• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.176-182
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• 1997

A simulation model for the analysis of the transmissivity of direct and diffuse solar radiation In glasshouse was developed. This model would be applicable to investigate the influences of time of year, orientation and slope of glasshouse, dimensions of the frames used, and latitude of the site on the transmissivity of direct and diffuse solar radiation in single-span or multispan glasshouse. The transmissivity of diffuse solar radiation was 60.4％ for the single-span glass-house. It was independent of both orientation and time of year, During the winter season, the transmissivity of direct solar radiation was 67~69％ for the E-W orientation single-span glasshouse, which was 14~16％ higher than that for the S-N orientation. Oppositely the transmissivity of direct solar radiation for the S-N orientation was higher than that for the E-W orientation. during the autumn season. There was no influence of the latitude In the country on the transmissivity of direct solar radiation.

• Journal of Bio-Environment Control
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• v.7 no.4
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• pp.324-329
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• 1998

Effect of roof slope on the transmissivities of direct and diffuse solar radiation using a computer simulation model developed by Kim and Lee(1997) was analyzed for 10-span glasshouse located in Seoul(37$^{\circ}$34' N), Chonju(35$^{\circ}$49' N) and Cheju(33$^{\circ}$31' N). Transmissivities of diffuse solar radiation in glasshouse with roof slopes of 15, 20, 24.6, 30 and 35 degree were calculated as 61.3, 61.6, 61.7, 56.8 and 58.6%, respectively. Transmissivities of direct solar radiation(TDSR) during the period except summer season were highly affected by the roof slope. During the winter season, TDSR in glasshouse with roof slopes of 30 and 35 degree were higher than those with other roof slopes. Also, during the period except winter season, TDSR in glasshouse with roof slope of 20 degree were higher than those with other roof slopes. Difference in TDSR with latitude was significant during the period from October to February. At this period TDSR were highly appeared at lower latitude. Effect of roof slope on TDSR in S-N greenhouse was smaller than those in E-W greenhouse. It is considered that direct solar radiation highly transmitted in the glasshouse with roof slope of 20 degree.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.11a
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• pp.1-7
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• 1997

온실이란 식물 생육에 요구되는 태양광을 유용하게 활용하기 위하여 투명한 피복재가 사용된 구조물을 일컫는다. 온실내로 투과되는 일사량은 온실이 설치된 지역의 위도, 온실의 동방위 및 형상, 구조물의 재원, 피복재의 광학적 특성, 년중일수, 기상 조건, 지붕면의 경사각 등에 따라 변화된다. 일반적으로 겨울철에 온실내의 일사량은 식물의 정상적인 생육에 제약이 되는 요소로 작용한다. (중략)

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.202-208
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• 1999

This study was conducted to investigate the effects of the frame ratio and greenhouse length on the transmissivities of direct and diffuse solar radiation in glasshouse using a computer simulation model developed by Kim and Lee(1997). Transmissivity of diffuse solar radiation slightly decreased as the frame ratio increased. There was no effect of number of spans on the transmissivity of diffuse solar radiation at the same frame ratio. In single or multispan glasshouse, transmissivity of direct solar radiation was 1.5-3.0% higher at the frame ratio of 11.3% than those at the frame ratio of 14.9%. Also the transmissivity of direct solar radiation was 1.5-3.0% lower at the frame ratio of 18.3% than those at the frame ratio of 14.9%. Effect of the increased or decreased frame ratio on the transmissivity of direct solar radiation was similar in I-W or S-N glasshouse. Since the high transmissivity of direct solar radiation exerted a beneficial influence upon the plant growth during winter season, the light and endurable structural members were needed to maximize the transmission of solar radiation in glasshouse. Transmissivity of direct solar radiation in I-W or S-N glasshouse did not vary with the length of 24.5m long or more.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.439-444
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• 1998

Effects of the number of spans, orientation and latitude on the transmissivities of direct and diffuse solar radiation in multispan glasshouse were analyzed using a computer simulation model (Kim and Lee, 1997). The number of spans did not affect the transmissivity of diffuse solar radiation, ranging 60∼61%. The transmissivities of direct solar radiation were 55∼64% for E-W orientation and 47∼70% for N-S orientation in ten multispan glasshouse. There was no effect of the latitude on the transmissivity of direct solar radiation in domestic regions. Differences in the transmissivity of direct solar radiation between single-span and multispan glasshouse were significant for E-W orientation during winter season; however, those were relatively small for N-S orientation throughout the year. Transmissivity of direct solar radiation decreased with the increasing number of spans for E-W glasshouse, whereas those for N-S glasshouse was hardly affected by the number of spans.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.12a
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• pp.150-155
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• 1998

