• Korean Chemical Engineering Research
• /
• v.53 no.2
• /
• pp.199-204
• /
• 2015

Response surface methodology (RSM) in combination with a 17-run central composite design (CCD) was applied to optimize the non-catalytic hydrolysis of lard using subcritical water to produce fatty acids (FA). The effects of three variables including temperature, molar ratio of water to oil and time, and their relationship on FA content were investigated. A quadratic regression model was employed to predict the FA contents. Optimum reaction conditions for maximizing the FA content were obtained as follows: reaction temperature of $288.5^{\circ}C$, molar ratio of water to oil of 39.5 and reaction time of 29.5 min. Under the optimum conditions, the predicted and experimentally obtained FA contents were 97.06% and 96.99%, respectively.

• Korean journal of food and cookery science
• /
• v.32 no.3
• /
• pp.279-289
• /
• 2016

Purpose: This study was to determine the optimal composite recipe of rice cookie with 3 concentrations of Spergularia Marina L. Griseb, sugar and grape seed oil, using central composite design (CCD). Methods: The mixing condition of rice cookie was optimized by subjecting it to sensory evaluation and mechanical and physicochemical analysis using response surface methodology (RSM). Results: The results of mechanical and physicochemical analysis showed significant values for lightness, redness, yellowness, hardness, spread factor, loss rate, leavening rate, density, pH, moisture, sweetness and saltiness (p<0.05), and the results of sensory evaluation showed significant values for color, flavor, taste, texture, appearance and overall quality (p<0.05). As a result, the optimal sensory ratio was found to be 6.40 g of Spergularia Marina L. Griseb, 63.49 g of sugar and 106.19 g of grape seed oil. Conclusion: In conclusion, Spergularia Marina L. Griseb is a good source in natural antioxidant aimed at replacing salt, and it is possible to use in cookie or other food products to substitute salt.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.1
• /
• pp.138-144
• /
• 2013

The automation technology for overlay welding is needed due to the occurrence of severe corrosion and abrasion on the surface of internal contact in different shape of fittings. In Korea, different shapes of fittings have been manufactured by using the imported equipment of overlay welding automation at some companies. Thus the research on the development of overlay welding automation system (in short, OWAS) for a large L-type tube is urgently needed. In this paper, the investigation is focused on the optimal design of a supporting base for the (currently developing) OWAS of large L-type tube. Specifically we assume that the base which supports the equipment during the process of overlay welding is loaded as self-weight in the direction of gravity through static analysis especially when it is rotated 180 degree on the OWAS. For optimal design of a supporting base for OWAS of large L-type tube, Solidworks(R) (for 3-dimensional modelling) and ANASYS Workbench(R) (for structural analysis) are incorporated so as to proceed an optimization routines based on Response Surface Method (RSM) and Design of Experiment (DOE). In more specific, DOE finds out major factors (or dimensions) of the supporting base by using MINITAB(R). Then the regression equations between design variables (the major factors of supporting base) and response variables (deformation, stress and safety factor for the supporting base), which will be resulted in by RSM, verify the major factors of DOE. In the next step, Central Composite Design (CCD) plans 20 simulations of ANASYS Workbench(R) and then figures out the optimal values of design variables which will be reflected on the manufacturing of supporting base. Finally welding experiment is conducted to figure out the influence of overlay welding quality in applying the optimized design values of supporting base to the actual OWAS.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.1
• /
• pp.116-120
• /
• 2009

Response surface methodology (RSM) was applied to optimize alcohol fermentation of concentrated grape juice. Sugar concentration ($X_1$), agitation rate ($X_2$) and fermentation time ($X_3$) were chosen as the independent variables of the central composite design (CCD). Dependent variables were alcohol content ($Y_1$) and total acidity ($Y_2$). To optimize two dependent variables, desirability function was defined as $Y_1$=10.0% and $Y_2$=minimum. The optimum conditions for alcohol fermentation were $19.98^{\circ}Bx$ (sugar concentration), 104.1 rpm (agitation rate) and 89.67 hr (fermentation time). The predicted responses were 10.0% in alcohol content and 0.86% in total acidity. The coefficients of determination ($R^2$) were 0.948 and 0.958, which indicate that the model fit was highly significant (p<0.001). The experimental values were 10.1% for alcohol content and 0.88% for total acidity. These values were similar to the predicted values from RSM.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.3 s.234
• /
• pp.455-461
• /
• 2005

This research studied robust design of composite hand for LTR (LCD glass Transfer Robot). $1^{st}$ DOE (Design of Experiment) was conducted to find out vital few Xs. 108 experiments were performed and their results were statistically analyzed. Pareto chart analysis shows that the geometric parameters (height and width of composite beam) are more important than material parameters $(E_{1},\;E_{2})$ or stacking sequence angle. Also, the stacking sequence of mid-layer is more important than that of outer-layer. The main effect plots shows that the maximum deflection of LTR hand is minimized with increasing height, width of beam and layer thickness. $2^{nd}$ DOE was conducted to obtain RSM (Response Surface Method) equation. 25 experiments were conducted. The CCD (Central Composite Design) technique with four factors was used. The coefficient of determination $(R^{2})$ for the calculated RSM equation was 0.989. Optimum design was conducted using the RSM equation. Multi-island genetic algorithm was used to optimum design. Optimum values for beam height, beam width, layer thickness and beam length were 24.9mm, 186.6mnL 0.15mm and 2402.4mm respectively. An approximate value of 0.77mm in deflection was expected to be a maximum under the optimum conditions. Six sigma robust design was conducted to find out guideline for control range of design parameter. To acquire six sigma level reliability, the standard deviation of design parameter should be con trolled within $2{\%}$ of average design value

