개복하 부신 절제술 경험이 없는 단일 술자에서 시행된 복강경하 부신 절제술의 학습곡선 및 초기 임상 경험 분석

이동헌,최유신,박성준,Dong Heon Lee,Yoo Shin Choi,Sung Jun Park 대한갑상선-내분비외과학회 2013 The Koreran journal of Endocrine Surgery Vol.13 No.4

Purpose: Adrenalectomy is a very rare operation and its associated learning curve has not yet been studied. The objective of this study was to determine whether the operation time decreases with experience and to evaluate the safety and feasibility of laparoscopic adrenalectomy performed by a surgeon who is new to laparoscopic and open-surgical adrenalectomy. Methods: This study is a retrospective analysis of laparoscopic adrenalectomies performed between April 2007 and September 2012. All surgeries were performed by a single young surgeon who had no experience in performance of open or laparoscopic adrenalectomy. All surgeries were performed using the transperitoneal approach. Results: In total, 42 cases were included. The average tumor size was 4.7 cm. The mean operating time was 125 min. Mean duration of hospital stay was 8.7 days. None of the cases showed conversion to open surgery or perioperative mortality. The operator achieved mastery after performance of left laparoscopic adrenalectomy in 12 cases and right laparoscopic adrenalectomy in 11 cases. Conclusions: A new surgeon can perform laparoscopic transperitoneal adrenalectomy successfully, independently, and safely after having performed the surgery in 12 cases.

A Study to Recover Si from End-of-Life Solar Cells using Ultrasonic Cleaning Method

이동헌,고민석,왕제필,Lee, Dong-Hun,Go, Min-Seok,Wang, Jei-Pil The Korean Institute of Resources Recycling 2021 資源 리싸이클링 Vol.30 No.5

In this study, we determine the optimal process conditions for selectively recovering Si from a solar cell surface by removal of impurities (Al, Zn, Ag, etc.). To selectively recover Si from solar cells, leaching is performed using HCl solution and an ultrasonic cleaner. After leaching, the solar cells are washed using distilled water and dried in an oven. Decompression filtration is performed on the HCl solution, and ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) full scan analysis is performed on the filtered solution. Furthermore, XRD (X-ray powder diffraction), XRF (X-ray fluorescence), and ICP-OES are performed on the dried solar cells after crushing, and the purity and recovery rate of Si are obtained. In this experiment, the concentration of acid solution, reaction temperature, reaction time, and ultrasonic intensity are considered as variables. The results show that the optimal process conditions for the selective recovery of Si from the solar cells are as follows: the concentration of acid solution = 3 M HCl, reaction temperature = 60℃, reaction time = 120 min, and ultrasonic intensity = 150 W. Further, the Si purity and recovery rate are 99.85 and 99.24%, respectively.

묽은 황산을 사용하여 볏짚으로부터 헤미셀룰로오스 회수

이동헌,김창준,김성배,Lee, Dong-Hun,Kim, Chang-Joon,Kim, Sung-Bae 한국미생물·생명공학회 2009 한국미생물·생명공학회지 Vol.24 No.3

희석 황산용액을 사용해 볏짚을 전처리했는데 반응조건은 2개의 반응온도(140, $150^{\circ}C$)와 5개의 황산농도($1.0{\sim}3.0 %wt$)를 사용했다. 볏짚을 구성하는 주요성분인 glucose, xylose, galactose와 arabinose의 생성과 분해속도를 조사했는데 생성속도는 arabinose, 분해속도는 xylose가 가장 컸다. 헤미셀룰로오스당 (xylose+galactose+arabinose)의 최고수율은 약 80%이었는데 최고수율에 도달하는데 산 농도가 높은 것은 유리하지만 반응온도가 높은 것은 불리하게 나타났다. 최적조건은 $140^{\circ}C$, 2.5%와 20분이었다. 최고 glucose 수율은 반응조건에 관계없이 거의 같았는데 대략 $16{\sim}18%$ 범위였다. Rice straw was pretreated using dilute sulfuric acid at reaction conditions covering two levels of reaction temperature (140, $150^{\circ}C$) and five levels of acid concentrations ($1.0{\sim}3.0%wt$). The production and decomposition rates of major components of rice straw indicating glucose, xylose, galactose and arabinose were investigated. The production rate of arabinose and the decomposition rate of xylose were greatest among them. The maximum attainable hemicellulose (xylose+galactose+arabinose) yield was about 80%. High acid concentration appears to favor the maximum yield but high temperature does not. The optimum condition was found to be $140^{\circ}C$, 2.5% and 20 minutes. The maximum glucose yields were almost same, around $16{\sim}18%$, regardless of reaction conditions.

