• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.731-745
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• 2021

In this study, the monthly temperature of the Han River basin was predicted by statistical multiple regression models that use global climate indices and weather data of the target region as predictors. The optimal predictors were selected through teleconnection analysis between the monthly temperature and the preceding patterns of each climate index, and forecast models capable of predicting up to 12 months in advance were constructed by combining the selected predictors and cross-validating the past period. Fore each target month, 1000 optimized models were derived and forecast ranges were presented. As a result of analyzing the predictability of monthly temperature from January 1992 to December 2020, PBIAS was -1.4 to -0.7%, RSR was 0.15 to 0.16, NSE was 0.98, and r was 0.99, indicating a high goodness-of-fit. The probability of each monthly observation being included in the forecast range was about 64.4% on average, and by month, the predictability was relatively high in September, December, February, and January, and low in April, August, and March. The predicted range and median were in good agreement with the observations, except for some periods when temperature was dramatically lower or higher than in normal years. The quantitative temperature forecast information derived from this study will be useful not only for forecasting changes in temperature in the future period (1 to 12 months in advance), but also in predicting changes in the hydro-ecological environment, including evapotranspiration highly correlated with temperature.

• Food Science and Preservation
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• v.30 no.5
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• pp.857-867
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• 2023

In this study, the extraction yield, acidic polysaccharides and ginsenosides of red and black ginseng were optimized by using the response surface methodology in consideration of the ethanol concentration and temperature of the extraction. The R² of the model formula for the yield, acidic polysaccharides and ginsenosides was 0.8378-0.9679 (p<0.1). An optimal extraction yield of 5.29% was reached for red ginseng soluble solids when 1.52% ethanol concentration was used at a temperature of 67.27℃. Additionally, the optimal extraction yield for black ginseng soluble solid was 6.11% when 3.12% ethanol concentration was used at a temperature of 66.13℃. Furthermore, the optimal conditions for extracting acidic polysaccharides from red ginseng were using an ethanol concentration of 4.03% at a temperature of 69.61℃; a yield of 1.86 mg/mL was obtained. The optimal extraction yield for acidic polysaccharides from black ginseng was 1.80 mg/mL when extracted using a concentration of 24.67% of ethanol at a temperature of 71.14℃. An optimal extraction yield of 0.22 mg/mL was reached for ginsenoside Rg₁ from red ginseng when 79.92% ethanol concentration was used at a temperature of 70.62℃. The optimal extraction yield of ginsenoside Rg₃ from black ginseng was 0.31 mg/mL when ethanol was used at a concentration of 75.70% at a temperature of 65.49℃. The ideal extraction conditions for obtaining the maximum yield of both acidic polysaccharide and ginsenoside from red and black ginseng were using ethanol at a concentration between 35 and 50% at an extraction temperature of 70℃.