자기베어링을 이용한 동기전동기 편심 자기력 모델 검증

김대연(D. Kim),노명규(M. D. Noh),이현석(H. Lee),민병국(B. Min),박영우(Y-. Park) 한국정밀공학회 2016 한국정밀공학회 학술발표대회 논문집 Vol.2016 No.5월

Fatigue Analysis for Transportation of Harmony Jacket

D.Y. Kim(김대연),Y.S. Jang(장영식),S.Y. Yoon(윤석용),K.N. Cho(조규남) 한국해양공학회 1987 韓國海洋工學會誌 Vol.1 No.1

지금까지 건조된 jacket 중에서 가장 큰 것으로 알려진 미국 Exxon사의 Harmony jacket이 현재 현대 중공업에 의해 제작되고 있다. Harmony jacket은 제작완료 후 울산으로부터 미국 California서안의 Santa Ynez 해역으로 운송될 예정인데, 이와 같이 긴 해상운송시에 jacket과 seafastening 부재들은 피로에 의하여 상당히 손상을 입을 수 있다.<br/> 본 연구에서는 두가지의 가능한 운송항로에 대해, jacket과 tie-down 부재가 받는 피르에 의한 손상 정도를 계산하고 그 결과를 비교하였다.<br/> 몇 가지 가정하에 행하여진 해석 결과에 따르면, 피로에 의한 손상을 적게 주는 운송항로는 Hawaii를 경유하는 남쪽 항로이며, 운송 barge와 인접하는 부분, 특히 barge 양단 부근의 jacket joint들이 손상을 받기 쉽다는 것을 알 수 있다.

다공성 금속으로 채워진 사각채널내부의 포화 비등 열유동 가시화

김대연(D. Y. Kim),오미드 네마톨라히(Omid Nematollahi),김경천(K. C. Kim) 한국가시화정보학회 2018 한국가시화정보학회 학술발표대회 논문집 Vol.2018 No.11

선천성 장폐쇄증 2차 조사 - 대한소아외과학회 회원을 주 대상으로 한 전국조사 -

김성철,김대연,김상윤,김인구,김인수,김재억,김재천,김현영,박귀원,박우현,박진영,서정민,설지영,오수명,오정탁,이남혁,이명덕,이석구,이성철,정상영,정성은,정연준,정풍만,최금자,Kim, Seong-Chul,Kim, D.Y.,Kim, S.Y.,Kim, I.K.,Kim, I.S.,Kim, J.E.,Kim, J.C.,Kim, H.Y.,Park, K.W.,Park, W 대한소아외과학회 2010 소아외과 Vol.16 No.1

본 조사는 2007년부터 2009년까지 3년간 본 학회 정회원들에 의하여 수술받은 장폐쇄증 환아를 대상으로 한 후향적 조사이다. 또한 본 학회에서는 1994년부터 1996년까지 3년간의 증례를 대상으로 같은 조사(1 차조사)를 진행한 바 있다. 1 차 조사와 비교하여 본 조사에서 보이는 특징은 아래와 같이 요약할 수 있다. - 총 증례 수는 비슷하였으나 출생률을 감안하여야 할 것이다. - 각 기형별 비율은 비슷하였다. - 미숙아 및 저출생체중아의 비율은 증가 하였다. - 산전진단율은 증가하였다. - 복부단순촬영만 한 경우는 감소하였다. - 다른 기형이 동반된 예가 증가하였다. - 사망률이 13.8 %에서 3.6 %로 감소하였다. 장운동의 회복은 공장폐쇄증에서 십이지장이나 회장폐쇄증에서 보다 더뎠다. 하지만 십이지장-공장 이행부에서 문합부까지의 거리가 기술되지 않은 예가 많아 소위 "High Jejunal obstruction"에서의 장운동 회복기간을 알아 보지 못 하는 아쉬움이 있었다. 또한 주름형성술(plication) 또는 장의 직경을 줄이는 수술(tapering)의 효과도 시행한 예수가 작고, 문합부 위치의 기술 부족으로 알아 보지 못 하였다. 십이지장폐쇄증의 화타씨유두부와 위치 역시 향후 보다 정확한 수술기록을 토대로 조사되어야 할 것으로 생각된다. 치료 성적의 눈부신 향상은 여러 회원들의 각고의 노력과 의학의 발달에 기인한 것으로, 사망률 0 %를 향한 노력이 지속되어야 할 것이다. The members of the Korean Association of Pediatric Surgeons conducted a retrospective study of two hundred and twenty-two cases of intestinal atresia for the period from January 1, 2007 to December 31, 2009. Seventeen hospitals were involved. There were 76 duodenal, 65 jejunal, and 81 ileal atresias (3 colonic). The male to female ratio was 0.85:1 in DA and 1.34:1 in JIA. Ninety-four patients(43.3 %) were premature babies (DA 40.3 %, JA 64.6 %, IA 28.8 %), and 70 babies (32.0 %) had low birth weight (DA 38.7 %, JA 44.4 %, IA 16.0 %). Antenatal diagnosis was made in 153 cases (68.9 %). However, 27 infants (17.6 %) with antenatal diagnosis were transferred to the pediatric surgeon's hospitals after delivery. Maternal polyhydramnios was observed in 81 cases (36.59 %) and most frequent with proximal obstruction. In forty-four cases (19.8 %), only simple abdominal film was taken for diagnostic study. The associated malformations were more frequently observed in DA - 61.8 % in DA and 22.6 % in JIA. Meconium peritonitis, small bowel volvulus and intussusception were more frequently associated with ileal atresia. The overall mortality rate was 3.6 %. (Abbreviations: DA;duodenal atersia, JA;jejunal atresia, JIA;jejunoileal atresia, IA;ileal atrsia).

