굴절조절내사시 환자의 조절눈모음비

이동철,박지현,이영춘,이세엽.Dong-Cheol Lee. MD. Ji-Hyun Park. MD. Young-Chun Lee. MD. Se-Youp Lee. MD 대한안과학회 2010 대한안과학회지 Vol.51 No.7

Purpose: The goals of the present study were to measure a ratio of accommodative-convergence to accommodation (AC/A ratio) in child patients with refractive accommodative esotropia (RAET) and to compare it to the ratio in normal children. Methods: Patient age, gender, and refractive errors were examined. The deviation angles were measured at near and distance using a prism cover test and were followed by the measurement of the interpupillary distance. The AC/A ratio was calculated using a heterophoria and a gradient method. Results: The present study consisted of 59 patients, 38 patients with RAET and 21 normal children. The mean ages were 9.6 years in patients with RAET and 9.0 years in the normal children. The refractive errors in spherical equivalent were shown to be 4.6D in the right eye and 4.5D in the left eye in patients with RAET and -0.4D and -0.5D in the normal children. The mean values of the AC/A ratio using a gradient method were 1.8 in patients with RAET and 2.2 in the normal children(p=0.44). According to the heterophoria method, the AC/A ratio was 6.2 in patients with RAET and was 5.4 in the normal children(p=0.04). Conclusions: The AC/A ratio of child patients with RAET was higher than that of normal children when using a heterophoria method. However, there was no difference in the AC/A ratio between the normal children and RAET child patients when using gradient method.

목시플록사신만으로 치료된 푸사륨 진균 각막염 1예

이동철,이중원,장성동,Dong Cheol Lee,MD,Jung Won Lee,MD,Sung Dong Chang,MD 대한안과학회 2012 대한안과학회지 Vol.53 No.2

Purpose: To report a case of fusarium keratitis treated with only moxifloxacin 0.5% ophthalmic solution (Vigamox?, Alcon Laboratories, Inc., Ft Worth, TX, USA). Case summary: A 37- year- old healthy male patient experienced a right eye injury due to grain 7 days prior to presentation at our hospital with visual disturbance and ocular pain. A 2.7 × 4.3 mm sized corneal epithelial defect with irregular featherlike midstromal infiltration was observed, and slit lamp examination revealed a dry, rough texture. Thus a smear and culture were performed. Moxifloxacin 0.5% ophthalmic solution (Vigamox?) and lubricant were applied for treatment. Three days after using the eye solution, all clinical features improved. Seven days later, Fusarium species was identified in culture. Conclusions: As standard treatment for Fusarium, the authors of the present study used an antifungal agent. Although hyphae were detected in culture, the use of only moxifloxacin 0.5% ophthalmic solution (Vigamox?) result in a satisfactory result and improvement in clinical features. J Korean Ophthalmol Soc 2012;53(2):338-341

