• 한국농림기상학회지
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• 제23권4호
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• pp.340-348
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• 2021

본 연구는 콩의 한발 스트레스 판별에 대하여 RGB 영상에 기반한 작물 생육 지수의 적용 가능성과 한계점을 구명하기 위해 수행되었다. RGB 영상에서 추출한 생육 지수들과 한발 스트레스에 반응하는 대표적인 표현형 지표들(군락 피복도, 엽면적, 엽록소 함량 등)과의 높은 상관관계를 통해 영상 기반 생육 진단 모델개발의 가능성을 확인할 수 있었다. 다만 판별의 정확도와 해상도를 개선시키기 위해서는 향후 다양한 재배조건에서 지속적인 성능 평가가 이루어져야 할 것이다. 본 연구의 결과는 향후 RGB 영상을 활용한 콩환경 스트레스 판별에 있어서 영상 전처리, 영상 분석방법, 생육 지수 정량화 기술 개발에 도움을 줄 수 있을 것이며, 개발된 생육 인자 예측 모델은 환경 스트레스 조기 진단을 통한 영농 의사결정 지원 모델의 개발에 기여할 수 있을 것으로 판단된다.

• 생물환경조절학회지
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• 제18권1호
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• pp.29-39
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• 2009

딸기 재배용 온실 내 재배 벤치에서 생산량을 높이기 위하여 벤치 주위에서 이산화탄소를 공급하는 경우 환기 등에 의한 풍속으로 인하여 작물 주변의 적정가스 농도가 유지되지 못하는 현상이 발생한다. 본 연구에서는 이산화탄소를 보존시키고자 벤치 주변에 방풍막을 설치하는 방안에 대하여 분석하였다. 온실 내 벤치와 방풍막을 2차원 CFD 시뮬레이션으로 모델링하고 온실 내 공기의 풍속과 이산화탄소의 공급을 구현하여 보존되는 이산화탄소의 농도 분포를 살펴보았다. 또한 이를 통하여 설계한 온실의 환경조건에서의 적정한 방풍막 설치 높이를 제안하고자 하였다. 시뮬레이션에서 구현한 온실 내 풍속조건은 0.5, 1.0, 1.5 m/s이고, 방풍막의 높이는 미설치, 0.15, 0.30 m이고, 각 조건에서의 이산화탄소 농도를 측정하였다. 설계상의 편의와 시뮬레이션의 간소화를 위하여 벤치위의 작물은 없는 것으로 가정하였다. 일반적인 온실 내의 풍속 조건은 1.0 m/s로, 시뮬레이션 결과 이 때 벤치 위에서의 평균 이산화탄소 농도는 방풍막 미설치 시 420 ppm, 방풍막 설치 높이 0.15 m일 때 580 ppm, 0.30 m일 때 653 ppm으로 나타났다 딸기의 최대 생산량을 위한 적정 생육 이산화탄소 농도가 $600{\sim}800ppm$ 정도인 것을 고려하여, 이와 같은 환경조건에서의 방풍막의 설치 높이는 0.30m가 적당할 것으로 판단하였으나 이산화탄소 공급조건, 작물의 배치 등의 조건변화에 따른 상황에서의 연구가 추가적으로 수행되어야 할 것이다. 이처럼 방풍막의 설치가 온실 내에 시비한 이산화탄소를 작물 주변에 머무르게 하는 효과가 상당함을 알 수 있었으며, 설계한 환경조건에서 작물별로 적정한 수준의 이산화탄소량이 공급되고 있는지를 판단하기 위하여 CFD 기술이 이용될 수가 있음을 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.276-279
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• 2007

This study aims to present the application of pv system for apartment buildings. Regarding to the domestic housing politics to improve residing environment and effective use of country land, apartment buildings have been constructed since early of 1790's. Now apartment is taking over 50% out of entire housing in Korea. PV System of apartment buildings has been developed periodically and recently gable roof or canopy is popular which pv installation is more favorable. For balcony part with double skin facade sassy window, it has a preferable condition to install on the wall depending on the window direction. In case of superhigh floor apartment buildings where facade is mostly double skin facade of curtain wall system, pv module can replace the traditional curtain wall and will reduce architectural materials and obtain various out look design thereof. So, the purpose of this research is a basic study for clean energy source and present to applicability of pv systems for apartment buildings in preliminary design step.

