• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.823-833
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• 2020

The Manila clam Ruditapes philippinarum, is an important marine bivalve that is widely distributed along the west and north coasts of South Korea. It has been used in a variety of Korean foods owing to its superior umami taste. In the present study, we developed a flavoring with an excellent sensory preference from Manila clam using extrusion cooking processing. Optimization of extrusion cooking conditions was performed using response surface methodology (RSM). Barrel temperature (X1, 140-160℃) and screw speed (X2, 400-560 rpm) of the extruder were chosen as independent variables. The dependent variable was overall acceptance (Y, points). The estimated optimal conditions were as follows: overall acceptance (Y): X1=140℃ and X2=560 rpm. The indicated value of the dependent variable overall acceptance (Y) under the optimal conditions was 8.94 points, which was similar to the experimental value (8.82 points). Overall acceptance of the Manila clam flavoring was related to its umami and Manila clam tastes. The electronic nose and tongue results successfully segregated different clusters of the samples between the lowest and highest sensory scores. The sample with the highest sensory score had higher sourness, umami, and sweetness intensities, and the lowest sensory scored sample showed more off-flavor compounds.

• Atmosphere
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• v.30 no.4
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• pp.377-390
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• 2020

Not only emissions, but also atmospheric circulation is a key factor that affects local particulate matters (PM) concentrations in Korea through ventilation effects and transboundary transports. As part of the atmospheric circulation, air stagnation especially adversely affects local air quality due to weak ventilation. This study investigates the large-scale circulation related to air stagnation over Korea during winter and projects the climate change impacts on atmospheric patterns, using observed PM data, reanalysis and regional climate projections from HadGEM3-RA with Modified Korea Particulate matter Index. Results show that the stagnation affects the PM concentration, accompanied by pressure ridge at upper troposphere and weaken zonal pressure gradient at lower troposphere. Downscaling using HadGEM3-RA is found to yield Added-Value in the simulated low tropospheric winds. For projection of future stagnation, SSP5-8.5 and SSP1-2.6 (high and low emission) scenarios are used here. It has been found that the stagnation condition occurs more frequently by 11% under SSP5-8.5 and by 5% under SSP1-2.6 than in present-day climate and is most affected by changes in surface wind speed. The increase in the stagnation conditions is related to anticyclonic circulation anomaly at upper troposphere and weaken meridional pressure gradient at lower troposphere. Considering that the present East Asian winter monsoon is mainly affected by change in zonal pressure gradient, it is worth paying attention to this change in the meridional gradient. Our results suggest that future warming condition increase the frequency of air stagnation over Korea during winter with response of atmospheric circulation and its nonlinearity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.349-360
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• 2020

Bio-conversion manufacturing technology has been developed to produce ginsenoside Rd which is increasingly in demand as a cosmetic material due to various possibilities related to improving skin function. In order to convert ginsenoside Rb1 which is contained in red ginseng saponin (RGS) into Rd, several commercial enzymes were tested. Viscoflow MG was found to be the most efficient. In order to optimize the conversion of RGS to ginsenoside Rd by enzymatic transition was carried out using response surface methodology (RSM) based on Box-Behnken design (BBD). The main independent variables were RGS concentration, enzyme concentration, and reaction time. Conversion of ginsenoside Rd was performed under 17 conditions selected according to BBD model and optimization conditions were analyzed. The concentration of the converted ginsenoside Rd ranged from 0.3113 g/L to 0.5277 g/L, and the highest production volume was obtained under condition of reacting 2% RGS and 1.25% enzyme for 13.5 hours. Consequently, RGS concentration, enzyme concentration which is 0.05 less than p-value and among the interactions between the independent variables, the interaction between enzyme concentration and reaction time was confirmed to be the most influential.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.33-46
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• 2020

