• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.343-348
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• 2015

Soybean is one of the important food crop around the world. Especially in East Asia, it is the main ingredient for traditional food like soy sauce and soy paste. The double cropping system including soybean following onion, Chinese cabbage, and potato is widely adopted in Southern region of Korea. In this system, sowing date of second crop (soybean) can be delayed depending on first crops' growth period and weather condition. When planting date is delayed it is known that soybean yield is declined because of shorter vegetative growth period and earlier flowering induced by warm temperature and changes in photoperiod. The objective of this study was to determine soybean growth and yield responses as plant populations at late planting date. Field experiment was conducted at Department of Functional Crop, National Institute of Crop Science, RDA located in Miryang, Gyeongsangnam-Do for two years ('13-'14) in upland field with mid-late maturity cultivar Daewon. A split-plot block design was used with three replications. Main plots were three sowing dates from June 20 to July 20 with 15 days intervals, and subplots were 4 levels of planting densities. Data of maturity (R8) was recorded, yield components and yield were examined after harvesting. Experimental data were analyzed by using PROC GLM, and DMRT were used for mean comparison. Optimum planting population for maximizing soybean yield in late planting which compared with standard population. In mid-June planting, higher planting density causes increased plant height and decreased diameter which lead to higher risk of lodging, however, reduced growth period due to late planting alleviated this problem. Therefore higher seeding rates can provide protection against low seedling emergence caused by late planting in this region.

• Food Science and Preservation
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• v.12 no.6
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• pp.591-599
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• 2005

This study was conducted to optimize the extraction conditions from cabbage by a response surface methodology. In extraction conditions based on the central composite design with variations, the ratio of solvent to sample ($10\~30$mL/g), ethanol concentration ($0\~100\%$) and extraction temperature ($35\~95^{circ}C$) coefficients of determinations ($R^2$) were 0.8162(p<0.1), 0.8173(p<0.1), 0.9374(p<0.01) and 0.9116(p<0.05) in extraction yield, electron donating ability, tyrosinase inhibition and SOD-like ability, respectively. Estimated extraction conditions for the maximizing yield, electron donating ability and SOD-like ability were $15\~30$ mL/g in ratio of solvent to sample, $40\~80\%$; ethanol concentration, and $50\~90^{\circ}C$ ; extraction temperature. Predicted values at the optimum condition (25 mL/g solvent to sample, $50\%$ ethanol concentration and $70^{\circ}C$ in extraction temperature) were in good agreement with observed values.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.389-395
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• 2017

A study was carried out to improve the field implementation of asphalt surface reinforcement method which is a preventive maintenance. Mean Texture Depth (MTD) was measured to quantify the surface condition and used to determine the optimum application rate. Determining the application rate using MTD can reduce the material loss from 30% to 15%. In order to reduce the curing time to 30 minutes, the heat capacity of $317kcal/m^2$ is required. Therefore, the design capacity of the heating curing device requires more than 380,000 kcal/hr. The asphalt surface reinforcement method is preferably applied at a time when slight cracking occurs before the permanent deformation becomes serious. Through the analysis of the pavement survey data, it was decided to apply the surface reinforcement method at the crack rate of 3~4%. Heating the surface reinforcement agent to $50^{\circ}C$ improves workability and ensures sufficient penetration depth even at a crack width of 1 mm. The results will be utilized as basic data for the development of automated construction equipment for efficiency improvement.

• Food Science and Preservation
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• v.15 no.6
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• pp.840-846
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• 2008

Microwave-assisted extraction (MAE) of grape seeds was performed under the different conditions based on a central composite design for independent variables of microwave power ($0{\sim}120\;W$), ethanol concentration ($0{\sim}100%$) and extraction time ($1{\sim}5\;min$). Response surface methodology (RSM) was used to predict the optimum extraction conditions for three dependent variables in grape seed extracts: total yield, total catechin and electron donating ability. Determination coefficients ($R^2$) of regression equations for the three dependent variables were higher than 0.9 (p < 0.01). The optimal MAE conditions to yield the maximum value of total catechin (434.16 mg%) were 122.76 W microwave power, 42.88% ethanol and 4.67 min extraction time. The superimposed contour maps for maximizing the three dependent variables indicated that the MAE condition ranges were 75150 W, 4060% ethanol and 3.55.0 min. The predicted values at the optimized conditions (6.72% total yield, 408.65 mg% total catechin, and 83.33% electron donation ability) were similar to the experimental values. The optimized MAE (112.5 W, 50% EtOH, 4.2 min) was more efficient than the conventional solvent extraction using 80% EtOH, $60^{\circ}C$ for 3h and 150 rpm.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.117-127
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• 2001

The Main object of this research is directed to LG Oil company harbor in kwangyang-hang, where various ships ranging from 300 ton to 48000ton DWT use seven berths in the harbor. This harbor suffered from inefficient and unsafe management procedures since it is difficult to set guidelines for arrival and departure of ships according to the weather conditions and the current guidelines dose not offer clear basis of its implications. Therefore, it has long been suggested that these guidelines should be improved. This paper proposes a decision-support system, which can quantitatively decide the possibility of entry or departure on a harbor by analyzing the weather conditions (wind, current, and wave) and taking account of factors such as harbor characteristics, ship characteristics, weight condition, and operator characteristics. This system has been verified using 5$_{th}$ and 7$_{th}$ berth in Kwangyang-hang harbor. Machine learning technique using genetic programming(GP) is introduced to the system to quantitatively decide and produce results about the possibility of entry or arrival, and weighted linear associative memory (WLAM) method is also used to reduce the amount of calculation the GP has to perform. Group of additive genetic programming trees (GAGPT) is also used to improve learning performance by making it easy to find global optimum.mum.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.53-60
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• 2015

