• Current Optics and Photonics
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• 제1권4호
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• pp.263-270
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• 2017

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field of atmospheric optics, the measurement of solar energy must be precise, and the equipment needs to be maintained frequently. However, there seem to be many errors with the existing type of pyranometer, which is an element of the solar-energy observation apparatus. In particular, the error caused by the thermal dome effect occurs because of the thermal offset generated from a temperature difference between outer dome and inner casing. To resolve the thermal dome effect, intensive observation was conducted using the method and instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation were analyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weather case, the temperature difference between the pyranometer's case and dome was highest, and the thermal dome effect was $0.88MJ\;m^{-2}\;day^{-1}$. Meanwhile, the thermal dome effect in the cloudy case was $0.69MJ\;m^{-2}\;day^{-1}$, because the reduced global solar radiation thus reduced the temperature difference between case and dome. In addition, the rainy case had the smallest temperature difference of $0.21MJ\;m^{-2}\;day^{-1}$. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiation gives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

• 한국대기환경학회지
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• 제33권5호
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• pp.435-444
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• 2017

In this study, we investigated the effect of aerosol feedback on $PM_{10}$ simulation using a two-way coupled air quality model (WRF-CMAQ). $PM_{10}$ concentration over Korea in January 2014 was simulated, and the aerosol feedback effect on the simulated solar radiation was intensively examined. Two $PM_{10}$ simulations were conducted using the WRF-CMAQ model with (FB) and without(NFB) the aerosol feedback option. We find that the simulated solar radiation in the west part of Korea decreased by up to $-80MJ/m^2$ due to the aerosol feedback effect. The feedback effect was significant in the west part of Korea, showing high $PM_{10}$ estimates due to dense emissions and its long-range transport from China. The aerosol feedback effect contributed to the decreased rRMSE(relative Root Mean Square Error) for solar radiation (47.58% to 30.75%). Aerosol feedback effect on the simulated solar radiation was mainly affected by concentration of $PM_{10}$. Moreover, FB better matched the observed solar radiation and $PM_{10}$ concentration than NFB, implying that taking into account the aerosol direct effects resulted in the improved modeling performance. These results indicate that aerosol feedback effects can play an important role in the simulation of solar radiation over Korean Peninsula.

• 태양에너지
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• 제9권3호
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• pp.13-24
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• 1989

Direct and diffuse components of solar radiation were measured inside and outside a single-span plastic greenhouse. To analyze the direct solar radiation inside the plastic greenhouse, the cross-section of the greenhouse was assumed to be circular. Then the direct solar radiation transmitted into the greenhouse was calculated theoretically, and compared with the experimental measurements. The results are summarized as follows: (1) The transmissivities of total solar radiation were about 65% on cloudy days and 50% on clear days. For cloudy days, the transmissivity of the total solar radiation was regarded as the transmissivity of sky diffuse radiation. (2) The ratio of the inside effective scattered component of direct solar radiation to the diffuse radiation was 60-65%. (3) It appeared that the seasonal variation of the transmissivity of total solar radiation was adversely affected by the transmissivity of direct solar radiation and the effective scattered coefficient. But the effect of the transmissivity of direct solar radiation was dominant factor. (4) Computer simulation showed that the inside direct solar radiation was decreased as the floor of the plastic greenhouse was higher. (5) The predicted value of the inside direct solar radiation was 3.3% to 29.0% higher than the measured value.

• Journal of Biosystems Engineering
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• 제23권5호
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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.

• 대기
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• 제29권5호
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• pp.537-550
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• 2019

To analyze the observation environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we analyzed the skyline, Sky View Factor (SVF), and solar radiation due to the surrounding topography and artificial structures using a Digital Elevation Model (DEM), 3D camera, and solar radiation model. Solar energy shielding of 25 km around the station was analyzed using 10 m resolution DEM data and the skyline elevation and SVF were analyzed by the surrounding environment using the image captured by the 3D camera. The solar radiation model was used to assess the contribution of the environment to solar radiation. Because the skyline elevation retrieved from the DEM is different from the actual environment, it is compared with the results obtained from the 3D camera. From the skyline and SVF calculations, it was observed that some stations were shielded by the surrounding environment at sunrise and sunset. The topographic effect of 3D camera is therefore more than 20 times higher than that of DEM throughout the year for monthly accumulated solar radiation. Due to relatively low solar radiation in winter, the solar radiation shielding is large in winter. Also, for the annual accumulated solar radiation, the difference of the global solar radiation calculated using the 3D camera was 176.70 MJ (solar radiation with 7 days; suppose daily accumulated solar radiation 26 MJ) on an average and a maximum of 439.90 MJ (solar radiation with 17.5 days).