The purpose of Electronic warfare is to disturbe, neutralize, attack, and destroy the opponent's electronic warfare weapon system or equipment. Suppression of Enemy Air Defense (SEAD) mission is aimed at incapacitating, destroying, or temporarily deteriorating air defense networks such as enemy surface-to-air missiles (SAMs), which is a representative mission supported by electronic warfare. This paper develops a simulator for analyzing the effectiveness of SEAD missions under electronic warfare support using C++ language based on the DEVS (Discrete Event Systems Specification) model, the usefulness of which has been proved through case analysis with examples. The SEAD mission of the friendly forces is carried out in parallel with SSJ (Self Screening Jamming) electronic warfare under the support of SOJ (Stand Off Jamming) electronic warfare. The mission is assumed to be done after penetrating into the enemy area and firing HARM (High Speed Anti Radiation Missile). SAM response is assumed to comply mission under the degraded performance due to the electronic interference of the friendly SSJ and SOJ. The developed simulator allows various combinations of electronic warfare equipment specifications (parameters) and operational tactics (parameters or algorithms) to be input for the purpose of analysis of the effect of these combinations on the mission effectiveness.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.445-454
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• 2022

Ice accretion on the aircraft components, such as wings, fuselage, and empennage, can occur when the aircraft encounters a cloud zone with high humidity and low temperature. The prevention of ice accretion is important because it causes a decrease in the aerodynamic performance and flight stability, thus leading to fatal safety problems. In this study, a shape design optimization of a multi-element airfoil is performed to minimize the amount of ice accretion on the high-lift device including leading-edge slat, main element, and trailing-edge flap. The design optimization framework proposed in this paper consists of four major parts: air flow, droplet impingement and ice accretion simulations and gradient-free optimization algorithm. Reynolds-averaged Navier-Stokes (RANS) simulation is used to predict the aerodynamic performance and flow field around the multi-element airfoil at the angle of attack 8°. Droplet impingement and ice accretion simulations are conducted using the multi-physics computational analysis tool. The objective function is to minimize the total mass of ice accretion and the design variables are the deflection angle, gap, and overhang of the flap and slat. Kriging surrogate model is used to construct the response surface, providing rapid approximations of time-consuming function evaluation, and genetic algorithm is employed to find the optimal solution. As a result of optimization, the total mass of ice accretion on the optimized multielement airfoil is reduced by about 8% compared to the baseline configuration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.67-75
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• 2022

Roots play important roles in water and nutrient uptake and in response to various environmental stresses. Investigating diversification of cultivars through root phenotyping is important for crop improvement in adzuki beans. Therefore, we analyzed the morphological and architectural root traits of 22 adzuki bean cultivars using 2-dimensional (2D) root imaging. Plants were grown in plastic tubes [6 cm (diameter) × 40 cm (height)] in a greenhouse from July 25^th to August 28^th. When the plants reached the 2^nd or 3^rd trifoliate leaf stage, the roots were removed and washed with tap water to remove soil particles. Clean root samples were scanned, and the scanned images were analyzed using the WinRHIZO Pro software. The cultivars were analyzed based on six root phenotypes [total root length (TRL), surface area (SA), average diameter (AD), and number of tips (NT) were included as root morphological traits (RMT); and link average length (LAL) and link average diameter (LAD) were included as root architectural traits (RAT)]. According to the analysis of variance (ANOVA), a significant difference was observed between the cultivars for all root morphological traits. Distribution analysis demonstrated that all root traits except LAL followed a normally distributed curve. In the correlation test, the most important morphological trait, TRL, showed a strong positive correlation with SA (r = 0.97^***) and NT (r = 0.94^***). In comparison, between RMT and RAT, TRL showed a significantly negative correlation with LAL (r = -0.50^***); however, TRL did not show a correlation with LAD. Based on RMT and RAT, we identified the cultivars that ranked 5% from the top and bottom. In particular, the cultivar "IT 236657" showed the highest TRL, SA, and NT, while the cultivar "IT 236169" showed the lowest values for TRL, SA, and NT. In addition, the coefficient of variance for the six tested root traits ranged from (14.26-40%) which suggested statistical variability in root phenotypes among the 22 adzuki bean varieties. Thus, this study will help to select target root traits for the adzuki bean breeding program in the future, generating climate-resilient adzuki beans, especially for drought stress, and may be useful for developing biotic and abiotic stress-tolerant cultivars based on better root trait attributes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.880-889
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• 2021