GMDH를 이용한 전력 수요 예측 알고리즘 개발

이동철,홍연찬,Lee, Dong-Chul,Hong, Yeon-Chan 한국지능시스템학회 2003 한국지능시스템학회논문지 Vol.15 No.2

In this paper, GMDH(Croup Method of Data Handling) algorithm which is proved to be more excellent in efficiency and accuracy of practical use of data is applied to electric power demand forecasting. As a result, it became much easier to make a choice of input data and make an exact prediction based on a lot of data. Also, we considered both economy factors(GDP, export, import, number of employee, number of economically active population and consumption of oil) and climate factors(average temperature) when forecasting. We assumed target forecast period from first quarter 1999 to first quarter 2001, and suggested more accurate forecasting method of electric power demand by using 3-step computer simulation processes(first process for selecting optimum input period, second for analyzing time relation of input data and forecast value, and third for optimizing input data) for improvement of forecast precision. The proposed method can get 0.96 percent of mean error rate at target forecast period. 본 논문에서는 데이터의 효율적인 활용과 정확성에서 보다 우수한 특성을 보이는 GMDH(Croup Method of Data Handling) 알고리즘을 전력수요예측에 적용함으로써 입력 데이터의 선정을 용이하게 하였고, 다양한 데이터를 기반으로 보다 정확한 예측을 할 수 있게 하였다. 그리고, 예측 시에 경제적인 요인(GDP, 수출, 수입, 취업자 수, 경제활동인구, 석유소비량)과 기후적인 요인(평균기온)을 모두 고려하였다. 또한 목표 예측 기간을 1999년 1/4분기에서 2001년 1/4분기까지 9개의 분기로 가정하고, 가정한 목표 기간의 예측 정확도를 높이기 위해 3단계의 시뮬레이션 과정(최적 입력 분기 수를 결정하는 과정, 입력 데이터와 예측값의 시간적 연관성을 분석하는 과정, 입력 데이터의 최적화 과정)을 이용함으로써 더 정확한 전력수요예측 방법을 제시하였고, 제안된 기법으로 목표한 예측 기간에서 0.96%의 평균 에러율을 얻을 수 있었다.

전방 십자 인대 파열후 자가 슬개건을 이용한 재건술군과 부분 손상후 보존적 치료군의 비교

이동철,이수호,김동한,Lee Dong Chul,Lee Su Ho,Kim Dong Han 대한정형외과스포츠의학회 2002 대한정형외과스포츠의학회지 Vol.1 No.2

목적: 전방십자인대부분파열후보존적치료군과완전파열후자가슬개건을이용한재건술군간의기능적평가, 활동도및전방안정성을비교평가하고자하였다.대상및방법: 전방십자인대손상으로진단되고관절경으로진단치료한38명의환자를대상으로2년이상추시하였으며전방십자인대50$\%$이하파열된부분손상군1 2명(평균연령: 38.3세), 완전파열후자가슬개건을이용한재건술군26명(평균연령: 25.3세)을대상으로하였다. 객관적인안정성은KT-2000 Arthrometer를이용하여15lb와20lb전방전위부하로측정하였으며,기능평가는Lysholm score, 활동도는Tegner activity score를이용하여분석하였다.결과: Lysholm의기능평가는부분손상군은88.5, 재건술군은89.3이었고, Tegner의활동도는부분손상군5.3, 재건술군5.1이었다( P<0.05 ) .전방안정성에서평균전방전위는20lb 부하하에부분손상군에서건측에비해1.7$\pm$1.4 mm, 재건술군에서는건측에비해2.3$\pm$1.9 mm였으며(P<0.05), 15lb 부하하에서는부분손상군은건측에비해1.2$\pm$1.0 mm, 재건술군에서는건측에비해1.4$\pm$1.5 mm였다(P<0.05). 합병증으로관절부종, 불안정성, 전방슬관절동통이었다. 불안정성은부분손상군에서흔한합병증이었다.결론: 양군에서임상결과들은비슷하였으며, Lysholm의기능평가는양호하였고, Tegner 활동도상태는양군에서평균적으로신체적인적당한활동(조깅, 규칙적인자전거타기)은유지되어50$\%$이하의부분손상군에대한보존적치료는양호한결과가나타난것으로사료되었다. Purpose: To evaluate and compare the functional results, activity status, and anterior stability between conservative group with partial ACL injury and reconstruction group with bone-patellar ten-don-bone autograft in ACL total rupture. Materials and Methods: Thirty-eight patients with ACL injury were diagnosed and treated with arthroscopy and followed for more than two years. The number of patients with partial injury was 12(mean age; 38.3) and reconstruction group was 26 (mean age; 25.3). Objective stability was estimated under anterior loading of 15 lb and 20 lb by KT-2000 Arthrometer (MED metric, USA). Functional evaluation using Lysholm score and Tegner activity score were performed. Results: Average functional score of Lysholm was 88.5 in partial injury group and 89.3 in reconstruction group. Average score of Tegner was 5.3 in partial injury group and 5.1 in reconstruction group(P<0.05).Average anterior displacement compared with normal side. Under loading of 20lb, 1.7$\pm$4.3 mm in partial injury group, 2.3$\pm$1.9 mm in reconstruction group were anterior displaced (P<0.05). Under loading of 15lb, 1.2$\pm$1.0 mm in partial injury group, 1.4$\pm$1.5 mm in reconstruction group were dis-placed (P<0.05). There were giving way, effusion, instability and anterior knee pain in complication. Giving way was the frequent complication in the partial injury group. Conclusions: Clinical results of both group were similar. Functional evaluation of Lysholm was good and status of Tegner activity was maintained to physical fitness activites (jogging, regular bik-ing) in both groups on average. The results of conservative treatment for the partial ACL injury (less than 50$\%$) was satisfactory and equivalent to that of reconstructive treatment for the total ACL injury.