아질산염의 재발견

이동헌,조철훈,Lee, Dongheon,Jo, Cheorun 한국축산식품학회 2020 축산식품과학과 산업 Vol.9 No.2

L-Methionine Ethyl Ester 유도체의 구리 이가 착물 합성 및 구조 분석

이동헌,Dong-Heon Lee 대한화학회 2003 대한화학회지 Vol.47 No.4

철도차량용 알루미늄 압출재 설계

이동헌,박재홍 ( Dong Heon Lee,Jay Hong Park ) 대한금속재료학회 1998 大韓金屬學會會報 Vol.11 No.2

회원칼럼-지진대비책 마련 시급하다

이동헌,Lee, Dong-Heon 한국건축구조기술사회 2005 건축구조 Vol.12 No.3

K평균 군집화를 이용한 벡터 데이터 압축 방법

이동헌,전우제,박수홍,Lee, Dong-Heon,Chun, Woo-Je,Park, Soo-Hong 한국공간정보학회 2005 한국공간정보시스템학회 논문지 Vol.7 No.3

최근 이동전화, PDA, 텔레매틱스 단말기 등과 같은 모바일 기기의 사용이 늘어나고 있다. 모바일 기기들에서 지원하는 서비스 중 큰 부분을 차지하는 것으로는 위치추적, 경로 탐색 등의 서비스가 있다. 이러한 서비스를 제공하기 위하여 모바일 환경에서의 공간데이터에 대한 사용이 증가하고 있다. 하지만 모바일 기기의 저장 공간이 늘어났음에도 불구하고 여전히 공간데이터에 대한 요구를 수용하기에는 한계가 따른다. 따라서 본 연구에서는 모바일 환경에서 사용되는 공간 데이터에 대한 손실 압축 기법을 제시하고, 실험을 통한 압축률, 데이터 손실 정도를 분석하고자 하였다. 이렇게 제시된 공간 데이터 압축 기법을 실제 데이터에 적용하여 실험해 보고 동일 데이터에 대하여 선행 연구에서 제시한 방법을 적용한 결과와 비교 분석을 통하여 제시된 압축 방법이 높은 위치 정확도를 요구하는 데이터에 적용하였을 때 더 나은 성능을 보이는 것을 제시할 수 있었다. Nowadays, using the mobile communication devices, such as a mobile phone, PDA, telematics device, and so forth, are increasing. The large parts of the services with these mobile devices are the position tracking and the route planning. For offering these services, it is increasing the use of the spatial data on the mobile environment. Although the storage of mobile device expands more than before, it still lacks the necessary storage on the spatial data. In this paper, lossy compression technique on the spatial data is suggested, and then it is analyzed the compression ratio and the amount of loss data by the test. Suggested compression technique on the spatial data at this paper is applied to the real-data, and others methods, suggested at the previous studies, is applied to same data. According as the results from both are compared and analyzed, compression technique suggested at this study shows better performance when the compression result is demanded the high position accuracy.

건축의 경제적 요인과 특성에 관한 연구

이동헌,Lee Dong Heon 한국주거학회 2005 한국주거학회 논문집 Vol.16 No.2

Korea has recently experienced a large change in civil architecture and urban environment. However most of civil architectures and urbanization have been accomplished without considering economic efficiency and impact. This study focuses primarily on an analysis on the relationship between architecture and economic efficiency through the foreign and domestic case studies. Secondly, it is going to elucidate the economic properties on Korean architecture recently established. With perspectives of the analysis, we need to consider the following factors in the production of architecture; labor intensive industry, seasonal industry, strong and domestic demand.

건축과 도시개발의 사회경제적 주요 영향과 효과에 관한 역사적 고찰

이동헌,Lee, Dong-Heon 한국건축역사학회 2005 건축역사연구 Vol.14 No.4

Tough Korean architecture and urban environment has been developed for almost 100 years, it still remains various kinds of problems. Many attempts was carried out by every new plan to reduce the problems, it result in requiring more investment than before. It means all the investment for the development has been inefficient and immature to protect economic problems compared with the developed country. For the reason of economic problems it must be studied in historical cases which influenced the economic impacts, before the proposal of index with the economic theory. Searching typical architecture or urban development that brought about economic impacts can be classified into 3 cases. First case is the impact that caused the economic growth, increase, boom like the Westminster & others and the american architectures after the economic crisis. Second case is the impacts that was the origin of decline, shrink in economic as the Palace of Versailles, the skyscrape buildings in america before the economic crisis. Third case is the impact that was the both role of increase and decline in economic as the modern architecture in industrial revolution which led to the national economic growth and the gap between the rich and the poor, and as the american architecture that was the root of crisis and the revival in economic. From the case study, it is clear that architecture has relation with economics in various factors as mass production, labour, and another industries all over the history & the world. Now, architecture strongly needed not only to raise functional, cultural effect and value, but to predict and control the economic impacts with theory from further research of historical cases to policy and practise.