괴사성 장염 - 대한소아외과학회회원 대상 전국조사 -

이석구,김대연,김신곤,김우기,김인구,김상윤,김성철,김재억,김재천,박귀원,박우현,서정민,송영택,오수명,오정탁,이남혁,이두선,이성철,전용순,정상영,정성은,최금자,최순옥,최승훈,한석주,Lee, Suk-Koo,Kim, D.Y.,Kim, S.G.,Kim, W.K.,Kim, I.K.,Kim, S.Y.,Kim, S.C.,Kim, J.E.,Kim, J.C.,Park, K 대한소아외과학회 2006 소아외과 Vol.12 No.1

본 조사 결과는 16개 병원에서 21명의 회원에 의해 수술 받은 환자 71명의 기록과 전체 설문응답지의 대상인 81명에 대한 설문 응답지를 후향적으로 분석한 것으로 자료로서의 정확성에 한계가 있으나 괴사성 장염이라는 질병에 대한 회원들의 전체적인 의견과 성향을 파악하는데 만족할 수 있었으며 회원들이 동일한 관심에 대하여 논의하는 과정 중에 각자의 관점을 정리하는 계기가 되었기를 기대한다. 앞으로 첨부한 설문지에 따라 환자마다 전향적으로 기술하여 학회에 등록하여 향후 괴사성장염에 대하여 다시 한번 논의하는 자리를 갖기를 바란다. A nationwide survey on necrotizing enterocolitis (NEC) was undertaken among members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and the case registration form for each patient during the three-year period from July 2001 to June 2004. Eighty one patients were included in the questionnaire, but only 71 patients were registered from 22 members in 16 hospitals. At the same time survey on focal intestinal perforation (FIP) was undertaken and 17 patients were registered from 11 members in 10 hospitals. Total 19,041 newborns were admitted to neonatal intensive care unit during the study period. Eighty one patients (17.27 %) were underwent surgery among 469 babies who were managed under the impression of NEC. The male to female ratio was 2.1:1. The premature were 60.6 %. The most common site of involvement was ileum. Overall and operation survival of NEC were 72 % and 79 %, respectively. The survival was lower in smaller babies, multiple segments involvement and involvement of both the small and large intestine. But there was no difference in survival according to sex or prematurity. The FIP showed very similarity with NEC in terms of incidence, and the age of diagnosis and operation. But the survival was much better and 100 %. The results showed the clinical characteristics of NEC and the trend of management in NEC in Korea. In the future we hope we can discuss about this topic in prospective manner.

