• Korean journal of food and cookery science
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• v.29 no.1
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• pp.1-10
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• 2013

The purpose of this study was to investigate the antioxidative effects of Opuntia humifusa powder and determine the optimal composite recipe by three different amounts of Opuntia humifusa powder, sugar and butter in cookies prepared with Opuntia humifusa powder. In regard to its antioxidant effects, Opuntia humifusa powder had a total phenolic content and DPPH free radical scavenging activity of $6.64{\pm}0.54mg/g$ and $90.12{\pm}0.42%$, respectively. response surface methodology was used to obtain sixteen experimental points(including three replicates for Opuntia humifusa powder, sugar and butter) and Opuntia humifusa cookie formulation was optimized using rheology. The results of the sensory evaluation produced very significant values for color (p<0.05), flavor (p<0.05), texture (p<0.05), sweetness (p<0.05), appearance (p<0.05), overall quality (p<0.05), and the results of instrumental analysis showed significant values in sweetness (p<0.001), hardness (p<0.001), lightness (p<0.001), redness (p<0.001), yellowness (p<0.01). As a results, the optimum formulations obtained by numerical and graphical methods were found to be 3.11 g of Opuntia humifusa powder, 35.00 g of sugar and 50.54 g of butter.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1071-1078
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• 2006

Robust design of products or processes is a way to produce products or processes with less variability on condition that the product specification is met, so that the ratio of nonconforming products can be as minimized as possible. In such models as robust parameter design(RPD) originated by Taguchi and response surface methodology(RSM), the variances of noise variables are assumed to be measurable. However, there are circumstances in which the experimenters are unable to measure noise variables or perhaps are not aware of what the noise variables are. In this paper, it is demonstrated through an example that Taguchi's RPD approach can be conducted within the framework of the analysis of variability, with a view to a comparison of the two methods.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.851-852
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• 2006

This paper presents methods to reduce acoustic noise in interior permanent magnet (IPM) motor. Mechanical and magnetic sources are considered to reduce noise of the machine, and structural and electromagnetic designs are performed. In the structural design to reduce mechanical source, the structural resonances are moved to higher frequency for enhancement of stiffness. Then, the electromagnetic design to reduce magnetic source, the amplitudes of magnetic force harmonics are reduced by using objective function of response surface methodology (RSM). The validity of the design process and objective functions is confirmed with their calculated and experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.286-297
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• 2016

This study proposes criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration. The optimal design of the stator and rotor can be enhanced using both a response surface method and finite element method. In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor. Finally, this study verifies that the proposed motor can efficiently replace interior permanent magnet synchronous motor in many industries.

• Advances in nano research
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• v.14 no.2
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• pp.155-164
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• 2023

Grain size in sheet metals in one of the main parameters in determining formability. Grain size control in industry requires delicate process control and equipment. In the present study, effects of grain size on the formability of steel sheets is investigated. Experimental investigation of effect of grain size is a cumbersome method which due to existence of many other effective parameters are not conclusive in some cases. On the other hand, since the average grain size of a crystalline material is a statistical parameter, using traditional methods are not sufficient for find the optimum grain size to maximize formability. Therefore, design of experiment (DoE) and artificial intelligence (AI) methods are coupled together in this study to find the optimum conditions for formability in terms of grain size and to predict forming limits of sheet metals under bi-stretch loading conditions. In this regard, a set of experiment is conducted to provide initial data for training and testing DoE and AI. Afterwards, the using response surface method (RSM) optimum grain size is calculated. Moreover, trained neural network is used to predict formability in the calculated optimum condition and the results compared to the experimental results. The findings of the present study show that DoE and AI could be a great aid in the design, determination and prediction of optimum grain size for maximizing sheet formability.

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.53-63
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• 2021

Sophora koreensis Nakai is an indigenous plant in Koreawith a restricted natural range, part of which is in Gangwon province. The species is known to contain phytochemicals that have beneficial effects on human health, and it is economically important in bioindustry. Because of the limited number of plants in a small range of habitats, the mass-propagation method should be developed for use and conservation. In vitro tissue culture is a reliable method in terms of mass propagation from selected clones of the species. We investigated the optimal conditions of the medium in this process, especially focusing on the concentrations of plant growth regulators(PGRs) in the culture of stem-containing axillary buds. Three statistical methods, i.e., ANOVA, response surface method(RSM), and fuzzy clustering were used to analyze the plant growth, number of shoots induced, and shoot length with various combinations of PGRs. Results from the RSM differed from those of the other two methods; thus, the method was not suitable. ANOVA and fuzzy clustering showed similar results. However, more accurate results were obtained using fuzzy clustering because it provided a probability for each treatment. On the basis of the fuzzy clustering analysis, stem tissue produced the greatest number of shoots(11.03 per explant; 63.33%) on a medium supplemented with 5-��M 6-benzylaminopurine and 2.5-��M thidiazuron(TDZ). Proliferation of shoots(2.18 ± 0.21 cm, 63.33%) was attained on a medium supplemented with 2.5-��M BA, 2.5-��M TDZ, and 2.5-��M gibberellic acid.