스키에 의한 슬관절 인대 손상

이동철,고진혁,김동한,Lee Dong Chul,Ko Jin Hyeok,Kim Dong Han 대한정형외과스포츠의학회 2003 대한정형외과스포츠의학회지 Vol.2 No.1

목적: 스키손상에서슬관절인대손상의형태와영향을줄수있는인자를분석하고, 수상전후의슬관절기능평가및스포츠활동도변화를알고자하였다. 대상및방법: 슬관절인대손상환자30명을대상으로설문및이학적검사, X선및MRI 촬영을통한평가를하였고, 기능평가는Lysholm Knee Scoring Scale, 스포츠활동도는Tegner activity score로평가하였다. 결과: 내측측부인대손상을동반한전방십자인대손상이11명으로가장많았고, 내측측부인대손상이9명으로그다음이었다. 수상기전은유령발현상(phantom foot phenomenon)과외전-외회전기전이각각13례와12례로83 $\%$를차지했다. 최종추시에서평균Lysholm score는93.4점으로매우양호하였으며, 활동도는수상전Tegner activity score 6.1점에서수상후4.2점으로감소되었다. 기능과활동도평가에서내측측부인대단독손상군이경과가가장양호하였으며, 내측측부인대손상을동반한전방십자인대손상군이경과가불량하였다. 스키손상에영향을미칠수있는요인으로는스키를지속적으로2시간이상탄경우, 바인딩이풀리지않는경우, 적절한스키강습프로그램을받지않은경우였다. 결론: 환자들의수상후Lysholm score는매우양호했지만, 수상후스포츠활동도에서는수상전과뚜렷한차이를보여적극적이고체계적인스포츠복귀프로그램이필요함을알수있었다. Purpose: This study is to analyse the injury patterns of knee ligament and the factors influencing ligament injuries of knee, and to evaluate the changes of knee function and activity after ski injury. Materials and Methods: Thirty cases of ligament injuries of knee were studied with a questionaire, stress radiographs, magnetic resolution imaging, and physical examination. Mean age was 28.6 years old and mean follow up was 29.6 months. Clinical evaluation of Lysholm knee scoring scale was used for knee function and Tegner activity score was used for activity change after ski injury. Results: The anterior cruciate ligament (ACL) injury accompanied with medial collateral ligament(MCL) injury was most in 11 cases and isolated MCL injury was the next in 9 cases. The common types of injury mechanism were Phantom foot phenomenon (13 cases, 43$\%$) and valgus external rotation injury (12 cases, 40$\%$), which constitute 83$\%$ of all case. At the last follow up, the mean Lysholm score was 93.4 and mean Tegner activity score was 4.2. The reduced Tegner activity score after injury was 1.9. Among several injury groups, the evaluation of knee function and activity was best in the isolated MCL injury group and worst in the ACL injury accompanied with MCL injury group. The factors to influence ski injury were participation to ski class, release of binding, and skiing long time more than 2 hours. Conclusions: Lysholm score at last follow up revealed good grading, but sports activity after ski injury was reduced when compared with pre-injury state. It seems to need a active, systemic sports rehabilitation program after sports injury.