담관낭종 -대한소아외과학회회원 대상 전국조사-

최금자,김대연,김상윤,김성철,김신곤,김우기,김인구,김재억,김재천,김해영,김홍주,박귀원,박우현,박진영,백홍규,서정민,송영택,오수명,유수영,이두선,이명덕,이석구,이성철,박영식,이태훈,정상영,Choi, Kum-Ja,Kim, D.Y.,Kim, S.Y.,Kim, S.C.,Kim, S.K.,Kim, W.K.,Kim, I.K.,Kim, J.E.,Kim, J.C.,Kim 대한소아외과학회 2003 소아외과 Vol.9 No.1

본 조사 결과는 32개 병원의 39명의 회원에 의해 수술받은 환자 348명의 기록과 회원 37명의 설문 응답자를 분석한 것으로 많은 수의 기록지가 내용이 불충분하거나 일치되지 않은 기술로 인해 자료로서의 한계가 있었다. 특히 췌담관합류 이상에 대한 기록 중 약 절반이 미상으로 기록된 것에서 알 수 있드시 자료가 매우 미흡하였고, 담관낭종의 유형을 정하는 것 예후 인자 및 산 전 진단된 담관낭종의 수술 적기등에 대하여도 회원마다 견해 차이가 있으나 심도있는 토론이 이루어지지 않았다. 따라서 이 결과를 외국의 통계 분석과 비교하는 것 보다는 회원들의 향 후 진료와 연구에 참고가 될 수 있다는 것에 의미를 두고자 하며, 회원들이 동일한 등록지를 작성하는 전향적 연구로 우리나라 담관낭종에 대한 분류, 췌담관 합류이상, 예후 인자들에 대한 재 논의의 출발점이 되기를 기대한다. A nationwide survey on choledochal cyst was undertaken among 39 members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and the case registration form for each patient during the five year period of 1997 to 2001. Three hundred and forty eight patients were registered from 32 institutions. The average number of patients per surgeon was one to two every year. The male to female ratio was 1:3.4. The age of patients on diagnosis was $49.0{\pm}44.4$ months. The geographic distribution was 34.8% in Seoul and Kyoungki-do, 33.3% in Kyoungsang-do, 17.9% in Cholla-do, and 8.5% in Choongchung-do, in order of frequency. The three common clinical presentations were abdominal pain (63.8%), vomiting (35.3%), and jaundice (29.1%). Only seven patients (2%) presented with classic triad, and 25 patients were diagnosed by antenatal ultrasonographic examination. According to the Todani Classification, 238 patients (7l.3%) were type 1, 3 (0.9%) type 11, and 93 (27.8%) type IV. At the time of the operation, three important associated conditions were choledocholithiasis in 45 patients (15.1%), liver fibrosis (Grade 1-4) in 35, and previous operative procedure for biliary diseases in 10. Associated anomalies were observed in 13 patients (3.8%). Three hundred thirty nine (98.8%) of 343 lesions were treated by Cyst excision and Roux-Y hepaticoiejunostomy. One hundred seventy-six patients had an anomalous arrangement of the pancreatobiliary ductal system (APBD): APBD was not in 92 patients, biliary duct joined to the pancreatic duct in 51, and pancreatic duct joined to the biliary duct in 26. There were 8.5% early, and 7.7% late phase operative complications. The major complications were bleeding, anastomotic leakage, and acute pancreatitis. The combination of acute abdomen and choledochal cyst may suggest spontaneous rupture. Because of the development of late intrahepatic bile duct stones, long term follow up after cyst excision and hepaticojejunostomy is required. The optimal time of surgical intervention should also be considered in the situation of routine use of antenatal ultrasonographic examination. This is the first review of the choledochal cyst in Korea and provides baseline data for future comparisons.

담도폐쇄증 -대한소아외과학회 회원 대상 전국 조사-

오정탁,김대연,김성철,김인구,김해영,김현영,남소현,박귀원,박우현,박진영,서정민,이남혁,이명덕,이석구,이성철,정상영,정성은,정재희,최금자,최순옥,최승훈,최윤미,한석주,홍정,Oh, J.T.,Kim, D.Y.,Kim, S.C.,Kim, I.K.,Kim, H.Y.,Kim, H.Y.,Nam, S.H.,Park, K.W.,Park, W.H.,Park, J.Y.,Seo 대한소아외과학회 2013 소아외과 Vol.19 No.1