• Food Science and Preservation
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• v.12 no.3
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• pp.223-229
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• 2005

Response surface methodology(RSM) was used for monitoring the quality change of muskmelon beverage with storage temperature and time. Muskmelon beverage was prepared with the ratio of liquid fructose($11\%$), muskmelon vinegar($3\%$), concentrated muskmelon juice($1\%$) and refined water($84\%$). To examine physicochemical properties of muskmelon beverage, various factors such as color, brown color intensity and sugar content were determined using physicochemical methods. Physicochemical properties of muskmelon beverage were more affordable with the increased storage temperature. While, organoleptic properties decreased with the increased storage time and temperature. The result of this study indicated that the quality of muskmelon beverage was mostly influenced by the storage temperature. Muskmelon beverage showed the good score under $60^{\circ}C$ as a storage temperature.

• Steel and Composite Structures
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• v.27 no.4
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• pp.427-438
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• 2018

In this paper, the single and multi-objective optimization of thin-walled conical tubes with different types of indentations under axial impact has been investigated using surrogate models called metamodels. The geometry of tapered thin-walled tubes has been studied in order to achieve maximum specific energy absorption (SEA) and minimum peak crushing force (PCF). The height, radius, thickness, tapered angle of the tube, and the radius of indentation have been considered as design variables. Based on the design of experiments (DOE) method, the generated sample points are computed using the explicit finite element code. Different surrogate models including Kriging, Feed Forward Neural Network (FNN), Radial Basis Neural Network (RNN), and Response Surface Modelling (RSM) comprised to evaluate the appropriation of such models. The comparison study between surrogate models and the exploration of indentation shapes have been provided. The obtained results show that the RNN method has the minimum mean squared error (MSE) in training points compared to the other methods. Meanwhile, optimization based on surrogate models with lower values of MSE does not provide optimum results. The RNN method demonstrates a lower crashworthiness performance (with a lower value of 125.7% for SEA and a higher value of 56.8% for PCF) in comparison to RSM with an error order of $10^{-3}$. The SEA values can be increased by 17.6% and PCF values can be decreased by 24.63% by different types of indentation. In a specific geometry, higher SEA and lower PCF require triangular and circular shapes of indentation, respectively.

• Journal of Ginseng Research
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• v.46 no.3
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• pp.367-375
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• 2022

Background: Short-term hydroponic-cultured ginseng (sHCG), which is 1-year-old ginseng seedlings cultivated for 4 weeks in a hydroponic system, is a functional food item with several biological effects. However, the optimal extraction conditions for sHCG, and the bioactivity of its extracts, have not been evaluated. Methods: Chlorogenic acid (CGA) and ginsenoside contents were evaluated in sHCG, white ginseng (WG), and red ginseng (RG) using high-performance liquid chromatography. Response surface methodology (RSM) was used to optimize the extraction conditions (temperature and ethanol concentration) to maximize the yield of dry matter, CGA, and four ginsenosides (Re, Rg₁, Rb₁, and Rd) from sHCG. The optimal extraction conditions were applied to pilot-scale production of sHCG extracts. The expression levels of tumor necrosis factor (TNF)-α/interferon (IFN)-γ-induced thymic and activation-regulated chemokines (TARC/CCL17) were measured after treatment with sHCG, WG, and RG extracts, and the effects of their bioactive compounds (CGA and four ginsenosides) on human skin keratinocytes (HaCaTs) were evaluated. Results: CGA and four ginsenosides, which are bioactive compounds of sHCG, significantly inhibited TNF-α/IFN-γ-induced TARC/CCL17 expression. The optimal sHCG extraction conditions predicted by the RSM models were 80 ℃ and 60% ethanol (v/v). The sHCG extracts produced at the pilot scale under optimal conditions greatly alleviated TNF-α/IFN-γ-induced TARC/CCL17 production compared with WG and RG extracts. Conclusions: Pesticide-free sHCG extracts, which contain high levels of CGA and the ginsenosides Re, Rg₁, Rb₁, and Rd as bioactive compounds, may have therapeutic potential for atopic diseases.

• Journal of the Korean GEO-environmental Society
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• v.13 no.5
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• pp.5-12
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• 2012

Antibiotics have been considered emerging compounds due to their continuous input and persistence in environment. Due to the limited biodegradability and widespread use of these antibiotics, an incomplete removal is attained in conventional wastewater treatment plants and relative large quantities are released into the environment. In this study, it was determined the adsorption and photocatalysis kinetics of antibiotics (Sulfamethoxazole, SMX) with various catalyst (Titanium dioxide; $TiO_2$, Hydroxyapatite; HAP) conditions under UV/$TiO_2$/HAP system. In addition, the statistical analysis of response surface methods (RSM) was used to determine the effects of operating parameters on UV/$TiO_2$/HAP system. $TiO_2$/HAP adsorbent were found to follow the pseudo second order reaction in the adsorption. In the result of applied intrapaticle diffusion model, the constants of reaction rate were $TiO_2$=$0.064min^{-1}$, HAP=$0.2866min^{-1}$ and $TiO_2$/HAP=$0.3708min^{-1}$, respectively.The result of RSM, term of regression analysis in analysis of variance (ANOVA) showed significantly p-value (p<0.05) and high coefficients for determination values($R^2$=96.2%, $R^2_{Adj}$=89.3%) that allowed satisfactory prediction of second order regression model. And the estimated optimal conditions for Y(Sulfamethoxazole removal efficiency, %) were $x_1$(initial concentration of Sulfamethoxazole)=-0.7828, $x_2$(amount of catalyst)=0.9974 and $x_3$(reation time)=0.5738 by coded parameters, respectively. According to the result of intraparticle diffusion model and photocatalysis experiments, it was shown that the $TiO_2$/HAP was more effective system than conventional AOPs(advanced oxidation processes, UV/$TiO_2$ system).