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조홍렬 ( Heung Ryeol Cho ),김세빈 ( Se Bin Kim ),오도교 ( Do Kyo Oh ) 한국환경보건기술학회(구 한국환경복원녹화기술학회) 2009 한국환경복원기술학회지 Vol.12 No.6
The purpose of this study is to analyze the profitability by selecting Pinus densiflora S. et Z worthy of ornamental tree from among the cutting timber in the urban development project, and then presents the improvements. The study site is the whole area of Oedong-eup Gyeongju city Gyeongsangbuk-do and subject trees numbers are 2,180 trees. Analysis method is cost analysis because it is used generously pubic land development. In results, at first, in case of forest development currently cutting tree costs 7.3 million Won/ha. and no profit is occurred at all. Secondly, the forward direction order of tree treatments expenses are in sawdust production, selling lumber, selling ornamental tree, and selling ornamental tree, sawdust production, selling lumbered on the aspect of profits by the selling stumpage. Especially, selling trees as ornamental tree costs 127 million Won/ha. which shows the highest profits. Third, the management of ornamental tree pine tree after transplantation from development site costs 5 times less than purchasing the same quality trees. Hence, it is recommended to re-utilize the trees from the development sites to produce a high standard gardens and it also provides the basis for the low carbon green growth society.
박진우(Jin-Woo Park),최연웅(Yeon-Ung Choi),조홍렬(Hong-Lyul Cho),손홍민(Hong-Min Son) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.9
본 논문에서는 추적식 태양광 발전 시스템에 응용하기 위한 태양 위치 측정용 전파 센서 수신기의 설계, 제작 및 성능 실험에 관한 과정 및 결과를 소개한다. 먼저, 전파 센서에 대한 요구 성능인 ±5° 이내의 위치 측정 오차범위를 만족시키기 위한 수신기의 사양을 구하였고, 이를 토대로 수신기를 설계하였다. 설계된 수신기의 시스템 이득 및 잡음 지수의 budget 분석을 통해 설계의 적절성을 점검하였으며, 이 결과를 활용하여 수신 주파수 5.1 ㎓, 대역폭 104 ㎒로 69 ㏈의 시스템 이득과 0.46 K 이내의 수신 감도를 갖는 고이득, 고감도 광대역 수신기를 제작하였다. 제작된 수신기와 표준 혼 안테나로 구성된 전파 센서로 흐린 날 실제 태양을 대상으로 실험한 결과, ±4° 이내의 오차 범위로 태양의 위치를 실시간으로 측정하는데 성공하여 요구 성능이 만족되었음을 검증하였다. In this paper, we propose a radio sensor to measure the position of the sun for the solar tracker of a photovoltaic system. In order to satisfy the requirement for the measurement accuracy within ±5°, the sensor receiver with high gain, high sensitivity and wide bandwidth is designed and implemented. The receiver has the bandwidth of 104 ㎒, the system gain of 69 ㏈ and the sensitivity of 0.46 K at 5.1 ㎓. The processes of design and implementation of the radio sensor receiver are described in this paper. The effectiveness of the proposed radio sensor in the measurement of the position of the sun is demonstrated experimentally under the condition of cloud cover. The results show the radio sensor can measure the position of the sun within the accuracy of ±4° successfully.