The home meal replacement (HMR) market has attracted significant attention due to COVID-19 pandemic and products that utilize the combination of different processed ingredients are now being developed. In this study, Broughton's ribbed ark Scapharca broughtonii was soaked in seasoned soy sauce with the incorporation of mustard leaf Brassica juncea (M-BRA), which is known to have a unique texture as well as excellent functional properties such as antioxidation, to develop a regional specialty product. The optimal conditions for manufacturing M-BRA from the seasoned soy sauce (the sauce to be added [X₁] and the soaking time [X₂]), were examined using response surface methodology (RSM) to analyze the significance of the salinity (Y₁), amino-N content (Y₂), and overall acceptance (Y₃). The coefficient of determination (R²) between X₁-X₂ and Y₁-Y₃ were close to 1, thereby confirming the suitability of the RSM model. The optimal conditions were seasoned soy sauce addition of 140% and soaking time of 156 min. The M-BRA manufactured under these conditions exhibited superior overall acceptance compared to seasoned commercial soy sauce, which was used as a control. We expect that the market for M-BRA manufactured by combining marine and agricultural materials will expand owing to superior overall acceptance compared with commercial products.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.3
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• pp.255-264
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• 2022

The active ingredients of Napttegi Kong(GML, Glycine max landrace), a type of native rare soybeans, were identified, and an ultrasonic extraction method was introduced as an eco-friendly extraction method. Through the component analysis of the Napttegi Kong extract, the epicatechin, which was not found in conventional soybeans, was identified. For effective extraction using ultrasonic, the main extraction conditions were optimized using the response surface analysis method. Through the Box-Behnken design process, 15 experiments were conducted with the extraction temperature, the ratio of extraction solvent/solution, and extraction time as key independent variables. A quadratic regression equation for the two dependent variables, epicatechin content and total isoflavone content, was derived, and the coefficients of determination were found to be high as R² = 0.9939 and R² = 0.9844, respectively, confirming that the correlation showed high significance. The extraction conditions satisfying the maximum expectations of these two dependent variables were predicted. to be 40.4℃ of extraction temperature, 19.3 times of extraction solvent/solution, and 91 sec of extraction time. The expected value and the actual experimental value of the epikatechin content and the total isoflavone content were similar, so it was confirmed that this experimental method is a highly reliable optimization model.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.479-485
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• 2021

To improve the oxidative stability of Glycyrrhiza uralensis extract (GU), GU extraction conditions were optimized for maximal antioxidant activity, and GU-loaded nanocapsules were prepared by chitosan ionic gelation. The optimized ethanol concentration and extraction time were 83.0% and 32.6 min, respectively, using response surface methodology. The particle size of the GU-loaded nanocapsules ranged from 280 to 370 nm. A GU extract of 0.8 mg/mL and chitosan concentration of 2.0 mg/mL were selected as the optimal conditions for entrapment and loading efficiency. Both free GU and GU-loaded chitosan nanocapsules exhibited concentration-dependent antioxidant activity. However, the antioxidant protection factor of GU was effectively maintained when it was entrapped within the chitosan nanocapsules. In conclusion, chitosan nanoencapsulation is a potentially valuable technique for improving the oxidative stability of GU.

• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.523-534
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• 2021

Meteorological drought originates from a precipitation deficiency and propagates to agricultural and hydrological droughts through the hydrological cycle. Comparing with the meteorological drought, agricultural and hydrological droughts have more direct impacts on human society. Thus, understanding how meteorological drought evolves to agricultural and hydrological droughts is necessary for efficient drought preparedness and response. In this study, meteorological and hydrological droughts were defined based on the observed precipitation and the synthesized streamflow by the land surface model. The Bayesian network model was applied for probabilistic analysis of the propagation relationship between meteorological and hydrological droughts. The copula function was used to estimate the joint probability in the Bayesian network. The results indicated that the propagation probabilities from the moderate and extreme meteorological droughts were ranged from 0.41 to 0.63 and from 0.83 to 0.98, respectively. In addition, the propagation probabilities were highest in autumn (0.71 ~ 0.89) and lowest in winter (0.41 ~ 0.62). The propagation probability increases as the meteorological drought evolved from summer to autumn, and the severe hydrological drought could be prevented by appropriate mitigation during that time.