• Agricultural and Biosystems Engineering
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• 제2권2호
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• pp.50-58
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• 2001

Chemical application is very hazardous in confined spaces under the canopy ceiling in Korean vineyard. For a small orchard sprayer adaptable to such a working condition, a low-cost autonomous steering control system was developed using two ultrasonic sensors, two electrically-operated cylinders and 80196kc microprocessor. A distance ranging system timed the round-trip for each ultrasonic wave to travel against parallel targets, placed every 1.5m spacing along both sides of a desired path. A steering control algorithm of the autonomous operation began with ranging left and right targets and the heading was decided using difference between the distances. Electrically-operated cylinders actuated steering clutches to guide the sprayer. Evaluation tests showed that the orchard sprayer could travel within RMS value of 5cm along the desired path. Ground speed did not affect the performance of the autonomous guidance system at the speed ranges of 0.29~0.52m/sec.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.571-574
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• 2010

Large-eddy simulation has been conducted to simulate turbulent boundary-layer flows over an array of regularly distributed obstacles considering various cases of a wind incident angle. The effect of wind direction was investigated in the square cube array that periodic boundary condition was imposed. Characteristics of the turbulent flow over the obstacle array have been found to be very sensitive to the direction of prevailing wind or of mean wind or of mean pressure gradient but varied with height, specially below the urban canopy. Turbulent statistics are changed sensitively with the direction of mean pressure gradient around 10 degree.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.332-335
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• 2008

Newly developing SAR (Synthetic Aperture Radar) sensors commonly include high resolution X-band those data are expected to contribute various applications. Recent few studies are presenting potential of X-band SAR data in forest related application. This study tried to investigate the relationship between forest stand parameters and multi-band SAR normalized backscattering. Multi-band SAR data was radiometric corrected to compare signal from different forest stand condition. Then correlation coefficients were estimated between attribute of forest stand map and normalized backscattering coefficients. Although overall correlation coefficients are not high, only X-band shows strong relationship with DBH class than other bands. The signal of C- and L-band is composed of a large number of discrete tree components such as leaves, stems, even background soil. In forest, strength of radar backscattering is affected by complex parameters. Further study might be considered more various forest stand parameters such as canopy density, stand height, volume, and biomass.

• 한국조경학회지
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• 제21권1호
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• pp.1-12
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• 1993

This studies were conducted to investigate on the shade adaptation of native Sedum kamchaticum and Disporum smilacinum. All plants were grow under the controlled light intensity conditions, which controlled by two shading materials, white and/or black shading net. The results obtained were as follow. 1. Daily changes of the shading area around of the building were various by building height, width and direction. 2. Upper canopy was composed to Pinus densiflora as dominant species in native sites of Disporum species. 3. Many branches of Disporum smilacinum were sprouted after pinching. However their growth were less elongated shorter than those of Disporum viridescens. 4. Sedum sarmentosum was poor growth under the low relative light intensity as 50%, however, the growth of this species closely was similiar as under the full sun condition.

• 한국농공학회지
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• 제43권6호
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• pp.103-112
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• 2001

The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

• 설비공학논문집
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• 제19권5호
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• pp.379-385
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• 2007

In the present study, ventilation flow in the Janggyeongpan-Jeon at Haein temple in case of building rearrangement has been investigated numerically. To achieve more accurate results, detailed shapes such as buildings and the window grills are modeled and tree canopy model is adopted to account for the effect of trees in the computation. Wind velocities as boundary condition are taken from meteorological statistical data. The numerical results show that ventilation flow distributions at Janggyeongpan-Jeon in case of building rearrangement are nearly similar to those before rearrangement.

• 한국환경생태학회지
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• 제26권3호
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• pp.382-393
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• 2012

경상북도 문경 희양산 산림식생 특성을 봉암사 산림유전자원보호구역을 중심으로 파악하였다. 총 92개 조사구($100m^2/plot$)에 대한 조사를 실시하고, Classification 분석과 Ordination 분석을 통해 군락분류를 실시한 결과 이 지역의 식생은 신갈나무군락, 굴참나무군락, 소나무군락, 소나무-졸참나무군락, 소나무-신갈나무군락, 졸참나무군락, 낙엽활엽수군락, 잣나무조림지, 일본잎갈나무조림지의 총 9개 군락으로 분류되었다. 각 군락간의 비교를 위해 지형조건과 식생조사 결과에 대한 통계분석을 실시하였으며, 해발고도, 경사, 출현종수, 교목층 출현 개체수, 아교목층 출현 개체수에서 통계적으로 유의하게 군락간 차이를 보였다. 층위별 상대우점치를 통한 각 군락의 군락구조를 분석한 결과, 참나무류군락은 교목층과 아교목층에 고르게 세력을 형성하고 있어 현재의 군락이 유지되거나 확대될 것으로 예상되는 반면, 소나무 우점 군락은 대부분 참나무류와의 경쟁이 심화되고 있어 향후 이들 참나무류로의 천이가 예상되었다.