실험적 안구천공상에서 일차적 공막돌륭술의 효과

이경원,이석준,이종혁,Kyung-won Lee,M,D,Seok-joon Lee,M,D,Jong-hyuck Lee,M,D 대한안과학회 2005 대한안과학회지 Vol.46 No.1

Purpose: Scleral buckles are frequently performed as an additional procedure in perforated ocular injury surgery, but little is known about their independent effect after ocular trauma. The authors made a posterior penetrating ocular injury model in rabbits to evaluate the isolated role of primary scleral buckle placement. Methods: Twenty eyes underwent surgery. The penetrating injury consisted of two 5 mm circumferential incisions placed five clock hours apart and 7 mm behind the limbus. A segmental scleral buckle was placed over a randomly chosen penetrating injury site after wound closure. The degree of the fibrous proliferation, traction, and the presence of retinal detachment were evaluated on follow-up examination. After enucleation and fixation, tissue sectioning was performed including injury sites. The greatest dimension of the fibrous proliferation at both wound sites was measured. Results: Two eyes were excluded from the study due to unsuccessful buckling. Four eyes developed a retinal detachment. The remaining 14 eyes showed varying degrees of proliferation and traction on the retina. The greatest dimension of the fibrous proliferation at the buckle site (1.69±0.29 mm) was significantly different from that at the non-buckle site (2.07±0.37 mm, P<0.05). Conclusion: Primary scleral buckle placement at the time of surgical repair reduces vitreous traction and decreases the degree of fibrous proliferation.

수정된 설계 방정식을 이용한 허니컴 구조의 차폐 효과 예측

이경원,정영철,홍익표,육종관,Lee Kyung-Won,Cheong Yeong-Chul,Hong Ic-Pyo,Yook Jong-Gwan 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.9

In this paper, the modified design equation of shielding effectiveness was presented to predict more accurately the shielding effectiveness of honeycomb structure with hexagonal waveguide. The design equation of shielding effectiveness in honeycomb was represented from adding shielding effectiveness of single lattice to shielding effectiveness of infinite array of single lattice. This paper proposed the generalized design equation of shielding effectiveness by analyzing basis lattice of hexagonal waveguide which composes honeycomb structure and infinite array structure of basis lattice. To provide the validity of the modified design equation of shielding effectiveness in this paper, comparison with other available date using 3D EM commercial software is made. 본 논문에서는 전자기 차폐 구조로 널리 알려진 육각형 도파관 구조를 갖는 허니컴 구조의 차폐 효과를 정확하게 예측하기 위하여 기존의 차폐 효과 설계식을 수정하여 새로운 차폐 효과 설계식을 제안하였다. 허니컴의 차폐 효과 설계 방정식은 단일 격자의 차폐 효과와 무수히 많은 격자 구조의 차폐 효과의 합으로 표현되는데, 본 논문에서는 허니컴 구조를 이루고 있는 육각형 기본 격자를 해석하고, 기본격자가 다수의 배열로 이루어진 해석을 통해 일반화 된 차폐 효과 설계 방정식을 제안하였다. 제안한 차폐 효과 설계 방정식의 유효함을 입증하기 위하여 상용 소프트웨어의 3D EM 시뮬레이션과 비교하였다. 또한, 측정 결과와 비교하여 본 논문에서 제안한 수정된 차폐 효과 설계 방정식이 기존의 설계 방정식보다 더 정확하다는 것을 보여주었다.

범주형 환경변수를 고려한 부대성과평가 방법에 관한 연구 - DEA와 CCCA의 결합을 중심으로 -

이경원,박명섭,임재풍,Lee, Kyung-Won,Park, Myung-Seop,Im, Jae-Poong 한국국방경영분석학회 2006 한국국방경영분석학회지 Vol.32 No.1

There are many occasions that the performance of a corps is influenced not only by its own efforts but by the commander of the next higher unit in a vertical organizational structure. When the direction of the commander in the next higher organization is different from that of the actual evaluation agency, the unit under evaluation may get rated lower than what it should deserve. This study suggests an alternative method to evaluate the performance of military units in the situation that there exist critical environmental factors which affect the performance. This method employes DEA, a non parametric method, and Constrained Canonical Correlation Analysis(CCCA), a parametric method which is used to estimate a efficient frontier with multiple dependent variables and constraints. This article also exploits a set of categorical environmental variables in the CCCA to improve the fairness of performance evaluation. It is shown that the introduction of the categorical variables helps evaluating the true performance of individual units such as battalions subordinated to different next higher commanders. 계층구조로 이루어진 군부대에서 예하부대의 성과는 피평가부대의 개별적인 노력뿐만 아니라, 그 부대가 속해있는 지휘라인의 1차 상급지휘관의 부대지휘방향에 따라 상당한 영향을 받는 경우가 많다 평가를 담당하는 기관인 2차 상급조직에서 제시하는 평가요소에 대한 중요도가 1차 상급지휘관의 부대지휘방향과 상이하다면, 해당부대는 1차 상급지휘관의 의도를 충실히 구현하였음에도 불구하고 다른 지휘라인의 부대들보다 낮은 평가를 받을 수 있다. 본 연구는 계층적 구조하에서 성과방향의 차이를 야기하는 지휘라인별 특성을 집단외생변수로 취급하여 평가의 공정성을 기하기 위한 연구이다. 비모수적 기법인 DEA와 모수적 기법으로서 다수의 종속변수가 존재하고 모수의 제약을 반영할 수 있는 제약정준상관분석(CCCA: Constrained Canonical Correlation Analysis)의 결합모형을 이용하였으며, 이 과정에서 성과에 영향을 미치는 집단환경변수를 범주화하여 대대급 부대의 성과평가를 수행하였다.

