적절한 정맥 재혈류 시점의 판단을 위한 조직산소분압의 유효성

이은상,정종필,박승하,이병일,Lee, Eun-Sang,Choung, Jong-Pil,Park, Seung-Ha,Lee, Byung-Il 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.5

Purpose: The purpose of this study is to delineate the optimal time of venous revascularization for preventing the flap necrosis due to venous occlusion, and to clarify the usefulness of tissue oxygen pressure ($TcpO_2$) in the determination of the point of time for venous revascularization. Methods: Thirty-six, $3{\times}3\;cm$ sized epigastric island flap was elevated in left abdomen of male Sprague-Dawley rat weighing 250 gram. Flaps were randomly assigned to six groups of six flaps according to the duration of venous occlusion with microvascular clamp; 10 minutes in the group I as the control, 60 minutes in the group II, 2 hours in the group III, 3 hours in the group IV, 4 hours in the group V, and 6 hours in the group VI, respectively. Just before removal of clamp after flap was reposed in situ, the ratio of $TcpO_2$ (tissue oxygen pressure) of the island flap to that of right abdomen was calculated in each group, and tissue specimen was harvested from the distal area of the flap for histological evaluation of vascular change. Five days later, survival area of the flap was estimated, and evaluated the correlation between the tissue oxygen pressure and the rate of flap survival. Results: The $TcpO_2$ and the survival rate of flap were decreased proportionally with the duration of venous occlusion. The ratio of the $TcpO_2$ of the flap is decreased abruptly to below sixty percentile compared to the $TcpO_2$ of normal tissue, and the survived area of the flap is decreased to nine-tenth of the designed size after three hours of total venous occlusion. Histologically, the number of congested vessels was increased according to venous occluded time, and proportionally increased after 3-hours of occlusion significantly. Conclusion: There is a close correlation between the $TcpO_2$ and the survival rate of flaps according to the duration of venous occlusion. Therefore, the $TcpO_2$ represents the hemodynamic changes within the flap, and thought to be an alternative effective tool in the flap monitoring for venous revascularization.

복수로 발현된 비 IgE 매개성 호산구성 위장관염 1예

이은상,김미진,하상윤,이유민,최경은,최연호,Yi, Eun-Sang,Kim, Mi-Jin,Ha, Sang-Yun,Lee, Yoo-Min,Choi, Kyong-Eun,Choe, Yon-Ho 대한소아소화기영양학회 2011 Pediatric gastroenterology, hepatology & nutrition Vol.14 No.2

저자들은 구토, 설사와 같은 비특이적인 증상과 복수가 발생한 13세 남아에서 말초혈액의 호산구 증가 소견이 있고 IgE는 정상범위이며, 내시경 생검상 식도, 소장, 대장 및 직장에서 특징적인 호산구 침윤 소견이 관찰되어 비 IgE 매개성 호산구성 위장관염으로 진단된 1예를 경험하였으며 스테로이드 투여로 증상 호전을 보였기에 문헌고찰과 함께 보고하는 바이다. Eosinophilic gastroenteritis is a rare disease occurring especially in children, and shows various nonspecific presentations with infiltration of eosinophils in the gastrointestinal organs. The pathophysiology of eosinophilic gastroenteritis is not yet clearly known, but allergic reactions are suspected to be related with the disease. Eosinophilic gastroenteritis is categorized into the mucosal, muscularis and subserosal types based on which layer of the intestinal wall is involved. There are different clinical manifestations according to the involved layer. Most cases to date have responded well to steroid therapy. In this study, we diagnosed and treated a case of non-IgE-mediated, subserosal eosinophilic gastroenteritis in a child with abdominal pain, diarrhea and ascites.

창상치유목적의 골수기질세포 동종이식을 위한 고분자막의 조건

이은상,김명주,한승규,홍성택,김우경,Lee, Eun-Sang,Kim, Myeong-Joo,Han, Seung-Kyu,Hong, Sung-Taek,Kim, Woo-Kyung 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.5

