• Title/Summary/Keyword: 일조 시간

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Solar Radiation Estimation Using Cloud Cover and Hours of Bright Sunshine (운량과 일조시간에 의한 태양자원 예측)

  • Jo, Dok-Ki;Yun, Chang-Yeol;Kim, Kwang-Deuk;Kang, Young-Heack
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.126-129
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    • 2012
  • In this work a new correlation has been made to predict the solar radiation for 16 different areas over Korea by estimating the regression coefficients taking into account cloud hours of bright sunshine. Particularly, the multiple linear regression model proposed shows reliable results for estimating the global radiation on a horizontal surface with monthly average deviation of -0.26 to +0.53% and each station annual average deviation of -1.61 to +1.7% from measured values.

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An Investigation on the Effect of Duration of Sunshine on the Heating Energy of Apartment Houses (일조시간이 아파트 난방에너지 소비량에 미치는 영향에 관한 조사연구)

  • Lee Jong-Won;Hwang Hye-Young
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.3
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    • pp.277-284
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    • 2005
  • The purpose of this study is to analyze the effect of sunshine on the heating energy consumption of apartment houses by a field investigation in Haeundae, Busan. In the field, heating energy consumption of every household is researched by reading a calorimeter and the duration of sunshine of every household is calculated by Sunlight V1.0. Then, the duration of sunshine and heating energy are done regression analysis by SPSS 10. According to this study the apartment houses by orientation spend more energies order of east, west, southeast, southwest, and south. When apartment houses are same orientation, there is difference of $29{\sim}58\%$ in heating energy consumption by the duration of sunshine. And the heating energy consumption in worst condition of sunshine increases $67\%$ on the best condition of sunshine.

Performance of Angstrom-Prescott Coefficients under Different Time Scales in Estimating Daily Solar Radiation in South Korea (시간규모가 다른 Angstrom-Prescott 계수가 남한의 일별 일사량 추정에 미치는 영향)

  • Choi, Mi-Hee;Yun, Jin-I.;Chung, U-Ran;Moon, Kyung-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.4
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    • pp.232-237
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    • 2010
  • While global solar radiation is an essential input variable in crop models, the observation stations are relatively sparse compared with other meteorological elements. Instead of using measured solar radiation, the Angstrom-Prescott model estimates have been widely used. Monthly data for solar radiation and sunshine duration are a convenient basis for deriving Angstrom-Prescott coefficients (a, b), but it is uncertain whether daily solar radiation could be estimated with a sufficient accuracy by the monthly data - derived coefficients. We derived the Angstrom-Prescott coefficients from the 25 years observed global solar radiation and sunshine duration data at 18 locations across South Korea. In order to figure out any improvements in estimating daily solar radiation by replacing monthly data with daily data, the coefficients (a, b) for each month were derived separately from daily data and monthly data. Local coefficients for eight validation sites were extracted from the spatially interpolated maps of the coefficients and used to estimate daily solar radiation from September 2008 to August 2009 when, pyranometers were operated at the same sites for validation purpose. Comparison with the measured radiation showed a better performance of the daily data - derived coefficients in estimating daily global solar radiation than the monthly data - derived coefficients, showing 9.3% decrease in the root mean square error (RMSE).

Global Hourly Solar Irradiation Estimation using Cloud Cover and Sunshine Duration in South Korea (운량 및 일조시간을 이용한 우리나라의 시간당 전일사량의 평가)

  • Lee, Kwan-Ho
    • KIEAE Journal
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    • v.11 no.1
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    • pp.15-20
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    • 2011
  • Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design. For the six locations (Seoul, Incheon, Daejeon, Deagu, Gwangju and Busan) in South Korea where the global hourly solar irradiation (GHSI) is currently measured, GHSI was calculated using a comparatively simple cloud cover radiation model (CRM) and sunshine fraction radiation model (SFRM). The result was that the measured and calculated values of GHSI were similar for the six regions. Results of cloud cover and sunshine fraction models have been compared with the measured data using the coefficient of determination (R2), root-mean-square error (RMSE) and mean bias error (MBE). The strength of correlation R2 varied within similar ranges: 0.886-0.914 for CRM and 0.908-0.934 for SFRM. Average MBE for the CRM and SFRM were 6.67 and 14.02 W/m2, respectively, and average RMSE 104.36 and 92.15 W/m2. This showed that SFRM was slightly accurate and used many regions as compared to CRM for prediction of GHSI.

A Study on the Improvement of the Accuracy of Photovoltaic Facility Location Using the Geostatistical Analysis (공간통계기법을 이용한 태양광발전시설 입지 정확성 향상 방안)

  • Kim, Ho-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.2
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    • pp.146-156
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    • 2010
  • The objective of this study was to improve the accuracy of calculation and estimation of solar radiation and duration of sunshine, which are the most important variables of photovoltaic power generation in deciding the location of photovoltaic facilities efficiently. With increasing interest in new and renewable energies, research on solar energy is also being conducted actively, but there have not been many studies on the location of photovoltaic facilities. Thus, this study calculated solar duration and solar radiation based on geographical factors, which have the most significant effect on solar energy in GIS environment, and corrected the results of analysis using diffuse radiation. Moreover, we performed ordinary kriging, a spatial statistical analysis method, for estimating values for parts deviating from the spatial resolution of input data, and used variogram, which can determine the spatial interrelation and continuity of data, in order to estimate accurate values. In the course, we compared the values of variogram factors and estimates from applicable variogram models, and selected the model with the lowest error rate. This method is considered helpful to accurate decision making on the location of photovoltaic facilities.

