• 경영과학
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• 제26권1호
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• pp.77-91
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• 2009

It is the most important sucess factor for the electricity generation industry to minimize operations cost of surplus electricity generation through accurate demand forecasts. Temperature forecast is a significant input variable, because power demand is mainly linked to the air temperature. This study estimates the information value of the temperature forecast by analyzing the relationship between electricity load and daily air temperature in Korea. Firstly, several characteristics was analyzed by using a population-weighted temperature index, which was transformed from the daily data of the maximum, minimum and mean temperature for the year of 2005 to 2007. A neural network-based load forecaster was derived on the basis of the temperature index. The neural network then was used to evaluate the performance of load forecasts for various types of temperature forecasts (i.e., persistence forecast and perfect forecast) as well as the actual forecast provided by KMA(Korea Meteorological Administration). Finally, the result of the sensitivity analysis indicates that a $0.1^{\circ}C$ improvement in forecast accuracy is worth about $11 million per year.

• 한국조경학회지
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• 제23권3호
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• pp.106-112
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• 1995

This study was conducted to investigate the environmental factors of habitat of Lindera erythrocarpa and to test seedling growth of the plant transplanted in a field of Sung Kyun Kwan Univ. in Suwon, Kyungkido. The results were as follows ; 1. The wild lindera erythrocarpa was growing in Mt. Kwan whose January average temperature was -3.4$^{\circ}C$, and minimum average temperature was -14.8$^{\circ}C$ in January. It was also growing in Mt. Suri whose daily minimum temperature is 3.4$^{\circ}C$ lower than that of Seoul. Therefore, there was no problem for Lindera erythrocarpa to grow in Seoul regions in terms of winter coldness. 2. The growth of seedlings of Lindera erythrocarpa transplanted in a field of Sung Kyun Kwan Univ. in Suwon, Kyunkido in 1990 showed that average height of the tree was 1.64m, average diameter of root was 2.44cm, and that average width of crown was 1m. Therefore, there was no problem for Lindera erythrocarpa to grow under winter coldness in Suwon area.

• 한국농림기상학회지
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• 제6권4호
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• pp.272-289
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• 2004

The spatial resolution of local weather and climate information for agronomic practices exceeds the current weather service scale. To supplement the insufficient spatial resolution of official forecasts and observations, gridded climate data are frequently generated. Most ecological models can be run using gridded climate data to produce ecosystem responses at landscape scales. In this lecture, state of the art techniques derived from geospatial climatology, which can generate gridded climate data by spatially interpolating point observations at synoptic weather stations, will be introduced. Removal of the urban effects embedded in the interpolated surfaces of daily minimum temperature, incorporation of local geographic potential for cold air accumulation into the minimum temperature interpolation scheme, and solar irradiance correction for daytime hourly temperature estimation are presented. Some experiences obtained from their application to real landscapes will be described.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.432-434
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• 2001

This paper proposes a special-day load forecasting method with the characteristics of temperature based on fuzzy linear regression. We can obtain a linear regression model from the relation between daily peak load and daily maximum or minimum temperature. Simulation results show that the proposed method can improve an accuracy of a special-day load forecasting.

• 상하수도학회지
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• 제10권2호
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• pp.88-103
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• 1996

The objective of this study is to develop stochastic and deterministic models which could be used to synthesize water application time series. Adaptive models using mulitivariate ARIMA(Transfer Function Model) are developed for daily urban water use forecasting. The model considers several variables on which water demands is dependent. The dynamic response of water demands to several factors(e.g. weekday, average temperature, minimum temperature, maximum temperature, humidity, cloudiness, rainfall) are characterized in the model by transfer functions. Daily water use data of Kumi city in 1992 are employed for model parameter estimation. Meteorological data of Seonsan station are utilized to input variables because Kumi has no records about the meteorological factor data.To determine the main factors influencing water use, autocorrelogram and cross correlogram analysis are performed. Through the identification, parameter estimation, and diagnostic checking of tentative model, final transfer function models by each month are established. The simulation output by transfer function models are compared to a historical data and shows the good agreement.

