• Title/Summary/Keyword: 일사량 예측

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A Comparative Evaluation of Multiple Meteorological Datasets for the Rice Yield Prediction at the County Level in South Korea (우리나라 시군단위 벼 수확량 예측을 위한 다종 기상자료의 비교평가)

  • Cho, Subin;Youn, Youjeong;Kim, Seoyeon;Jeong, Yemin;Kim, Gunah;Kang, Jonggu;Kim, Kwangjin;Cho, Jaeil;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.37 no.2
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    • pp.337-357
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    • 2021
  • Because the growth of paddy rice is affected by meteorological factors, the selection of appropriate meteorological variables is essential to build a rice yield prediction model. This paper examines the suitability of multiple meteorological datasets for the rice yield modeling in South Korea, 1996-2019, and a hindcast experiment for rice yield using a machine learning method by considering the nonlinear relationships between meteorological variables and the rice yield. In addition to the ASOS in-situ observations, we used CRU-JRA ver. 2.1 and ERA5 reanalysis. From the multiple meteorological datasets, we extracted the four common variables (air temperature, relative humidity, solar radiation, and precipitation) and analyzed the characteristics of each data and the associations with rice yields. CRU-JRA ver. 2.1 showed an overall agreement with the other datasets. While relative humidity had a rare relationship with rice yields, solar radiation showed a somewhat high correlation with rice yields. Using the air temperature, solar radiation, and precipitation of July, August, and September, we built a random forest model for the hindcast experiments of rice yields. The model with CRU-JRA ver. 2.1 showed the best performance with a correlation coefficient of 0.772. The solar radiation in the prediction model had the most significant importance among the variables, which is in accordance with the generic agricultural knowledge. This paper has an implication for selecting from multiple meteorological datasets for rice yield modeling.

A Study on Optimum Composition of Solar-Wind Hybrid Power System (태양광-풍력 복합발전 시스템의 최적구성에 관한 연구)

  • Kwon, Byeong-Gook;Lee, Seung-Chul;Park, Chan-Eom
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.1306-1308
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    • 2002
  • 본 논문에서는 태양광-풍력 복합발전시스템의 구성에 있어서 태양전지 어레이, 풍력발전기 및 축전지의 최적 용량 결정방법에 관하여 연구하였다. 본 연구에서는 서울지역의 일사량 및 풍속 데이터를 사용하여 일사량과 풍속의 확률밀도함수를 구하였고, 또한 태양전지와 풍력발전기의 파라미터를 사용하여 복합발전시스템의 평균출력을 예측하였다. 이 평균출력과 도시지역 주택 수용가의 전형적인 부하패턴을 고려하여 태양광-풍력 복합발전시스템을 구성할 경우 태양전지 어레이, 풍력발전기 및 축전지의 용량을 최적으로 결정하는 방법에 관하여 연구하였다.

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Solar Access and Shading Analysis of Traditional Building Using a Solar Trajectory Meter (태양 궤적 측정기를 이용한 전통 건축물 음영 분석)

  • Kim, Myoung Nam;Park, Ji Hee
    • Journal of Conservation Science
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    • v.37 no.2
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    • pp.90-100
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    • 2021
  • Outdoor cultural buildings and their accessories receive different amounts of solar radiation depending on their location's latitude, azimuth, and tilt. Shading is also affected by the surrounding terrain and objects, necessitating individual and quantitative shading analysis. In July 2019, this study conducted a shading analysis on the tops, midpoints, and bottoms of wooden pillars in the azimuth of Cheongpunggak, a traditional building in South Korea's National Research Institute of Cultural Heritage. The shading analysis found that the solar access/shade predicted by the solar trajectory meter was 30 minutes slower than measured in the field. The highest solar access and solar radiation levels came from the south, followed by the west, east, and north. The pillars' bases received the highest solar access and solar radiation, followed by their midpoints and tops. Solar access was high at tilt 90°, but solar radiation was high at tilt 0°, due to the light-collection efficiency and the irradiance. Shading on the pillars' tops was caused by the roof eaves, while shading on the midpoints and bases were affected by the surrounding pillars, topography, and other objects. Simultaneous solar access at the tops, midpoints, and bottoms was possible for 365 days for the northwest, west, and southwest pillars but only from October to March for the south and southeast pillars.