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.361-362
• /
• 2006

This paper presents the robust design of gripper part for a high-speed LCD (Liquid Crystal Display) transfer system. In this paper, the 1st DOE (Design of Experiment) is conducted to find out main-effect factors fur the design of gripper part. Thirty-six experiments are performed using $ANSYS^{(R)}$ and their results are statistically analyzed using $MINITAB^{(R)}$, which shows that the factors, i.e., First-width, Second-width, Rec-width, and thickness of gripper part, are more important than other factors. The main effect plots shows that the maximum deflection and mass of gripper part are minimized by increasing First-width, Second-width, Rec-width and thickness. The 2nd DOE is conducted to obtain RSM (Response Surface Method) equation. The CCD (Central Composite Design) technique with four factors is used. Optimum design is conducted using the RSM equation. Genetic algorithm is used for optimal design. Six sigma robust design is conducted to find out a guideline for control range of design parameter. To obtain six sigma level reliability, the standard deviations of design parameters are shown to be controlled within 5% of average design value.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.1
• /
• pp.50-60
• /
• 2013

High temperature proton exchange membrane fuel cells (PEMFCs) using phosphoric acid (PA) doped polybenzimidazole (PBI) membranes have been concentrated as one of solutions to the limits with traditional low temperature PEMFCs. However, the amount of reported experimental data is not enough to catch the operational characteristics correlated with cell performance and durability. In this study, design of experiments (DOE) based operational optimization method for high temperature PEMFCs has been proposed. Response surface method (RSM) is very useful to effectively analyze target system's characteristics and to optimize operating conditions for a short time. Thus RSM using central composite design (CCD) as one of methodologies for design of experiments (DOE) was adopted. For this work, the statistic models which predict the performance and degradation rate with respect to the operating conditions have been developed. The developed performance and degradation models exhibit a good agreement with experimental data. Compared to the existing arbitrary operation, the expected cell lifetime and average cell performance during whole operation could be improved by optimizing operating conditions. Furthermore, the proposed optimization method could find different new optimal solutions for operating conditions if the target lifetime of the fuel cell system is changed. It is expected that the proposed method is very useful to find optimal operating conditions and enhance performance and durability for many other types of fuel cell systems.

• Journal of Environmental Health Sciences
• /
• v.48 no.3
• /
• pp.167-175
• /
• 2022

Background: Disinfection is essential to provide drinking water from a water source. The disinfection process mainly consists of the use of chlorine and ozone, but when chlorine is used as a disinfectant, the problem of disinfection by-products arises. In order to resolve the issue of disinfection by-products, electro-chlorination technology that produces chlorine-based disinfectants from salt water through electrochemical principles should be applied. Objectives: This study surveys the possibility of optimally producing active chlorine from synthetic NaCl solutions using an electro-chlorination system through RSM. Methods: Response surface methodology (RSM) has been used for modeling and optimizing a variety of water and wastewater treatment processes. This study surveys the possibility of optimally producing active chlorine from synthetic saline solutions using electrolysis through RSM. Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. Results: Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. A central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. Conclusions: The concentration of the synthetic NaCl solution and the distance between electrodes had the greatest influence on the generation of hypochlorite disinfectant. The closer the distance between the electrodes and the higher the concentration of the synthetic NaCl solution, the more hypochlorous acid disinfectant was produced.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.18 no.2
• /
• pp.29-43
• /
• 2019

The calibration of microscopic traffic simulation models has received much attention in the simulation field. Although no standard has been established for it, a genetic algorithm (GA) has been widely employed in recent literature because of its high efficiency to find solutions in such optimization problems. However, the performance still falls short in simulation analyses to support fast decision making. This paper proposes a new calibration procedure using a dual GA and central composite design (CCD) in order to improve the efficiency. The calibration exercise goes through three major sequential steps: (1) experimental design using CCD for a quadratic response surface model (RSM) estimation, (2) 1st GA procedure using the RSM with CCD to find a near-optimal initial population for a next step, and (3) 2nd GA procedure to find a final solution. The proposed method was applied in calibrating the Gipps car-following model with respect to maximizing the likelihood of a spacing distribution between a lead and following vehicle. In order to evaluate the performance of the proposed method, a conventional calibration approach using a single GA was compared under both simulated and real vehicle trajectory data. It was found that the proposed approach enhances the optimization speed by starting to search from an initial population that is closer to the optimum than that of the other approach. This result implies the proposed approach has benefits for a large-scale traffic network simulation analysis. This method can be extended to other optimization tasks using GA in transportation studies.

• Journal of the Korean Dietetic Association
• /
• v.16 no.4
• /
• pp.332-340
• /
• 2010

This study was conducted to develop an optimal composite recipe for nutritional cookies containing beet powder. Flour was substituted with whole wheat flour containing germinated brown rice powder. The sensory optimal composite recipe was determined by making cookies containing two levels of beet powder (A) or butter (B) according to Central Composite Design (CCD) and by conducting the sensory evaluation and instrumental analysis according to Response Surface Methodology (RSM). Using CCD, the results of physical measurement for ten conditions with two variables were obtained. The values of lightness (L), redness (a), and yellowness (b) were in the range of 36.65~49.03, 22.15~29.31, and 13.96~19.34, respectively. Lightness decreased significantly (P<0.001) and redness increased significantly (P<0.01) upon an increase in beet powder. The results of sensory evaluation showed very significant values in color (P<0.05), texture (P<0.05), flavor (P<0.01), taste (P<0.05), and overall quality (P<0.05), whereas those of the instrumental analysis showed significant values in lightness (P<0.001), redness (P<0.01), spread ratio (P<0.01), and hardness (P<0.05). As a result, the optimal sensory ratio of beet cookie was calculated for beet powder 7.75 g and butter 77.88 g.