The Korean Association of Pediatric Surgeons (KAPS) performed the second nationwide survey on biliary atresia in 2011. It was a follow-up study to the first survey, which was performed in 2001 for the retrospective analysis of biliary atresia between 1980 and 2000. In the second survey, the authors reviewed and analyzed the clinical data of patients who were treated for biliary atresia by the members of KAPS from 2001 to 2010. A total of 459 patients were registered. Among them, 435 patients primarily underwent the Kasai operation. The mean age of patients who underwent the Kasai operation was $66.2{\pm}28.7$ days, and 89.7% of those patients had type III biliary atresia. Only five patients (1.4%) had complications related to the Kasai operation. After the Kasai operation, 269 (61.8%) of the patients were re-admitted because of cholangitis (79.9%) and varices (20.4%). One hundred and fifty-nine (36.6%) of the patients who underwent the Kasai operation subsequently underwent liver transplantation. The most common cause of subsequent liver transplantation was persistent hyperbilirubinemia. The mean interval between the Kasai operation and liver transplantation was $1.1{\pm}1.3$ years. Overall the 10-year survival rate after the Kasai operation was 92.9% and the 10-year native liver survival rate was 59.8%. We had 23 patients for primary liver transplantation without the Kasai operation. The mean age patients who underwent primary liver transplantation was $8.6{\pm}2.9$ months. In summary, among the 458 Kasai-operation and liver-transplantation patients, 373 lived, 31 died, and 54 were unavailable for follow up. One-third of the patient who survived have had complications correlated with biliary atresia. In comparison with the first survey, this study showed a higher survival rate and a greater number of liver transplantation.

선천성 보흐다레크 횡격막 탈장 - 대한소아외과학회 회원 대상 전국 조사 -

김재천,김대연,김상윤,김성철,김인구,김재억,김해영,김현영,박귀원,박우현,박진영,백홍규,서정민,송영택,오수명,이남혁,이두선,이명덕,이석구,이성철,정상영,정성은,정연준,정을삼,정풍만,Kim, Jae-Chun,Kim, D.Y.,Kim, S.Y.,Kim, S.C.,Kim, I.K.,Kim, J.E.,Kim, H.Y.,Kim, H.Y.,Prak, K.W.,Prak, 대한소아외과학회 2006 소아외과 Vol.12 No.1

This is a survey on congenital posterolateral diaphragmatic hernia, conducted by the Korean Association of Pediatric Surgeons(KAPS). A registration form for each patient during the 5-year-period between 1998 and 2002 and a questionaire were sent to each member. Twenty-ninemembers in 22 institutions returned completed forms. The average number of patients per surgeon was 1.4 cases a year. The male to female ratio was 1.64: 1, and annual incidencewas 1/14,522 live births. In this review, factors influencing survival in congenital posterolateral diaphragmatic hernia were age at admission, birth weight, time of antenatal diagnosis, birth place, Apgar score, onset time of symptoms and signs, preoperative cardiopulmonary resuscitation, associated anomalies of themusculoskeletal system, central nervous system, or chromosomes, preoperative stabilization, levels of preoperative $FiO_2$, pH, and $AaDO_2$, perioperative complications, bilaterality of defect, size of the defect, and presence or absence of hernia sac.

급성 충수염 - 2006년 대한소아외과학회회원 대상 전국조사 -

이석구,김대연,김상윤,김성철,김신곤,김우기,김인구,김재억,김재천,박귀원,박우현,서정민,송영택,오정탁,이남혁,이두선,이명덕,이성철,장수일,전용순,정상영,정성은,정을삼,정풍만,Lee, Suk-Koo,Kim, D.Y.,Kim, S.Y.,Kim, S.C.,Kim, S.G.,Kim, W.K.,Kim, I.K.,Kim, J.E.,Kim, J.C.,Park, K.W. 대한소아외과학회 2007 소아외과 Vol.13 No.2

