• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.192-197
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• 2015

In many fields, the importance of reducing weight is increasing. A product should be designed such that it is profitable, by lowering costs and exhibiting better performance than other similar products. In this study, the mass and deflection of steel structures have to be reduced as objective functions under constraint conditions. To reduce computational analysis time, central composite design(CCD) and D-Optimal are used in design of experiments(DOE). The accuracy of approximate models is evaluated using the $R^2$ value. In this study, the objective functions are multiple, so the non-dominant sorting genetic algorithm(NSGA-II), which is highly efficient, is used for such a problem. In order to verify the validity of Pareto solutions, CAE results and Pareto solutions are compared.

• Communications for Statistical Applications and Methods
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• v.21 no.2
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• pp.161-168
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• 2014

In mixture experiments with process variables, we consider the case that some of process variables are either uncontrollable or hard to control, which are called noise variables. Given the such mixture experimental data with process variables, first we study how to search for candidate models. Good candidate models are screened by the sequential variables selection method and checking the residual plots for the validity of the model assumption. Two methods, which use numerical optimization methods proposed by Derringer and Suich (1980) and minimization of the weighted expected loss, are proposed to find a cost-effective robust optimal condition in which the performance of the mean as well as the variance of the response for each of the candidate models is well-behaved under the cost restriction of the mixture. The proposed methods are illustrated with the well known fish patties texture example described by Cornell (2002).

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.67-74
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• 2008

The important dynamic specifications in the aluminum automobile body design are the vibrations and crashworthiness in the views of ride comforts and safety. Thus, considerable effort has been invested into improving the performance of mechanical structures comprised of the interactive multiple sub-structures. Most mechanical structures are complex and are essentially multi-criteria optimization problems with objective functions retained as constraints. Each weight factor can be defined according to the effects and priorities among objective functions, and a feasible Pareto-optimal solution exists for the criteria-defined constraints. In this paper, a multi-criteria design based on the Pareto-optimal sensitivity is applied to the vibration qualities and crushing characteristics of front structure in the automobile body design. The vibration qualities include the idle, wheel unbalance and road shake. The crushing characteristic of front structure is the axial maximum peak load.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.167-173
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• 2014

Surimi (or fish paste) products are one of the most representative processed seafoods in Korea. In a previous study, we evaluated the potential use of rice flour as an agent to replace wheat flour in surimi products. In this study, we optimized the content of rice flour and water in surimi products using response surface methodology. Rice flour content ($X_1$, w/w) and water content ($X_2$, v/w) were chosen as independent variables and gel strength ($Y_1$) and overall acceptance ($Y_2$) as dependent variables. Optimal conditions of $X_1$ and $X_2$ were 14% and 9.1%, respectively, and the predicted values of the multiple response optimal conditions were $Y_1=656.4(g{\cdot}cm)$ and $Y_2=6.34$. Under optimal conditions, the experimental values of $Y_1$ and $Y_2$ were $647.8(g{\cdot}cm)$ and 6.21, respectively, which were similar to the predicted values. Surimi products that are prepared under optimum conditions were similar in gel strength to those of commercial products. However, its sensory evaluation score was higher than that of the commercial products. In conclusion, rice flour can not only be used as an alternative to wheat flour, but it also can be used to improve the quality of surimi products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.31-36
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• 2011

This study developed a normal temperature-circulatable retort-sterilized crab analog (RSCA) with a long shelf-life by retort sterilization. We examined the optimum sterilization conditions and quality characteristics of the RSCA. A central composite design for response surface methodology (RSM) was adopted to optimize of the retort sterilization. The central composite design consisted of 11 samples: four factorial points, four star points, and three central points. The sterilization temperature and $F_0$-value for retort sterilization were the independent variables, and the shearing force, whiteness, and sensory score for texture were the dependent variable. The RSM analysis of the multiple response optimization for the RSCA using the Minitap statistical programing gave an $F_0$-value of 3.3 min. at $117.5^{\circ}C$. The RSM analysis also indicated that the sterilization temperature during retort sterilization was the most influential factor, while the $F_0$-value had little effect on the quality of the RSCA. The moisture, pH and volatile basic nitrogen contents of the RSCA product were 73.1%, 7.3 and 17.2 mg/100 g, respectively, and viable cells count was >18 CFU/g. And sensory quality characteristics of this RSCA was similar to those of a commercial crab analog.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.275-283
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• 2023

This study optimized the vegetable rice porridge preparation process with Israeli carp Cyprinus carpio (VRP-IC). The optimum heating period for Israeli carp paste (IC-P) in a retort was 120 min as per yield results. Response surface methodology was performed with IC-P/[rice (glutinous rice: non-glutinous rice=6:4) (Rice, RI)+vegetable (carrot: zucchini=1:1) (vegetable, VE)] (X₁) and RI/VE (X₂) as independent variables; viscosity (Y₁), hardness (Y₂), amino nitrogen (Y₃), and overall sensory acceptance (Y₄) as dependent variables. Optimum rates of IC-P, RI, and VE were 47.37%, 24.49%, and 28.15%, respectively; predicted multiple response optimum values for the dependent variables were 20,150 mPa·s, 2,002.9 N/m2, 193.1 mg/100 g, and a 6.4 score for Y₁, Y₂, Y₃, and Y₄, respectively. Under optimum conditions, experimental values for Y₁, Y₂, Y₃, and Y₄ were 20,359.8±191.9 mPa·s, 2,015.0±9.6 N/m2, 188.1±4.9 mg/100 g, and a 6.5±0.2 score, respectively, which were not significantly different from the predicted values (P < 0.05). Results of F0 value, viscosity, hardness, volatile odor intensity, and browning suggested that the optimum sterilization period was 25 min. VRP-IC prepared under the optimum conditions was superior to commercial vegetable rice porridges in sensory evaluations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.284-292
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• 2023