• 인간식물환경학회지
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• 제24권5호
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• pp.519-527
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• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• 한국강구조학회 논문집
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• 제23권3호
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• pp.283-294
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• 2011

강재 거더교의 다이아프램과 상 하부 플랜지에 부착된 온도게이지의 값을 측정하여, 온도 분포와 시간적 변화를 검토하고, 도로교 설계기준과 비교하였다. 또한 측정 자료를 기초로 하여 일일 기온, 일 최고기온, 일 최저기온에 대한 교량 부재온도와의 상관관계를 각각 분석하여 회귀분석식과 신뢰도를 나타내는 상관계수를 산정하였다. 구조해석에서는 대상교량을 3차원 전체모델링을 수행하고, 실제의 온도 측정 자료를 기반으로 한 온도 하중을 부과하여 계산된 온도 응력값과 시방 규정상의 온도하중에 의한 단면력을 서로 비교 분석한다. 본 연구에서 구해진 대기 온도분포와 강교량 부재 온도 상관관계로부터 상하 플랜지의 온도차를 예측할 수 있고 이 결과를 이용하면 설계 시 신뢰성 있는 부재의 온도하중을 산정할 수 있어, 추후 강합성교량의 온도 영향 평가에 있어서 기초적 자료가 될 것이라 기대한다.

• 한국농림기상학회지
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• 제17권1호
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• pp.69-74
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• 2015

제주지역에서 재배되고 있는 감귤류의 일종인 온주밀감을 대상으로 지형, 기후 등 현재의 재배환경을 공간기술을 이용하여 정량화하여 환경특성 범위를 분석하고, 앞으로 기후변화에 대비하여 온주밀감의 재배가 가능한 지역을 판단할 수 있는 환경 기준을 도출하고자 하였다. 해발고도, 경사도, 경사향, 연평균기온, 1월 평균기온, 일최저기온의 극 값, $-5^{\circ}C$ 이하 일수, 강수량 등 8종의 기후요소에 대하여 지리정보시스템(GIS) 기술을 이용하여 분포지도의 형태로 제작하였고, 이 분포도에서 감귤원이 분포하는 지역에 포함되는 격자 값을 추출하여 환경요소의 분포를 분석할 수 있었다. 온주밀감의 재배 가능 여부를 판단할 수 있도록 $14.5^{\circ}C$ 이상의 연평균기온, $-10.0^{\circ}C$ 이상의 일 최저기온의 극 값, 연중 $-5^{\circ}C$ 이하 저온일수가 5일 이상일 것 등 3 가지 기후학적 환경요소에 대한 기준을 설정하였다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2000년도 춘계임시총회 및 학술발표대회
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• pp.26-33
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• 2000

This study was conducted to investigate the relationships between yearly variations of elimatic elements and yearly variations of productivity in potato. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 9 years from 1987 to 1995. The meteorological data what gathered at the Goheung Weather Station for the same period of crop growing season were used to find out the relationships between climatic elements and crop productivity. Yearly variation of the daily minimum temperature in March and April were large with coefficients of variation (C.V.) of 126.0%, 368%, respectively, but the variation of the daily mean and maximum temperature in May and June were relative small. Stem length and number of stem show more C.V. of 9.3%, 14.3%, respectively, but the variation of the yield was relative small with 3.7%. Correlation coefficients between the amount of precipitation in April and yield, yield and daily mean temperature in June were negatively significant at the level of 5, 1 %, respectively. Correlation coefficients between the growth habits and yield are positively significant at the level of 5, 1 %, respectively. Simple linear regression equations by the least square method are estimated for stem length (Yl) and the precipitation in April(X) as Y,=82.47-0.11x (R2=0.3959), and for yield(Y2) and the precipitation in April(X) as Y,=2003.61-0.94X (R2=0.5418).

• 한국농림기상학회지
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• 제7권3호
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• pp.185-191
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• 2005

An accurate prediction of dormancy release and bud burst in temperate zone fruit trees is indispensable for farmers to plan heating time under partially controlled environments as well as to reduce the risk of frost damage in open fields. A thermal time-based two-step phenological model that originated in Italy was applied to two important grapevine cultivars in Korea for predicting bud-burst dates. The model consists of two sequential periods: a rest period described by chilling requirement and a forcing period described by heating requirement. It requires daily maximum and minimum temperature as an input and calculates daily chill units (chill days in negative sign) until a pre-determined chilling requirement for rest release is met. After the projected rest release date, it adds daily heat units (anti-chill days in positive sign) to the chilling requirement. The date when the sum reaches zero isregarded as the bud-burst in the model. Controlled environment experiments using field sampled twigs of 'Campbell Early' and 'Kyoho' cultivars were carried out in the vineyard at the National Horticultural Research Institute (NHRI) in Suwon during 2004-2005 to derive the model parameters: threshold temperature for chilling and chilling requirement for breaking dormancy. The model adjusted with the selected parameters was applied to the 1994-2004 daily temperature data obtained from the automated weather station in the NHRI vineyard to estimate bud burst dates of two cultivars and the results were compared with the observed data. The model showed a consistently good performance in predicting the bud burst of 'Campbell Early' and 'Kyoho' cultivars with 2.6 and 2.5 days of root mean squared error, respectively.