본 조사 결과는 21개 병원에서 수술 받은 환자 476명의 기록에 대한 전향적인 분석과 23명의 회원에 대한 설문 응답지에 의한 것이다. 미리 환자등록지를 배부하여 6개월 간 전향적으로 기록한 것으로 그 의의가 크다고 할 수 있다. 그러나 전향적 연구계획에 의한 것이 아니므로 통계적인 비교는 시도하지 않았고 급성충수염에 대한 회원들의 전체적인 의견과 성향을 파악하는데 중심을 두었다. 복강경수술은 아직 전체 충수절제술의 30 %에 못 미치고 있으나 설문지에 답한 회원 약 50 %가 복강경 충수절제술을 시행하고 있으며 이 숫자는 계속 증가할 것으로 보인다. 그러나 복강경수술의 결과는 아직 개복수술과 크게 차이가 없는 것으로 보인다. 한편 단순충수염에 대한 예방적 항생제투여 방법과 기간 등에 대한 설문결과에 큰 차이가 있어 이에 대한 학회 중심의 논의가 필요하다고 생각한다. A nationwide survey on acute appendicitis (AAP) was undertaken among members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and the case registration form for each patient during the 6 months period from the $1^{st}$ October, 2005 to $31^{st}$ March, 2006. Questionnaires were collected from 23 members. Four hundred seventy six patients were registered from 21 hospitals where the members were working. The male to female ratio was 1.67:1. Average age was 9 years and 5 months (range 21 months-20 years). Operations were performed on average 10.4 hours (range 1-230 hours) from arrival at hospital. The average operation time was 59.1 minutes. The average admission days were 5.8 days (range 2-45 days). The most frequent symptoms were abdominal pain (95.1 %), vomiting (50.6 %) and fever (43.7%). The average duration of symptoms was 42.2 hours (range 1 hour-22 days). Leukocytosis (WBC count > 10,000) was found in 85.9%. The most popular diagnostic tools were ultrasonography and CT. Open surgery was performed in 72.1 % and laparoscopic surgery in 27.5 %. Two laparoscopic surgeries were converted to open surgery (0.4 %). Simple appendicitis was found in 54.5 % and complicated appendicitis such as abscess, gangrenous change and perforation in 45.5%. According to the questionnaires 12 hospitals were performing open surgery only in all patients. Four hospitals were performing laparoscopic surgery in all patients. Seven hospitals are performing both surgical methods according to surgeon or occasion. Regarding the use of antibiotics in acute appendicitis, three kinds of antibiotics were used in 40 % of total simple appendicitis patients. The results showed the trend of management in acute appendicitis in Korea. Especially it is necessary for the members to discuss the use of antibiotics for prophylaxis in the simple appendicitis.

엉치꼬리 기형종에 대한 24년 간의 치료 경험 분석

공충식,김성철,김대연,김인구,남궁정만,황지희,김종재,Gong, C.S.,Kim, S.C.,Kim, D.Y.,Kim, I.K.,Namgung, J.M.,Hwang, J.H.,Kim, J.J. 대한소아외과학회 2013 소아외과 Vol.19 No.2

The purposes of this study was to describe the clinical correlation of mass size and gestational age, prognostic factors in sacrococcygeal teratoma (SCT) at a tertiary pediatric surgery, University of Ulsan College of Medicine and Asan Medical Center (AMC), Seoul, Korea. Fifty five patients admitted to the AMC with a SCT between May 1989 and April 2013 were included in this retrospective review. Mean follow up was 861 days. Mean maternal age at delivery was $30{\pm}2.7$ year, mean gestational age (GA) was $36.9{\pm}3.6$ wks, and preterm delivery was 21.8%. Birth body weight was $3182{\pm}644$ g and male vs. female ratio was 1:2.05. We can't find significant difference between Caesarean section and maternal age at delivery (p =0.817). But, caesarean section was favored by gestational age (p = 0.002), larger tumor size (p =0.029) or higher tumor weight fraction rate to birth body weight (p =0.024). Type I was 13, II 21, III 17, and IV 3 according to Altman et al. classification. The tumor component was predominantly cystic(> 50%) in 73.1 %. And the majority histological classification of tumors were mature teratoma (70.3%). The motality rate was 5.5%. Three patients expired because of postpartum bleeding, post-op bleeding related complication such as DIC. SCT recurred in four patients. The interval between first and second operation was $206.2{\pm}111.0$ d (range 53~325 d). In two patients, serum AFP levels were elevated at a regular checkup without any symptom, and subsequent imaging studies revealed SCT. The most common cause of death was bleeding and bleeding related complication. So Caesarean section and active peripartum and perioperative management will be needed for huge solid SCT. In the case of Yolk sac tumor or huge immature teratoma, possibility of recurrence have to be always considered, so follow up by serial AFP and MRI is important for SCT management.