This study was conducted to optimize the cookie preparation using Israeli crap Cyprinus carpio paste (C-ICP). The results of response surface methodology suggested the selection of other supplementary materials/[soft flour (SF) + ICP] (X₁) and SF/ICP (X₂) as independent variables, and hardness (Y₁), yellowness (Y₂), amino acid nitrogen (Y₃), and overall sensory acceptance (Y₄) as dependent variables. The optimal conditions of OS, SF, and ICP were 35.0%, 40.3% and 24.7%, respectively, and the predicted values of the multiple response optimal conditions Y₁, Y₂, Y₃, and Y₄ were 2,006.2 N/m2, 21.1, 30.0 mg/100 g, and a score of 6.6, respectively. Under the optimum conditions, experimental values of Y₁, Y₂, Y₃, and Y₄ were 2,010.5 ± 22.3 N/m2, 21.6 ± 0.5, 29.6 ± 0.7 mg/100 g, and a score of 6.9 ± 0.3, respectively, which were not significantly different from the predicted values (P < 0.05). The results on hardness, moisture, VCI yellowness, and lightness suggested that the optimum heating period was 20 min. C-ICP prepared under the optimum conditions was superior in sensory evaluation to cookies without the Israeli carp paste.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.83-89
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• 2003

2,4-Dichlorophenoxyacetic acid (2,4-D) as a widely used herbicide has caused serious environmental problems because of its difficult decomposition in nature. We isolated the strain capable of metabolizing 2,4-D as sole carbon and energy source by an enrichment culture technique from the 2,4-D contaminated soil collected at orchard in Gwangju, Korea. This strain was identified tentatively as Aeromonas sp. NOH2. With this strain, we established the response surface methodology (Box-Behnken Design) to optimize the principle parameters for maximizing biodegradation of 2,4-D such as culture pH, temperature, and nutrient concentration in liquid batch culture. The ranges of parameters were obtained from preliminary works done at our laboratory and chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 5, 20, and 35 g/1 nutrient concentration. Initial concentration of 2,4-D was 500 ppm and nutrient source was tryptic soy broth. The experimental data were significantly fitted to a second order polynomial equation using multiple regression. The most important parameter influencing 2,4-D degradation and biomass production was nutrient concentration. For 2,4-D degradation, the optimum values of pH and temperature, and nutrient concentration were obtained at pH (6.5), temperature (31.8 to $32.1^{\circ}C$), and nutrient concentration (29.6 to 30.1.0 g/1).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.197-206
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• 2011

This study was conducted to optimize processing of functional seasoning sauce for instant noodles (SSIN) using response surface methodology (RSM), and to compare the functional properties of commercial SSIN. Central composite designs were adopted in the SSIN processing for ingredient formula optimization. Concentrations of sea tangle ($X_1$), traditional soy sauce ($X_2$), yeast extract ($X_3$) and Ecklonia cava extract (ECE) ($X_4$) were chosen as independent variables. The dependent variables were glutamic acid content ($Y_1$), score of sensory evaluation ($Y_2$), and antioxidative activity ($Y_3$). We found the optimal conditions to be $X_1$=3.91%, $X_2$=20.57%, $X_3$=3.04% and $X_4$=3.78%. The predicted values of the multiple response optimal conditions were $Y_1$=124.0 mg/100 g, $Y_2$=7.6 and $Y_3$=1.95. The antioxidative activity (PF, PF=oil induction period with sauce/oil induction period with distilled water) and ACE inhibitory activity of ECE-added SSIN were 1.98 and 29.0%, respectively, which were significantly higher than those of commercial SSIN (1.09 and 4.4%, respectively).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.724-732
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• 2021

This study used response surface methodology to investigate the optimal conditions to reduce the bitterness of alcalase-treated anchovy hydrolysate (AAH) by the aminopeptidase active fraction (AAF) derived from the common squid Todarodes pacificus hepatopancreas. The central composite design selected AAF/AAH ratio (X₁, %) and hydrolysis time (X₂, h) as independent variables, and the degree of hydrolysis (Y₁) and bitterness (Y₂) as dependent variables. The uncoded values of the multiple response optimization for independent variables were 3.4% for the AAF/AAH ratio and 9.2 h for the hydrolysis time. The predicted values of the yield and bitterness score of alcalase-AAF continuously treated anchovy hydrolysate (AAAH) under the optimized conditions were 68.9% and 4.6 points, respectively. Their measured values of 69.5% for yield and 4.6±0.5 points for bitterness were similar to the predicted values. The food components of AAAH were 91.4% (moisture), 7.5% (protein), 0.1% (lipid) and 0.6% (ash). The findings indicate the potential value for use as an anchovy seasoning base. The results also confirm that the bitterness of AAH was remarkably improved by AAF and implicates AAF derived from squid hepatopancreas as a good enzyme to catalyze reduced bitterness.