Purpose: Major drawbacks of conventional bone marrow stromal cells (BSCs) transplantation method are mainly caused by direct transplanted cell to host cell interactions. We hypothesized that separation of the transplanted cells by a microporous membrane might inhibit most of the potential adverse effects and induce superior effect. The purpose of the study is to determine the optimal condition of the microporous membrane. Methods: First, BSCs were placed in polyethylene terephthalate (PET) transwell inserts with 3, 8, or $12{\mu}m$ pore size, and cultured in 24 well culture plates. After 5 days, bottoms of the plates were observed for presence of attached BSCs in monolayer and cell numbers were evaluated. Second, BSCs were placed PET, polycarbonate (PCT), and mixed cellulose esters (MCE) transwell inserts with 3 and $8{\mu}m$ pore size, and cultured in 24 well culture plates. After 3 days, the supernatants of the media left in culture plate were analyzed for collagen, vascular endothelial growth factor (VEGF), platelet derived growth factor BB (PDGF-BB), and basic fibroblast growth factor (bFGF). Third, BSCs were placed in 15% and 70% of the PET membrane with $3{\mu}m$ pore size. All the experimental conditions and methods were same as the second study. Results: The optimal pore sizes to prevent BSC leakage were $3{\mu}m$ and $8{\mu}m$. The amounts of type I collagen and three growth factors tested did not show significant differences among PET, PCT, and MCE groups. However, the collagen, VEGF, and bFGF levels were much higher in the high (70%) density group than in the low (15%) density group. Conclusion: This study revealed that the optimal pore size of membrane to prevent direct BSC to recipient cell contact is in between $3{\mu}m$ and $8{\mu}m$. Membrane materials and pore sizes do not influence the collagen and growth factor passage through the membrane. The most striking factor for collagen and growth factor transport is pore density of the membrane.

최적 연속 전해드레싱에 의한 연삭기구의 규명에 관한 연구

이은상,김정두,Lee, Eun-Sang,Kim, Jeong-Du 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.8

In recent years, grinding techniques for precision machining of brittle materials used in electric, optical and magnetic parts have been improved by using superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective precision grinding of brittle materials. However, the present dressing system cannot have control of optimum dressing of the superabrasive wheel. In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This system can carry out optimum in-process dressing of superabrasive wheel, and give very effective control according to unstable current and gap increase. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of brittle materials.

명승과 자연자원의 보호 법적인 보장과 국민의 인식을 위하여

이은상,Lee, Eun-Sang 국립문화재연구원 1969 헤리티지:역사와 과학 Vol.4 No.-

의약분업 실시로 인한 세수변화에 관한 연구

이은상 ( Eun Sang Lee ),전동훈 ( Dong Hoon Jeon ) 慶熙大學校 社會科學硏究院 2001 社會科學硏究 Vol.27 No.-

체인지메이커 교육 프로그램 개발 연구

이은상(Lee Eun-Sang),김하늬(Kim Honey),임세은(Yim Se-Eun),이태경(Lee Tae-Kyung),김성광(Kim Sung-Kwang) 부산대학교 교육발전연구소 2019 교육혁신연구 Vol.29 No.2

연구목적: 최근, 기업가정신은 공공분야 뿐만 아니라 모든 조직 구성원이 지녀야 하는 개념으로 확장되고 있다. 본 연구는 기존의 창업 중심의 기업가정신 교육의 한계를 보완하고, 공공의 문제를 해결하는 기업가정신 함양을 위한 체인지메이커 교육 프로그램을 개발하는 것이다. 연구방법: 이를 위하여 아쇼카(Ashoka)의 청소년 체인지메이커 양성 프로그램인 유스벤처 프로그램, 기존의 기업가정신 교육 프로그램을 분석한 후 1차 프로그램을 도출하였다. 그리고 학생 및 현장교육자의 요구를 반영하여 2차 프로그램을 구성하였고, 전문가 검토를 통해 최종 프로그램을 개발하였다. 연구결과: 프로그램의 핵심요소로서 ‘정체성 형성하기’, ‘문제발견하기’, ‘해결책 찾기’, ‘실행하기’, ‘퍼뜨리기’, ‘지속적인 변화 만들기’가 도출되었다. 그리고 학생과 현장교육자, 전문가 검토를 통해 총 48개의 활동모듈이 개발되었다. 논의 및 결론: 본 연구에서 개발한 프로그램은 초중등교육에서 모든 청소년들이 기업가정신을 함양함으로써 공공의 문제를 해결하는 체인지메이커로 성장하는데 활용되기를 기대한다. Purpose: The importance of entrepreneurship has been increasing not only to the public sector but also to the members of every organization. The primary purpose of this study is to develop a changemaker education program for fostering the extended notion of entrepreneurship that complements the limitations of existing start-up-oriented entrepreneurship education and includes solving social problems. Methods: To this end, the Youth Venture program, the youth social entrepreneurship education program in Ashoka, and the existing entrepreneurship education programs in South Korea were analyzed. Results: As a result, ‘establish identity’, ‘define problems’, ‘discover solutions’, ‘implementation’, ‘create movement’, and ‘make sustainable change’ were concluded to be key elements of the program. Based on this, feedback was collected from students and teachers to gain relevant information to help develop the second draft of the program. The final version was completed in a way that reflects review from expert groups in the field. Conclusion: The program developed in this study is expected to be used in primary and secondary education to help every youth become a changemaker in order to solve social problems by fostering entrepreneurship.

