• Journal of Ginseng Research
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• v.18 no.1
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• pp.53-59
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• 1994

To develop the methodology of the quantitative analysis of saponin in ginseng milk, conditions of the saponin extraction were optimized using the fractional factorial design with 3 variables and 3 levels by a RSM computer program. The extraction of saponin increased with an increase in extraction temperature up to $90^{\circ}C$ and then decreased significantly at $100^{\circ}C$. Extraction time affected the saponin yield in a similar trend. On the other hand, decreasing cooling temperature increased the amount of the saponin extracted. Recovery yield of the saponin from ginseng milk varied from 70.0% to 92.9%. The optimum extraction temperature, time and cooling temperature determined by partial differentiation of the model equation were $86^{\circ}C$, 2.83 hrs and $4^{\circ}C$, respectively. Key words Ginseng milk, saponin, response surface methodology.

• Progress in Medical Physics
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• v.17 no.1
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• pp.1-5
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• 2006

A parallel plate detector containing PTFE films in FEP film for relative dosimetry was designed to measure the response of detectors to S and 10 MV X-rays from a medical linear accelerator through different thicknesses of lead. The dielectric materials were 100 m thick. The set-up conditions for measurements with this detector were as follows: SSD=100 cm the test detector was at a depth of 5 cm and the reference chamber was at a depth of 10 cm from the phantom surface for 6 and 10 MV X-rays. Lead blocks were designed to cover the irradiated field. They were added to the tray to increase thickness sequentially. We found that the detector response decreased exponentially with the thickness of lead added. The linear attenuation coefficients of the test detector and reference chamber were 0.1414 and 0.541, respectively, for 6 MV X-rays and 0.1358 and 0.5279 for 10 MV X-rays. The test detector response was greater than that of the reference chamber. The response function was calculated from the measured values of the test detector and reference chamber using optimization. These optimized constants for the detector response function were independent of theenergy. As a result of optimizing the response function between detectors, the use of a relative dosimeter was validated, because the response of the test detector was 1% for 6 MV X-rays and 4% for 10 MV X-rays.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.1
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• pp.27-33
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• 2010

This paper focuses on the design of microspeakers with minimum flux leakage, for use in radiotelegraphy. The response surface methodology (RSM) is applied as the optimization technique for obtaining a large magnetic force and a small flux leakage on diaphragm. The object functions of this optimization are the magnetic force and the flux leakage along three factors; pole piece thickness, magnet grade and yoke thickness, which are determined by the design of the experiment. The magnetic force and the flux leakage are calculated for each condition and optimized by results evaluated with RSM. For a pole piece thickness of 0.9 mm, a magnet grade of N42H and a yoke thickness of 0.75 mm, the magnetic force is satisfied as initial model and flux leakage is decreased to 11.8% than initial model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1331-1337
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• 2013

This study deals with the structural optimization of hybrid vertical-axis wind turbine blades using a response surface method (RSM). The structural analysis results suggest that the stress of hybrid vertical-axis wind turbine blades exceeds the yield strength. Optimization techniques are then applied to structural design to ensure a safe structure. First, the design factors that strongly influence the structural response are identified. The RSM was applied based on the design of experiments. The objective function and constraint terms set the weight and allowable stress, respectively. Furthermore, sensitivity analysis was conducted to indicate the effects of the design factors on the stress and weight. Finally, structural design was performed for the hybrid vertical-axis wind turbine blade.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.32-38
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• 2005

In this research, a procedure to improve the feasibility of design space is proposed by an approximation model. The Chebyshev Inequality is used as the criterion of modification of design space. This procedure is applied to the aero-elastic transonic wing design problem and the feasibility of the design space is greatly improved. Also the optimization results are improved by appling this procedure. That is, the probability to satisfy all imposed constraints is increased and the better design points are included in design space after this procedure. And the use of both a second-order response surface model and the Kriging model is investigated and compared in accuracy, efficiency, and robustness as approximation models in this procedure for different sampling methods. As a result, the second-order response surface model is more appropriate for our application than the Kriging model, because it is linear enough to be fitted well by the response surface model.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.621-627
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• 2016

