• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.6
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• pp.591-597
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• 1999

When fuzzy logic controllers which are designed based on plant models and intuitive base are applied to real plants, the control systems may not give satisfactory control results due to the modeling error and the lack of knowledge on the plants. In that case. the controller must be retuned by adjusting the control parameters; this retuning process may require a large number of trial-and-error evaluations and thus much time and cost. In order to resolve these problems, we propose a systematic and efficient procedure for designing a fuzzy logic controller using response surface methodology. First wc select the initial optimal conditions of control parameters using a genetic algorithm, in which a nominal plant model with intrinsic modeling errors is used. And then we determine the tinal optimal conditions of the control parameters using response surface methodology. Computer simulations are performed to verify the capability of the proposed method.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.67-73
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• 2014

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.943-950
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• 2009

Cadmium (Cd) adsorption onto the activated carbon containing hydroxyapatite (HAP) was investigated in batch experiments and response surface methodology (RSM) using the Box-Behnken methods were applied to the experimental results. Cd adsorption with different HAP mass ratio of from 10% to 30%. With more HAP, Cd was more adsorbed. These results suggest that the higher HAP mass causes an increase of the ion exchange potential of the HAP sorbent. Equilibrium experimental results from Cd adsorption was fitted to Langmuir and Freundlich isotherm models. Cd adsorption on HAP sorbent were found to follow the Freundlich isotherm model well in the initial adsorbate concentration range. Also, Cd adsorption was a function of the HAP mass ratio ($x_1$), initial Cd concentration ($x_2$), and initial pH ($x_3$) from the application of the RSM. Statistical results showed the order of significance of the independent variables to be initial Cd concentration > HAP mass ratio > initial pH.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.623-636
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• 2014

This study was performed to determine the optimal composition of muffins added with dropwort powder, egg and sugar. The experiment was designed based on BBD (Box-behnken design), and evaluation was carried out by means of RSM (response surface methodology), consisting of 13 experimental points with three replicates each for three independent variables dropwort powder, eggs and sugar. Using F-test, height, moisture, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity, L-value, a-value, springiness, cohesiveness, chewiness, brittleness, color, and appearance acceptability were expressed as a linear model, whereas pH, b-value, flavor, taste, and texture were expressed as a quadratic model. After swallow and overall acceptability were expressed as a 2FI model. As dropwort powder content increased, 1,1-diphenyl-2picriylhydrazyl (DPPH) radical scavenging activity increased. Increasing amounts of dropwort powder led to reduction of sensory scores for color, appearance, flavor, taste, and texture quality. The optimum formulation determined by the numerical and graphical methods were similar: dropwort powder 6 g, egg 77 g, and sugar 60 g.

• Natural Product Sciences
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• v.23 no.1
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• pp.9-15
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• 2017

DF formula is comprised of three traditional herbs, Ephedra intermedia, Rheum palmatum and Lithospermum erythrorhizon, and locally used for treating of the metabolic diseases, such as obesity and diabetes in Korea. We tried to optimize the extraction conditions of two major components, (-)-ephedrine and (+)-pseudoephedrine, in DF formula using response surface methodology with Box-Behnken design (BBD). The experimental conditions with 70% for EtOH concentrations, 4.8 hour for extraction hours and 8.7 times for the solvent to material ratio were suggested for the optimized extraction of DF formula with the highest amounts of (-)-ephedrine and (+)-pseudoephedrine in the designed model.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1342-1350
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• 2009

This paper investigates the production and optimization of $\beta$-galactosidase enzyme using synthetic medium by Kluyveromyces lactis NRRL Y-8279 in stirred tank bioreactor. Response surface methodology was used to investigate the effects of fermentation parameters on $\beta$-galactosidase enzyme production. Maximum specific enzyme activity of 4,622.7 U/g was obtained at the optimum levels of process variables (aeration rate 2.21 vvm, agitation speed 173.4 rpm, initial sugar concentration 33.8 g/L, incubation time 24.0 hr). The optimum temperature and pH of the $\beta$-galactosidase enzyme produced under optimized conditions were $37^{\circ}C$ and pH 7.0, respectively. The enzyme was stable over a pH range of 6.0-7.5 and a temperature range of $25-37^{\circ}C$. The $K_m$ and $V_{max}$ values for O-nitrophenol-$\beta$-D-galactopyranoside (ONPG) were 1.20 mM and $1,000\;{\mu}mol/min{\cdot}mg$ protein, respectively. The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in $\beta$-galactosidase enzyme production. Hence, this study fulfills the lack of using mathematical and statistical techniques in optimizing the $\beta$-galactosidase enzyme production in stirred tank bioreactor.

• Food Quality and Culture
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• v.2 no.1
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• pp.13-19
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• 2008

Recently, though mulberry's superiority as a functional food has been proven, its use as a food material is limited. Therefore, in this study, to develop jelly using mulberry that is compatible with Korean tastes as health functional food by grafting the method to manufacture jelly consumed as a dessert or a snack in the west, according to the central composite design, mulberry jelly was produced by varying the content of citric acid ($X_1$), sucrose ($X_2$), and gelatin ($X_3$) at 5 levels. And by applying the response surface methodology, rheology and sensory preference experiment results were analyzed, the optimization of mulberry jelly manufacturing condition was carried out, and studies on the analysis of composition were performed. As the sensory preference of mulberry jelly, except the flavor, the remaining hardness, elasticity, sweetness, color, and the overall quality were found to be significant. And similarly, it was found to be influenced greatly by gelatin content generally. Based on the overlapped part of categories, in the range of factors that satisfy all the sensory categories, the value located in the middle was calculated, the optimization point was obtained, and it was found to be 6.2 g citric acid, 141.0 g sugar, and 13.5 g gelatin.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.176-182
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• 2011

The bacteriocin-producing lactic acid bacteria Enterococcus faecium DB1 was isolated from Korean traditional gajami sikhae. Culture conditions were optimized by response surface methodology (RSM) to maximize bacteriocin DB1 production. E. faecium DB1 displayed the highest bacteriocin activity when grown in modified MRS medium containing sucrose, rather than glucose, as a carbon source. The effects of temperature, initial pH, and sucrose concentration were tested to determine the optimum conditions for maximum bacteriocin production by E. faecium DB1. A central composite design was used to control the three variables in the experiment. RSM revealed that the optimum values for bacteriocin production were 27.66 g/L sucrose, temperature of $34.37^{\circ}C$, and an initial pH of 6.54. A 2.08-fold increase in bacteriocin production was obtained with sucrose-containing MRS medium compared to production in standard MRS medium.

• Culinary science and hospitality research
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• v.23 no.4
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• pp.81-92
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• 2017

This research was studied to optimize the recipe of rice pound cake with two concentrations of Euonymus alatus and grape seed oil, using central composite design (CCD). The mixing condition of rice pound cake was optimized by subjecting it to sensory evaluation and mechanical and physicochemical analysis, using response surface methodology (RSM). The results of the mechanical and physicochemical analysis showed significant values for color (lightness, redness, yellowness), texture (hardness, springiness, chewiness, gumminess, cohesiveness), loss rate, volume, specific volume, sweetness, saltiness, moisture content and pH (p<0.05). The results of the sensory evaluation showed significant values for color, flavor, taste, softness, appearance and overall quality (p<0.05). As a result, the optimized compounding ratio was found to be 4.28 g of Euonymus alatus and 33.18 g of grape seed oil.