흉부손상의 임상적 고찰: 473예

곽영태,유세영 慶熙大學校 醫科大學 1981 慶熙 醫大 論文集 Vol.6 No.1

기관 재건술 후 발생한 기관 무명동맥루

곽영태,신원선,맹대현,이신영,김수철,박주철,김동원 대한흉부심장혈관외과학회 1996 Journal of Chest Surgery (J Chest Surg) Vol.29 No.11

기관 무명동맥루는 매우 드문 질환이지만 일단 발생하면 예후가 아주 불량하며 치명적일 수 있다. 본 인제대학교 상계백병원 흉부외과학 교실에서는 한 명의 환자에서 기관 절개술 후 합병된 기관 협착증에 대한 기관 재건술 후 기관 무명동맥루가 발생하였다. 본 례는 11세의 소녀로 뇌동정맥 기형으로 뇌실외 유출로 조성술 및 4회에 걸친 신경외과적 수술을 받은 환자로서 6개월 전에 기관 절개술을 받았다. 이기관 절개술 후 5개월 후부터 호홉 곤란과 발작성 기침을 호소하여 기관 협착증으로 진단받고 본과로 전과되어 기관 협착 부위의 절제 및 단단 문합으로 기관 재건술을 시행하였다. 기관 재건술 후 3일째 다량의 출혈이 발생하여 기관 무명동맥루로 진단하였고 무명 동맥의 파열 부위의 봉합 및 기관의 재 재건술로 응급수술을 시행하였으나 재 수술후 3일째 재 출혈로 사망하였다. Tracheoinnominate artery fistula is a rare but a catastrophic complication after tacheostomy or tracheal reconstruction. We experienced one case of tracheoinnominate artery fistula after tracheal reconstruction. The patient was a 11 year old girl with cerebral arteriovenous malformation who maintained tracheostomy for 6 months before undergoing tracheal reconstruction. She complained of dyspnea and paroxysmal cough 5 months after tracheostomy and was diagnosed as tracheal stenosis. We performed 4cm of tracheal resection and end to end anastomosis. Three days after tracheal reconstruction, massive bleeding occurred through the intubation tube. She underwent emergency reoperation of repair the innominate artery with 5-0 Prolene and re-reconstruction of trachea. The patient died of bleeding 3 days after the reoperation.

Stapler 를 사용한 폐절제술에 대한 임상적 고찰

곽영태 대한흉부심장혈관외과학회 1983 Journal of Chest Surgery (J Chest Surg) Vol.16 No.2

A comparative study was taken for pulmonary resection between group stapler used and not used. 1 ] There was no bronchopleural fistula in 22 cases of stapler used group, but in 4.5% in not used group. 2] The postoperative amount of fluid and air leakage through the chest tube were lesser in stapler used group. 3] The operating time was shorter in stapler used group because of lesser dissection of hilar structure.

동맥관 개존증의 임상적 고찰

곽영태 대한흉부심장혈관외과학회 1984 Journal of Chest Surgery (J Chest Surg) Vol.17 No.4

With the ligation of patent ductus arteriosus by Gross in 1938, surgeons first entered the field of congenital heart disease. Interruption of a ductus is one of the most satisfactory and curative operations in the field of surgery for congenital heart disease. 27 cases of isolated patent ductus arteriosus were operated from Jan. 1978 to July 1984 at the Department of Thoracic & Cardiovascular Surgery in Kyung-Hee University Hospital. Retrospective clinical analysis of these patients were: 1. Sex ratio, female: male, was 2:1. 2. Mean age at operation was 9.85\ulcorner.58 years. The youngest patient was a 23 month-old girl and the oldest one was a 24 year-old male. 3. More than half of the patients had less than 50 percentile of growth retardation. 4. Chief complaints of the patients were frequent URI [52%], dyspnea on exertion [33%], generalized weakness [22%], palpitation [7%], but 7 patients [26%] had no subjective symptoms. 5. Continuous machinery murmur could be heard at the 2nd or 3rd intercostal space on the left sternal border in 22 patients [81%]. The other S patients made systolic murmur with accentuation of the second heart sound and those were associated with pulmonary hypertension. 6. Radiologic findings of Chest P-A were cardiac enlargement in 15 patients [55%], enlargement of pulmonary conus and/or increasing density of pulmonary vascularity in 20 patients [74%]. 7. Electrocardiographic findings of the patients were within normal limit in 13 patients [48%], LVH in 4 patients [15%], biventricular hypertrophy in 3 patients [11%]. 8; echocardiogram was obtained from 11 patients. Ductus was directly visualized in 7 patients. Left atrial enlargement is the secondary change of left to right shunt, 10 patients had LA/Ao ratio more than 1.2. 9. Cardiac catheterization performed in 25 patients. The mean value of the results were:SO2[PA-RV]= 14.72\ulcorner6.01%, Qp/Qs=2.22\ulcorner.80, peak systolic pulmonary arterial pressure=48.28\ulcorner1.60 mmHg. 10. 26 patients were operated through the left posterolateral thoracotomy: closure of ductus by double ligation in 14 cases, triple ligation in 5 cases, and division with suture in 8 cases. One patient suffer from aneurysmal rupture of main pulmonary artery, endocarditis, hemopericardium was treated with cardiopulmonary bypass via median sternotomy and closure of ductus through the ruptured main pulmonary artery. 11.There was no death associated with the operation, but 3 cases were experienced with intraoperative rupture around the ductus resulting in massive bleeding. The other complications were transient hoarseness in one patient, atelectasis in left lower lobe in 3 patients, and postoperative systemic hypertension in 4 patients with unknown etiology. 12. Pulse pressure was reduced, 11.47+5.92 mmHg, postoperatively, as compare to preoperative status. 13. Intraoperative wedge lung biopsy from lingular segment for the evaluation of the pulmonary vascular disease was taken in S patients with severe pulmonary hypertension. The result was Heath-Edward grade I in one case, grade II in two cases, and grade III in two cases.

