• 농업과학연구
• /
• 제41권2호
• /
• pp.149-155
• /
• 2014

The surface solar radiation is an important indicators for climate and agricultural research over the Earth system. For the climate and agricultural research, long-term meteorological data and accurate measured data are needed. The daily solar radiation from Jan. 2001 to Dec. 2010 have been employed in this study analyze atmospheric transmissivity for Chupungryeong. The corresponding daily value of atmospheric transmissivity is calculated for Chupungryeong meteorological data. In this paper, relationship analysis of daily solar radiation and atmospheric transmissivity is presented. It shows that atmospheric transmissivity over late December peaked in the 2000s, substantially decreased from the early-January, and changed little after that in summer. Reduction of solar radiation caused a reduction of more than 0.3 in atmospheric transmissivity during July to August. It was concluded that the atmospheric transmissivity could be very useful for evaluating solar radiation. Atmospheric transmissivity approach is suitable for daily-term simulation studies and useful for computing solar radiation.

• KIEAE Journal
• /
• 제7권6호
• /
• pp.23-28
• /
• 2007

Limited fossil fuels and unstable energy supply are considered as one of the critical problems in architecture requiring large amounts of energy. In order to this challenge, environment-friendly architecture design is required. Clear data should be prepared to apply solar energy to architecture aggressively and properly. This study used FS statistical analysis data regarding average daily solar radiation of Seoul observed over 20 years to find out standard year and standard daily solar radiation. This study also aims to compare and evaluate an appropriate method of selecting a standard year which is too close to measurement value through comparison and analysis with daily solar radiation acquired by applying overseas researchers' suggesting weight factor. As a result, the data nearest to measurement value of daily solar radiation was UK CIBSE TRY(TYPE 2) displaying 0.100in t-statistic index. For UK CIBSE TRY(TYPE 2), weight factor was applied to three climatic elements except relative humidity. TYPE 1 and TYPE 3 recorded 0.343 and 0.367, respectively, showing higher record of t-statistic than TYPE 2. TYPE 1 was calculated through FS statistical value of single data about daily solar radiation with other climatic elements excluded. For TYPE 3, relative humidity was added to TYPE 2. In particular, since TYPE 2 was closer to the measurement value compared to the others, it is necessary to consider relationship with other climate elements if other climate elements are added.

• 한국관개배수논문집
• /
• 제19권1호
• /
• pp.87-96
• /
• 2012

Information of local solar radiation is essential for many field, including water resources management, crop yield estimation, crop growth model, solar energy systems and irrigation and drainage design. Unfortunately, solar radiation measurements are not easily available due to the cost and maintenance and calibration requirements of the measuring equipment and station. Therefore, it is important to elaborate methods to estimate the solar radiation based on readily available meteorological data. In this study, two empirical equations are employed to estimate daily solar radiation using Cheongju Regional Meteorological Office data. Two scenarios are considered: (a) sunshine duration data are available for a given location, or (b) only daily cloudiness index records exist. Simple linear regression with daily sunshine duration and cloudiness index as the dependent variable accounted for 91% and 80%, respectively of the variation of solar radiation(H) at 2011. Daily global solar radiation is highly correlated with sunshine duration. In order to indicate the performance of the models, the statistical test methods of the mean bias error(MBE), root mean square error(RMSE) and correlation coefficient(r) are used. Sunshine duration and cloudiness index can be easily and reliably measured and data are widely available.

• Journal of Biosystems Engineering
• /
• 제25권2호
• /
• pp.123-130
• /
• 2000

A forcasting scheme for daily solar irradiance on agricultural field sis proposed by application of chaos theory to a long term observation data. It was conducted by reconstruction of phase space, attractor analysis, and Lyapunov analysis. Using the methodology , it was determined whether evolution of the five climatic data such as daily air temperature , water temperature , relative humidity, solar radiation, and wind speed are chaotic or not. The climatic data were collected for three years by an automated weather station at Hwasung-gun, Kyonggi-province. The results showed that the evolution of solar radiation was chaotic , and could be predicted. The prediction of the evolution of the solar radiation data was executed by using ' local optimal linear reconstruction ' algorithm . The RMS value of the predicting for the solar radiation evolution was 4.32 MJ/$m^2$ day. Therefore, it was feasible to predict the daily solar radiation based on the chaos theory.

