• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.199-207
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• 2016

This study was conducted to develop a forest fire occurrence model using meteorological characteristics for practical forecasting of forest fire danger rate by reflecting the climate change for the time period of 2000yrs. Forest fire in South Korea is highly influenced by humidity, wind speed, temperature, and precipitation. To effectively forecast forest fire occurrence, we developed a forest fire danger rating model using weather factors associated with forest fire in 2000yrs. Forest fire occurrence patterns were investigated statistically to develop a forest fire danger rating index using times series weather data sets collected from 76 meteorological observation centers. The data sets were used for 11 years from 2000 to 2010. Development of the national forest fire occurrence probability model used a logistic regression analysis with forest fire occurrence data and meteorological variables. Nine probability models for individual nine provinces including Jeju Island have been developed. The results of the statistical analysis show that the logistic models (p<0.05) strongly depends on the effective and relative humidity, temperature, wind speed, and rainfall. The results of verification showed that the probability of randomly selected fires ranges from 0.687 to 0.981, which represent a relatively high accuracy of the developed model. These findings may be beneficial to the policy makers in South Korea for the prevention of forest fires.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.43-52
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• 2000

Deodorization characteristics and removal rate of sulfur-containing odor have been investigated in the soil filter reactors packed with montmorillonites (Mont.), rice hulls(Rh.), and thickening-activated sludge(Ts.). And variation of pH and $SO_4{^{2-}}$ with the removal of malodorous sulfur compounds have been investigated together. As compared removal rate of montmorillonites between wet and dry condition for sulfur compounds through batch test, it showed that wet condition was better than dry one; removal ratio, as wet/dry, was $H_2S$ of 1.2 and $CH_3SH$ of 1.9, and decrease of pH and increase of $SO_4{^{2-}}$ concentration in the wet condition also showed to be larger than in dry condition. In continuous test for biological deodorization experiment, removal rate of sulfur compounds in reactor packed with Mont., Rh. and Ts, was more than 98 %, and the variation of static pressure was maintained stably under condition of SV $150h^{-1}$, LV 4.2 mm/sec and SV $200h^{-1}$, LV 5.6 mm/sec, and in reactor packed with Mont. and Rh., $H_2S$ was 76.4 % to 87.2 % and $CH_3SH$ was 87.8 % to 93.3 % under the same condition. From above results, it ascertained that it can obtain the high deodorization efficiency by inoculating thickening-activated sludge in soil filter using montmorillonites.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.184-192
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• 2015

This study is a basic research for low maintenance constructed wetlands which can prevent water quality deterioration due to wetland soils. The purpose of this study is to analyze water quality control mechanisms of constructed wetland on the artificial ground which installed the modular revetment structure(MRS), a device that separates water and soil. This study was then conducted with two different wetland mesocosms (a treatment plot and a control). These mesocosms were monitored to analyze effects of water quality control of the MRS. A treatment plot was built, and separated into soil and water, by filling the MRS with the decomposed granite soil in the mesocosm made of rubber material. A control plot was built where the decomposed granite soils were exposed to water by leaving the soil on the bottom of the mesocosm made of rubber material. Water quality was then analyzed by using Kolmogorov-Smirnov Z examination which then showed that pH, BOD, SS, Chl-a, T-P, T-N had statistically valid difference between a container with the MRS and one without it. According to the analysis of the water quality, the temperature and the EC level came out similarly and both mesocosm showed same level on pH and DO. A treatment plot had higher levels of BOD, SS Chl-a, and T-P. A control plot's T-N value was little lower than that of the treatment plot. This study suggests method of constructed wetlands using the MRS prevents problems occurring in wetland soils: aridity of wetlands by soil erosion, eutrophication, and algal blooms due to nutrients released from wetland soil. These functions of constructed wetland with the MRS increase aesthetic, ecologic, social, and economic value of the wetland. Outcomes of this research will later enable more proficient way of stabilizing water quality and provide data for planning low maintenance constructed wetlands.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.176-183
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• 2013

