• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.101-110
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• 1996

Using response surface methodology(RSM), the various conditions(agitation speed, air flow, glucose concentration) in jar fermentor culture were investigated to find the optimum conditions for maximum enzyme production. Central-composite-design was used to control the variable constant in the experiment. The glucose isomerase production of Steptomyces chibaensis J-59 was mostly affected by the air flow rate and glucose concentration. The estimated optimum conditions were as follows: 1% birchwood xylan, 1.5% CSL, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, pH 7.0; air flow, 2.2vvm; agitation speed, 587rpm; glucose concentration, 0.586%. Experimental values(7.43GIU/ml) for the enzyme production obtained from the given optimum conditions had a almost resemblane to response values(7.67GIU/ml) predicted by the RSM. The jar fermentor culture by the RSM produced xylose isomerase about 2.7 times as much as the baffled flask culture.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.191-198
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• 2010

This research was performed to investigate the effect of hydrogen peroxide on the stain removal in japanese hackberry. Response surface method (RSM) was used to optimize the bleaching conditions such as reaction temperature, reaction time and the concentration of hydrogen peroxide. Fifteen different bleaching conditions were selected according to $2^3$ factorial central composite design (CCD). The bleaching effect were evaluated by lightness differences of wood surface before and after the bleaching. The RSM model was determined and its $R^2$ values were 0.93, showing it well represented the bleaching effect. The most affecting factor on the stain removal was the concentration of hydrogen peroxide, followed by reaction time and reaction temperature. Second degree of concentration was proved to have an effect on the bleaching. Bleaching rates above 3% concentrations of hydrogen peroxide were tended to be slightly decreased, and low bleaching effect was found at $20^{\circ}C$. The determined RSM model may offer very practical ways to obtain the desired levels of bleaching because it offers multiple solutions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.319-323
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• 2010

This study was carried out to investigate proximate compositions, acidity, and soluble solids of various blueberries produced in Korea and to prepare jam with optimized overall palatability by a response surface methodology. Proximate compositions were 75~88% in moisture, 0.32~0.62% in crude protein, 0.12~0.39% in crude lipid, and 10.18~23.80% in carbohydrate. Acidity and soluble solids of blueberries showed 0.82~1.58% and $7~12^{\circ}Brix$, respectively. The effect of sucrose ($X_1$, 200~300 g), pectin ($X_2$, 0~10 g), and citric acid ($X_3$, 0~0.5 g) on overall palatability of blueberry jam were investigated at five levels using a central composite design. Overall palatability of blueberry jam showed maximum score in 200 g blueberry, 248 g sucrose, 4.8 g pectin, and 0.26 g citric acid.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.113-125
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• 2017

In spite of bulk literature about the tuning of TMD, the effectiveness of TMD in reducing the seismic response of engineering structures is still in a row. This paper deals with the optimum tuning parameters of a passive TMD and simulated on MATLAB with a ten-story numerical shear building. A weighted multi-objective optimization method based on computer experiment consisting of coupled with central composite design(CCD) central composite design and response surface methodology(RSM) was applied to find out the optimum tuning parameters of TMD. After the optimization, the so-conceived TMD turns out to be optimal with respect to the specific seismic event, hence allowing for an optimum reduction in seismic response. The method was employed on above structure by assuming first the El Centro seismic input as a sort of benchmark excitation, and then additional recent strong-motion earthquakes. It is found that the RSM based weighted multi-objective optimized damper improves frequency responses and root mean square displacements of the structure without TMD by 31.6% and 82.3% under El Centro earthquake, respectively, and has an equal or higher performance than the conventionally designed dampers with respect to frequency responses and root mean square displacements and when applied to earthquakes.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.243-251
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• 2009

Changes in pH and acidity were investigated in kimchi containing different amounts of added onion and/or pear during fermentation at $10^{\circ}C$. As the fermentation period increase, the pH and sugar contents of the onion and/or pear kimchi were higher compared to the control kimchi. However, the acidity of the kimchi containing onion and/or pear was lower than that of the control. To enhance the acceptance of kimchi, the optimal conditions for the addition of onion and pear were evaluated with the central composite design, ANOVA, and response surface methodology. According to variations in the mixing ratio of onion and pear, smell, taste and overall acceptability differed significantly, but the appearance and texture were not different. The optimal levels of onion and pear, predicted on the basis of each corresponding sensory parameters for kimchi, were $4.55{\sim}5.00%$ and $0{\sim}0.30%$ for smell, 2.61% and 2.38% for taste and 2.78% and 2.57% for overall acceptability, respectively.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.65-72
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• 2002

