• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.105-116
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• 2014

The objective of this study was to compare and analyze of radiation environment between downtown and suburban area by observation of short, diffuse and long-wave radiation during summer season. The followings are main results from this study. 1) The trends of long-wave radiation is increasing from May to August and the variation of daily range is decreased. It is confirmed that the temperature was closely relevant to long wave radiation. 2) During observation period, suburban area is higher than downtown the value of direct solar radiation. 3) There are much direct solar radiation in suburban area than downtown. But, it was measured much more horizontal solar radiation at the downtown area. From the this result, we can conclude that diffuse radiation play a important role at horizontal solar radiation.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.198-199
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• 2000

다목적 실용위성 (KOMPSAT) 1호기에 탑재되는 해양관측카메라 Ocean Scanning Multi-spectral Imager (OSMI)는 해양 결상계의 노화에 따른 성능 변화 감지 및 보정을 위해 태양광 보정을 궤도운영 중 수행한다. 태양광 보정의 구조 및 광학적 특성을 분석하고 OSMI 주요 관측파장대역별로 태양광 보정계의 출력신호량을 예측하였다. 이 분석은 OSMI 센서보정 계획 및 영상 품질 이해에 유용할 것이다. (중략)

• The Bulletin of The Korean Astronomical Society
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• v.24 no.2
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• pp.68-68
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• 1999

• The Bulletin of The Korean Astronomical Society
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• v.20
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• pp.17.1-17.1
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• 1995

• Optical Science and Technology
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• v.16 no.1
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• pp.30-34
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• 2012

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.12-21
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• 2019

In order to investigate the effect of various pavement materials (artificial grass, natural grass, and clay sand) on the human thermal environment, the microclimate data in early autumn (air temperature, humidity, wind speed, and shortwave and longwave radiation) were measured and compared on each surface. The mean air temperature, humidity and wind speed of the pavement materials did not differ significantly and showed the greatest difference in the mean radiant temperature. Natural grass, which has the highest albedo, has the highest amount of shortwave radiation. The artificial turf had the highest surface temperature and the highest amount of longwave radiation. In the human thermal environment index PET, artificial grass > clay sand > natural grass. Natural grass had a maximum 2/3 level lower and a mean 1/2 level lower in PET as compared to artificial grass. The clay sand pavement had a maximum 2/3 level lower and a mean 1/3 level lower than the artificial grass. Natural grass had a maximum 1/3 level lower than the clay sand pavement. Their UTCIs showed smaller differences than the PETs. Therefore, it is necessary to carefully choose materials from the planning stage when designing outdoor spaces, including playgrounds.

• Solar Energy
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• v.13 no.2_3
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• pp.79-90
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• 1993

A theoretical study is conducted for the design of solar air heaters using porous material. Radiative characteristics of glazing and porous absorbing media are found through spectral transmittances measured by the Visible spectrometer and the FT-IR. Using those characteristics the efficiencies of collectors are calculated one-dimensionally with the use of the Two-Flux radiation model. The efficiencies increase, as the air flow rates or albedos in the visible range increase, and as albedos in the IR range decrease. The optimum thickness of the porous medium of 15-mesh stainless steel wire screens is 0.001m, which represents the opacity of one.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.133-144
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• 2011

The objective of this study is to analyze the characteristic of radiation environment in the urban and rural through the field observation in the summer. The radiation balance was compared through the measurement of the shortwave radiation and long-wave radiation in the urban, sub-urban, and rural. The following conclusion could be obtained from this research. (1)In the results of observation including the rain-day, it was found that the short wave radiance in the urban is lower about 10% than the rural. (2)The upper part of atmosphere layers in the urban are aabsorb much short wave radiation energies compared with the rural relatively. It can increase the temperature of the upper part of atmosphere layers and the emittance of long wave radiation. (3)The ratio of the downward short wave radiation to the downward long wave radiation was 1.24 for the urban, 1.28 for sub-urban and 1.35 for rural. It can be estimated that the atmosphere condition of the rural is better than that of other areas. (4)The net radiation of the rural was lower that of the urban. It was found that the energy in and outflow of the rural is easier than that of the urban. (5)The temperature variation for the long-wave radiation change of the rural showed more sensitive than that of the urban. It was came from the radiation characteristics of the surrounding environment and can be used as the important index to evaluate the thermal environment characteristic of urban.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.89-96
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• 2005

This paper discusses the daytime atmospheric conditions and the possibility of daytime star detection with the purpose of practical use of the star sensor for daylight navigation. In order to estimate the daytime atmospheric data, we use the standard atmospheric model (LOWTRAN 7), from which atmospheric transmittance and radiance from background sky are calculated. Assuming the star sensor with an optical filter to reduce background radiation, different separation angles between the star sensor and the sun are set up to express the effect of the solar radiation. As considerations of field of view (FOV) of the star sensor, the variation of the sky background radiation and the star density of the detectable star are analyzed. In addition, the integration time to achieve a required signal-to-noise ratio and the number of the radiation-caused electrons of the charge coupled detector(CCD) working as the limit to daylight application of the star sensor are calculated.

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.71-81
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• 2012

This study for the understanding of the radiation environment according to the altitude in urban area in the summer observes the long and short wave radiation environment at the 4 urban areas with different height and the 1 suburban area. The results of this study are as follows. (1) When the altitude was high, the more short wave radiation was observed. (2) As the altitude was high, the temperature of atmosphere got lower. And because of that the downward long wave radiation was also lower. This general trend was confirmed through the study. (3) Through the observation of long wave radiation, the upper atmosphere of suburban area had the atmosphere characteristic which the temperature was rising and decreasing faster. Therefore, the difference radiation characteristics between the urban and suburban area were confirmed. (4) The result of the ratio of short wave radiation to long wave radiation(short wave radiation/long wave radiation) according to the altitude and location, the value was increased when the distance was far from the artificiality structure or a heat source, and the urban effect became smaller. Thus, it is expected that the ratio will be an evaluation index for evaluating urbanization effect.