기후변화에 따른 재난방지와 해상풍력개발 토목분야의 융합기술로 해결하자

채장원(Jang-Won Chae) 대한토목학회 2011 대한토목학회지 Vol.59 No.11

초대형 컨테이너선용 신개념 하이브리드 안벽시스템 개발

채장원(Chae Jang-Won),장인성(Jang In-Sung),한상훈(Han Sang-Hoon),박우선(Park Woo-Sun) 대한토목학회 2005 대한토목학회 학술대회 Vol.2005 No.10

인공판막 치환수술후의 용혈

장원채,이계영,김상형,Jang, Won-Chae,Lee, Gye-Yeong,Kim, Sang-Hyeong 대한흉부심장혈관외과학회 1992 Journal of Chest Surgery (J Chest Surg) Vol.25 No.12

Forty two consecutive patients who had had valve replacement with St. Jude Medical prosthesis were studied on a view point of intravascular hemolysis. Patients were consisted of 14 mitral valve replacement, and 7 aortic valve replacement, and 21 double, mitral and aortic, valve replacement. Serum LDH, indirect bilirubin, GOT, hemoglobin levels and ret-iculocyte count were pursued in postopeative 1st day, 3rd day, 7th day, 14th day and 21th day. Postoperatively, all patients were not detected paravalvular leakage on the ech-ocardiographical study. The patients with double valve replacement revealed higher levels of LDH on postopeative 14th day[P<0 05] than those with single valve replacement. Among the patients with single valve replacement, the patients with aortic valve replacement revealed slightly higher levels of entire postopeative data, but considered insignificant. There was correlation between the severity of hemolysis and the size of replaced aortic valve. In the postoperative LDH levels, the patients with small sized-aortic valve[less than 21mm in diameter] replacement revealed higher levels of postoperative 3rd day, 7th day and 14th day than those with large size[more than 23mm in diameter]. The patients with high level LDH of greater than 800 WU /L on postoperative 7th day were 61.9%[26 of 42]. The high LDH frequency of DVR was 71.4%[15 of 21], MVR 50.0%[7 of 14] and AVR, 57.1%[4 of 7]. The level of LDH declined gradualiy thereafter through postoperative 3 weeks. In conclusion, intravascular hemolysis after prosthetic valve replacement was dependent on position of valve replacement and size of valve. And this study supports the conventional valve selection and usage in our hospital. The patients with subclinical hemolysis after valve replacement should be placed on a close observation.

개흉술을 시행하였던 자발성 기흉의 임상적 고찰

안병희,장원채,An, Byeong-Hui,Jang, Won-Chae 대한흉부심장혈관외과학회 1993 Journal of Chest Surgery (J Chest Surg) Vol.26 No.5

This study elvaluated clinically the surgical results of the thirty-eight patients who had exploratory thoracotomy for spontaneous pneumothorax between Jan. 1989 and Nov. 1992. Thirty three, or 86.8%, of the patients were male. The most frequent age of the spontaneous pneumothorax requiring thoracotomy was between fifteen years and twenty years. Sudden onset dyspnea and chest pain, which developed in thirty-five patients[89.5%], were the major chief complaints. Bleb and Bulla located in the both upper lobes were the most frequent causes of spontaneous pneumothorax for exploratory thoracotomy. There was no operative death. Postoperative morbidity included three cases of residual air space in the apical pleural space, tow cases of atrial fibrillation, and one each case of reoperation for bleeding, mediasitinitis, and sternal osteomyelitis. All postoperative complications were treated without any serious problems. This study suggests that early exploratory thoracotmy is desirable for patients with prolonged air-leak, massive air-leak, or multiple blebs and giant bullae on the computed tomography of the chest.

고도의 폐혈류장애를 동반한 원발성 우심실 지방육종

안병희,장원채,김상형,An, Byeong-Hui,Jang, Won-Chae,Kim, Sang-Hyeong 대한흉부심장혈관외과학회 1994 Journal of Chest Surgery (J Chest Surg) Vol.27 No.2

Primary tumors of the heart are extremely rare, and about 25 per cent of primary cardiac tumors are malignant. Recently, We experienced a case of primary cardiac liposarcoma occurred on the right ventricular outflow tract and extended into the main pulmonary artery. The patient was 57 year-old man and the chief complaints was severe exertional dyspnea. Emergency operation to relieve the right ventricular outflow tract obstruction was performed under cardiopulmonary bypass. The tumor was 5$\times$4$\times$3 cm in size and infiltrated into the right ventricle and ventricular septum. The tumor in the main pulmonary artery was removed without any difficulty but the on the right ventricular outflow tract was difficult to remove completely. The patient was recovered without any specific problems. After successful surgical resection and postoperative radiotherapy the patient discharged with good condition. Herein, the clinical characteristics of cardiac liposarcoma, the problems in differential diagnosis, the prognosis and current therapy are reviewed.