To explore hydrolysis methods for the efficient manufacture of sugar solutions from the freshwater alga Water-net (Hydrodictyon reticulatum, HR), acid hydrolysis, enzymatic hydrolysis, and combined hydrolysis (acid followed by enzymatic hydrolysis) were investigated. In the one-step acid hydrolysis, the reaction of 8% solids content using 2% sulfuric acid at $120^{\circ}C$ for 1 hour was desirable. In this case, glucose 27.44 g 100 g $DM^{-1}$ could be obtained from the HR-d13 samples. In the two-step acid hydrolysis, the primary hydrolysis (HR powder : 72% sulfuric acid = 1 g : 1.5 mL) was carried out for 1 hour at $60^{\circ}C$, and then the secondary hydrolysis was done for 1 hour at $120^{\circ}C$ after addition of distilled water 23.5 mL. In this case, glucose 35.11 g/100 g DM could be obtained from the HR-d13 samples. In the combined hydrolysis, 25% solids content using 2% hydrochloric acid were reacted for 1 hour at $120^{\circ}C$, and then citrate buffer and hydrolysis enzyme complexes (E1 1.0 mL+E2 0.2 mL $g^{-1}$ dried matter) were added and reacted for 1 - 2 days at $50^{\circ}C$. In this case, glucose 33.5 g 100 g $DM^{-1}$ could be obtained from the HR-d23+26 samples. In conclusion, combined hydrolysis was likely to be more useful saccharification method of HR biomass at a practical level, considering the glucose productivity, generation of fermentation-inhibiting substances (hydroxyl methyl furfural, furfural), and limited use of strong acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.926-934
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• 2006

The base for preparing oyster hydrolysate-added yogurt was consisted of whole milk (1,000 mL), skim milk (44.05 to 42.05 g), enzymatic oyster hydrolysates powder (OHP, 0 to 2.0 g) and pectin. The yogurt base was fermented with 7 kinds of starter cultures (3% based on yogurt volume), such as Lactobacillus acidophilus, lactobacillus bulgaricus, lactobacillus casei, Lactobacillus fermentum, Lactobacillus pentosus, Streptcoccus thermophilus and the mixed starters (L. bulgaricus and S. thermophilus) at optimal temperature. Processing condition and quality characteristics of the yogurt were evaluated by analyzing pH, titratable acidity, viscosity, viable cell count, functional properties and sensory evaluation. The results suggested that the optimal conditions for preparing the good quality yogurt revealed the mixed starters (L. bulgaricus and S. thermophilus) for starter culture, 1.0 g of 3 kDa hydrolysate for amount, and 5.5 hrs for fermentation time. The good quality yogurt showed 4.31 for pH, 1.07% for titratable acidity, 469 cps for viscosity and $4.9{\times}10^8\;CFU/mL$ for viable cell count. The hydrolysate-added yogurt was 2 times higher in ACE inhibitory and antioxidant activities than commercial yogurt, and kept good quality during storage of 15 days at $5^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.860-865
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• 2006

This study was performed to investigate the effect of ethanol and citric acid-treated anchovy, caseino-phosphopeptides (CPPs), calcium lactate, and calcium phosphate as dietary calcium supplements on calcium metabolism in rats for 5 weeks. Experimental animals were randomly assigned to five treatments with 15 heads of SD male rats (mean body wt. of 100 g) in each group. The experimental diets were as follows; dried large anchovy powder (C) as control, ethanol+citric acid group (EC), ethanol+citric acid+cpps group (ECC), calcium lactate group (CL) and calcium phosphate group (CP), which were formulated with commercial semi-purified Chow diet, while maintaining the same level of calcium in all diets (1%) groups. The weight gain of EC group was significantly higher than ECC, CL and CP groups (p<0.05), food efficiency (FER) was not different. In vitro and in vivo calcium absorption rates of ECC group treated with citric acid and CPPs were 20.4 and 28.4%, respectively, and the highest among the experimental groups (p<0.05). The blood glucose levels of CL group (105.7 mg/dL) was significantly higher than control group (98.5 mg/dL). In terms of serum lipids, total-cholesterol concentration of EC group (75.1 mg/dL) was significantly higher than CP group (65.6 mg/dL) and triglyceride concentration of CP group (33.5 mg/dL) was the lowest (p<0.05). ALP activity and 057 level were not different among experimental groups. The serum calcium concentration of control group (C) was the lowest among groups (p<0.05). The femur weight of CP group was the lowest (p<0.05) and the femur length of ECC group is the longest (P<0.05). The bone density of CP group $(0.1116\;g/cm^2)$ was the lowest while ECC group $(0.1149\;g/cm^2)$ was the highest, and the bone density was increased by added CPPs. These data demonstrated that ECC group significantly increased in vitro and in vivo calcium absorption rate, serum Ca level, and the length and bone density of femur.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1140-1147
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• 2007

