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.

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.

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.

조골세포에서 p-38 MAP kinase의 nitric oxide 및 interieukin-6 생성조절에 관한 연구

이경원(Kyung-Won Lee),이도훈(Doe-Hoon Lee),강경화(Kyung-Hwa Kang),김상철(Sang-Cheol Kim) 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.3

치아이동 시 발생한는 골흡수에서 이미 여러 cytokine의 중요성이 강조된 바 있으며 이 가운데 intreleukin-6는 구강 및 연골조직 등에서 많은 연구의 초점이 되어 왔으나 확실한 기전은 아직까지 정확히 확립되어 있지 못하다. 골흡수 시조골세포에서 유리되는 Interleukin-6 (IL-6)와 nitric oxide (NO) 등이 골흡수의 조절자로 최근 대구되고 있으며 Mitogen-activated protein kinase (MAPK)의 활성화로 인해 염증성 cytokine등이 유리될 수 있음이 최근 macropage등이 증명된 바 있다. 그러므로 치아이동을 비롯한 구강 내 여러 염증의 조건에서 골흡수의 대표인자 IL-6및 NO 유리가 MAPK등의 활성 등을 통해 조절된 수 있는 가능성을 시사하고 있다. 본 연구에서 조골세포 특징을 대부분 가지고 있는 조골세포주, MC3T3E1에서 p-38 MAP kinase을 매개로 NO 와 IL-6가 유리됨을 확인하고자 하였다. 10% Fetal Bovine Serum이 첨가된 -MEM 배양약으로 배양한 조골세포주인 MC3T3E1 세포에 tumor necrosis factor-α (TNF-α), interferon-r (IFN-r) 및 lipopolysacchalide(LPS)등의 단독처리 시 NO와 IL-6의 증가는 확인되지 않았으나 TNF-α/IFN-r 혹은 LPS/IFN-r 등의 처치시 NO 와 IL-6이 유의한 증가를 보였으며, NO발현에 직접 관여하는 inducible nitric oxide synthase (iNOS)와 IL-6 단백질 및 mRNA의 발현을 관찰하였다. 또한 specific p-38 MAP kinase inhibitor인 SB203580의 NO와 IL-6의 생성 억제를 관찰하고 단백질과 mRAN 발현억제를 통해서도 확인함으로써 SB203580은 transcription 단계에서 NO와 IL-6의 생성을 조절하고 있음을 시사하여 주고 있다. TNF-α/IFN-r 혹은 LPS/IFN-r 처치 시 p-38 MAP Kinase의 활성을 관찰하였으나 단독 처치 시 역시 p-38 MAP Kinase의 활성율 확인함으로써 NO 와 IL-6유리를 확인하였으며, 또한 이들의 생성기전중의 하나로 p-38 MAP Kinase 가 transcription 단계에서 관여하고 있음을 확인하였다. Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(116) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the release of the inflammatory cytokines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-l osteoblast cultures with combined interferon-y(IFN-r), lipopolysaccharide,(LPS) and tumor necrosis factor-a(TNF-a) induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, IFN-r, LPS, and TNF-a individually induce a non-detectable or small amount of NO and IL-6 in AMC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iI1OS and IL-6 transcription in the combined agents-stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4fuorophenyi)-2-(4-metylsulfinylphenyl)-5-(4pyridyl)imidazole) (SB203580), were significantly diminished, In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p38 MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in LPS/IFNr- or TNF-a/IFN-r-treated MC3T3E-1 osteoblasts.

응급수술을 시행한 응급의료센터 내원 외상 환자 분석; 응급의학과 진료는 외상환자에 대한 외과의 수술과 같은 전문적인 진료를 오히려 지연시키는가?

이경원 ( Kyung Won Lee ) 대한외상학회 2007 大韓外傷學會誌 Vol.20 No.1

Purpose: Trauma surgery is not an official medical specialty in the Republic of Korea (South Korea). Thus, a trauma victim transported to an emergency room (ER) is resuscitated and surveyed by an intern, a resident, or an emergency physician (EP) at first. Currently an operative management is decreasing because of multiple factors. Nevertheless, trauma surgery is the key for some patients. Does the EP`s treatment in the ER delay the surgeon`s emergency operation? Methods: A retrospective study was performed for trauma victims who underwent trauma surgery from March 2004 to February 2005 in a local emergency center of Daegu-city. We reviewed the medical records and analyzed the trauma victim`s age, sex, cause of injury, method of transport, time from the trauma to the operation, EP`s treatment, surgical department, mortality, and injury severity score (ISS). Results: Of the 223 trauma victims included in this study, males were predominant (83.4%). The mean age was 37.98 years of age. The main Causes of trauma were trauma NOS (not otherwise specified) and motor vehicle accidents (MVA). The main methods of transport was privately owned automobile. The mean time from trauma to operation was 617.46 min. The mean ISS was 7.67. Trauma surgery with the EP`s treatment group included 40 trauma victims with higher ISS, and the time from trauma to operation was shorter than it was for the 183 trauma victims not in that group. Conclusion: The EP`s treatment of high-ISS multiple-injury trauma victims can shorten the time from trauma to trauma surgery and will help the surgical department treatment. In the trauma care system of the Republic of Korea, and increased role should be encouraged for emergency physician. (J Korean Soc Traumatol 2007;20:19-25)