• 한국농림기상학회지
• /
• 제12권4호
• /
• pp.232-237
• /
• 2010

작물모형의 필수 입력자료인 일간 누적일사량은 다른 기상요소들에 비해 관측밀도가 낮아 대안으로서 일조 시간을 기반으로 한 Angstrom-Prescott 모형 추정값이 널리 사용되고 있다. 추정의 간편성 때문에 월 단위 일사량 및 일조시간 자료가 모형의 계수(Angstrom-Prescott coefficients, 이하 A-P 계수) 도출에 사용되고 있지만 작물생육모형에서 요구하는 일간 일사량을 추정하는 데는 한계가 있다. A-P 계수 도출에 월 단위 자료 대신 일 단위 자료를 사용함으로써 기대되는 개선효과를 판정하기 위해 일사량과 일조시간을 동시에 관측하는 국내 18개 기상대의 25년 간(1983~2007) 일 단위 및 월 단위 자료로부터 A-P 계수를 각각 도출하였다. 이 계수들의 공간분포로부터 일사 미관측 기상대 8곳의 A-P 계수를 추출하고 지점별 일 단위 및 월 단위 계수를 실측 일조시간자료에 적용하여 2008년 9월부터 2009년 8월까지 일사량을 일별로 추정하였다. 같은 기간 중 이들 일사 미관측기상대에 검증용 일사계를 설치하여 얻은 실측 일사량자료와 비교한 결과 일 단위자료 기반의 추정오차가 월 단위자료 기반 오차에 비해 평균 9.3% 적었다.

• 한국수자원학회논문집
• /
• 제37권6호
• /
• pp.479-485
• /
• 2004

이 연구에서는 일교차를 이용하여 일평균 증발산량을 산정한다. 이를 위하여 Thornton과 Running(1999)의 일평균 태양 복사열 산정을 위한 경험식을 이용하여 태양복사열을 계산하여 이를 현장 자료와 비교한 결과 비교적 정확한 범위 내에 있다는 것을 확인하였다. 이렇게 산정된 일평균 태양 복사열을 증발산량의 계산을 위해 Priestly Taylor 공식과 Penman 공식에 적용함으로써 현장에서의 정확성과 사용가능성을 확인해 보고자 하였다. 그 결과로 태양 복사열에 중점을 둔 Priest-Taylor 공식은 과다추정하는 경향을 보이나, Penman 공식은 비교적 정확한 증발산량의 산정을 보여 줌으로써 기상 관측 자료가 풍부하지 않은 지역에서의 사용가능성을 보여주었다. 또 계산된 증발산량을 일단위 온도만을 이용하여 증발산량을 산정하는 Hargreaves 공식과 비교하여 각 공식의 장단점을 공학적 측면에서 알아보고자 하였다.

• KIEAE Journal
• /
• 제12권6호
• /
• pp.93-98
• /
• 2012

The concerns on high ozone concentration phenomenon is significantly growing in Seoul metropolitan area including the industry complex area, like Shiwha Banwol area. The aims of this research is the analysis of relationship between high concentrations of $O_3$ and solar radiation parameters in atmosphere. The understanding of the effects of solar radiation intensity, humidity, high air temperature on ozone concentration in a day is very useful to provide a direction for reducing of the high ozone concentration to a local government or a metropolitan government. The correlation analysis between maximum ozone concentration and various meteorological parameters in 2009 - 2011 carried out using IBM's SPSS program. The results showed that the mean correlations coefficient (R) between daily Ozone maximum and solar radiation resulted R = 0.64 during 2011. May - September in 10 air pollution stations. In case of correlations between daily ozone maximum and relative humidity showed negative correlation R = -0.61. The correlation analysis with mean air temperature during 1-3 PM resulted R = 0.29. This low correlation coefficient could be corrected by using of categorized data of ozone concentration. The daily maximum ozone concentration is more dependent on peak solar radiation and high air temperature during 1-3 PM than its simple daily maximum values. The results of this research would be used to develop the high ozone alert system around Seoul metropolitan area. This correlation analysis could be partially integrated to prediction of ozone peak concentration in connection with other methods like classification and regression tree(CART).

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2015년도 학술발표회
• /
• pp.479-482
• /
• 2015

The objective of this study is to develop adaptive neuro-fuzzy inference system (ANFIS) model for estimating daily solar radiation using limited weather variables at Champaign and Springfield stations in Illinois. The best input combinations (one, two, and three inputs) can be identified using ANFIS model. From the performance evaluation and scatter diagrams of ANFIS model, ANFIS 3 (three input) model produces the best results for both stations. Results obtained indicate that ANFIS model can successfully be used for the estimation of daily global solar radiation at Champaign and Springfield stations in Illinois. These results testify the generation capability of ANFIS model and its ability to produce accurate estimates in Illinois.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2015년도 학술발표회
• /
• pp.483-486
• /
• 2015

The objective of this study is to develop generalized regression neural networks (GRNN) model for estimating daily solar radiation using limited weather variables at Champaign and Springfield stations in Illinois. The best input combinations (one, two, and three inputs) can be identified using GRNN model. From the performance evaluation and scatter diagrams of GRNN model, GRNN 3 (three input) model produces the best results for both stations. Results obtained indicate that GRNN model can successfully be used for the estimation of daily global solar radiation at Champaign and Springfield stations in Illinois. These results testify the generation capability of GRNN model and its ability to produce accurate estimates in Illinois.

• 한국태양에너지학회 논문집
• /
• 제29권3호
• /
• pp.12-18
• /
• 2009

The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since January, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The theoretical analysis of solar radiation as a component has compared with the experimental data obtained by the KIER station. The Result of simulation analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,457cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.