Understanding the light environment in greenhouse cultivation and the light utilization characteristics of crops is important in the study of photosynthesis and transpiration. Also, as the plant grows, the form of light utilization changes. Therefore, this study aims to develop a light extinction coefficient model reflecting the plant growth. To measure the extinction coefficient, five pyranometers were installed vertically according to the height of the plant, and the light intensity by height was collected every second during the entire growing season. According to each growth stage in the early, middle, and late stages, the difference between the top and bottom light intensity tended to increase to 69%, 72%, and 81%. When leaf area index and plant height increased, the extinction coefficient decreased, and it showed an exponential decay relationship. Three-dimensional model reflecting the two growth indexes, the paraboloid had the lowest RMSE of 1.340 and the highest regression constant of 0.968. Through this study, it was possible to predict the more precise light extinction coefficient during the growing period of plants. Furthermore, it is judged that this can be utilized for predicting and analyzing photosynthesis and transpiration according to the plant height.

Detailed low spectral resolution observations of the spectrum have been made for three early spectral type standard stars, HR718, HR1544, HR3454, respectively, for the wavelength region 4,300 A to 7,500 A, using the Bohyunsan Optical Astronomy Observatory (BOAO) Middle- Dispersion Spectrograph. These standard stars were chosen from well-known bright northern standard stars. All of the observed long slit spectral data has been reduced and analyzed using the IRAF reduction procedure. The derived extinction coefficients are compared with the other observatory result. The derived value can be used in the determination of flux calibration of BOAO spectroscopic observation. However, until the high quality data are secured from a new series of observation in the blue region and are re-analyzed together, the extinction coefficients below the 4,000 A wavelength remains unknown.

최근 공동주택은 편리한 교통이나 우수한 교육여건보다 풍부한 녹지와 주변 자연경관을 선호하는 경향으로 변화하고 있다. 공동주택에서 교목, 관목, 초본이 다양하게 혼식되어 풍부한 생태공간을 조성하기 위해서는 공동주택 건물에 의한 공간별 일조환경의 정확한 예측이 요 구된다. 본 연구는 다층구조식재를 위해 관목과 초본의 일조에 영향을 미치는 건물과 교목류 하부의 일조환경을 예측하기 위해 수종별 광 소멸계수를 도출하였다. 공동주택에 식재되는 대표적인 18종의 교목을 대상으로 180도 화각을 가진 어안렌즈로 측정한 영상자료를 Hemisfer 프로그램을 이용하여 식물의 엽면적 지수를 산출한 후 Goudriaan의 방정식으로 수종별 광소멸 계수를 산정하였다. 엽면적 지수 증가에 따른 광소멸계수는 꽃사과, 대왕참나무, 고로쇠나무가 유사한 패턴으로 가장 급격하게 감소하여 일사의 차이가 가장 큰 수종 그룹 으로 나타났다. 향후 정원 설계 및 유지관리용 소프트웨어 개발을 통한 공동주택 일조환경 분석에 필요한 기초데이터로 활용하고자 한다.