• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.206-206
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• 2023

지구온난화로 인한 기후변화에 따라 평균강수량과 증발량이 증가하며 강우지역 집중화와 강우강도가 높아질 가능성이 크다. 우리나라의 경우 협소한 국토면적과 높은 인구밀도로 기후변동의 영향이 크기 때문에 한반도에 적합한 유역규모의 수자원 예측과 대응방안을 마련해야 한다. 이를 위한 수자원 관리를 위해서는 유역에서 강수량, 유출량, 증발량 등의 장기적인 자료가 필요하며 경험식, 물리적 강우-유출 모형 등이 사용되었고, 최근들어 연구의 확장성과 비 선형성 등을 고려하기 위해 딥러닝등 인공지능 기술들이 접목되고 있다. 본 연구에서는 ASOS(동해, 태백)와 AWS(삼척, 신기, 도계) 5곳의 관측소에서 2011년~2020년까지의 일 단위 기상관측자료를 수집하고 WAMIS에서 같은 기간의 오십천 하구 일 유출량 자료를 수집 후 5개 관측소를 기준으로Thiessen 면적비를 적용해 기상자료를 구축했으며 Angstrom & Hargreaves 공식으로 잠재증발산량 산정해 3개의 모델에 각각 기상자료(일 강수량, 최고기온, 최대 순간 풍속, 최저기온, 평균풍속, 평균기온), 일 강수량과 잠재증발산량, 일 강수량 - 잠재증발산량을 학습 후 관측 유출량과 비교결과 기상자료(일 강수량, 최고기온, 최대 순간 풍속, 최저기온, 평균풍속, 평균기온)로 학습한 모델성능이 가장 높아 최적 모델로 선정했으며 일, 월, 연 관측유출량 시계열과 비교했다. 또한 같은 학습자료를 사용해 다층 퍼셉트론(Multi Layer Perceptron, MLP) 앙상블 모델을 구축하여 수자원 분야에서의 인공지능 활용성을 평가했다.

• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1445-1458
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• 2016

This paper derives a correlation coefficient using detrended cross-correlation analysis (DCCA) method for 59 regional temperature series for 40 years from 1976 to 2015. The average temperature, maximum temperature, and minimum temperature series for 4 year units are analyzed; consequently, we estimated that a temperature correlation exists between the two regions during the unit period where the correlation coefficient is greater than or equal to 0.9; subsequently, we construct a network linking the two regions. Based on network theory, average path length, clustering coefficient, assortativity, and modularity were derived. As a result, it was found that the temperature network satisfies a small-worldness property and is a network having assortativity and modularity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.201-217
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• 2022

The United States is one of the largest producers of major crops such as wheat, maize, and soybeans, and is a major exporter of these crops. Therefore, it is important to estimate the crop production of the country in advance based on reliable long- term weather forecast information for stable crops supply and demand in Korea. The purpose of this study is to improve the seasonal predictability of the agro-climatic indices over the United States by using regional-scale daily temperature. For long-term numerical weather prediction, a dynamical downscaling is performed using Weather Research and Forecasting (WRF) model, a regional climate model. As the initial and lateral boundary conditions of WRF, the global hourly prediction data obtained from the Pusan National University Coupled General Circulation Model (PNU CGCM) are used. The integration of WRF is performed for 22 years (2000-2021) for period from June to December of each year. The empirical quantile mapping, one of the bias correction methods, is applied to the timeseries of downscaled daily mean, minimum, and maximum temperature to correct the model biases. The uncorrected and corrected datasets are referred WRF_UC and WRF_C, respectively in this study. The daily minimum (maximum) temperature obtained from WRF_UC presents warm (cold) biases over most of the United States, which can be attributed to the underestimated the low (high) temperature range. The results show that WRF_C simulates closer to the observed temperature than WRF_UC, which lead to improve the long- term predictability of the temperature- based agro-climatic indices.

• Journal of the Korean Wood Science and Technology
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• v.38 no.1
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• pp.66-74
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• 2010

This study was carried out to investigate the optimum condition for sap exudation of Acer mono Max. tree in a site of Mt. Baekun, Kwangyang city, Korea. Amount of sap exudation, air temperature, relative air humidity and tree diameter at breast height (DBH) were monitored for the period of January 5 through March 28, 2008, and correlation analysis of several factors affecting on sap exudation was carried out. As the diameter of Acer mono at breast height increased, the amount of sap was linearly proportional. Sap exudation initiated at February 18, and occurred intensively in the period of February 28 through March 10, resulting in 84% of total sap amount by volume. During sap exudation, the minimum temperature was averaged at $-2.4{\pm}1.5^{\circ}C$ and the maximum at $6.0{\pm}1.8^{\circ}C$, while there was no sap exudation whenever temperature was below or above $0^{\circ}C$ all the day long. The maximum temperature, range of temperature and the maximum, minimum and mean humidities in air were significant factors affecting on amount of sap. The maximum air temperature had the highest correlation coefficient with 0.768 (P < 0.01) and was also considered as the principal factor by partial-correlation analysis. These results showed that sap exudation required daily air-temperature fluctuation from below to above $0^{\circ}C$, and the amount of sap was strongly dependent on the highest daily-temperature and DBH of tree.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.42-49
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• 2008