St.Jude Medical 판막의 임상성적

김상형,장원채,Kim, Sang-Hyeong,Jang, Won-Chae 대한흉부심장혈관외과학회 1994 Journal of Chest Surgery (J Chest Surg) Vol.27 No.2

St. Jude Medical cardiac valve replacement was performed in 135 consecutive patients from Aug.1986 to Dec. 1991.72 had mitral, 28 had aortic, 1 had tricuspid and 34 had double valve replacement. The hospital mortality rate was 4.4% & the late mortality rate was 3.7 %. Follow-up was done on 115 surviving patients:mean follow-up period was 29.78 $\pm$ 18.32 months. Paravalvular leakage was observed in two patients, possible prosthetic valvular endocarditis wasobserved in one patient and other specific valve-related complications were none. The overall actuarial survival rate at 6 years were 91.6% in total, 96.4% in aortic, 95.5 % in mitral and 81.9 % in double valve replacement.We concluded, therefore that good clinical results and a low complication rate could be achieved with St. Jude Medical valve in short-term follow-up & long-term follow-up was also necessary.

연안개발공사로 인한 부유토사의 환경 악영향 저감방안 고찰

송원오,진재율,채장원,안희도,맹준호,오재경,Song, Won-Oh,Jin, Jae-Youll,Chae, Jang-Won,Ahn, Hee-Do,Maeng, Jun-Ho,Oh, Jae-Kyung 한국해양과학기술원 2003 Ocean and Polar Research Vol.25 No.suppl3

Coastal development works generally increase the suspended sediment concentration of the ambient water, causing environmental impacts in various manners. The most active measures in three sides have been reviewed for their applicabilities in Korea. Referring to the cases in the USA, the legislation of environmental windows seems to be not proper for Environmentally Sound and Sustainable Developments (ESSD) until sufficient scientific data are obtained to address the individual issues of potential negative impacts. Feedback monitoring can be regarded as the best way for ESSD. Korea also has the basic legal system for the feedback monitoring as well as Environmental Impact Assessments (EIA). However, the frequency, period and parameter of related surveys should be improved for the true ESSD. Moreover, environmental facilities such as environmental dredgers should be widely used for mitigating environmental Impacts caused by coastal development works.

동해항(東海港)의 부진동(副振動) 특성(特性)(2. 수치계산(數値計算))

정원무,정경태,채장원,Jeong, Weon Mu,Jung, Kyung Tae,Chae, Jang Won 대한토목학회 1993 대한토목학회논문집 Vol.13 No.3

장주기파(長週期波)의 침입(侵入) 변형(變形)에 의한 항내(港內) 수면교란(水面攪亂) 현상(現像)을 효과적(效果的)으로 분석(分析) 및 예측(豫測)하기 위하여 해석해(解析解)와 유한요소(有限要素)를 복합적(複合的)으로 사용한 수치모형(數値模型)을 이용하였다. 기본방정식(基本方程式)으로 완경사(緩傾斜) 방정식(方程式)을 사용하였으며, 고체(固體) 경계면(境界面)에서는 부분흡수(部分吸收) 경계조건(境界條件)을 사용하였다. 방파제(防波堤) 주변(周邊)과 항내(港內) 영역(領域)은 유한요소(有限要素)로 모형화(模型化)하고 항외(港外) 영역(領域)에서는 Helmholtz 방정식(方程式)의 해석해(解析解)를 이용하였다. Chen과 Mei(1974)의 방법(方法)을 이용하여 경계치(境界値) 문제(問題)의 범함수(凡?數)를 구한 후 구성(構成)되는 최종적(最終的)인 연립방정식(聯立方程式)을 Gauss 소거법(消去法)으로 푸는 수치모형(數値模型)을 수립(樹立)하였다. 현장관측(現場觀測) 자료(資料)의 스펙트럼 분석(分析)으로 제시된 동해항(東海港)의 Helmholtz natural period 및 제(第)2 첨두주기(尖頭週期)는 수치계산(數値計算)으로 구해진 것과 잘 일치(一致)하였다. 항만구조물(港灣構造物)에서의 반사율(反射率)을 변화(變化)시키면서 구한 증폭비(增幅比)와 관측치(觀測値)의 비교(比較) 결과(結果) 반사계수(反射係數)를 0.99로 했을 때 가장 양호(良好)한 일치(一致)를 나타내었다. A numerical model has been used for the prediction of wave agitations in a harbor which are induced by the intrusion and transformation of incident waves. Based on linear wave theory a mild-slope equation has been used. A partial absorbing boundary condition has been used on solid boundary. Functional has been derived following Chen and Mei(l974)'s technique based on Hybrid Element Method which uses finite discretisation in the inner region and analytical solution of Helmholtz equation in the outer region. Final simultaneous equation has been solved using the Gaussian Elimination Method. Helmholtz natural period and second peak period of seiche in Donghae Harbor coincide very well with the results from numerical calculation. Computed amplification factors show good agreement, especially when the reflection coefficient on solid boundary is 0.99, with those of measurements.

