• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.13-26
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• 2004

This paper examined the possibility of NET application for a relative weather stress index in Korea. The characteristic of NET distribution used temperature, relative humidity, wind speed which forecasting at Korean Meteorological Administration were analyzed. Regional critical values of daily maximum NET of stress index for summer resembled the distribution of daily maximum temperature because were not impacted wind and humidity but temperature. Regional critical values of daily minimum NET of stress index for winter distributed variously compared with summer. The highland region and the northern region of Seoul were impacted of low temperature and coastal region which strong wind. The occurrences of stressful days did not vary in summer, but obviously increased in winter after mid-1990s.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.84-90
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• 1986

An experiment was conducted to know the effects of planting dates (March 5, 15, and 25 and April 4) and transparent polyethylene (P.E.) film treatments(tunnel, tunnel slit, and mulch) on air and soil temperatures and growth and yield of a sweet corn variety, Great Bell. Maximum air and soil temperatures and minimum air and soil temperatures were greater at tunnel>tunnel slit>mulch in that order. Differences in maximum air and soil temperatures among the P.E. film treatments were much greater than those in minimum air and soil temperatures. However, when film was opened due to high air temperature over 40$^{\circ}C$ in the tunnel, air temperature was similar but soil temperature was lower com-pared to mulch. High temperature stress could be avoided in tunnel slit without opening film by increase in the number of slits. Cold damage of corn seedlings was avoided by tunnel and reduced by tunnel slit, and frost-damaged seedlings under the mulch were recovered in few days. The number of days from planting to silking was reduced as planting date delayed. At early plantings, tunnel enhanced early growth and silking, but it delayed at late plantings because tunnel was opened during the most of day time due to high temperature. Black streaked dwarf virus(BSDV) disease was more severe at early plantings and it was reduced in tunnel slit at late plantings because plants were grown under the film at the time of infection. The number of marketable ears was similar among all treatments except mulch at March 5 planting where BSDV was severely infected. Gross income was high in tunnel and tunnel slit at March 25 planting which had more larger marketbale ears and tunnel and tunnel slit at March 5 planting which had higher market price.

• 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.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.257-276
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• 2011

This study aimed to analyze the changes of extreme temperature indices in order to investigate impacts of urbanization on changes of extreme temperature. It was analyzed 16 indices related to extreme temperature indices to 60 weather stations in South Korea. Extreme temperature indices-related summer mostly increased, and its related to winter decreased. Percentile-based indices were clearly increased more than fixed-based indices as a tropical night. Decreasing trend of extreme temperature indices related to winter had more clear than increasing trend of extreme temperature indices related to summer. It was similar to trend that urban temperature was more clearly increased in winter than summer. Decreasing trend of indices-related daily minimum temperature had more clear than increasing trend of indices-related daily maximum temperature. Also, it was similar to increasing trend of minimum temperature had more clear than maximum temperature.

• 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.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.135-142
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• 2009

In order to predict frostfall, nocturnal cooling rate and air temperature changes were analyzed on days with and without frost when the maximum temperature was lower than $20^{\circ}C$. In general, the nocturnal cooling rates on frosty days were higher than those on non-frosty days. The cooling rates averaged from 19:00 to 24:00 on frosty and non-frosty days were $1.7^{\circ}Ch^{-1}$ and $0.7^{\circ}Ch^{-1}$ respectively. As expected, the nocturnal temperature on frosty days was lower than that on non-frosty days. Especially, the midnight air temperature averaged about $3.9{\pm}1.5^{\circ}C$ on frosty days, which was lower than that on non-frosty days (i.e., $10.1{\pm}2.9^{\circ}C$). The discriminant analysis using three independent variables (i.e., total cloud amount, air temperature at 24:00, and 5-day rainfall amount) successfully classified the presence of frost with 87% accuracy.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2002.11a
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• pp.77-80
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• 2002

기온은 생물의 대사과정에 직접적인 영향을 끼침으로서 생장과 발육을 결정하는 중요한 환경요인이며, 특히 식물은 개체 및 군락 수준에서 기온의 일 변화, 계절변화, 혹은 영년 변화에 반응한다. 최근의 농업 및 삼림 생태계 연구는 기온을 비롯한 환경요인의 영향을 생리과정의 정량적 모의를 근거로 이해하고, 이를 넓은 지역으로 확대하여 다양한 시간적 주기로 예측하는 방향으로 나아가고 있다 (Chung et al., 2002).(중략)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.444-450
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• 1995

It was very hard to gather the seeds of Eleutherococcus senticosus Max. known as a medicinal plant for they tend to drop under the high temperature condition during the summer period in Korea. Therefore, this study was conducted to select seed production site for Eleutherococcus senticosus in Korea, comparing the climate of Hokkaido of Japan, in which the seeds have been produced, with that of various place in this country. It was low that the average maximum temperature during the hottest summer two months (July and August) as a 24.4$^{\circ}C$ in Hokkaido and 21.2$^{\circ}C$ in Daegwanryeong compared with 27.4$^{\circ}C$ in Changsu. Especially in Daegwanryeong, average maximum temperature from June to September remained as low as 21$^{\circ}C$. Effective accumulated temperature(>5$^{\circ}C$) was 807$^{\circ}C$ in Hokkaido and 964$^{\circ}C$ in Daegwanryeong during the ripening period. Monthly sunshined hours from July to August were 121.7~128 hours in Daegwanryeong and 83.5~85.4 hours in Hokkaido. The Eleutherococcus senticosus sprouts at 8.5$^{\circ}C$, comes to flowering season in mid-August, and ripens during late-August and October in Hokkaido, the climate of which is similar to that of Daegwanryeong.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.96-104
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• 2001

Usage of ecosystem models has been extended to landscape scales for understanding the effects of environmental factors on natural and agro-ecosystems and for serving as their management decision tools. Accurate prediction of spatial variation in daily temperature is required for most ecosystem models to be applied to landscape scales. There are relatively few empirical evaluations of landscape-scale temperature prediction techniques in mountainous terrain such as Korean Peninsula. We derived a periodic function of seasonal lapse rate fluctuation from analysis of elevation effects on daily temperatures. Observed daily maximum and minimum temperature data at 63 standard stations in 1999 were regressed to the latitude, longitude, distance from the nearest coastline and altitude of the stations, and the optimum models with $r^2$ of 0.65 and above were selected. Partial regression coefficients for the altitude variable were plotted against day of year, and a numerical formula was determined for simulating the seasonal trend of daily lapse rate, i.e., partial regression coefficients. The formula in conjunction with an inverse distance weighted interpolation scheme was applied to predict daily temperatures at 267 sites, where observation data are available, on randomly selected dates for winter, spring and summer in 2000. The estimation errors were smaller and more consistent than the inverse distance weighting plus mean annual lapse rate scheme. We conclude that this method is simple and accurate enough to be used as an operational temperature interpolation scheme at landscape scale in Korea and should be applicable to elsewhere.