Correlation between Paldang Reservoir Discharge and Causes of Algal Blooming (팔당호 방류량과 조류발생요인들의 상관성)

  • Yoo, Hosik;Lee, Byonghi;Rhee, Seung-Whee
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.3
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    • pp.93-98
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    • 2013
  • Main causes of algal bloom was studied in Paldang reservoir. Statistical approach was tried using meteorological and water quality data. Algae alert system showed that more than ten days were counted in a year, once it happened in Paldang reservoir. Alert dates increased in recent 5 years. Correlation coefficients between chlorophyll-a and other indexes did not showed strong relations resulting in coefficients less than 0.4. Among them, sunshine duration, BOD, and flow rate were appeared relatively main causes of algal blooming. Sunshine duration and BOD showed positive relation while flow rate did negative one, which is resonable for photosynthetic microorganisms. Water temperature and total phosphorus, which were presumed probable main causes before study, resulted in low correlation coefficients. Correlation coefficients between discharge flow and rainfall, water temperature showed positive relation due to seasonal effect.

Changing Trends of Climatic Variables of Agro-Climatic Zones of Rice in South Korea (벼 작물 농업기후지대의 연대별 기후요소 변화 특성)

  • Jung, Myung-Pyo;Shim, Kyo-Moon;Kim, Yongseok;Kim, Seok-Cheol;So, Kyu-Ho
    • Journal of Climate Change Research
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    • v.5 no.1
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    • pp.13-19
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    • 2014
  • In the past, Korea agro-climatic zone except Jeju-do was classified into nineteen based on rice culture by using air temperature, precipitation, and sunshine duration etc. during rice growing periods. It has been used for selecting safety zone of rice cultivation and countermeasures to meteorological disasters. In this study, the climatic variables such as air temperature, precipitation, and sunshine duration of twenty agro-climatic zones including Jeju-do were compared decennially (1970's, 1980's, 1990's, and 2000's). The meteorological data were obtained in Meteorological Information Portal Service System-Disaster Prevention, Korea Meteorological Administration. The temperature of 1970s, 1980s, 1990s, and 2000s were $12.0{\pm}0.14^{\circ}C$, $11.9{\pm}0.13^{\circ}C$, $12.2{\pm}0.14^{\circ}C$, and $12.6{\pm}0.13^{\circ}C$, respectively. The precipitation of 1970s, 1980s, 1990s, and 2000s were $1,270.3{\pm}20.05mm$, $1,343.0{\pm}26.01mm$, $1,350.6{\pm}27.13mm$, and $1,416.8{\pm}24.87mm$, respectively. And the sunshine duration of 1970s, 1980s, 1990s, and 2000s were $421.7{\pm}18.37hours$, $2,352.4{\pm}15.01hours$, $2,196.3{\pm}12.32hours$, and $2,146.8{\pm}15.37hours$, respectively. The temperature in Middle-Inland zone ($+1.2^{\circ}C$) and Eastern-Southern zone ($+1.1^{\circ}C$) remarkably increased. The temperature increased most in Taebak highly Cold zone ($+364mm$) and Taebak moderately Cold Zone ($+326mm$). The sunshine duration decreased most in Middle-Inland Zone (-995 hours). The temperature (F=2.708, df=3, p= 0.046) and precipitation (F=5.037, df=3, p=0.002) increased significantly among seasons while the sunshine duration decreased significantly(F=26.181, df=3, p<0.0001) among seasons. In further study, it will need to reclassify agro-climatic zone of rice and it will need to conduct studies on safe cropping season, growth and developing of rice, and cultivation management system etc. based on reclassified agro-climatic zone.

Cross Correlation Analysis of Gamma Exposure Rates and Rainfall, Hours of Saylight, Average Wind Speed in Gangneung Area (강릉 지역 공간 감마선량률과 강수량, 일조시간, 평균풍속 사이 교차 상관성 분석)

  • Cha, Hohwan;Kim, Jaehwa
    • Journal of the Korean Society of Radiology
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    • v.7 no.5
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    • pp.347-352
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    • 2013
  • In this study, we analyze the cross correlation between Gamma exposure rates and Rainfall, Hours of daylight, Average wind speed using cross-correlation coefficient ${\rho}_{DCCA}$ and DCCA cross-correlation coefficient(DCCA ${\rho}$) method. Our data are measured simultaneous in Gangneung regional. First, we find the ${\rho}_{DCCA}$ between Gamma exposure rates and Rainfall is Day(3~7days) 0.57~0.48, Month(30days) 0.39, Season(90days) 0.34, Year(360days) 0.26, between Gamma exposure rates and Hours of daylight is Day -0.20~-0.23, Month -0.22, Season -0.17, Year -0.13, between Gamma exposure rates and Average wind speed is Day -0.10~-0.12, Month -0.11, Season -0.05, Year -0.05. Second, our finding is cross- correlation between Gamma exposure rates and Rainfall, is no cross-correlation between Gamma exposure rates and Hours of daylight, Average wind speed.