성인 식도 기관지루의 외과적 치료

곽영태,김동원 대한흉부심장혈관외과학회 1996 Journal of Chest Surgery (J Chest Surg) Vol.29 No.1

Bronchoesophageal fistula is a rare clinical entity whether congenital or acquired in adult. We experinced 8 cases of bronchoesophageal fistula and performed surgical correction from 1991 to 1994. Of the 8 patients, 5 patients were male and three were female aging from 21 to 61 years(mean 44.12$\pm$14.62 years). Seven of 8 patients had congenital bronchesophageal fistula and the other one had acquired bronchoesophageal fistula. According to the classification of Braimbridge and Keith, 4 cases were belonged to type I and 3 cases were type II . The diagnosis was confirmed by esophagogram in six patients, by bronchoscopy and bronchogram in two patients, and in one patient, the fistula was discovered i cidentally during operation. All patients received astulectomy and concomitant procedures were applied as follows ; 4 diverticulectomy, 4 right lower lobectomy, 1 bilobectomy, 1 left lower lobectomy and 1 wedge resection of left lower lobe. All but one patient were discharged without any complication and have been in good condition. 성인에서의 식도 기관지루는 임상적으로 드문 질환으로, 본 인제대학교 상계백병원 흉부외과학교실에서는 1991년 부터 1994년까지 8명의 환자에서 수술적 교정을 시행하였다. 대상환자의 남녀비는 5:3이었으며 연령분포는 21~61세까지 평균 44.12 $\pm$ 14.62세 이었다. 이중 선천성 식도 기관지루 환자가 7명이었으며, 1명의 환자는 후천성 식도 기관지루 환자이었다. Braimbridge와 Keity에 의한 선천성 식도 기관지루 분류상, 4명이 제1형에 해당하였으며 3명이 제2형에 해당하였다. 수술 전 진단방법으로는 6명의 환자에서 식도 조영술에 의해 식도 기관지루를 발견할 수 있었으며 기관지 내시경 검사와 기관지 조영술로 2례가 진단되었고, 식도 내시경에 의해 1례가 진단되었다. 또한 한명의 환자에서는 우측 폐 하엽의 기관지 확장증으로 폐엽 절제술을시행하는수술시야에서 우연히 발견하여 진단이 되었다. 수술은 모든 례에서 루 절제술을 시행하였으며, 동반된 수술적 조치로는 게실절제술이 4례, 우측 폐하엽절제술이 4례, 우측폐 중하엽 절제술이 1례, 좌측폐 하엽 쐐기 절제술이 1례이었다. 동반된 폐 질환들은 우측폐 하엽의 기관지 확장증이 4례로 가장 뭬弩만\ulcorner 우측폐 하엽의 기질화하는 폐렴이 2례, 좌측폐 하엽의 기질화하는 폐렴이 1례씩 있었다. 수술 후 환자들의 입원 기간은 10일 부터 38일까지 평균 19.75$\pm$11.40일이 었으며, 모든 환자들은 현재 외래 통한 추적 관찰하고 있는 바(6개월에서 49개월, 평균 22.38 $\pm$ 10.47개월), 이상 없이 잘 지내고 있다.

