• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.886-891
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• 2010

Importance of climate change and its impact on agriculture and environment have increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which caus an increase of temperature in Earth. Greenhouse gas emissions such as carbon dioxide ($CO_2$), methane ($CH_4$) and nitrous oxide ($N_2O$) in the Upland field need to be assessed. GHGs fluxes using chamber systems in two upland fields having different soil textures during pepper cultivation (2005) were monitored under different soil textures at the experimental plots of National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA) located in Suwon city, Korea. $CO_2$ emissions were 12.9 tonne $CO_2\;ha^{-1}$ in clay loam soil and 7.6 tonne $CO_2\;ha^{-1}$ in sandy loam soil. $N_2O$ emissions were 35.7 kg $N_2O\;ha^{-1}$ in clay loam soil and 9.2 kg $N_2O\;ha^{-1}$ in sandy loam soil. $CH_4$ emissions were 0.054 kg $CH_4\;ha^{-1}$ in clay loam soil and 0.013 kg $CH_4\;ha^{-1}$ in sandy loam soil. Total emission of GHGs ($CO_2$, $N_2O$, and $CH_4$) during pepper cultivation was converted by Global Warming Potential (GWP). GWP in clay loam soil was higher with 24.0 tonne $CO_2$-eq. $ha^{-1}$ than that in sandy loam soil (10.5 tonne $CO_2$-eq. $ha^{-1}$), which implied more GHGs were emitted in clay loam soil.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.447-453
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• 2007

With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.

• Journal of Mushroom
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• v.19 no.3
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• pp.166-175
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• 2021

In this study, monokaryons of "Heukari" (Pleurotus ostreatus) and "Hosan" (Pleurotus pulmonarius) were separated to remove the cell wall, and a cross-species protoplast fusion was developed through chemical treatment with polyethylene glycol. The protoplast-fused PF160306 and PF160313 strains have a culture period of 10 and 2 days shorter than that of the "Heuktari" and "Hosan" cultivars, respectively. Furthermore, the growth of the strains was faster than that of the existing cultivars. The yield was 135.9 g per bottle, which was approximately 8% higher than that of the commercially available "Hosan" cultivar; however, it was not statistically significant. A growth survey was conducted after treatment at five temperatures (15, 18, 21, 23, and 25℃). The growth of the strains accelerated with the increase in temperature. However, at 21℃, the yellow color of pileus was the brightest. Band pattern, assessed using URP Primer 7, was similar to that of the "Hosan" cultivar. The DPPH radical scavenging capacity and polyphenol content were 62.5% and 43.5 mg/mL, respectively, for "Sunjung" and 65.7% and 49.9 mg/mL, respectively, for PF160313. Furthermore, the antihypertensive activities of the "Sunjung" cultivar and PF160313 were similarly high at 74% and 75%, respectively. In conclusion, cross-species hybridization via the protoplast fusion technique can be used for obtaining primary data for mushroom breeding to develop new varieties. In addition, the protoplast fusion technique might aid in expanding the market for yellow mushrooms.

• Clean Technology
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• v.27 no.4
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• pp.359-366
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• 2021

Halloysite nanotubes (HNTs), the multiwalled clay mineral with the composition of Al₂Si₂O₅(OH)₄·nH₂O, have been highlighted as a low-cost adsorbent for the removal of dyes from wastewater. Although a powder of halloysite presents a high specific surface area, forming media are significantly considered due to sludge-clogging induced by the water-bound agglomeration. However, higher firing temperature to achieve the structural durability of the media and lower utilization rate due to longer penetration depth into the media act as hurdles to increase the dye-adsorption capacity. In this work, the retention of the adsorption capacity of halloysite was evaluated with methylene blue solution after the heat treatment at 750 ℃. In order to improve the utilization rate, tubular media were fabricated by extrusion. The images taken by transmission electron microscopy show that HNTs present excellent structural stability under heat treatment. The HNTs also provide superb capacity retention for MB adsorption (93%, 18.5 mg g^-1), while the diatomite and Magnesol^® XL show 22% (7.65 mg g^-1) and 6% (11.7 mg g^-1), respectively. Additionally, compositing with lignin enhances adsorption capacity, and the heat treatment under the hydrogen atmosphere accelerates the adsorption in the early stage. Compared to the rod-type, the tubular halloysite media rapidly increases methylene blue adsorption capacity.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.31-40
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• 2019