GDD models of corn were developed in bare soil, while sweet and super sweet corns are grown under black polyethylene (P. E.) film mulch in Korea. To develop a suitable GDD model under black P. E. film mulch, a super sweet com hybrid "Cambella-90" was planted from 1 April to 30 June in 2003 at the 10-day intervals under black P. E. film mulch and in bare soil. In bare soil the best GDD model was $GDD\;=\;{\sum}[H"+L')/2\;-\;10^{\circ}C]$, where H" was daily maximum temperature but is was substituted for $30^{\circ}C$ - (daily maximum temperature - $30^{\circ}C$) when higher than $30^{\circ}C$ and L' was daily minimum temperature, but it was substituted for $10^{\circ}C$ when lower than $10^{\circ}C$. The same GDD model could be adapted for com grown under black P. E. film mulch, but base temperature was substituted for $9^{\circ}C$. To determine planting date for the scheduled harvests, accumulated GDDs were calculated using 30-year average temperature data during the growing season. Under black P. E. film mulch planting dates were determined by subtracting GDD of the hybrid, $970^{\circ}C$, from accumulated GDD of scheduled harvest dates.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.390-390
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• 2021

본 연구에서는 통계적 방법에 의해 예측된 미래기간의 기온정보와 기온기반의 기준증발산량 산정방법을 연계하여 한강권역을 대상으로 최대 12개월의 미래기간에 대한 기준증발산량을 전망하였다. 기온정보는 Kim et al. (2020)의 연구와 같이 글로벌 기후지수와의 원격상관성을 기반으로 개발된 다중회귀모형을 이용하여 미래기간(예측시점 기준 1~12개월)에 대해 월 평균기온을 예측하고 이를 상세화하여 한강권역 내 주요 ASOS 지점별로 최고/최저기온을 도출하였다. 기준증발산량은 Hamon 방법(Hamon, 1960, 1963)을 기반으로 각 지점별로 상세화된 최고/최저기온을 이용하여 동일한 미래기간(1~12개월)에 대해 산정하였다. 한강권역 전체에 대해 2015년 1월~2020년 12월의 월별 평균기온과 각 지점별 산정한 기준증발산량을 활용하여 기온 및 기준증발산량에 대한 예측성을 분석하였다. 한강권역 전체에 대해 예측된 월별 평균기온의 경우 실제 관측값과 비교하였을 때, PBIAS 4.2~6.4%, R² 0.97~0.98, NSE 0.97~0.98 등으로 매우 높은 예측성을 보였다. 지점별로 상세화된 기온정보를 이용하여 산정한 기준증발산량을 실제 기온으로부터 산정한 기준증발산량과 비교한 결과는 PBIAS 5.0~6.8%, R² 0.97~0.98, NSE 0.96~0.97로 기온에 대한 예측성과 유사하게 나타났다. 기온과 기준증발산량 모두 일부 월이나 일부 지점에서 관측값과 비교했을 때 다소 차이를 보이는 경우도 있었으나, 대상유역 전반적으로는 매우 안정적인 예측결과를 확인할 수 있었다. 기준증발산량에 대한 예측결과(미래 1~12개월)는 계절 및 월 단위의 유역 수자원 전망에 유용하게 활용될 수 있을 것으로 판단된다.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.181-186
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• 2001

In this study, we observed air temperature to make clear that land coverage condition and forest form has a certain relationship to air temperature in a day in various green space. And with revolution analysis, interpreted relationship of air temperature distribution in the green space, of land coverage rate and air temperature, of volume of tree and temperature. With this experimental result, propose green plan, taking into consideration lower effect of air temperature. In this result lower zone is formed in forest and water area, higher zone is done in paved surface and barren ground. And arbor＋subarbor area, water area sur-rounded forest and small river is formed relative lower air temperature. In my opinion to promote efficiency lower air temperature area, it is need to make water area surrounded forest, to make forest form lower air temperature 2∼3 layer forest. Lower air temperature effect is in order of arbor, subarbor, shrub and is proportioned increasing of tree.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.107-114
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• 2000

We constructed climagraphs for 16 regions of Korea by using the average monthly minimum air temperature, maximum air temperature and global radiation. We characterized the outside climate requirements corresponding to the climate requirements of crops in greenhouses. The climagraphs allow to decide the appropriate climate periods for greenhouse cultivation without heating and cooling equipment. These graphs may be used for analyzing climatic characteristic of a given area, selecting the suitable region and greenhouse and making a rational plan for greenhouse cropping in Korea. We found difficulty in deciding the beginning and end of greenhouse heating and cooling period due to insufficient references.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.45-51
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• 2003

The purpose of this study was to find out how different types of land use around green belts affect temperature decrease effects. For this, temperatures within and outside of green belts were measured. Based on the collected data, the study analyzed the land cover status and temperatures within green belts, temperature decrease effects and the range of effects around green belts, and the correlation between trees and temperature decrease effects by way of regression analysis. As a result, areas of the high temperature within green belts were formed on paved surfaces, whereas areas of low temperature were formed around forests or water surfaces. In addition, deviation was bigger in the highest temperature than the lowest one for areas of Leeward around green belts, but in general, there was a tendency that temperature became low near to green belts. As for the relation between land cover rate and temperature, what was effective to temperature decrease included forests, pasture and water surfaces. On the other hand, the effects of temperature decrease varied depending on increase or decrease of land cover rates. As for the influence of the different land use types around green belts on temperature decrease effects, the Shakuzi Park showed relatively stronger effects than the Ageomaruyama Park.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.283-294
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• 2011

The variation of temperature in the steel girder bridge by air temperature is measured. A correlation between the daily temperature range, the maximum and minimum temperatures of the day, and the temperature of the bridge are analyzed. With the statistical data from the Korea Meteorological Administration, the temperature correlations analyzed in this study is able to predict temperature variations between the upper flange and the lower flange which calculates the realistic displacement values of a movable support and an expansion joint in design.