액와접근법을 이용한 무기하 내시경 갑상선 절제술 후 국소 부위 통증 조절 장치(On-Q^Ⓡ PainBuster^Ⓡ)와 자가 통증 조절 장치의 무작위 대조 연구에 대한 예비 자료

이경원,박찬흔,박용래,현기훈,윤지섭,Kyung-Won Lee,Chan-Heun Park,Yong-Lai Park,Ki-Hun Hyun,Ji-Sup Yoon 대한갑상선-내분비외과학회 2013 The Koreran journal of Endocrine Surgery Vol.13 No.4

Purpose: Gasless transaxillary approach to endoscopic thyroidectomy is a widely performed procedure for benign or malignant thyroid neoplasms. However, it requires wide dissection for approaching the target area. The intravenous patient-controlled analgesia (IV PCA) is an effective method for postoperative pain control and patients can use it according to their requirement. However, patients suffer from nausea, vomiting, sleep disturbance, etc. due to opioids. Pain pump ON-Q^Ⓡ PainBuster^Ⓡ (pain buster) has been used widely in various surgeries for control of postoperative localizing and wide area pain without side effects of opioid analgesia because it consists of Ropivacaine. Methods: From Aug. 2008 to Jan. 2013, Gasless transaxillary endoscopic thyroidectomy was performed in 90 patients in a single institution, who were divided into three groups, including the IV PCA, pain buster, and null groups. We compared postoperative outcomes, pain severity between groups. We recorded scores immediately, 6, 12, 24, and 48 hours after surgery following visual analog pain score (VAS), and investigated hospital stay and occurrence of events of nausea, vomiting, and complications. Results: In the IV PCA group, it was discontinued due to nausea in 36.7% of patients. No significant difference in pain severity following VAS score was observed among the three groups. However, smaller numbers of analgesia injections were required in the Pain buster group than in the other groups, and fewer patients suffered from constipation, compared with the PCA group. Conclusion: Pain buster showed even effects compared to IV PCA, with few side effects and less discomfort of patients, compared with the other groups. Therefore, pain buster was thought to be the proper method for pain control after dissection of the anterior chest wall, cervical area in order to secure an operative view for transaxillary endoscopic thyroi-dectomy.

NF₃와 O₂ 리모트 플라즈마 노출에 따른 니트릴 가교 과불소고무와 과산화물 가교 과불소고무의 무게 손실과 모폴로지 특성

이경원(Kyung Won Lee),김태호(Tae Ho Kim) 한국고분자학회 2011 폴리머 Vol.35 No.2

니트릴 가교 과불소고무와 과산화물 가교 과불소고무의 내플라즈마 특성을 평가하기 위해 고온상태에서 NF3, O2 리모트 플라즈마에 노출된 과불소 고무 재질의 오링(O-ring)에 대해 각각의 무게 손실 및 표면 특성을 확인하였다. 이를 위해 컴파운드는 반도체 및 LCD 생산라인에서 적용되고 있는 오링/씰 제조를 위한 전형적인 처방에 맞춰 설계하고 오픈 롤을 사용하여 혼련작업을 실시하였으며, 이후 열프레스로 작업한 후 오븐을 이용한 후가교 공정을 거쳐 최종 오링 형태로 제조하였다. 가교된 과불소고무 오링을 고온 플라즈마 환경에 노출시킨 후 무게 감량 및 표면 특성 변화를 전자 저울 및 주사전자현미경을 사용하여 관찰하였다. 그 결과, 과불소고무의 가교타입, 필러 시스템, 플라즈마의 종류에 따라 무게 손실과 표면 상태의 변화가 상당한 수준으로 발생되는 것을 확인하였다. The plasma resistances of nitrile curable perfluoro elastomer (NT PFE) and peroxide curable PFE (PO PFE) after exposing to NF3 and O2 remote plasmas were investigated by analyzing weight loss and morphology of O-ring made of PFE. The compounds were designed following the typical formulations of O-ring/seal which were applied in semiconductor and LCD production site. They were blended by an open roll mill, and then, O-ring was finally made by hot press molding and oven curing. The weight loss was calculated and morphology was observed for each atmosphere and temperature by a digital weighing machine and SEM. As results, it was confirmed the weight loss and related morphology were meaningfully different according to the cure type of PFE, filler system, and the species of remote plasma.