This study was to determine the optimum conditions of malt extracting temperature, extracting time of malt in water, ratio of malt to water, and rice volume of malt extract water on saccharification in producing sikhe (sweet rice drink) using central composite design of response surface methodology. Glucose and maltose were analyzed by a biosensor having dual cathode system. The optimum temperatures of malt extracting for glucose and maltose were 60 and $55^{\circ}C$. The saccharification power for the two sugars was highest when malt powder soaked for 6.5 and 5.75 hour, respectively. And ratios of malt to water for optimum saccharification were 1 : 6.3 to 1 : 8.8, respectively. The optimum volumes of malt extracting to rice for the two sugars were 0.48% and 0.6%, respectively. The application of response surface methodology to sikhe processing showed a good correlation with high significance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1102-1107
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• 2001

The mixing conditions of kochujang added pumpkin extract were optimized by response surface methodology. The organoleptic color of pumpkin kochujang showed the maximum score for the mixing condition of 433.63 g pumpkin extract, 81.76 g red pepper powder and 17.03 g meju powder. The organoleptic aroma of pumpkin kochujang revealed the maximum score for the condition of 437.07g pumpkin extract, 83.65 g red pepper powder and 11.90 g meju powder. The organoleptic taste of pumpkin kochujang showed the maximum score in 382.94 g pumpkin extract, 63.44 g red pepper powder and 13.10 g meju powder. The optimum mixing conditions for overall acceptability of pumpkin kochujang were 442.04 g pumpkin extract, 62.58 g red pepper powder and 16.30 g meju powder.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.202-206
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• 2014

A response surface method based on a central composite design experiment was used to determine the optimum conditions for pretreatment of persimmon peel. It was mathematically predicted that the maximum amount of reducing sugars would be obtained at an $H_2SO_4$ concentration of 1.77% (w/v) and a heat treatment time of 26.4 min. A reducing sugar concentration of 63.23 g/l was obtained under the optimum pretreatment conditions determined by RSM. Under anaerobic growth conditions, Saccharomyces cerevisiae NK28 produced 15.52 g/l of ethanol with a yield of 0.34 g ethanol/g glucose from pretreated persimmon peel, which corresponded to 14% and 26% enhancements in ethanol productivity and ethanol yield, respectively, compared with those obtained in aerobic growth conditions. This study suggests that persimmon peel might be a useful substrate for bioethanol production by yeast fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.654-661
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• 1997

Response surface methodology was applied to monitor dynamic changes in free sugars and free amino acids associated with browning reaction during roasting of Polygonatum odoratum roots. Second-order model for qualities of water- soluble extracts was employed to generate contour maps and response surfaces. Browning color intensity of water-soluble extracts was increased with the roasting time up to around 14$0^{\circ}C$, but decreased in increasing temperature above L6O"C. Free sugars, mainly composed of sucrose and fructose, were remarkably decreased at roasting under the higher temperature and longer time, while glucose linearly increased with the increase of roasting temperature up to 15$0^{\circ}C$. Most of free amino acids was decreased in their amounts in Proportion to the roasting temperature and time, while threonine and lysine were insignificantly increased under the roasting conditions at above 17$0^{\circ}C$ and 60min.0min.

• Food Science and Preservation
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• v.12 no.3
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• pp.209-215
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• 2005

Response surface methodology(RSM) was applied to monitor the elimination rate of heavy metals(Pb, Cd) and soluble solids depending on the steaming and roasting conditions of Polygonatum odoratum roots. Experiments of 16 different steaming and roasting conditions based on a central composite design for steaming time($60{\sim}180$ min), roasting temperature($110{\sim}150^{\circ}C$), and roasting time($10{\sim}50$ min) were conducted, thereby predicting the steaming and roasting conditions for the maximal responses; soluble solids($71.47\%$) at 65.24 min, $126.93^{\circ}C$ and 37.58 min; Pb removal rate($18.87\%$) at 71.23 min, $119.81^{\circ}C$ and 24.35 min; Cd removal rate($50,85\%$) at 160.89 min, $126.43^{\circ}C$ and 15.81 min, respectively. The optimum conditions estimated by RSM for the maximized values of soluble solids and heavy metal elimination rates were $165{\sim}180$ min of steaming time, $120{\sim}135^{\circ}C$ of roasting temperature, and $30{\sim}45$ min of roasting time, respectively. These estimated values were in agreement with those measured by real experiments.