흰쥐에서 L-carnitine 투여 후에 혈청 지방산과 Carnitine의 농도 변화

이재원,홍영미,Lee, Jae Won,Hong, Young Mi 대한소아청소년과학회 2002 Clinical and Experimental Pediatrics (CEP) Vol.45 No.9

Purpose : Obesity is known to be associated with hypertension, dyslipidemia, and fatty liver and is thought to be associated with increased levels of free fatty acids. One of the strategies for decreasing free fatty acid levels is stimulation of hepatic lipid oxidation with L-carnitine. Carnitine is an essential cofactor for transport of long-chain fatty acid into mitochondria for oxidation. This study was designed to evaluate the changes of serum fatty acids and carnitine levels after exogenous injection of L-carnitine. Methods : Sprague Dawley rats were divided into two groups. Group A was control. Group B was given intraperitoneal injection with L-carnitine(200 mg/kg) daily for two weeks. Serum lipid (total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) and fatty acid levels were analyzed on the first day of the first and second weeks after injection of L-carnitine. Total, free, and acyl carnitine levels also were performed by a enzymatic cycling techniques at the same day intervals. Results : There was no significant difference between the two groups in total cholesterol, HDL-cholesterol, LDL-cholesterol levels before and after the administration of L-carnitine. But triglyceride levels were significantly decreased at the first week in group B compared with group A. Among free fatty acids, linoleic acid showed significant decrement(A group : $131.3{\pm}31.3mg/dL$ vs B group : $90.0{\pm}7.0mg/dL$) at the first week. Total, free, and acyl carnitine levels showed significant increments at all days intervals, but only free carnitine showed significant increments according to cumulative doses of carnitine. Conclusion : Plasma linoleic acid, a long-chain fatty acid, showed significant decrement after administration of L-carnitine in the first week. This may suggest that L-carnitine can be used as an antilipidemic agent for obese patients. A prospective study will investigate obese children in the future.

좌심방 양심실 연결증 [DOLA]

이재원,서경필,Lee, Jae-Won,Seo, Gyeong-Pil 대한흉부심장혈관외과학회 1985 Journal of Chest Surgery (J Chest Surg) Vol.18 No.2

The case of a patient with abnormal position of the atrial septum resulting in a left atrium with two atrioventricular valves and a disconnected right atrium is presented with review of related articles. Anatomic details showed atrial situs solitus and a left sided cardiac apex. The right atrium received both venae cavae and a coronary sinus. No AV valve was found in the right atrium, and the floor of this chamber was placed above the posterior wall of right ventricular chamber. The atrial septum with secundum ASD was displaced to right anteriorly at its lower portion and inserted to right of tricuspid annulus. The tricuspid and mitral valve configuration was that of so-called partial ECD, i.e. mitral cleft with large anterior mitral leaflets. The ventricular septum was intact and both ventricular chambers were equally well developed with normal relationships. Surgical repair of this anomaly was performed by resecting the abnormally positioned lower part of the atrial septum, repairing the cleft of the anterior mitral leaflet, and septating the atrium for diverting the systemic and pulmonary venous blood to RV and LV, respectively.

개심술시 체외순환이 신장기능에 미치는 영향

이재원,서경필,Lee, Jae-Won,Seo, Gyeong-Pil 대한흉부심장혈관외과학회 1985 Journal of Chest Surgery (J Chest Surg) Vol.18 No.4