A recipe for diet kimchi containing 20% of sea tangle to Korean cabbage kimchi (SK) was developed for weight reduction purpose. The fermentation process of SK showed typical Lactobacillus sp. growth pattern like other kimchis. The effects of SK on weight reduction was studied in high fat diet (HFD) fed rats (n=40). Diet groups used for the animal study were HFD, HFD supplemented either with Korean cabbage kimchi used as experimental control (HCK), or with SK (HSK), or with J-kimchi (JK) which was purchased at market (FJK). The effect of kimchi on preventing obesity in rat fed HFD was found to be obvious by means of reducing visceral fat contents and improving serum lipid profiles through enhancing the lipid excretion in the feces (p<0.05). Leptin concentration of rat was significantly decreased by kimchi consumption (p<0.05). This result can be interpreted that adipocytes in these animals were fewer than that of HFD group. The plasma bililubin concentration was lower in kimchi group than HFD, meaning that returning bile from ileum to the liver was reduced. When the observe beneficial effects of kimchi on preventing obesity were compared among kimchi groups, SK only reduced the relative visceral fat contents significantly than other kimchi groups (p<0.05). Besides this, other parameters such as plasma lipid profiles, feces lipids, leptin, and bililubin concentration were not significantly different, even though the most beneficial effect on these parameters was observed from SK. In conclusion, long term consumption of SK seems to have a beneficial effect on the prevention of obesity through enhancing the excretion of lipids in the feces. The dietary fiber content of SK was increased by 7% compared to CK when 20% of sea tangle was added.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.159-170
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• 2010

This study was aimed to evaluate the effects garlic such as fresh garlic powder (FGP), red garlic powder (RGP) and black garlic powder (BGP) by lyophilized, on serum lipid metabolism in obese rats induced high fat diet. Food efficiency ratio (FER) of the experimental groups was lower than the control group and it was significant difference. Total lipid content of serum decreased from 7.0 to 20.9% compared to the control group. Especially, triglyceride content decreased from 40.8% (BGP) to 42.1% (RGP) group as compared to the control group. There was no significant difference in HDL-C content between groups fed garlic powder and normal group. LDL-C contents of the experimental groups were lower than the control group, but has not showed significant diggerence compared to control group. Total lipid content was significantly increased in liver compared to the control group, but decreased over 30% in RGP and BGP groups to the control group. The lipid level in feces was increased by feeding periods of garlic powder, while total cholesterol and triglyceride were significantly increased in feces of RGP group. TBARS content in serum and liver of RGP and BGP groups was significantly decreased than the control group. Antioxidant activity of serum was 68.05% in the RGP group, which was significantly higher than the control group. From the above result, we suggested that red and black garlic powder were effective in the improvement of lipid level in obese rats induced high fat diet.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.872-879
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• 2010

Layered copper hydroxides [LCHs, $Cu_2(OH)_3{\cdot}NO_3$] has the agricultural potentials as a fungicide because of its high crystallinity, excellent anion exchange capacity, and its regular layered particle size. The study, for the first time, has synthesized LCHs in highly concentrated solution and evaluated its physicochemical properties including the crystallinity and suspension stability. Optimal synthetic condition of LCHs was determined by crystallinity and stability of suspension as follow; 1) concentrations of $Cu(NO_3)_2$ and NaOH solutions were 3.0 M respectively, 2) reaction temperature and solution pH were $25^{\circ}C$ and 6.0, respectively, and 3) aging time after reaction was 2hr. Crystallinity of LCHs enhanced with increase in pH up to 9.0. Whereas, stability of suspension was decrease by increase in crystal size. Especially, increase in reaction temperature decreased stability of suspension. XRD patterns and SEM images exhibited that LCHs had regular layered particle size with 0.2~0.8 ${\mu}m$ and high crystallinity in optimal synthetic condition. The particle size was increased with increase in reaction temperature and pH. These results showed that LCHs synthesized in highly concentrated solution exhibited high stability of suspension as well as high crystallinity suitable to their potential as a fungicide.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.348-356
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• 2018

Most of fires were human-caused fires in Korea, but meteorological factors are also big contributors to fire behavior and its spread. Thus, meteorological factors as well as topographical and forest factors were considered in the fire danger rating systems. This study aims to develop an advanced national integrated daily weather index(DWI) using weather data in the spring and fall to support forest fire prevention strategy in South Korea. DWI represents the meteorological characteristics, such as humidity (relative and effective), temperature and wind speed, and we integrated nine logistic regression models of the past into one national model. One national integrated model of the spring and fall is respectively $[1+{\exp}\{-(2.706+(0.088^*T_{mean})-(0.055^*Rh)-(0.023^*Eh)-(0.014^*W_{mean}))\}^{-1}]^{-1}$, $[1+{\exp}\{-(1.099+(0.117^*T_{mean})-(0.069^*Rh)-(0.182^*W_{mean}))\}^{-1}]^{-1}$ and all weather variables significantly (p<0.01) affected the probability of forest fire occurrence in the overall regions. The accuracy of the model in the spring and fall is respectively 71.7% and 86.9%. One integrated national model showed 10% higher accuracy than nine logistic regression models when it is applied weather data with 66 random sampling in forest fire event days. These findings would be necessary for the policy makers in the Republic of Korea for the prevention of forest fires.