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.

특이값 제거 기법을 적용한 수중 이동체의 음향 거리 추정

이경원,오단비,김기만,김태형,이희창,Kyung-won Lee,Dan-bi Ou,Ki-man Kim,Tae Hyeong Kim,Heechang Lee 한국음향학회 2024 韓國音響學會誌 Vol.43 No.4

수중 이동체의 방사소음을 측정하는 경우 이동체와 수신기 사이의 거리 정보가 중요한 요소이지만 수중에서는 Global Positioning System(GPS)를 사용할 수 없기 때문에 대체 수단이 필요하다. 대체 수단으로써 별도의 음향신호를 이용하여 도달 시간, 도달 시간 차 및 도달 주파수 차 등을 추정하여 거리를 측정한다. 하지만 채널 환경에 의해 오류가 발생하며, 이러한 특이값들은 연속적으로 거리를 측정함에 있어서 장애 요인이 된다. 본 논문에서는 거리 정보를 측정하는 과정에서 발생한 특이값들을 제거하기 위하여 사후 처리로써 V-곡선 형태의 함수로 곡선 적합하여 오류를 감소시키는 방법을 제안한다. 제안한 방법의 성능검증을 위해 모의, 호수 및 해상실험을 수행하였다. 호수실험 결과에서는 Root Mean Square Error(RMSE) 관점에서 약 85 % 정도로 거리 추정 오차가 감소하였다. When measuring the radiated noise of an underwater vehicle, the range information between the vehicle and the receiver is an important factor, but since Global Positioning System (GPS) is not available in underwater, an alternative method is needed. As an alternative, the range is measured by estimating the arrival time, arrival time difference, and arrival frequency difference using a separate acoustic signal. However, errors occur due to the channel environment, and these outliers become obstacles in continuously measuring range. In this paper, we propose a method to reduce errors by curve fitting with a function in the form of a V-curve as a post-processing to remove outliers that occurred in the process of measuring range information. Simulation, lake and sea trials were conducted to verify the performance of the proposed method. In the results of the lake trial, the range estimation error was reduced by about 85 % from the Root Mean Square Error (RMSE) point of view.

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.

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.

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.

전자제품의 물류공동화에 관한 연구

이경원 ( Kyung Won Lee ),옥선종 ( Sun Jong Ok ),윤동훈 ( Dong Hoon Yun ) 한국물류학회 2001 물류학회지 Vol.11 No.2

The electronic commerce has increased with the rapid growth of Internet uses. The role of physical distribution and marketing strategy are so important that they can encourge the activation of electronic commerce. In the first place, the rationalization of physical distribution will be one of subjects to be solved by the decreasing of physical distribution cost and improvement of physical distribution service. Devices for improvement will be offered in accordance with grasping problems at. issues of physical distribution industry through the analysis of domestic conditions. In addition, the Japanese cooperation example of physical distribution is studied. Government policy of physical distribution will be more effective with promoting specification of industrial classification than with generality. Therefore, the plan of physical distribution cooperation for the electronic industry is found, and it is presented the support from the government.

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

이경원 ( Kyung Won Lee ) 대한외상학회 2007 대한외상학회지 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)

토지피복지도 제작 품질 개선

이경원(Lee, Kyung Won),이병길(Lee, Byoungkil) 한국측량학회 2014 한국측량학회 학술대회자료집 Vol.2014 No.4

중소기업 신용정보 생산 및 유통 활성화 방안 연구

이경원 ( Kyung Won Lee ),박창균 ( Chang Gyun Park ) 한국금융정보학회 2013 금융정보연구 Vol.2 No.2

Ever since the foreign exchange crisis in 1997, SME loans have taken a firm position as an important tool of asset management in Korean commercial banking sector and the trend is expected to continue for the foreseeable future. Even though it is well known that smooth and adequate supply of credit to SME sector has important implication on the economy, Korean banking sector is still maintains the old practices that rely heavily on collateral and guarantee in making decisions related to loans. The practices are severely criticized based on the ground that they hamper financial intermediation and pose impediments to enhancing credit evaluation abilities of the banks. The paper starts with the presumption that the poor performance of non-collateral loans to SMEs in Korea is mainly due to the inadequacy of ability to evaluate credit-worthiness of borrowers in Korean banks and then proceeds to offer a possible solution, that is, promoting production and sharing of SME credit information. Several necessary policy measures are suggested.

한국 성인의 지역유형별 혼밥 패턴과 정신건강의 연관성

이경원(Kyung Won Lee),신다연(Dayeon Shin) 대한지역사회영양학회 2021 대한지역사회영양학회지 Vol.26 No.6