• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.274-284
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• 2014

Crops and varieties are mostly affected by temperature, the amount of precipitation, and duration of sunshine. This study aims to identify the weather factors that directly influence to apple yield among the series of daily measured weather variables during growing seasons. In order to identify them, 1) a priori natural scientific knowledge with respect to the growth stage of apples and 2) pure statistical approaches to minimize bias due to the subject selection of variables are considered. Each result estimated by the Panel regression using fixed/random effect models is evaluated through suitability (i.e., Akaike information criterion and Bayesian information criterion) and predictability (i.e., mean absolute error, root mean square error, mean absolute percentage). The Panel data of apple yield and weather factors are collected from fifteen major producing areas of apples from 2006 to 2013 in Korea for the case study. The result shows that variable selection using factor analysis, which is one of the statistical approaches applied in the analysis, increases predictability and suitability most. It may imply that all the weather factors are important to predict apple yield if statistical problems, such as multicollinearity and lower degree of freedom due to too many explanatory variables used in the regression, can be controlled effectively. This may be because whole growth stages, such as germination, florescence, fruit setting, fatting, ripening, coloring, and harvesting, are affected by weather.

• Journal of Korea Water Resources Association
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• v.50 no.5
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• pp.303-313
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• 2017

In environmental impact assessments for large urban development projects, the Korean government requires analysis of stormwater runoff before, during and after the projects. Though hydrological models are widely used to analyze and prepare for surface runoff during storm events, accuracy of the predicted results have been in question due to limited amount of field data for model calibrations. Intensive field measurements have been made for storm events between July 2015 and July 2016 at a sub-basin of the Gwanpyung-cheon, Daejeon, Republic of Korea using an automatic monitoring system and also additional manual measurements. Continuous precipitation and surface runoff data used for utilization of SWMM model to predict surface runoff during storm events with improved accuracy. The optimal values for Manning's roughness coefficient and values for depression storage were estimated for pervious and impervious surfaces using three representative infiltration methods; the Curve Number Methods, the Horton's Method and the Green-Ampt Methods. The results of the research is expected to be used more efficiently for urban development projects in Korea.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.22-34
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• 2017

The K-DRUM(K-water hydrologic & hydraulic Distributed RUnoff Model), a distributed rainfall-runoff model of K-water, calculates predicted runoff and water surface level of a dam using precipitation data. In order to obtain long-term hydrometeorological information, K-DRUM requires long-term weather forecast. In this study, we built a system providing long-term hydrometeorological information using predicted rainfall ensemble of GloSea5(Global Seasonal Forecast System version 5), which is the seasonal meteorological forecasting system of KMA introduced in 2014. This system produces K-DRUM input data by automatic pre-processing and bias-correcting GloSea5 data, then derives long-term inflow predictions via K-DRUM. Web-based UI was developed for users to monitor the hydrometeorological information such as rainfall, runoff, and water surface level of dams. Through this UI, users can also test various dam management scenarios by adjusting discharge amount for decision-making.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.1-19
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• 2004

Metallic deposits in Korea have a variety of genetic types such as hydrothermal veins, skarns, hydrothermal replacement and alaskite deposits and so on. Geological, mineralogical and geochemical features including host rock, wall-rock alteration, ore and gangue mineralogy, mineral texture and secondary mineralogy related to weathering process control the environmental signatures of mining areas. The environmental signatures of metallic deposits closed from early 1970s to late 1990s in Korea show complicate geochemistry and mineralogy due to step weathering of primary and secondary minerals such as oxidation-precipitation-remobilization. The potentiality of low pH and high heavy metal Concentration s from acid mine drainage is great in base-metal deposits associated with polymetallic mineralization, breccia-pipe type and Cretaceous hydrothermal Au veins with the amount of pyrite whereas skam, hydrothermal replacement, hydrothermal Cu and Au-Ag vein deposits are in low contamination possibility. The geoenvironmental models reflecting the various geologic features closely relate to disuibution of sulfides and carbonates and their ratios and finally effect on characteristics of environmental signatures such as heavy metal species and their concentrations in acid mine drainage.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.515-522
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• 1998

Plant root rotting fungi, Fusarium solani are suppressed their growth by the chitinase which is produced from the antagonistic soil bacteria. The chitinase producable antagonistic bacterium Pseudomonas sp. 3098 was selected as a powerful biocontrol agent of F. solani from ginseng rhizosphere. The antagonistic Pseudomonas sp. 3098 was able to produce a large amount of extracellular chitinase which is key enzyme in the decomposition of fusarial hypal walls. The chitinase was purified from cultural filtrate of Pseudomonas sp. 3098 by the procedure of ammonium sulfate precipitation, anion exchange chromatography, gel filtration on Bio-Gel P-100, and 1st and 2nd hydroxyapatite chromatography. The molecular mass of the purified enzyme was ca. 45 kDa on SDS-FAGE. The optimal pH and temperature for the activity of purified chitinase were 5.0 and 45$^{\circ}C$, respectively. The enzyme was stable in pH range of 5.0 to 9.0 up to 5$0^{\circ}C$ The enzyme was significantly inhibited by metal compounds such as FeCl$_2$, AgNO$_3$ and HgCl$_2$, and was slightly inhibited by p-CMB, iodoacetic acid, urea, 2,4-DNP and EDTA. The enzyme had ability of digestion on colloidal chitin and chitin from shrimp shell, but could not digest chitosan and chitin from crab shell. Km value of the enzyme was 0.11% on colloidal chitin, and the maximum hydrolysis rate of the enzyme was 34% on colloidal chitin.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.284-288
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• 1992