Low-priced hydrogen is required in petrochemical industry for producing low-sulfur oil, and upgrading low-grade crude oil since environmental regulations have been reinforced. Steel industry can produce hydrogen from by-product gases such as Blast Furnace Gas (BFG), Coke Oven Gas (COG), and Linze Donawitz Gas (LDG) with water gas shift (WGS) reaction by catalysis. In this study, we optimized conditions for WGS reaction with commercial catalysts by BFG and LDG. In particular, the influence on activity of gas-hourly-space-velocity, and $H_2O/CO$ ratios at different temperatures were investigated. As a result, 99.9%, and 97% CO conversion were showed with BFG, and LDG respectively under $350^{\circ}C$ High Temperature Shift (HTS), $200^{\circ}C$ Low Temperature Shift (LTS), 3.0 of $H_2O/CO$, and $1500h^{-1}$ of GHSV. Furthermore, 99.9% CO conversion lasted for 250 hours with BFG as feed gas.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.617-622
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• 2003

Experimental designs were applied to optimize the mixture ratio for the extrudate made by soymilk residue and corn grits. Nine candidate points were examined for their significance on extrudate using the modified distance design. Bending force, expansion ratio, bulk density, water solubility index (WSI), water absorption index (WAI) and color $(L^*,\;a^*,\;b^*)$ were the significant factors improving the extruded cereal production, and these values were applied to the mathematical models. Results showed that bending force, expansion ratio WSI, WAI and color $(L^*,\;b^*)$ increased with increasing the corn grits, whereas bulk density tended to decrease. The statistical study showed that the fitted models were adequate to describe the contour plot and all responses. Optimum mixture ratio allowing to maximize the two responses (expansion ratio and $b^*$) and minimize the response (WAI) were examined with a numerical optimization methods. The numerical optimization method was obtained as 53.18% : 46.19% (corn grits : soymilk residue).

• Membrane Journal
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• v.2 no.1
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• pp.21-32
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• 1992

Hydrogen-permselective silica membranes were synthesized within tim walls of porous Vycor tubes by chemical vapor depostion of $SiO_2$. Film deposition was carried out using $SiCl_4$ hydrolysis either in the oppm shag reactants or in the one-sided geometry. At temperatures above $600^{\circ}C$ the permeation rate of hydrogen thorough the silica films varied between 0.01 and $025cm^3(STP)/cm^2-min-atm$ depending on the reaction geometry and the $H_2 : N_2$ permeation ratio was about 1000. Permeation rates of both $H_2$ and $N_2$ increased with increasing temperature. The silica membranes produced by one-sided deposition have higher hydrogen permmeation rates than those produced by the opposing reactants geometry although the membranes formed in an opposing reactants geometry were relatively stable during the heat treatment or after exposure to ambient air. These membranes can be applied to high temperature gas separations or membrane reactors once the film deposition process is optimized to get high permeability as well as good stability.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.416-421
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• 2011

In this paper, the relationship of chamber contamination and the intensity change of specific wavelength was investigated. "diff_CO" formula was introduced to rule out background noise caused by external conditions and to detect when the polymer is removed from the chamber. As RF time increased, diff_CO trend showed the decrease of the maximum peak and increased number of small intensity peaks. From the diff_CO change, it was possible to determine when the chamber needs to be cleaned without opening the chamber.

• Food Science and Preservation
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• v.18 no.3
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• pp.319-327
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• 2011

This study was conducted to monitor the quality characteristics of mate (Ilex paraguarensis) ethanolic extracts via the response surface methodology. In the extraction conditions that were based on the central composite design with variations in the ethanol concentration (0-100%), extraction temperature($35-95^{\circ}C$), and the ratio of the solvent to the sample (10~30 mL/g). The extraction yield and total polyphenol content improved with the increase in the ethanol concentration than in the extraction temperature. The caffeic acid content increased with the decrease in the solvent ratio. The coefficients of determinations ($R^2$) were 0.8842 (p<0.05), 0.8729 (p<0.05), and 0.9205 (p<0.05) in terms of the electron donating ability, nitrite scavenging effect (pH 3.0), and SOD-like ability, respectively. The estimated conditions for the maximized extraction, including in terms of the yield, total polyphenol content, caffeic acid content, and electron donating ability, were a 21-48% ethanol concentration, a $76.4^{\circ}C$ extraction temperature, and 10-14mL/g solvent-to-sample ratio.