Renal dysfunction is a common complication of open-heart surgery: a form of controlled hemorrhagic shock, and successful perioperative management of renal dysfunction depends on recognition of the risk factors and optimal management of factors influencing renal function, including cardiopulmonary bypass, and early detection of renal failure. Changes in renal functional parameters including Ccr, Cosm, CH2O, FENa, and RFI were observed prospectively in forty five patients operated on at Dept. of Thoracic and Cardiovascular Surgery, S.N.U.H., from April to June, 1985. They were 23 males and 22 females with 35 acquired and 10 congenital heart diseases and the mean age and body surface area of them were 38.010.3 years [22-63] and 1.5518 M2[1.151.92] respectively. Followings are the conclusion. 1. The Ccr, representative of renal function, is significantly improved from 90.231.3 ml/min/M2 preoperatively to 101.536.4 ml/min/M2 postoperative and day [P<0.05], and all patients were classified as postoperative renal functional class I of Abel, which representing adequate renal protection during our cardiopulmonary bypass. 2. The Cosm is significantly elevated at immediate postperfusion time and remained high at postoperative one day representing osmotic diuresis at that time, but CH2O shows no significant changes at immediate postperfusion period and is decreased significantly at postoperative one day, representing recovery of renal concentrating ability at that time with decreasing urine flow. 3. The absolute value and changing tendency in FENa and RFI during perioperative period shows no diagnostic reliability on these parameters, but those of CH2O appear to reveal future renal function more accurately than Ccr 4. The depth of hypothermia may be protective upon renal function against the ill effects of prolonged nonpulsatile cardiopulmonary bypass. 5. The depth of the hypothermia, pump time of more than 150 minutes, poor cardiac function, and intraoperative events such as embolism appear to be related with immediate postperfusion renal function. 6. Hemoglobinuria and hemolysis, poor preoperative renal function, history of cardiac surgery, and massive transfusion associated with bleeding appear not to be related with renal dysfunction.

이종심조직판막기능부전에 대한 외과적 요법

이재원,서경필,Lee, Jae-Won,Seo, Gyeong-Pil 대한흉부심장혈관외과학회 1986 Journal of Chest Surgery (J Chest Surg) Vol.19 No.1

Results of reoperation for tissue valve failure were presented with review of current knowledge. Through January 1986, 19 patients required reoperation: 18 had undergone mitral, 2 aortic, and 1 tricuspid valve. Primary tissue failure was the main cause of tissue valve failure: it occurred in 18 valves [15 mitral, 2 aortic, and 1 tricuspid] at a mean postoperative interval of 54-25 months [range 29-120]. During the same period, 2 patients required reoperation for prosthetic valve endocarditis, 1 for paravalvular leakage. The types of valves failed were 12 lonescu-Shiley valves, 5 Hancock valves, and 1 Carpentier-Edwards valve. All 6 patients younger than 15 years of age at first operation had been implanted with lonescu-Shiley valves and failed after a mean interval of 35 months. In contrast, 11 patients older than 15 years had been implanted with 5 Hancock, 6 lonescu-Shiley, and 1 Carpentier-Edwards valve initially, and eventually failed after mean intervals of 81, 53, 47 months each other. The kinds of valves used at reoperation were 8 lonescu-Shiley, 4 Bjork-Shiley, and 6 St. Jude Medical valves for primary tissue failure cases and 3 lonescu-Shiley valves for the other 3 cases. Overall mortality at reoperation was 10%: 5.6% for primary tissue failure, 50% for prosthetic valve endocarditis. In 15 cases [all mitral] primary tissue failure were caused by calcification associated with or without leaflet destruction or fibrous ingrowth, and in 2 cases [all aortic] caused by cusp perforation and tearing without any evidence of calcification. In conclusion: 1 primary tissue failure is the main cause of reoperation in patients with tissue valve failure; 2. the majority of the failed valves is in mitral position; 3. leaflet calcification is the leading pathology of primary tissue failure; 4, reoperation for tissue valve failure may be a major concern, although the mortality is low; 5. the limited durability of tissue valve suggests its use be restricted to selected cases.

Robust tracking control for uncertain linear systems using linear matrix inequlities

이재원,권욱현,Lee, Jae-Won,Kwon, Wook-Hyun 제어·로봇·시스템학회 1998 제어·로봇·시스템학회 논문지 Vol.4 No.3

본 논문에서는 상태행렬과 입력행렬에 시변 불확실성이 있는 선형시스템에 대한 강인 추적 제어기를 제안한다. 본 논문에서 대상으로 하는 불확실성은 block-diagonally structured uncertainty와 norm bounded uncertainty인데 모두 정합 조건을 만족시킬 필요는 없다. 폐루프 시스템이 불확실성하에서 안정할 수 있는 조건을 제시하고 이 조건이 선형행렬 부등식으로 나타낼 수 있음을 보인다. 추적 오차를 줄이고 오차 감소 비율을 증가시킬 수 있는 최적화 방법도 제아한다. 또한 불확실성의 크기가 0으로 줄어들면 추적 오차도 0으로 줄어듬을 보인다.