Newly, nutrients recovery by bioconversion in the swine waste which caused serious problems due to its high organic fraction and content of nutrients such as phosphorus and nitrogen is viewed as a considerable approach since it produces valuable product as well as recycling of resources. Consequently, it is necessary to find new methods to treat swine waste. One possible solution to this problem is to use this potential pollutant as a growth substrate for economically valuable products. The study for the fundamental improvement of bioconversion efficiency by finding optimum growth conditions using statistical models and biotechnology was performed. A novel approach to utilize swine waste by cultivating mycelia of the mushroom Phellinus linteus are described. A central composite face-centered design (CCF) for the experiments was used to develop empirical model providing a quantitative interpretation of the relationships among the three variables, which were substrate concentration, pH, and temperature. The maximal radial extension rate (2.78mm/d) of P.linteus was determined under the condition of 5.0 g COD/L, pH 5.0, and temperature $29.7^{\circ}C$. The results of this study suggest that swine waste could be utilized as a growth substrate for the cultivation of mushroom mycelia enhancing an efficiency of utilizing this by-product of the livestock industry.

• Food Science and Preservation
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• v.18 no.2
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• pp.178-183
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• 2011

The consumer awareness concerning coffee beverages has increased in Korea. The objective of this study was to optimize the roasting conditions of coffee bean for consumer's attribute. The optimal roasting conditions for Colombian coffee beans were analyzed by using a central composite design with a quadratic polynomial model by response surface methodology (RSM). The experimental conditions for coffee bean roasting were $194.82^{\circ}C{\sim}250.00^{\circ}C$ and 7.93~22.07 minutes. The responses of sensory attributes. physicochemical and physical properties were analyzed with RSM. The width. length and height of green beans increased when the beans were roasted. The higher degree of roasting gave the higher pH and solid contents but the lower total acidity and total phenolic compounds. In sensory tests, the roasting temperature and time had a significant effect on the flavor score. The optimum roasting condition of Colombian coffee bean predicted for maximizing the length, width, solid contents, total phenolic compounds and flavor score were 20 minutes at $225^{\circ}C$ by RSM.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.575-593
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• 2012

This paper briefly introduces the scope and objectives of SKB Task 8, which is an international cooperative research project. In addition, the hydraulic behaviors of bentonite buffer focusing on the interactions between bentonite and a rock mass with a joint were investigated using TOUGH2 code as part of a sub-mission of Task 8a. The effects of a rock joint and high capillary pressure of bentonite on the re-saturation properties and pressure distribution in a buffer were identified and successfully incorporated in the TOUGH2 code. Based on the numerical results, it was found that the speed of re-saturation in bentonite surrounded by a rock mass with a joint is 2.5 to 12 times faster than that in a condition without a rock joint, while the degree of saturation in the lower part of the buffer material is generally higher than in the upper part in both the cases of with and without a joint. It can be anticipated that the results obtained from this study can be applied to an estimation of the full saturation time and a determination of optimum thickness with regard to the design of the bentonite buffer in a high level waste disposal system.

• Journal of Life Science
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• v.20 no.11
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• pp.1729-1737
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• 2010

This study was conducted to establish the optimal medium condition for the animal probiotic Lactobacillus plantarum by using onion juice. Cell yield and antioxidant activity increased in proportion to high additive levels of onion juice in medium. Onion juice, sucrose and yeast extract were selected as media ingredient factors and the effects of their mixed ratio in medium were evaluated. The full factorial design consisted of 24 experimental runs and was employed to estimate the main effects of the factors and their interactions. Significant positive effects on cell yield and antioxidant activity was shown with yeast extract and onion juice, respectively. Significant interaction was found only between sucrose and yeast extract in antioxidant activity. Finally, we selected an optimal medium that was composed of (g/l) onion juice, 600; sucrose, 15; yeast extract, 5. The efficiency of this optimum medium was estimated by using a 5 l jar fermenter. As a result, the maximum cell yield was $9.7\;{\log}_{10}$ (CFU/ml) at 12 hr. Cell yield at the end of incubation (20 hr) was $8.9\;{\log}_{10}$ (CFU/ml) and it was very similar with the predicted value, $9.0\;{\log}_{10}$ (CFU/ml). Antioxidant activity of culture was maintained at about 60~65% during all incubation time, resulting in a higher-than-predicted activity of 47.1%.

• Journal of the Korean Geotechnical Society
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• v.33 no.10
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• pp.33-47
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• 2017

A self-supported temporary excavation method called IER is normally applicable to excavation depth ranging from 6.0 m to 7.0 m though the method depends on ground condition and overburden load. Combining IER with another method is required in deeper excavation depth in order to maintain the structural stability of the IER. In this study, we performed model tests and 3D FE analysis to check the stability of the IER adopting soil nailing method, and to propose its effective installation method. The lateral displacement of the IER using soil nailing decreased by 92% of that of IER without soil nailing. Optimum design is possible for both economic feasibility and stability when interval spacing and length of soil nails is $1.5m(S_h){\times}0.75m(S_v)$ and 86% of excavation depth, respectively. Excavation depth using IER increases 1.71 times by adopting soil nailing in increment of lateral displacement of IER right before the last excavation stage.