현행 분할과세제도의 문제점과 개선방안

이은상 ( Eun Sang Lee ),남동철 ( Dong Chil Nam ) 慶熙大學校 社會科學硏究院 2000 社會科學硏究 Vol.26 No.-

중학생의 기술 경험과 기술 교과 흥미가 공학 진로 지향에 미치는 영향

이은상(Lee Eun Sang) 학습자중심교과교육학회 2015 학습자중심교과교육연구 Vol.15 No.5

이 연구의 목적은 중학생의 기술 경험, 기술 교과 흥미, 공학 진로 지향 간의 관계를 알아보고, 기술 경험과 기술 교과 흥미가 공학 진로 지향에 미치는 영향을 검증하는데 있다. 연구 대상은 경기, 충남, 충북 지역의 중학생을 대상으로 하였으며, 불성실하게 응답한 28부를 제외한 총 421부를 SPSS 21.0을 이용하여 통계처리 하였다. 연구의 결과는 첫째, 기술 경험과 기술 교과 흥미 및 공학 진로 지향 간에 높은 정적 상관이 있는 것으로 나타났으며, 기술 경험과 기술 교과 흥미의 하위 요인도 공학 진로 지향의 하위 요인과 정적 상관이 있는 것으로 나타났다. 둘째, 기술 경험과 기술 교과 흥미가 공학 진로 지향에 유의미한 영향을 미치는 것으로 나타났으며, 구체적으로 기술 교과 흥미의 하위 요인인 기술 교과 내용 관심과 기술 교과 가치가 영향을 미치는 것으로 나타났다. 이러한 결과는 중학생이 공학에 대한 진로를 좀 더 지향하기 위해서 기술 교과 내용 관심과 기술 교과 가치에 더 많은 비중을 두어야함을 의미한다. 또한 중학생의 기술 교과 내용 관심과 기술 교과 가치는 교육을 통해 향상될 수 있으므로 중학교에서 이들의 향상을 위한 교육 활동이나 교육 프로그램이 제공되어야 함을 시사한다. The purpose of this study was to analyze the relations among technology experience, interest on technology, orientation on engineering career, to investigate the effects of technology experience, interest on technology subject and orientation on engineering career. The subjects for this study were 421 middle school students in Gyeonggi, Chungnam and Chungbuk province. The results of this study were as follows; First, the total score of technology experience, interest on technology subject showed a significant correlation with orientation on engineering career. Also the sub-factors of technology experience and interest on technology subject showed a significant correlation with sub-factors of orientation on engineering career. Second, technology experience and interest on technology subject showed a significant effects with orientation on engineering career. Concretely, among the sub-factors of interest on technology subject contents and value on technology subject showed effective on their orientation on engineering career. This result shows that is important to raise interest on technology subject contents and value on technology subject because they enhance their orientation on engineering career. Also, middle school student s interest on technology subject contents and value on technology subject could be improved through their educations. Therefore it shows that middle school student education institutes have to offer education activities and program for improvement of student’s interest on technology subject contents and value on technology subject.

항공관제통신용 AeroMACS 시스템의 시간 동기 성능 분석

이은상 ( Eun Sang Lee ),손경열 ( Kyun Gyeol Sohn ),박윤옥 ( Youn Ok Park ),정윤호 ( Yun Ho Jung ) 한국항행학회 2012 韓國航行學會論文誌 Vol.16 No.2

본 논문에서는 항공관제통신용 AeroMACS 시스템을 위한 다양한 시간 동기 알고리즘을 분석하고, 이들의 시간 동기 획득 성능을 제시한다. AeroMACS 시스템은 IEEE 802.16e mobile WiMAX 규격에 기반하여 구현되지만, WiMAX 시스템과 달리 5GHz 항공 주파수 대역에서 5MHz의 대역폭을 활용하여 통신을 수행한다. 변경된 사양에 따른 시스템 모델링 후에 apron (APR), runway (RWY), taxiway (TWY), park (PRK) 등 다양한 공항 환경에 대한 채널 모델에 기반하여 동기 획득 성능 평가가 수행되었다. In this paper, the performance evaluation results of the timing synchronization schemes are presented for aeronautical mobile airport communication systems (AeroMACS). AeroMACS, which is based on IEEE 802.16e mobile WiMAX standard, uses the aeronautical frequency band of 5GHz with the bandwidth of 5MHz. The simulation model of AeroMACS is constructed and the evaluation for the timing synchronization performance is performed with the various channel models such as apron (APR), runway (RWY), taxiway (TWY), and park (PRK).