Effects of Photosynthetic rate of Hydroponically Grown Cucumber Plants as Affected by Light Intensity, Temperature, Carbon Dioxide and Leaf Nitrogen Content (일사량, 온도, 탄산가스 농도 및 엽중 질소농도가 양액재배 오이엽의 광합성율에 미치는 영향)

  • 임준택;김학진;정순주;이범선
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1999.11a
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    • pp.187-191
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    • 1999
  • 식물의 호흡에 영향하는 환경요인은 총 광합성율에 영향하는 모든 요인을 들 수 있으며 뿌리의 호흡에는 근권환경요인 및 질소 흡수량과 같은 영양요인도 들 수 있다. 환경요인의 변화에 따른 식물의 생장 및 수량을 예측하는 식물생장모형의 개발은 식물의 생장이 광합성과 호흡에 의해 좌우되므로 환경요화의 변이에 따른 생육모형개발이 우선적이라 할 수 있다. (중략)

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Study on the Prediction of short-term Algal Bloom in Juksan weir Using the Model Tree (모델트리를 활용한 죽산보 단기조류예측에 관한 연구)

  • Lee, Bo-Mi;Yi, Hye-Suk;Chong, Sun-A;Joo, Yong-Eun;Kim, Ho-Joon;Choi, Kwang-Soon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.450-450
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    • 2018
  • 최근 기후변화와 수온상승으로 인한 녹조발생이 빈번하게 나타나며, 녹조발생에 관한 관심은 꾸준히 증가하고 있는 추세이다. 본 연구는 효율적인 녹조관리를 위하여 모델트리를 활용하여 클로로필-a 단기조류예측 기법을 개발하였다. 대상지역으로 영산강수계의 죽산보를 선정하였으며, 2013년 1월부터 2016년 12월까지 나주 수질자동측정망의 일 단위자료와 동일기간 광주 기상청의 일별 기상자료를 이용하였다. 상관 분석을 통해 T-N, T-P, N/Pratio와 클로로필-a, 수온, 일사량, 강수량을 독립변수로, 단기(t+1일, t+3일, t+5일, t+7일) 클로로필-a를 종속변수로 선정하여 단기조류예측기법을 개발하였다. 수집한 자료의 데이터세트는 격일 간격으로 Training, Testing 기간으로 구분하여 적용한 결과, 상관계수는 1일 예측 시, Training 기간에 0.89, Testing 기간에 0.91, 3일 예측 시, Training 기간에 0.74, Testing 기간에 0.68, 5일 예측 시, Training 기간에 0.70, Testing 기간에 0.66, 7일 예측 시, Training 기간에 0.63, Testing 기간에 0.62로 나타났다. RMSE(Root Mean Square Error)는 1일 예측 시, Training 기간에 13.96, Testing 기간에 12.22, 3일 예측 시, Training 기간에 20.03, Testing 기간에 22.14, 5일 예측 시, Training 기간에 21.32, Testing 기간에 22.57, 7일 예측 시, Training 기간에 23.52, Testing 기간에 23.45로 나타났다. 예측주기에 따라 모델트리와 회귀식에서 활용한 독립변수는 1일 예측 시, 모델트리는 N/Pratio, 클로로필-a, 회귀식은 클로로필-a로 다르게 나타났다. 반면, 3일, 5일, 7일 예측 시, 모델트리와 회귀식에 활용된 변수는 같게 나타났다. 클로로필-a, 수온, 일사량은 5일 예측 시 활용된 변수로, 3일 예측 시에는 기상항목인 강수량이, 7일 예측 시에는 수질항목인 T-N, N/Pratio가 추가되었다. 특히 1일 예측 시 일 때, 높은 예측정도와 활용된 변수의 수가 적게 나타나는 것을 확인하였으며, 예측기간이 길어질수록 예측의 정확성이 낮아지고, 활용된 변수의 수가 많아지는 것을 확인하였다. 향후 적정한 예측기간을 판단하고 예측가능성을 높이기 위해서는 지속적인 자료취득 및 개선이 필요하며, 이를 바탕으로 적절한 단기조류예측이 가능할 것으로 판단된다.

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Comparison of Measured and Predicted Photovoltaic Electricity Generation and Input Options of Various Softwares (태양광 발전량 예측 도구별 입력 요소 분석 및 실제 발전량 비교에 관한 연구)

  • No, Sang-Tae
    • KIEAE Journal
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    • v.14 no.6
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    • pp.87-92
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    • 2014
  • The objectives of this study are to investigate input variables of photovoltaic generation programs and to compare their prediction to actual generation of photovoltaic system in the C city hall and the C city sewage treatment plant. We investigated the actual amount of generation, the forecast amount of generation, the amount of solar radiation data, and calculated the relative errors. We simulated the photovoltaic system of C city hall and the C city sewage treatment plant located in Chungju using existing programs, such as SAM, RETSCREEN, HOMER, PV SYST, Solar Pro. The result of this study are as follows : Through examining the relative errors of monthly predicted and actual generation data, monthly generation data showed big errors in winter season?. Except winter season, actual amount of generation and the predicted amount of generation showed no large errors.

