• Title/Summary/Keyword: 일사차폐

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Study on Improvement of Thermal Environment by Green Roof Systems on RC Building - utilization of solar insulating block and the grass - (옥상녹화에 따른 콘크리트 건축물의 열환경 개선효과 -일사차폐블록과 잔디를 대상으로-)

  • Park, Chanpil;Furukawa, Nobuhisa
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.1
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    • pp.1-9
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    • 2004
  • Caused on the excessive heat accumulation of concrete material, the indoor thermal environment of reinforced concrete building is so bad in Okinawa. As the interruption of solar radiation could be one of the methods to improve it, the purpose of this study is to find out the effect of adopting solar radiation interrupting materials -Solar insulating block, Grass, and both of them- for the improvement of thermal environment. As the result, it was found that grass on the solar insulating block which has an air layer obviously improved the indoor thermal environment of RC building which was applied to. And it was found that the systems have an effectuality on heat island phenomenon simultaneously. It could be proposed as a good system which improve the indoor thermal environment of the existent houses.

A Study on the Retrievals of Downward Solar Radiation at the Surface based on the Observations from Multiple Geostationary Satellites (정지궤도 위성자료를 이용한 지표면 도달 태양복사량 연구)

  • Jee, Joon-Bum;Zo, Il-Sung;Lee, Kyu-Tae
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.123-135
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    • 2013
  • The reflectance observed in the visible channels of a geostationary meteorological satellite can be used to calculate the amount of cloud by comparing the reflectance with the observed solar radiation data at the ground. Using this, the solar radiation arriving at the surface can be estimated. This study used the Meteorological Imager (MI) reflectance observed at a wavelength of 675 nm and the Geostationary Ocean Color Imager (GOCI) reflectance observed at similar wavelengths of 660 and 680 nm. Cloudy days during a typhoon and sunny days with little cloud cover were compared using observation data from the geostationary satellite. Pixels that had more than 40% reflectance in the satellite images showed less than 0.3 of the cloud index and blocked more than 70% of the solar energy. Pixels that showed less than 15% reflectance showed more than 0.9 of the cloud index and let through more than 90% of the solar energy to the surface. The calculated daily accumulated solar radiation was compared with the observed daily accumulated solar radiation in 22 observatories of the Korean Meteorological Administration. The values calculated for the COMS and MTSAT MI sensors were smaller than the observation and showed low correlations of 0.94 and 0.93, respectively, which were smaller than the 0.96 correlation coefficient calculated for the GOCI sensor. The RMSEs of MTSAT, COMS MI and GOCI calculation results showed 2.21, 2.09, 2.02 MJ/$m^2$ in order. Comparison of the calculated daily accumulated results from the GOCI sensor with the observed data on the ground gave correlations and RMSEs for cloudy and sunny days of 0.96 and 0.86, and 1.82 MJ/$m^2$ and 2.27 MJ/$m^2$, respectively, indicating a slightly higher correlation for cloudy days. Compared to the meteorological imager, the geostationary ocean color imager in the COMS satellite has limited observation time and observation is not continuous. However, it has the advantage of providing high resolution so that it too can be useful for solar energy analysis.

Developing a Model to Predict Road Surface Temperature using a Heat-Balance Method, Taking into Traffic Volume (교통량을 고려한 열수지법에 의한 노면온도 예측모형의 구축)

  • Son, Young-Tae;Jeon, Jin-Suk;Whang, Jun-Mun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.2
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    • pp.30-38
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    • 2015
  • In this study, to improve effectiveness of road management services and the safety of the road in winter, road surface temperature prediction model was developed. We have utilized the existing input data of meteorological data and additional traffic data. This Road surface temperature prediction model was utilizing a Heat-Balance Method additionally considering amount of traffic that produce heat radiation by vehicle-tire friction. This improved model was compared to the based model to check into influence of traffic affecting the road surface temperature. There were verified by comparing the real observed road surface temperature of the third Gyeong-In highway and road surface temperature from the two models. As a result, the error of real observed and the predicted value (RMSE) was found to average $1.97^{\circ}C$. Observed road surface temperature was dramatically affected by the sunlight from 6 a.m. to 2 p.m. and degree of influence decreases after that. The predictive value of the model is lower than the observed value in the afternoon, and higher at night. These results appear due to the shielding of solar radiation caused by the vehicle in the afternoon and at night, the vehicle appeared to cause thermal heat supply.