이동 Ad-hoc 무선망에서 효율적인 라우팅 알고리즘에 관한 연구

이동철,김기문,Lee, Dong-Chul,Kim, Ki-Moon 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.1

본 논문은 Ad-hoc 네트워크에서의 전송을 효율적으로 하기 위한 클러스터링 알고리즘에 대해 실험을 통하여 살펴보았다. Ad-hoc 네트워크상 노드들은 정보전송과 위치등록, 노드간의 라우팅 경로 유지를 위해 많은 패킷전송이 이루어진다. 이러한 환경에서의 트래픽은 고정망에서 보다 이동성 변수에 따라 더욱 많은 수가 발생하게 될 것이다. 본 논문에서는 무선 Ad-hoc 다중 홉에서의 트래픽 제어를 위한 클러스터링 알고리즘을 통해 패킷 전송효율을 분석하여 그 결과를 제시한다. The nodes of Ad-hoc network are made up of location registration for sending information and a great number of packet transmissions to maintain routing route among the nodes. under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extend of the traffic in order to control the traffics of the multi-hop in Ad-hoc.

CCITT 표준화 동향

이동철,손홍,배일성,Lee, Dong-Cheol,Son, Hong,Bae, Il-Seong 한국전자통신연구원 1986 전자통신 Vol.8 No.3

본고에서는 CCITT표준화 동향에 대해 제 8차 연구회기('85-'88)의 연구과제를 SG별로 소개하고 여기서 다루어진 연구분야를 조사하여 우리가 연구해야 할 중요분야를 지원 육성하기 위한 토대를 마련하고자 하였다.

교차로에서 자율주행을 위한 심층 강화 학습 활성화 함수 비교 분석

이동철,Lee, Dongcheul 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.6

자율주행은 자동차가 사람 없이 운전할 수 있도록 해 주며 최근 인공지능 기술의 발전에 힘입어 매우 활발히 연구되고 있다. 인공지능 기술 중에서도 특히 심층 강화 학습이 가장 효과적으로 사용되는데 이를 위해서는 적절한 활성화 함수를 이용한 신경망 구축이 필수적이다. 여태껏 많은 활성화 함수가 제시됐으나 적용 분야에 따라 서로 다른 성능을 보여주었다. 본 논문은 교차로에서 자율주행을 학습하기 위해 심층 강화 학습을 사용할 때 어떤 활성화 함수를 사용하는 것이 효과적인지 성능을 비교 평가한다. 이를 위해 평가에서 사용할 성능 메트릭을 정의하고 각 활성화 함수에 따른 메트릭의 값을 그래프로 비교하였다. 그 결과 Mish를 사용할 경우 보상이 다른 활성화 함수보다 평균적으로 높은 것을 알 수 있었고 보상이 가장 낮은 활성화 함수와의 차이는 9.8%였다. Autonomous driving allows cars to drive without people and is being studied very actively thanks to the recent development of artificial intelligence technology. Among artificial intelligence technologies, deep reinforcement learning is used most effectively. Deep reinforcement learning requires us to build a neural network using an appropriate activation function. So far, many activation functions have been suggested, but different performances have been shown depending on the field of application. This paper compares and evaluates the performance of which activation function is effective when using deep reinforcement learning to learn autonomous driving on highways. To this end, the performance metrics to be used in the evaluation were defined and the values of the metrics according to each activation function were compared in graphs. As a result, when Mish was used, the reward was higher on average than other activation functions, and the difference from the activation function with the lowest reward was 9.8%.

우리출판사 이책!

이동철,Lee, Dong-Cheol 대한출판문화협회 2006 출판저널 Vol.372 No.-

회원작품 - 봉화군 사회복지회관

이동철,Lee, Dong-Cheol 대한건축사협회 1996 建築士 Vol.1996 No.3