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.479-491
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• 2005

지구환경문제와 에너지 수급관계를 감안할 때, 청정 및 대체에너지 연구개발은 불가피하며, 그 중에서도 태양에너지는 대표적인 대안의 하나로 인식된다. 따라서 태양에너지의 적극적인 활용에 필요한 기초자료의 마련은 필수적이다. 태양에너지의 이용 및 관련 절약 기술에 필요한 태양에너지 자원(기상)에 대한 기술자료는 최소한 30년간의 측정 자료를 필요로 한다. 이들 자료에는 시간별 수평면전 일사량, 법선면 직달일사량 및 수평면 산란일사량은 물론 시간별 평균치로 운량, 기온, 습도 등이 포함된다. 이들 자료로부터 자료의 분포, 평균 및 최고, 최저값 등과 같은 기초자료들을 선별하여 관련 시스템 설계에서 요구하는 기준을 충족하여야 하는 것이다. 그러나 우리나라의 경우, 태양에너지 자원에 대한 정밀한 측정은 1982년 이후 수평면 전일사량, 1990년 이후에서나 법선면 직달일사량에 대하여 본격적으로 이루어진 실정으로, 자료의 표준화 및 신뢰성 확보에는 여전히 상당한 시간과 노력이 요구되는 실정이다. 지속적인 측정과 더불어 요구되는 것으로 측정자료의 가공기술을 들 수 있다. 즉, 측정자료의 품질평가 및 관리 기술, 미측정 또는 불량자료의 복원 기술 및 측정 지역외 자료의 추정을 위한 보간기술 등이다. 이와 같은 기초자료 및 기술에 관한 연구개발은 보다 구체적인 적용에 앞서 필수적으로 이루어져야 할 과제이다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.55-62
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• 1998

온실내에서 직달 및 산란일사의 투과율은 온실이 설치된 지역의 위도, 온실의 동방위 및 형상, 피복재의 광학적 특성, 년중일수, 기상 조건, 지붕면의 경사각 뿐만 아니라 온실의 길이, 구조물의 크기 등에 따라 달라질 수 있다. 현재 국내의 기상 조건에 적합한 표준형 유리온실의 설계 기준이 부분적으로 제시되고 있으나, 온실내의 광환경과 관련된 설계 기준은 제시되지 않고 있는 실정이다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.27-32
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• 1998

국내에 보급되어 있는 유리온실은 네덜란드에서 수입된 벤로형(Venlo type or Dutchlite)과 벤로형에 비해서 동고가 높으며 온실 한 동의 폭이 상대적으로 큰 광폭형(widespan type)이 대부분을 차지하고 있다. 벤로형 은실의 측고는 3.5~4.0m로서 다소 차이가 있으나, 한 동의 폭과 지붕경사면의 길이가 일정하기 때문에 온실의 지붕경사각은 대부분 22$^{\circ}$를 나타낸다. (중략)

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.56-60
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• 2002

Since the transmittance of solar radiation directly affected by the structural frames of greenhouse can be changed according to the ratio of diffuse to direct radiations, it is necessary to investigate the transmittance of greenhouse at the different weather conditions. We can easily get the data of total solar radiation from the Meteorological Administration, but we have to personally measure the photosynthetic photon flux (PPF). If the relationship between total solar radiation and PPF is established, the PPF can be simply acquired from the relationship. Sol it is required to develop the equation to calculate PPF depending on weather condition. This study was conducted to determine the transmittance of PPF at canopy level in glasshouse and the correlation between total solar radiation and PPF at clear and cloudy days. The variation phase of greenhouse transmittance at clear day was very different from that at cloudy day. It was concluded that the proper transmittance, depending on the weather condition, should be adopted to calculate the accurate total solar radiation and PPF in greenhouse. The transmittance of solar radiation was the same as that of PPF in greenhouse. It was confirmed that the ratio of PPF to total radiation increased as the amount of cloud increased. The correlation between the hourly total solar radiation and PPF was derived.