대학 기관리포지터리 접근 경로 분석에 관한 연구

이재원,Lee, Jae-Won 한국도서관정보학회 2019 한국도서관정보학회지 Vol.50 No.2

In this study, the use statistics by type of data in the A university of a Institutional Repository(IR) with exponential growth in usage and the trend of changes in the access path for users to access A-IR were analyzed. In particular, it was verified that securing various exposure paths contributed to the spread of A-IR by focusing on the change in the approach path, and also confirmed that the method of communication between the ages, such as SNS, is used as the approach path of A-IR. Through this process, the company was planning to suggest the direction of operation, including diversification of exposure paths that activate the institutional repository.

하이드로포밍에 의한 튜브 확관에 대한 해석

이재원,박종진,Lee, Jae-Won,Park, Jong-Jin 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.11

Recently the hydroforming technology has drawn a lot of attention because of its capability to produce high quality and light weight parts. In the present study, the tube expansion - one of the simplest hydroforming processes, has been investigated in order to understand fundamental phenomena such as deformation characteristics and effect of process parameters. As a result, the most important process parameters, which determine the state of stress at the expanded zone, were found to be pressure and die displacement. If the stress becomes equi-axial tension at the zone, necking occurs at some distance from the weld line and develops into a crack along the axial direction. Some aspects of mechanical property measurements as well as distributions of hardness and microstructure are also discussed in this paper.

QFD를 이용한 미래 공격헬기의 핵심기능 도출

이재원,권용수,고남경,Lee, Jae-Won,Kwon, Yong-Soo,Ko, Nam-Kyoung 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.3

This work describes an approach that contributes to derive from mission to critical functions of the attack helicopter under future battle space environment. An existing mission of the attack helicopter is limited to the only shooter oriented functions. In the future environment, mission and its functions of the helicopter might be much expanded. The functions should be derived by the top down approach based on systems engineering approach. In this point of view, this work describes network based future battle environment. From this environment, the missions of the attack helicopter are identified and optimized functions are derived through sequential procedures like from missions to tasks, tasks to activities, and activities to functions. The selected activities are obtained from the tasks using QFD. The weighting scores of the QFD are calculated by the AHP computational procedure. Finally the critical functions are presented through the similar procedure.

인위적 진화의 세계

이재원(Lee, Jae-Won) 동남어문학회 2012 동남어문논집 Vol.1 No.33

This writing is an attempt to examine the logic behind artificial evolution in the early writing of Lee Kwang-su. According to his account, human civilization is the result of artificial evolution. By defining human personality as abilities of artificial evolution, he tried to change the way of basic understanding human being. He presented in the existence which comes true the essence of the human being which is such the civilized person. At logic of his artificial evolution, the problem of civilization was converted with creation of individual all who have the desire toward civilization. He looked at the situation and position of korean society from the viewpoint of world history and admitted the differential temporality which is dividing between korean society and western civilization. The Lee’s ideas of artificial evolution serves as alternative way to jump over the differential temporality. In the early writing, the methods of the artificial evolution are reform of education system, reading literature and revolution. Through this method, Lee tried to prepare ‘Civilized people’ and ‘shared commitment to social values’ that are practical foundation of artificial evolution.

베노이트의 ‘이미지 회복 전략’에 대한 비판적 고찰

이재원(Lee, Jae?Won) 한국수사학회 2016 수사학 Vol.0 No.26

The Stasis Theory was first developed by Hermagoras, a Greek rhetorician who taught in Rome during the Second Century B.C. The techniques were refined by Roman rhetoricians Cicero and Quintilian and used for many centuries to develop arguments for debates, persuasive speeches, and trials. ‘Stasis (from Greek στάσις ‘a standing still’)’ is a system designed to assist rhetors in identifying the central issues in given controversies, and in finding the appropriate argumentative topics useful in addressing these issues. There is a strong revival of interest in rhetoric in general and in Stasis Theory in particular. For example, Benoit (1995) maintained that the top priority of crisis management should be to recover a damaged image. He defined the communication strategy to recover an image as the Image Recovery Strategy and theorized that the Image Recovery Strategy is based on the Stasis Theory of Hermagoras in ancient Greek. This study sets out to compare the theory of ‘stasis’ in ancient Greek and ‘The Image Recovery Strategy’ of modern times.