidents that occurred between 2016 and 22 and analyze road views based on the field survey evaluation items provided in the Traffic Safety Diagnosis Guidelines. Result: The main result was that Sasang-gu was most vulnerable to accidents involving elderly pedestrians at Sasang-ro, Daedong-ro, and Hakjang-ro. As a result of a detailed analysis of vulnerable points through Road View, Sasang-ro needed control of commercial vehicles and protection of the transportation vulnerable in the market commercial area. Daedong-ro was vulnerable to illegal on-street parking and slope merging sections, and Hakjang-ro was vulnerable to roads that were prone to speeding. When evaluating the possibility of replacing Roadview's field survey based on the results of this analysis, Roadview was able to effectively evaluate most items, such as separation of sidewalks and the location and spacing of safety facilities. However, there were limitations in items such as actual measurement performance. Conclusion: In other words, the road view can replace most field surveys, and the actual measurement evaluation items can be judged to be useful as auxiliary data, resulting in time and cost savings and high efficiency.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.438-441
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• 1999

Background: Minimally invasive cardiac surgery has emerged as a new approach to the conventional median sternotomy. The suggested advantages of the minimally invasive technique includes improved cosmesis, simplicity of opening and closing the chest, less postoperative pain, less risk of infection and bleeding, early rehabilitation, and reduced length of hospital stay. Material and Method: Between March 1997 and December 1997, we performed 36 cases of minimally invasive cardiac surgery via three different approaches ; right paramedian, transverse sternotomy and mini-sternotomy with upper sternal split. Result: There was no operative mortality. Postoperative complications were atrial fibrillation in 4 patients, bleeding that required reoperation in 1 patient, and delayed wound closure in 1 patient who underwent 3rd redo operation. Average length of skin incision was 9.1${\pm}$0.9 cm. Average duration of stay in the intensive care unit was 48${\pm}$29 hours and the patients were discharged 10${\pm}$7 days after the operation. Conclusion: In spite of the difficulties in defibrillation, deairing, and cardiac decompensation, minimally invasive approaches will be applied increasingly because of the suggested advantages.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.553-557
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• 2005

유역의 강우-유출 분석에서 유효우량의 산정은 매우 중요하다고 할 수 있다. 이러한 유효우량의 산정에서 대상호우에 대한 유출량 자료가 있는 경우는 침투지수법(infiltration index method)중 하나인 $\Phi$-지표법이나 W-지표법을 사용하여 그 양을 산정할 수 있다. 그러나 대상호우에 대한 유출량 자료가 없는 경우는 침투지수법을 이용하여 유효우량을 산정 할 수 없으며, 이러한 경우 유역의 토양 특성과 식생피복 상태에 대한 자료만으로 총우량으로부터 유효우량을 산정할 수 있는 NRCS(Natural Resources Conservation Service)의 유효우량 산정방법이 널리 사용되고 있다. NRCS유효우량 산정 방법은 선행토양함수조건(antecedent moisture condition, AMC)을 이 용하여 유출곡선지수(runoff curve number, CN)를 결정하는데, 이때 AMC의 산정을 위해 선행5일강우량(total 5-day antecedent rainfall)을 그 기준으로 하고 있으나, 이는 미국의 유역을 대상으로 하여 얻어진 결과이므로 이를 국내 유역에 검증 없이 적용하는 데에는 문제가 있을 것으로 예상되었다. 따라서 본 연구에서는 HEC-HMS모형을 이용하여 선행강우일수을 변화시켜 가면서 실제 유역의 강우-유출에 적용하여 본 뒤 강우-유출을 가장 잘 모의하는 선행강우일수을 결정하였다. 이를 위해, IHP 대상유역인 보청천의 탄부소유역에 대하여 AMC의 산정을 위한 선행강우량을 1일부터 7일까지 변화시키며 적용한 결과 탄부소유역에서는 선행2일강우량이 가장 적합한 결과를 주는 것으로 나타났다. 국내 유역에서 NRCS유효유량 산정방법을 통한 강우-유출모의시 보다 정확한 값을 산정하기 위해서는 대상유역에 적합한 선행 강우일수의 결정이 중요하리라 판단된다.인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고

• Journal of Chest Surgery
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• v.34 no.10
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• pp.745-753
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• 2001

capillary leak syndrome and organ dysfunction in infants. Removing harmful cytokines and complement anaphylatoxins after cardiopulmonary bypass may attenuate this response. This study was conducted to see if the modified ultrafiltration and postoperative peritoneal dialysis can reduce plasma inflammatory mediators in pediatric cardiac surgery. Material and Method: 30 infants (age 1.1 to 12.6 months) who underwent closures of ventricular septal defect using cardiopulmonary bypass (CPB) were enrolled in this study. These patients were divided into three groups; 10 patients selected randomly underwent modified ultrafiltration (Group U), 10 with small body weights ($\leq$5 kg) received postoperative peritoneal dialysis (Group P), and 10 patients did not undergo modified ultrafiltration nor receivcd peritoneal dialysis (Group C). Serum samples were obtained before and after CPB, and after peritoneal dialysis. Effluents sample were also obtained after modified ultrafiltration or peritoneal dialysis. C3a and interleukin-6 (IL-6) were measured by radioimmunoassay and enzyme-linked immunosorbent assay respectively. Result: There was no differences in CPB time, aortic cross-clamping title, and lowest temperature during CPB. The effluents of peritoneal dialysis contained significant amount of C3a and IL-6, but there was no definitive decrease of serum concentration of C3a and IL-6. The effluents of modified ultrafiltration had some amount of C3a and negligible IL-6, and there was no decrease of serum concentration of these (actors. Conclusion: The effluents of peritoneal dialysis contained significant amount of proinflammatory cytokine, IL-6 and complement, C3a. However this study failed to elucidate the decrease in serum levels of these factors. The modified ultrafiltration also was not able to reduce the serum levels of C3a or IL-6 in our study as well.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.434-439
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• 2006

Background: Deep hypothermic circulatory arrest during repair of aortic arch anomalies may induce neurological complications or myocardial injury. So we surveyed if the regional cerebral and myocardial perfusion might eliminate those potential side effects. Material and Method: From March 2000 to December 2004, 62 neonates or infants with aortic arch anomaly underwent one stage biventricular repair using the regional perfusion technique by single surgeon. Preoperative diagnosis of the arch anomaly consisted of coarctation (n=46), interruption of the aorta (n=12), hypoplastic left heart syndrome (n=2) and truncus areteriosus (n=2). Combined anomalies were ventricular septal defect (n=51), TAPVR (n=1), PAPVR (n=1) and atrioventricular septal defect (n=2). Arterial cannula was inserted at the innominate artery. Result: The mean regional perfusion time of brain was $28{\pm}10min$. Operative mortality rates was 0 (0/62). Late death was 1 (1/62) during $11{\pm}7$ months of follow-up. Neurologic complications consisted of transient chorea in 1 case. There was no reoperation associated with arch anolamy. Pulmonary complication associated with arch repair occurred in f case which was managed by aortopexy. Conclusion: One-tage rch repair using the regional profusion is safe and effective in minimizing the neurologic and myocardial complications.