In Korea, 51,013 thousand tons of livestock manure was generated in 2018. A total of 46,530 thousand tons, which is 91.2% of the total amount of livestock manure generated, was treated by composting(40,647 thousand tons) or liquid fertilization(5,884 thousand tons) method. At present, the policy of livestock manure treatment in Korea is to make livestock manure into organic fertilizer(compost, liquid fertilizer) and then to applicate it on agricultural land. And this policy is very effective in terms of livestock manure treatment and nutrient recycling. However, considering the steadily declining farmland area for decades, the use of livestock manure compost could be limited in the future. There is also concern that local nutrient overloading, nutrient management regulation, and restrictions on the number of livestock may become serious problem for livestock manure treatment. In addition, there are some opinions that nutrient derived from livestock manure may flow into tributaries of major dams. In recent years, there has been a suspicion that fine dust may be generated from livestock manure compost. In recent years, the use of livestock manure fertilizer has been rapidly increasing, there is a growing demand of the development of new technologies for livestock manure treatment. Especially, cow excretes a larger amount of manure than other livestock, so that the efficiency of development of new technology for cow manure treatment will be high. Therefore, in this study, the combustion characteristics of cow manure pellet were investigated in order to analyzed whether cow manure could be used as source of solid fuel. During the combustion test, the weight loss of the cow manure pellet began to increase when the temperature of the combustion chamber reached $300^{\circ}C$. The ratio of $H_2$, $CH_4$, CO in the pyrolysis gas produced in the pyrolysis process of cow manure pellet were 6.65~11.62%, 0.58~1.54 and 11.47~14.07%, respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.64-80
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• 2018

In Korea, citizens can only know general information about crime. Thus it is difficult to know how much they are exposed to crime. If the police can predict the crime risky area, it will be possible to cope with the crime efficiently even though insufficient police and enforcement resources. However, there is no prediction system in Korea and the related researches are very much poor. From these backgrounds, the final goal of this study is to develop an automated crime prediction system. However, for the first step, we build a big data set which consists of local real crime information and urban physical or non-physical data. Then, we developed a crime prediction model through machine learning method. Finally, we assumed several possible scenarios and calculated the probability of crime and visualized the results in a map so as to increase the people's understanding. Among the factors affecting the crime occurrence revealed in previous and case studies, data was processed in the form of a big data for machine learning: real crime information, weather information (temperature, rainfall, wind speed, humidity, sunshine, insolation, snowfall, cloud cover) and local information (average building coverage, average floor area ratio, average building height, number of buildings, average appraised land value, average area of residential building, average number of ground floor). Among the supervised machine learning algorithms, the decision tree model, the random forest model, and the SVM model, which are known to be powerful and accurate in various fields were utilized to construct crime prevention model. As a result, decision tree model with the lowest RMSE was selected as an optimal prediction model. Based on this model, several scenarios were set for theft and violence cases which are the most frequent in the case city J, and the probability of crime was estimated by $250{\times}250m$ grid. As a result, we could find that the high crime risky area is occurring in three patterns in case city J. The probability of crime was divided into three classes and visualized in map by $250{\times}250m$ grid. Finally, we could develop a crime prediction model using machine learning algorithm and visualized the crime risky areas in a map which can recalculate the model and visualize the result simultaneously as time and urban conditions change.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.438-446
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• 2018

The purpose of this study was to investigate food safety awareness, knowledge, and behavior in college students, to provide basic data for the increase in food safety awareness. Data were collected from 252 college students in Gyeonggi region, using a self-administered questionnaire. In results of concern about food safety, subjects responded 3.48 of 5.00 and have knowledge about food safety education revealing significantly higher awareness and concern than subjects without knowledge about food safety education. Food safety awareness of distributed food was 2.55, considered unsafe. Among reasons in perceiving food as unsafe, 62.3% of subjects expressed distrust about safety relative food production. As for risk factors relative to food safety, subjects responded that the highest risk factor was food additives (2.35), followed by heavy metal (2.38) and endocrine disrupters (2.38). Correlation analysis resulting in risk factors for food had positive correlation with each other, heavy metal revealed highest correlation with pesticide residue (r = 0.674), than with endocrine disrupters (r = 0.672). Also, genetically modified food revealed high correlation with radiation irradiated food. Regression analysis demonstrated that concern about food safety significantly influenced pro-actively engaging in food safety education. Meanwhile, 63.5% of subjects correctly responded to food safety knowledge items. The item 'the heavy metals are contaminated the most, in the roots of vegetables' revealed the lowest correct answer rate (38.1%). In food safety behavior, the item 'always wash hands before handling food and meal's revealed 3.85, and subjects with awareness and concern about food safety education, responded in significantly higher numbers than subject without awareness and concern about food safety. The most neglected concern was relative to frozen food thawed at room temperature. Together, students recognize that distributed foods are unsafe, and students with awareness and concern about food safety education showed higher knowledge compared to without awareness and concern experience about food safety eduction. So, systematic education using accurate and objective data is required to reduce anxiety and raise the level of awareness and concern about food safety.