폐격리증 2례 보고 및 대한 흉부외과학회지에 발표된 19례의 문헌 고찰

곽영태 대한흉부심장혈관외과학회 1987 Journal of Chest Surgery (J Chest Surg) Vol.20 No.4

Bronchopulmonary sequestration is a rare congenital malformation of the lung, concerning about the abnormal feeding systemic artery, may happen a serious complication of heeding during operation if not recognized before operation. High index of suspicion of sequestration is the key to successful operative procedure with the aid of characteristic recurrent and long-standing symptoms, its location, and invasive or non-invasive diagnostic tools. We report 2 cases of intralobar type of bronchopulmonary sequestration and review 10 articles about the subject, totaling of 21 cases.

한 일 낙농경영의 구조변화에 관한 비교분석

곽영태,류제창 ( Young Tae Kwak,Je Chang Ryu ) 한국축산경영학회 1994 韓國畜産經營學會誌 Vol.10 No.1

An accelerated Levenberg-Marquardt algorithm for feedforward network

곽영태 한국데이터정보과학회 2012 한국데이터정보과학회지 Vol.23 No.5

This paper proposes a new Levenberg-Marquardt algorithm that is accelerated by adjusting a Jacobian matrix and a quasi-Hessian matrix. The proposed method partitions the Jacobian matrix into block matrices and employs the inverse of a partitioned matrix to find the inverse of the quasi-Hessian matrix. Our method can avoid expensive operations and save memory in calculating the inverse of the quasi-Hessian matrix. It can shorten the training time for fast convergence. In our results tested in a large application, we were able to save about 20% of the training time than other algorithms.

은닉층 다차원공간의 Vertex를 이용한 MLP의 은닉 노드 축소방법

곽영태,이영직,권오석 한국통신학회 1999 韓國通信學會論文誌 Vol.24 No.9

This paper proposes a method of removing unnecessary hidden nodes by a new cost function that evaluates the variance and the mean of hidden node outputs during training. The proposed cost function makes necessary hidden nodes be activated and unnecessary hidden nodes be constants. We can remove the constant hidden nodes without performance degradation. Using the CEDAR handwritten digit recognition, we have shown that the proposed method can remove the number of hidden nodes up to 37.2%, with higher recognition rate and shorter learning time. 본 논문은 학습하는 동안 은닉 노드의 출력에 대한 분산과 평균을 평가하는 새로운 cost function을 이용하여 불필요한 은닉 노드를 축소하는 방법을 제안한다. 제안한 cost function은 필요한 은닉 노드를 활성화시키고 불필요한 은닉 노드를 상수화 시켜 제거한다. 필기체 숫자인식을 통한 실험에서 제안한 방법은 높은 인식률과 단축된 학습 시간을 나타내며 은닉 노드의 수를 37.2%까지 축소할 수 있었다.

다층퍼셉트론의 오류역전파 학습과 계층별 학습의 비교 분석

곽영태 한국정보통신학회 2003 한국정보통신학회논문지 Vol.7 No.5

본 논문은 MLP의 학습 방법으로 사용되는 EBP학습, Cross Entropy함수, 계층별 학습을 소개하고, 필기체 숫자인식 문제를 대상으로 각 학습 방법의 장단점을 비교한다. 실험 결과, EBP학습은 학습 초기에 학습 속도가 다른 학습 방법에 비해 느리지만, 일반화 성능이 좋다. 또한, EBP학습의 단점을 보안한 Cross Entropy 함수는 학습 속도가 EBP학습보다 빠르다. 그러나, 출력층의 오차 신호가 목표 벡터에 대해 선형적으로 학습하기 때문에, 일반화 성능이 EBP학습보다 낮다. 그리고, 계층별 학습은 학습 초기에, 학습 속도가 가장 빠르다. 그러나, 일정한 시간 후, 더 이상 학습이 진행되지 않기 때문에, 일반화 성능이 가장 낮은 결과를 얻었다. 따라서, 본 논문은 MLP를 응용하고자 할 때, 학습 방법의 선택 기준을 제시한다. This paper surveys the EBP(Error Back Propagation) learning, the Cross Entropy function and the LBL(Layer By Layer) learning, which are used for learning the MLP(Multi Layer Perceptrons). We compare the merits and demerits of each learning method in the handwritten digit recognition. Although the speed of EBP learning is slower than other learning methods in the initial learning process, its generalization capability is better. Also, the speed of Cross Entropy function that makes up for the weak points of EBP learning is faster than that of EBP learning. But its generalization capability is worse because the error signal of the output layer trains the target vector linearly. The speed of LBL learning is the fastest speed among the other learning methods in the initial learning process. However, it can't train for more after a certain time, it has the lowest generalization capability. Therefore, this paper proposes the standard of selecting the learning method when we apply the MLP.