• Journal of Astronomy and Space Sciences
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• 제27권1호
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• pp.43-54
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• 2010

This study was performed by the policy research project of Ministry of Land, Transport and Maritime Affairs, which title is "Developing safety standards and management of space radiation on the polar route". In this research, total six experiments were performed using Korean commercial flights (B747). Three of those are on the polar route and the other three are on the north pacific route. Space radiation exposure measured on the polar route is the average 84.7 uSv. The simulation result using CARI-6M program gives 84.9 uSv, which is very similar to measured value. For the departure flight using the north pacific route, the measured space radiation is the average 74.4 uSv. It seems that is not so different to use the polar route or not for the return flight because the higher latitude effect causing the increase of space radiation is compensated by the shortened flight time effect causing decreasing space radiation exposure.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.210-210
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• 2009

This paper describes the analysis results of an generated power with a inclined solar radiation. 2 different types of modules were employed to study the effect of the a inclined solar radiation on the generated power amount. As a result, it was confirmed that the generated power increased with the solar radiation and the mono crystal type cells generated higher power than the thin film type cells.

• 한국지구과학회지
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• 제40권2호
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• pp.119-134
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• 2019

기상청 일사관측소 관측환경 분석을 위하여 수치표고모델(DEM)과 태양복사모델을 이용하여 주변지형에 의한 차폐와 하늘시계요소(SVF) 및 일사량을 산출하였다. 지형고도자료(10 m 해상도)를 통해 관측소를 중심으로 주변 25 km내의 지형들을 이용하여 스카이라인과 SVF를 계산하였다. 또한, 일사관측소별 산출된 천기도와 스카이라인을 중첩하여 지형에 의한 차폐를 분석하였다. 특히 인천 관측소는 주변지형의 차폐가 적었고 청송군과 추풍령 관측소는 주변 지형에 의한 차폐가 큰 관측소로 나타났다. 태양복사모델을 이용하여 동일 조건에서 지형 특성에 따른 일사량을 산출하여 지형에 의한 기여도를 분석하였다. 연누적 일사량 계산결과, 청송군 관측소의 경우 수평면 일사량과 비교하였을 때 직달일사량은 12.0% 이상 차폐되었고 산란일사량은 5.6% 그리고 전천일사량은 4.7% 감소하였다. 평균 일누적 일사량을 기준으로 편차를 분석하였을 때 0.3% 이상 전천일사량이 감소되는 지점은 6개 관측소였다. 42개 관측소 중 8소는 관측소의 이전 또는 관측장비의 이동설치가 시급한 것으로 분석되었고 1/2 이상(24소)의 관측소는 일사관측환경에 대한 검토가 필요한 것으로 분석되었다. DEM자료는 관측소 주변의 인공구조물과 식생 등이 포함되지 않기 때문에 더 상세한 관측환경분석이 요구된다.

• Structural Engineering and Mechanics
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• 제43권6호
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• pp.725-737
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• 2012

The temperature on steel structures is larger than the ambient air temperature under solar radiation and the temperature distribution on the affected structure is non-uniform and complicated. The steel tube, as a main structural member, has been investigated through experiment and numerical analysis. In this study, the temperature distribution on a properly designed steel tube under solar radiation is measured. A finite element transient thermal analysis method is presented and verified by the experimental results and a series of parametric studies are carried out to investigate the influence of various geometric properties and orientation on the temperature distribution. Furthermore, a simplified approach is proposed to predict the temperature distribution of steel tube. Based on both the experimental and the numerical results, it is concluded that the solar radiation has a significant effect on the temperature distribution of steel tubes. Under the solar radiation, the temperature of steel tubes is about $20.6^{\circ}C$ higher than the ambient air temperature. The temperature distribution of steel tubes is sensitive to the steel solar radiation absorption, steel tube diameter and orientation, but insensitive to the solar radiation reflectance and thickness of steel tube.

• 한국주거학회논문집
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• 제15권3호
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• pp.93-99
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• 2004

This study was conducted to estimate the solar energy, as an alternative energy evaluating an effect of solar radiation on indoor space of residential building. The basic data of solar radiation which is useful for architectural design was suggested using theoretical and experimental analysis. Accordingly, this study was carried out measuring the solar energy using Explicit Method. These results were compared with the results using steady state heat transfer method. The results of this study are summarized as follows; Based on the results using Explicit Method and steady state heat transfer on the indoor space of building, it was shown that an analysis on heat transfer using Explicit Method is more sensitive to the outdoor environmental changes. The results using Explicit Method to analysis and evaluate the solar radiation should be used for residential building design.