• Journal of Climate Change Research
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• v.1 no.2
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• pp.133-145
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• 2010

This study examined the characteristics of tropical cyclone(TC) activity over the western North Pacific(WNP) in 2009. Twenty-two TCs formed in 2009, which is slightly below normal(1979~2009 average: 25.8) and most of these occurred during the months of July to October. Most TCs in 2009 was formed over the northern Philippines and the eastern part of the WNP and they moved towards the South China Sea and the east of Japan, resulting in less TC affecting the East China Sea and Korea. The TC activity in 2009 is modulated by the large-scale circulations induced by the El $Ni{\tilde{n}}o$ and vigorous convection activity over the WNP. As the general characteristics of El $Ni{\tilde{n}}o$ year, the difference in sea surface temperature between the central Pacific and the eastern Pacific causes an anomalous westerly winds, expanding the WNP monsoon trough farther eastward. Accordingly, TC formation has relatively increased in the east part of the WNP. Active convection activities over the subtropical western Pacific excite a Rossby wave propagating from the South China Sea to mid-latitudes, resulting in an anomalous easterly steering flow in the South China, anomalous northwesterly over the East China Sea and Korea, and anomalous southwesterly over the east of Japan. Summing up, the TCs cannot enter the East China Sea and Korean region and instead they move towards the South China Sea or south-east of Japan. There were no effects of TCs in Korea in 2009. It is anticipated that this study which analyzed unusual TC activity and large-scale circulations in 2009 would help the predictability of TC effects to increase according to climate change in the East Asia.

• Journal of Climate Change Research
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• v.3 no.4
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• pp.245-257
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• 2012

Vulnerability assessment has been required for establish climate adaptation plan to prevent damage from climate change. In this study we assessed vulnerability with 1 km resolution and determined which sectors have the highest priority in each municipality of Gangwon province based on the result of vulnerability assessment. All sectors of vulnerability assessment are composed of three criteria; sensitivity, exposure and adaptation capacity. And suitable indicators of each sector were selected and spatial data set was prepared using GIS. Priority of vulnerability was classified with the degree of vulnerability in present and variation in vulnerability between present and future. The results of vulnerability assessment were different among municipalities due to the contribution of indicators. Present and future trends in vulnerability showed similar results but high vulnerable area was predicted to expand in the future. In addition increase in temperature led whole area to be more vulnerable generally. The result of prioritizing sectors of vulnerability indicated the most considerable sectors within a municipality. Also, the municipalities which have similar geographic, climatic and social conditions tended to be classified as the same priority class. The method of vulnerability assessment and determining priorities suggested in this study could be used to support decision makers to establish adaptation plan of local area.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1091-1103
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• 2018

Having knowledge regarding to which region is prone to drought or flood is a crucial issue in water resources planning and management. This could be more challenging when the occurrence of these hazards affected by climate change. In this study the future streamflow during the wet season (July to September) and dry season (October to March) for the twenty first century of South Korea was investigated. This study used the statistics of precipitation, maximum and minimum temperature of one global climate model (i.e., INMCM4) with 2 RCPs (RCP4.5 and RCP8.5) scenarios as inputs for The Precipitation-Runoff Modelling System (PRMS) model. The PRMS model was tested for the historical periods (1966-2016) and then the parameters of model were used to project the future changes of 5 large River basins in Korea for three future periods (2025s, 2055s, and 2085s) compared to the reference period (1976-2005). Then, the different responses in climate and streamflow projection during these two seasons (wet and dry) was investigated. The results showed that under INMCM4 scenario, the occurrence of drought in dry season is projected to be stronger in 2025s than 2055s from decreasing -7.23% (-7.06%) in 2025s to -3.81% (-0.71%) in 2055s for RCP4.5 (RCP8.5). Regarding to the far future (2085s), for RCP 4.5 is projected to increase streamflow in the northern part, and decrease streamflow in the southern part (-3.24%), however under RCP8.5 almost all basins are vulnerable to drought, especially in the southern part (-16.51%). Also, during the wet season both increasing (Almost in northern and western part) and decreasing (almost in the southern part) in streamflow relative to the reference period are projected for all periods and RCPs under INMCM4 scenario.