한국 농민으로서 삶과 새로운 가치발견

이원희,Lee, Won-Hui 전국농업기술자협회 2008 농업기술회보 Vol.45 No.2

각막굴절교정학 콘택트렌즈가 근시 및 난시의 진행에 미치는 영향

이원희,박영기,서종모,신종훈,Won Hee Lee,Young Kee Park,Jong Mo Seo,Jong Hoon Shin 대한안과학회 2011 대한안과학회지 Vol.52 No.11

Purpose: To investigate the clinical effects of orthokeratology lens wear on inhibition of the progression of Korean myopia and astigmatism. Methods: The authors reviewed out-patient records of 144 eyes of 74 patients wearing orthokeratology lenses. The cycloplegic refraction and keratometry before and after wearing the lens were compared. The 190 eyes wearing spectacles were included into the control group. We evaluated the relationship between orthokeratology lens wear and control group according to age, initial myopia, initial astigmatism, myopic progression, astigmatic progression and duration of orthokeratology lens wearing. Results: The mean cycloplegic refractive error of spherical equivalent was -3.36 ± 1.96 diopters (D) in the patients wearing orthokeratology lenses, the mean astigmatism was -0.86 ± 0.72 D, and the mean wearing period was 3.41 ± 1.5 years. The mean myopic progression was 0.25 ± 0.31 D in lens wearing, and 0.62 ± 0.39 D in glasses wearing, respectively. There were statistically significant differences between lens and glasses wearing group (t-test, p < 0.01). The mean astigmatic progression was 0.06 ± 0.22 D in lens wearing, and 0.15 ± 0.21 D in glasses wearing control group respectively, and the results also show statistically significant differences (t-test, p < 0.01). There were no relationships between two groups as for age, initial myopia, initial astigmatism and duration of orthokeratology lens wearing (t-test, p > 0.01). Conclusions: The orthokeratology lens was found to be effective in suppression of the progression of Korean myopia and astigmatism, compared with the glasses. J Korean Ophthalmol Soc 2011;52(11):1269-1274

HEC-HMS와 HEC-RAS모형의 연계에 의한 댐 유역의 홍수영향 분석

이원희,김선주,김필식,Lee, Weon-Hee,Kim , Sun-Joo,Kim , Phil-Shik 한국농공학회 2004 한국농공학회논문집 Vol.46 No.2

For the effective operation of irrigation reservoirs, a general and systematic policy is suggested to make balance of the conflicting purposes between water conservation and flood control. In this study, the flood effective analysis system was developed through the integration of long-term water budget analysis model, GIS-based HEC-HMS model and HEC-RAS model. The system structure consists of long-term water budget model using modified TANK theory, flood runoff and flood effects analysis model using HEC-GeoHMS, HEC-HMS and HEC-RAS models. The flood effects analysis system simulated the flood runoff from the upstream, downstream flood and long-term runoff of the watershed using the observed data collected from 1998 to 2002 of Seongju dam. The simulated results were reasonably good compared with the observed data. The optimal management method of the reservoir during the whole season is suggested in this study, and the flood analysis system can be a useful tool to evaluate a reservoir operation quantitatively for the mitigation of flood damages of reservoir basin.

목탄과 황토함유 목질소재의 기초물성

이원희,Lee, Wun-Hee 한국가구학회 2006 한국가구학회지 Vol.17 No.2

This research was carried out to examine the FIR (far-infrared rays) emissivity and emission power of five types of flooring board by the mixing ratio of charcoal and loess, and the physical property of five types of injected flooring board by the amount of mixture. Type D was appeared the most high value of FIR emissivity and emission power. But there was a little difference among the five types of flooring board values. In physical properties, control type flooring board and injected flooring board showed a similar tendency. Among the domestic trees, all of hard wood seems to be used to surface wood for strong hardness flooring board. But a coniferous tree was not.

숯과 황토 복합소재의 흡착성능

이원희,Lee, Won-Hee 한국가구학회 2006 한국가구학회지 Vol.17 No.3

The purpose of this study was to evaluate the relationships between the mixing ratio and water vapor sorption property of charcoal-based loess composites for furniture & building materials with environmental friendly. Charcoal-based loess composite can be easily made by blending method with water. But the composites had much brittle fracture pattern with the increase of charcoal content. That is due to the lack of loess that takes linkage role of composites. In water vapor sorption properties, adsorption ability of charcoal was about six times higher than that of loess. Therefore, vapor sorption ability was maximum at the mixture ratio of charcoal 80% and loess 20%. It is considered that wood charcoal based inorganic composite materials can be used for various purposes as a building interior & exterior and furniture members.

오피스용 SFFS(Solid Freeform Fabrication System) 기술 개발

이원희,이택민,김동수,Lee, Won-Hui,Lee, Taek-Min,Kim, Dong-Su 재료연구소 2004 機械와 材料 Vol.16 No.1

구름을 포함한 푸쉬브룸 스캐너 영상의 밴드간 상호등록

이원희,유수홍,허준,Lee, Won-Hee,Yu, Su-Hong,Heo, Joon 대한원격탐사학회 2011 大韓遠隔探査學會誌 Vol.27 No.1