Drude 모형 특성을 갖는 메타 물질의 임계각에 관한 연구

이경원(Kyung-Won Lee),홍익표(Ic-Pyo Hong),정영철(Yeong-Chul Chung),육종관(Jong-Gwan Yook) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.9

본 논문에서는 드루드 모형(Drude model) 특성을 가지는 메타 물질의 굴절각 및 임계각을 해석적으로 분석하였다. 메타 물질 슬래브(slab)에서의 전자기파의 반사 및 투과 특성을 해석하기 위해 메타 물질에서 적용된 드루드 모형에서는 30 ㎓에서 각각 -1의 값을 갖는 유전율, 투자율을 사용하였다. 해석 결과로부터 드루드 모형에서 물리 상수(physical constant)의 부호가 주파수에 따라 연속적으로 변하기 때문에 주파수 대역별로 굴절각과 임계각이 각각 서로 다른 특성을 갖는다는 사실을 유도하였다. 본 논문에서 유도한 메타 물질의 주파수에 따른 굴절각 및 임계각 특성은 메타 물질의 주파수와 물리 상수간의 특성과 같은 전자기적 특성을 이해하고, 메타물질과 유전체간 다층 결합의 전파 특성 해석, 레이돔에 적용 가능한 신소재 메타 물질, 전기적 초소형 안테나와 같은 다양한 전자기파 응용에 유용하게 사용할 수 있다. In this paper, the refraction angles and the critical angles of metamaterials which is assumed by the Drude model are analytically studied. To analyze the electromagnetic reflection and the transmission properties of metamaterial slab, we used "-1" for the permeability and the permittivity at 30 ㎓ in Drude model for metamaterials in this paper, respectively. Due to the variation of signes of material constants for frequency ranges in Drude model, the derived refraction angle and the critical angles for each frequency ranges are differently observed. The results in this paper show that the properties the refraction angles and the critical angles for the broadband in metamaterials can be used to understand the electromagnetic properties of metamaterials and microwave applications.

응급의료센터에서 수혈을 시행한 성인 외상환자에서 사망 예측 인자

이경원 ( Kyung Won Lee ) 대한외상학회 2012 大韓外傷學會誌 Vol.25 No.3

Purpose: The most common cuase of transfusion for trauma victims in an emergency department is hypovolemic shock due to injury. After an injury to an internal organ of the chest or the abdomen, transfusion is needed to supply blood products and to compensate tissue oxygen transport and bleeding. From the 1990`s, there have been some reports that transfusion is one of the major factors causing multiple-organ failure. Thus, as much as possible, tranfusion has been minimized in the clinical setting. This study aims to analyze the prognostic factors for mortality among trauma victims transfused with blood products in an emergency department. Methods: We conducted this study for the year of 2010 retrospectively. The study group included adult trauma victims tranfused with blood products in our ED. The exclusion criteria were discharge against medical advice, and missing follow-up due to transfer to another facility. During the study period, 34 adult trauma victims were enrolled. We compared the clinical variables between survivors and non-survivors. Results: the mean age of the 34 victims was 58.06 years, and males account for 58.5% of the study group. The most-frequently used form transportation was ambulance(119, 55.9%), and the most common injury mechanism was mobile vehicle accidents(67.6%). The mean revised trauma score (RTS) was 5.9, and the mean injury severity score (ISS) was 47.76. The mortality rate in the ED was 58.5%, Comparison of survivors with non-survivors showed statistical differences in injury mechanism, initial SBP, DBP, RTS, ISS, and some laboratory data such as AST, ALT, pH, PO2, HCO3, glucose (p<0.05). Regression analyses showed that mortality among adult trauma victims transfused in the ED correlated with RTS. Conclusion: When an adult trauma victim is transported to the ED and needs a tranfusion, the emergency physician carefully assess the victim by using physiologic data. (J Korean Soc Traumatol 2012;25:79-86)

누구를 위한 혁명인가?: 파농의「베일 벗은 알제리」와 여성해방의 복화술

이경원 ( Kyung Won Lee ) 한국영어영문학회 2014 영어 영문학 Vol.60 No.4

The opening question of “what does the black man want?” in Black Skin, White Masks remains Fanon’s overriding concern in his whole career. The generic terms like ‘the Negro’ and ‘the native’ are almost always marked as male. A meticulous reading of “Algeria Unveiled” reveals that Fanon is just another black nationalist who recognizes gender relations as a formative dimension of national liberation. In highlighting the Algerian women’s resistance to the civilizing mission of colonial power, Fanon unknowingly denies “the historic dynamism of the veil” within Algerian patriarchal society. Preoccupied with the nationalist agenda of debunking colonialist rescue fantasy, Fanon is unaware that the veil, once a means to exclude Algerian women from public space, is now a cultural and ideological battleground between Algerian patriarchy and European colonialism. Moreover, Fanon’s notions of female instrumentality are unmistakable. Though Fanon applauds Algerian women for their courageous and self-immolating struggle, his narrative still hinges upon the hierarchical binarism between male fighter and female helper. So women’s liberation in Fanon becomes a ventriloquial discourse for national liberation. Algerian women, without any histories before the Algerian War, are called upon by Algerian men to play an ideological upstart as well as freedom fighter, and their place ever remains within and below the nation.

수중 무선 광통신에서 태양광 잡음 제거

이경원(Kyung-won Lee),오단비(Dan-bi Ou),윤창현(Chang-hyun Youn),김기만(Ki-man Kim) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.11