아체베와 응구기 -영어제국주의와 탈식민적 저항의 가능성-

이경원 ( Kyung Won Lee ) 영미문학연구회 2002 안과 밖 Vol.12 No.-

대립의 상보성과 길항성 -로마노 과르디니의 사상을 중심으로-

이경원 ( Kyung Won Lee ) 한국동서철학회 2006 동서철학연구 Vol.41 No.-

Particle Swarm Optimization을 이용한 다층 구조 레이돔 설계

이경원(Kyung-Won Lee),홍익표(Ic-Pyo Hong),박범준(Beom-Jun Park),정영철(Yeong-Chul Chung),육종관(Jong-Gwan Yook) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.7

본 논문에서는 PSO(Particle Swarm Optimizaation)를 이용하여 다층 구조(c-sandwich) 레이돔을 설계하고, 레이돔 특성을 분석하였다. PSO를 이용한 레이돔 설계는 두 경우를 바탕으로 설계되었다. 첫 번째는 c-sandwich 레이돔의 skin과 core의 물질이 정해진 상태에서 PSO를 이용하여 각 층들의 최적의 두께를 결정하였으며, 두 번째는 양쪽 skin의 물질과 두께는 고정하고, 가운데 3개의 층에 대해 물질 상수와 두께를 PSO를 이용하여 최적의 값을 결정하였다. 설계된 두 레이돔 모두 0.1 ㎓에서 15 ㎓ 관심 주파수 대역 중, X-band에서 삽입 손실이 -0.3㏈ 이내의 우수한 성능을 가짐을 알 수 있었다. 레이돔 설계에 PSO를 적용함으로써 빠르고 정확하게 설계 업무를 수행할 수 있음을 보였으며, 경사 입사에 대한 경우에도 최적의 레이돔을 설계할 수 있음을 보였다. 또한 다양한 파라미터의 조합에서도 요구 성능에 부합하는 최적의 값이 결정됨을 보였다. 본 논문의 결과로부터 레이돔을 설계하기 위한 복잡하고 많은 계산을 생략할 수 있으며, 다양한 성능을 가지는 레이돔 설계 및 개발에 활용할 수 있다. In this paper, the design of multilayer radome within, the insertion loss, -0.3 ㏈ in X-band with PSO was carried out based on two cases. The first is that, deciding material constant of skin and core, each layer thickness of c-sandwich radome with PSO is found and the second is that, deciding material constant and thickness of the skins of both sides, the material constant and thickness of three layers between skins of both sides using PSO is decided. The performance of the designed radome almost agreed with the required performance. It was showed that the radome design applying PSO algorithm is easy and fast and the optimum radome is also designed in combination of the various parameters of radome. From these results, the radome having various performance can be designed except the tedious calculation and also be applied to various radome structure.

한국 법조인의 행태적 특성 분석

이경원(Lee Kyung-Won),김정화(Kim Joung-Hwa) 서울행정학회 2002 한국사회와 행정연구 Vol.13 No.1

Historically the legal profession has established its professional autonomy based on the exclusive knowledge and technology which are claimed as essential for the specific conflict-solving. However, according to Freidson(1970a; 1970b; 1986), there are some conditions that make possible the legal profession to maintain such autonomy. The self-regulation constitutes the essential part of what the autonomy is to be upheld. We assume that the legal professionals in Korea have failed to maintain the rule of self-regulation at collective level. They have beefed up their own interests regardless of what the public want. The failure of self-regulation has brought about its consequences. The government not the professionals in collective manner has tried to intervene and set the reform agenda. It is in fact major setback in terms of maintaining autonomy which is essential character, according to Freidson, of what the professionals are all about. We focus on the behavior characteristics of legal professionals in Korea. As professionals what are the distinctive characteristics of they have formed and their ramification to the government policy toward the profession. We intend to examine the issues from the perspective of professionalism.

가스터빈용 촉매 연소기를 위한 촉매-화염 복합 연소 특성연구

이경원(Kyung-Won Lee),정남조(Nam-Jo Chung),유인수(In-soo Ryu),조성준(Sung-June Cho),서용석(Yong-Seog Seo),강성규(Sung-Kyu Kang),송광섭(Kwang-Sup Song),전광민(Kwang-min Chun) 한국연소학회 2002 KOSCOSYMPOSIUM논문집 Vol.- No.-