Analysis of Light Environments in Reclaimed Land and Estimation of Spatial Light Distributions in Greenhouse by 3-D Model (간척지 광환경 특성 분석 및 3-D 모델을 통한 온실 내 공간적 광분포 예측)

  • Lee, June Woo;Shin, Jong Hwa;Kim, Jee Hoon;Park, Hyun Woo;Yu, In Ho;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.23 no.4
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    • pp.303-308
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    • 2014
  • Reclaimed lands, expected as high-tech export horticultural complex, have unusual light environments due to sea fog. For adequate greenhouse design at reclaimed land, spatial light distributions in greenhouse should be required considering diffusive and direct lights. The objectives of this study were to analyze light environments and estimate spatial light distributions in greenhouse at reclaimed land by 3D greenhouse models. Total and diffusive lights were compared between reclaimed land and inland. For verification of the 3D greenhouse models, spatial light distributions and measured light intensities in greenhouse were compared with the estimated ones. Light environments at reclaimed land showed a higher diffusive irradiation than at inland, especially near sunrise and sunset. The estimated spatial light distributions in greenhouse showed good agreements with the measured ones. By using this method, we could estimate the average light intensity with time and spatial light distributions in greenhouse at specific outside light conditions. This result will be useful for analysis of light environments but also estimation of crop light inception in greenhouse at reclaimed land.

A Correlation Study Between Fruit Wholesale Price And Weather Factor (과일 도매가격과 날씨 요인에 대한 상관관계 연구)

  • Chang, Jeong-Hyun;Kim, Ji-Won;Kwak, Da-eun;Aziz, Nasridinov
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.11a
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    • pp.706-708
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    • 2017
  • 노지에서 재배되는 실외작물의 경우 외부 환경에 노출되어 재배되기에 생육 또는 수학시기가 외부 요인에 많은 영향을 받는다. 이러한 외부 요인 중 과일의 당도 및 수확량에 많은 영향을 미치는 요인은 바로 날씨이다. 고온의 날씨 또는 저온의 날씨가 지속되거나 강한 풍속, 적절한 강수가 이루어지지 않을 경우 과일의 당도가 낮아지거나, 흠집이 발생할 수 있어 과일 도매가격에 영향을 미치게 된다. 본 논문에서는 월별 평균 온도, 강우량, 습도, 일사량, 최대풍속 등의 날씨 관련 데이터와 제사 또는 명절에 자주 사용되는 과실류인 배, 단감, 사과, 수박의 도매가격간의 상관관계를 분석을 통해 얻은 결과로 추후 농산물 가격 예측 또는 과일 가격 예측 연구에 기여를 하고자 한다.

A LSTM Based Method for Photovoltaic Power Prediction in Peak Times Without Future Meteorological Information (미래 기상정보를 사용하지 않는 LSTM 기반의 피크시간 태양광 발전량 예측 기법)

  • Lee, Donghun;Kim, Kwanho
    • The Journal of Society for e-Business Studies
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    • v.24 no.4
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    • pp.119-133
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    • 2019
  • Recently, the importance prediction of photovoltaic power (PV) is considered as an essential function for scheduling adjustments, deciding on storage size, and overall planning for stable operation of PV facility systems. In particular, since most of PV power is generated in peak time, PV power prediction in a peak time is required for the PV system operators that enable to maximize revenue and sustainable electricity quantity. Moreover, Prediction of the PV power output in peak time without meteorological information such as solar radiation, cloudiness, the temperature is considered a challenging problem because it has limitations that the PV power was predicted by using predicted uncertain meteorological information in a wide range of areas in previous studies. Therefore, this paper proposes the LSTM (Long-Short Term Memory) based the PV power prediction model only using the meteorological, seasonal, and the before the obtained PV power before peak time. In this paper, the experiment results based on the proposed model using the real-world data shows the superior performance, which showed a positive impact on improving the PV power in a peak time forecast performance targeted in this study.

A Study on the Estimating Solar Radiation by Empirical Regression Models (경험적인 회귀모델에 의한 일사예측에 관한 연구)

  • Jo, Dok-Ki;Kim, Eun-Ill;Lee, Tae-Kyu;Chun, Il-Soo;Jeon, Hong-Seok;Auh, Chung-Moo
    • Solar Energy
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    • v.14 no.2
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    • pp.17-28
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    • 1994
  • It is necessary to estimate enpirical constants in order to predict the monthly mean daily global radiation on a horizontal surface in the developing areas for alternative energy. Therefore many different equations have propoed to evaluate them for certain areas. In this work a new corrlation has been made to predict the solar radiation for any areas over Korea by cululating the regression models taking into account latitude, percentage of possible sunshine, and cloud cover. From the results, the single linear equation proposed by using percentage of possible sunshine method shows reliable results for estimating the global rdiation with average annual deviation of -4 to +2% from measured values.

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