푸쉬브룸 스캐너 PAN영상과 MS영상 사이에는 오프셋이 존재하며 서로 다른 시간과 각도로 촬영하고 있다. 이로 인하여 구름과 같이 빠르게 움직이는 물체는 오정합 점들을 생성하며 이는 PAN영상과 MS영상간의 상호영상등록의 오차를 발생시킨다. 특히 구름(안개 및 스모그 포함)이 있는 기상조건 하에서 얻어진 위성영상은 구름에 의해 가려진 지형정보를 추출하는 데 있어 많은 문제를 야기하기 때문에 정확한 영상등록을 위해서는 효과적인 구름 탐지 및 제거 알고리즘이 필요하다. 구름 제거를 위한 관련 연구들은 크게 다음과 같은 세 가지로 나누어지는데 (1) 구름 검출 알고리즘을 통해 구름으로 여겨지는 영역을 분리하여 구름영역을 제거하는 방법 (2) 다중분광영상의 밴드정보를 이용하는 방법 (3) 다시기 영상정보를 이용하는 방법들로 나눌 수 있다. 본 연구에서는 구름 지역을 제거하는 방법과 다시기영상을 이용하는 방법을 사용하여 구름이 포함된 푸쉬브룸 스캐너 밴드간 영상등록의 정확도를 비교, 분석하였다. Since PAN(panchromatic) and MS(multispectral) imagery of pushbroom scanner have the offset between PAN and MS CCD(charge coupled device) in the focal plane, PAN and MS images are acquired at different time and angle. Since clouds are fast moving objects, they should lead mis-registration problem with wrong matching points on clouds. The registration of cloudy imagery to recognize and remove the contamination of clouds can be categorized into three classes: (1) cloud is considered as nose and removed (2) employing multi-spectral imagery (3) using multi-temporal imagery. In this paper, method (1) and (3) are implemented and analysed with cloudy pushbroom scanner images.

리액턴스의 변화를 이용한 정삼각형 마이크로스트립 패치 안테나의 대역폭 개선

이원희,이재욱,전승길,최홍주,허정,Lee, Won-Hui,Lee, Jae-Wook,Jeon, Seung-Gil,Choi, Hong-Ju,Hur, Jung 한국전자파학회 2003 한국전자파학회논문지 Vol.14 No.6

삼각형 패치 안테나에 대해 이론적인 방법과 실험을 통해 연구하였다. 삼각형 패치 안테나는 사각형 패치 안테나와 비슷한 복사 특성을 갖으나, 그 크기를 더 줄일 수 있다. 본 논문에서는 정삼각형 마이크로스트립 패치 안테나를 공동 모델을 사용하여 해석하고, 설계 하였다. 또한 대역폭 향상을 위해 커패시티브 갭과 공기층 갭을 이용하였다. 커패시티브 갭은 패치의 급전점 부근에서 사각형 모양으로 만들었고, 공기층 갭은 유전체 기판과 그라운드 사이에 삽입하여 프로브 인덕턴스를 조정하였다. 안테나 각 부분의 효과와 특성 해석을 위해 상업용 시뮬레이션 툴인 Ensemble 5.0을 사용하였다. 시뮬레이션과 실험을 통하여 삼각형 마이크로스트립 안테나의 대역폭 개선의 가능성을 발견하였다. Triangular patches have been studied, both theoretically and experimentally. We feund that provided radiation characteristics similar to those of rectangular patches, but with smaller size. In this paper, we designed an equilateral triangular microstrip patch antenna using cavity model analysis. Then, in order to improve narrow bandwidth, we add capacitive gap and air gap. Capacitive gap is located with square shape beside feeding point on the patch, and air gap is inserted between substrate dielectric and ground plane to adjust probe inductance. The analysis of characteristics and effects of each component was performed by commercial simulation tool, Ensemble 5.0. Throughout the simulation and experiment, we found the possibility of bandwidth enhancement in triangular microstrip antenna.

영동산 일라이트의 성형 및 비유전율 측정

이원희,최홍주,구경완,허정,Lee, Won-Hui,Choi, Hong-Ju,Koo, Kyung-Wan,hur, Jung 한국전자파학회 2001 한국전자파학회논문지 Vol.12 No.5

영동산 일라이트의 비유전율 측정에 대해 기술한다. 비유전율을 측정하기 위해 윗면 조정이 가능한 원통형 공동 공진기가 이용되었다. 동심 유전체 봉이 삽입된 원통형 공동 공진기를 이용하는 방법과 non-decaying 모드의 정확한 전자계 표현은 비유전율을 측정하기 위해 소개되었다. 동심 유전체 봉이 삽입된 경우에 정확한 전자계 표현들을 해석하였다. 유전체가 삽입된 공진기를 이용한 비유전율의 계산은 특성방정식의 해석에 의해 계산된다. 특성방정식은 상용 수학 툴인 Mathematica의 ContourPlot 그래프 기능을 이용하여 풀이하였다. Non-decaying 모드 해석법은 근사적인 해석법이 아니라, 정확한 해석법이다. 결과적으로 바인더가 들어있는 유전체 시료에 대해서는 7.820의 비유전율이 측정되었고, 바인더가 없는 유전체 시료에 대해서는 7.894의 비유전율이 측정되었다. This paper describes measurement of relative permittivity of illite found in young-dong area. A measurement of relative permittivity of the illite was made using cylindrical cavity resonators with a moveable cap. A concentric dielectric-rod inserted the cylindrical cavity resonator and an exact field representation of non-decaying mode of the resonator are introduced for the measurement of relative permittivity. The exact electromagnetic fields in cylindrical cavity with a concentric dielectric rod is analysed. The relative permittivity of dielectric in the cavity is calculated by analyzing a characteristic equation. The characteristic equation is solved by using the ContourPlot graph of Mathematica. We know that the field representation of non-decaying mode is exact. As a result, the relative permittivity of dielectric materials was 7.820 for a sample with binder and 7.894 for a pure sample.

정보통신서비스시장 현황 및 전망

이원희,Lee, Won-Hui 한국정보통신집흥협회 2004 정보화사회 Vol.171 No.-