This study was undertaken to investigate the effect of pH and phytate level on the solubility of the protein due to binding between phytate and low-phytate rapeseed protein isolate by means of SDS-polyacrylamide gel electrophoresis. Results showed that the number of protein bands decreased by the increasing amount of phytate added to the soluble extract at pH 2.0 and 5.0 whereas there was no change at pH 11.5. Among 18 bands of rapeseed proteins at pH 2.0, seven bands (105.8, 52.3, 37.3, 34.8, 26.3, 21.3, 18.4 KDa) were removed by precipitation with 100 mg phytate addition and six bands (78.8, 46.5, 19.4, 16.8, 11.7, 8.5 KDa) further disappeared by 150 mg phytate addition. Among 15 bands at pH 5.0, only four bands disappeared by phytate addition. It is suggested that the functionality of rapeseed protein isolate can be improved by lowering the phytate content.

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.251-254
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• 1977

Pectin, hesperidin and naringin were extracted from hot air-dried peel ($60^{\circ}C$, 1 hr and air velocity 160 fpm) of citrus produced in Korea in order to see the amount of each component contained in the peel. Pectin was extracted by three different methods and the quality and contents of the pectins were determined respectively. 1. The pectin yield by the total pectic substance method was the highest (26.0% for unshiu (U) and 28.5% for natsudaidai (N) expectedly and the soluble pectic substance method the least (13.5%(U) and 15.6% (N)) The yield by method III (extraction by water at pH 1.5 followed by isopropanol precipitation) was intermediate (18.1% (U) and 20.8%(N)). Anhydrouronic acid (AUA) content was the highest (92.0% (U) and 90.3%(N)) in those by method III. The AUA contents of the other pectins were 80.0% for soluble pectin (for both U and N), 71.6% for the commercial pectin (Sunkist Groups Inc., U.S.A.), 58.0%(N) and 63.4%(U) for total pectic substance. 2. The methoxyl content of total pectic substance was the lowest (4.81%(U) and 4.88%(N)). However, there was no significant difference in methoxyl content among the rest which were found to have low levels(5.27-7.20%). 3. The pectin by method III gave the highest jelly strength. The commercial pectin, soluble pectice substance and total pectic substance were next in order. 4. The hesperidin content of unshiu was 5.07% (dry basis) and the naringin content of natsudaidai 3.03% (dry basis).

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.57-63
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• 1971

1) Among five lactic acid bacteria examined, Str. thermophilus and Str. diacetilactis produced remarkably greater amount of acids in soybean milk than Str. lactis, Str. cremoris and L. bulgaricus. 2) Soybean milk and skimmed dry milk were combined in the ratio of 7 : 3 and were carried out in lactic acid fermentation for 24 hours at optimum temperature. The result indicated that the yield of precipitation and protein content of it were the most, the moisture content was the least and curd structure formed was considered too hard. 3) Based on these and other results, following procedure was used for manufacturing: soybean milk and skimmed dry milk were combined in the ratio of 7 : 3, heated at $121^{\circ}C$ for 20 min., cooled, added Str. thermophilus as lactic acid starter and incubated for 24 hours and $37{\pm}1^{\circ}C$. The curd was cooked, hooped, and pressed for 24 hours, to the surface of which, Penicillium caseicolum and sodium chloride were spread. During ripening of the curd at $15^{\circ}C$ and $85{\sim}90%$ RH for 21 days, Pen. caseicolum was highly developed after 7 days, pH was increased and proteolytie activity has reached to the peak point after 14 days. After 7 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino acids nitrogen were begun to increase. After 21 days of ripening total water soluble nitrogen, water soluble protein nitrogen and amino-N reached to 52%, 32% and 14% of total nitogen. In the soybean cheese, after 21 days of ripening, 17 or more kinds of amino acids were detected by two-dimentional paper chromatography. The product contained 63.2% of moisture, 17.5% of crude protein, 13.2% of crude fat, 2.8% of crude ash and 2.5% of sodium chloride.

• Research in Plant Disease
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• v.10 no.4
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.567-579
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• 2011

Scirpus planiculmis is one of the most dominant species found in the Nakdong River estuary. In order to understand the recent changes in S. planiculmis and the environmental characteristics of the estuary, from 2005 to 2010, an analysis of the density, total dry biomass, tuber biomass, and distribution pattern of S. planiculmis as well as an analysis of the temperature, salinity, precipitation, barrage discharge, and soil texture of the estuary were conducted. In 2006, the density ranged from 10.1 to $87.6no./m^2$, but in 2009, it ranged from 0.4 to $2.2no./m^2$ in 2009 and drastic reductions were observed throughout the sampled areas in the Nakdong river estuary. In 2010, S. planiculmis was observed on the tidal flats of Myungji and Mangummerydeung, at a density of $18.3{\pm}7.7no./m^2$ and $17.5{\pm}20.7no./m^2$, respectively. Hence, S. planiculmis is considered to be in a recovery phase. The aboveground/belowground ratio reduced from $4.54{\pm}0.70$ in 2005 to $1.91{\pm}0.35$ in 2009, clearly showing a large decrease in the biomass amount of the aboveground than of the belowground. Tubers were distributed in the soil, with only 36.0% at the 0~15 cm depth but 64.0% at the 15~30 cm depth. Apparently, tubers were more likely to be found at 15~30 cm below the soil in the Nakdong River estuary. A drastic reduction in the S. planiculmis biomass in 2009 is possibly due to the high salinity in S. planiculmis habitats.