진해 용원수로의 COD 및 영양염류 농도 추세분석

조홍연(Cho, Hong-Yeon),채장원(Chae, Jang-Won),박정규(Park, Joung-Guy),구명서(Koo, Myung-Seo) 한국해안해양공학회 2008 한국해안해양공학회 논문집 Vol.20 No.4

부산 신항 개발사업으로 형성된 용원수로는 좁고 긴 형태로 해수흐름이 정체되어 환경악화가 우려되는 지역이다. 본 연구에서는 2003년부터 2007년까지의 월별 관측 자료를 이용하여 용원수로의 수질변화 양상을 분석하였다. 추정된 연평균 농도와 오차범위를 분석한 결과 용원수로 내부가 용원수로 입구에 비하여 전반적으로 뚜렷하게 수질이 악화되어 있는 것으로 파악되었다. 수로 입구의 수질농도를 기준으로 수로 내부의 수질농도는 COD, TN, TP 항목의 경우 각각 1.34배, 2.08배, 1.80배로 높은 것으로 파악되었다. 한편, Mann-Kendall 방법을 이용한 오염물질 농도변화의 추세검정 결과, 일반적으로 사용되는 95% 신뢰수준에서 추세를 가지는 경우는 SW-26 지점 TP 항목(증가추세)을 제외하고는 모두 뚜렷한 변화 추세는 없는(엄밀한 통계적인 용어로는 "있지 않은") 것으로 파악되었다. Youngwon channel located in Chinhae city and formed by the Busan New Port Construction Project has been concerned about the water quality degradation problems because of the flow and pollutants stagnation due to its long-narrow shape. In this study, the water quality(hereafter WQ) variation is analysed by using the monthly WQ data measured in Yongwon channel from 2003 to 2007. The analysis shows that the TN and TP concentration in the inside Yongwon channel is definitely worse than the TN and TP concentration in the entrance of the Yongwon channel based on the 95% confidence level. The COD, TN, and TP concentrations in the Yongwon channel are 1.34, 2.08, and 1.80 times larger than that in the entrance of the Yongwon channel, respectively. It has been found that only the TP concentration in SW-26 station has an increasing trend based on the Mann-Kendall test with respect to 95% confidence level. The other stations and the other WQ constituent changes do not have the any significant trends.

최근 10년간 장기연속관측에 근거한 부산항 신항 인근 해역의 파랑특성

정원무(Jeong, Weon-Mu),오상호(Oh, Sang-Ho),백원대(Baek, Won-Dae),채장원(Chae, Jang-Won) 한국해안해양공학회 2012 한국해안해양공학회 논문집 Vol.24 No.2

부산항 신항 인근 해역에서 10년간 파랑 장기 관측을 수행하고, 주요한 파랑 특성을 분석하였다. 부산항 신항은 S계열 파랑이 연중 우세하며, 겨울철에는 거제도 북부 해역에서 발달하는 W계열 파랑이 이에 상응하는 정도로 나타나는 계절적 변동성이 뚜렷이 나타났다. 관측기간 중 유의파고는 대부분 1 m 이하였으나 2003년 9월 태풍 매미 내습 시 최대 유의파고 7.4 m가 관측되었다. 또한, 7월을 제외하고는 계절적 변동성은 거의 없었다. 반면에, 유의파 주기는 평균파향의 영향으로 뚜렷한 계절적 변동성을 나타내었으며, 첨두주기는 여름철에 4~5초, 겨울철에는 3초 내외에 분포하였다. 유의파주기 최대값은 2003년 6월에 관측된 15.56초였다. 한편, 평균파향, 유의파고 및 유의파주기 모두 연별 변동성은 나타나지 않았다. 남측으로 약 4.5 km 떨어진 대죽도 남측 해역에서 5년간 관측된 자료도 함께 분석하여 여름철에는 두 지점 간 높은 상관관계가 존재하는 반면 겨울철에는 그렇지 않음을 확인하였다. Long-term wave observation was carried out near Busan New Port and the major wave characteristics were analyzed. At Busan New Port, waves from south direction were predominant throughout the year, while waves from the west, developed at the north sea of Geoje island, appeared almost the same frequency in winter season, showing apparent seasonal variation. During the observation period, the significant wave height was mostly less than 1 m, but it reached its maximum of 8.0 m when typhoon Maemi passed on September 2003. Also, the seasonal variation was hardly observed except July. In contrast, seasonal variation was apparent for the significant wave period, whose peak ranges 4~5 s in summer whereas about 3 s in winter. The largest significant wave period was 15.56 s, observed on June 2003. Meanwhile, the annual variation was negligible for mean wave direction as well as significant wave height and period. Further analysis of the wave data acquired for 5 years at 4.5 km south, in the south sea of Daejuk island, confirmed high correlation between the two observation points in summer and vice versa in winter.