• Structural Engineering and Mechanics
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• v.83 no.3
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• pp.327-340
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• 2022

The Collapse Margin Ratio (CMR) is a notable index used for seismic assessment of the structures. As proposed by FEMA P695, a set of analyses including the Nonlinear Static Analysis (NSA), Incremental Dynamic Analysis (IDA), together with Fragility Analysis, which are typically time-taking and computationally unaffordable, need to be conducted, so that the CMR could be obtained. To address this issue and to achieve a quick and efficient method to estimate the CMR, the Artificial Neural Network (ANN), Response Surface Method (RSM), and Adaptive Neuro-Fuzzy Inference System (ANFIS) will be introduced in the current research. Accordingly, using the NSA results, an attempt was made to find a fast and efficient approach to derive the CMR. To this end, 5016 IDA analyses based on FEMA P695 methodology on 114 various Reinforced Concrete (RC) frames with 1 to 12 stories have been carried out. In this respect, five parameters have been used as the independent and desired inputs of the systems. On the other hand, the CMR is regarded as the output of the systems. Accordingly, a double hidden layer neural network with Levenberg-Marquardt training and learning algorithm was taken into account. Moreover, in the RSM approach, the quadratic system incorporating 20 parameters was implemented. Correspondingly, the Analysis of Variance (ANOVA) has been employed to discuss the results taken from the developed model. Additionally, the essential parameters and interactions are extracted, and input parameters are sorted according to their importance. Moreover, the ANFIS using Takagi-Sugeno fuzzy system was employed. Finally, all methods were compared, and the effective parameters and associated relationships were extracted. In contrast to the other approaches, the ANFIS provided the best efficiency and high accuracy with the minimum desired errors. Comparatively, it was obtained that the ANN method is more effective than the RSM and has a higher regression coefficient and lower statistical errors.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.879-884
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• 2012

In this present study, Aspergillus niger NRRL 567 was cultivated on an inert support material and the effects of various fermentation parameters including temperature, nutrient solution pH, inoculation level, and moisture content were observed and optimized by one-factor-at-a-time (OFAT) and response surface methodology (RSM), sequentially. It was found that the incubation temperature of $30^{\circ}C$ with 75% moisture content, nutrient solution pH of 7.1 and inoculation level of $4.0{\times}10^6$ spores/ml were the most favorable. Again, fermentation parameters were optimized using RSM. The determined optimum condition is $26.5^{\circ}C$, pH 9.9, 75.1%, and $6.0{\times}10^6$ spores/ml. Under this optimized condition, A. niger NRRL 567 produced 118.8 g citric acid/kg dry peat moss at 72 hr. Maximum citric acid production of optimized condition by RSM represented a 1.6-fold increase compared to that obtained from control experiment.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.1040-1049
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• 2016

In this study, we aimed to develop a mixed tea prepared with roasted mulberry leaf and fruit using response surface methodology (RSM). Roasting of mulberry leaf was by 6 stages, as shown in Fig. 1; and mulberry fruit was roasted in 4 stages, as shown in Fig. 2. Subsequently, physicochemical measurements such as total polyphenol content, nitric oxide production content, and ${\alpha}$-glucosidase inhibitory effect were obtained for each sample. Central composite design was applied to prepare samples containing varying contents of roasted mulberry leaf (RoML) and roasted mulberry fruit (RoMF); subsequently, sensory evaluation was conducted. The total polyphenol content of roasted samples (RoML and RoMF) were significantly higher than that of raw samples (RaML and RaMF), respectively. The nitric oxide (NO) production of roasted samples were significantly lower than that of control (LPS induced RAW 264.7 cell). The ${\alpha}$-glucosidase inhibitory effect of roasted samples was significantly higher than that of raw samples, respectively. Based on the RSM estimation for determination of optimum ratio by sensory evaluation (taste, color, and flavor) among 13 mixed samples, the optimum mixing ratio of RoML and RoMF for taste, color, and flavor were 1.64 g (RoML) and 0.88 g (RoMF), 1.35 g (RoML) and 0.92 g (RoMF), 1.65 g (RoML) 1.03 g (RoMF), respectively. Based on results of three sensory evaluations, mixing ratio comprising 1.54 g of RoML and 0.92 g of RoMF is desirable for delicious tea with functionality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.839-848
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• 2015

This study examined the optimal salting drying method and processing conditions (salt concentration, curing time, dry temperature, and drying time) for preparing salted semi-dried common gray mullet (SSD-CGM) Mugil cephalus based on the moisture content, salinity, and overall acceptance using response surface methodology (RSM). The moisture content, salinity, and overall acceptance of SSD-CGM prepared with different salting methods revealed that dry salting was the optimal salting method for preparing high-quality SSD-CGM. The optimal drying method for preparing high-quality SSD-CGM based on the drying velocity and sensory color was hot air-blast drying. The results of the RSM program indicated that the optimal independent variables ($X_1$, salt concentration; $X_2$, curing time; $X_3$, dry temperature; $X_4$, drying time) based on the dependent variables ($Y_1$, moisture content; $Y_2$, salinity; $Y_3$, overall acceptance) for high-quality SSD-CGM were 5.6% for $X_1$, 2.7 h for $X_2$, $47.0^{\circ}C$ for $X_3$, and 8.5 h for $X_4$ for uncoded values. The predicted values of $Y_1$, $Y_2$, and $Y_3$ for SSD-CGM prepared under optimal conditions were 54.4%, 4.2%, and 6.3, respectively, while the experimental values were $55.2{\pm}1.0%$, $4.1{\pm}0.3%$ and $6.7{\pm}0.8$. The actual and predicted values did not differ.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1273-1284
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• 2000

In this study, ultrafiltration was performed to remove humic acid from aqueous solution. Since the effects of system variables on the ultrafiltration were tangled with non-linearly. Response Surface Methodology(RSM) was used to know optimum conditions of ultrafiltration process, relations among system variables, and the effects of system variables such as pressure difference across the membrane, concentration of humic acid, and feed flow rates. As concentrations of humic acid were 10ppm, 40ppm, and 70ppm in feed stream, permeation fluxes were 2.56, 2.27, and $2.10({\times}10^{-2}cc/cm^2{\cdot}min)$ respectively ; in other words, permeation fluxes of 10ppm, 40ppm and 70ppm feed concentration decreased by 17.7%, 26.7% and 32.2% of pure water permeation flux respectively. Concentration of humic acid in permeate side were 0.5ppm, 1.2 ppm, and 2.1ppm respectively. When pressure difference(${\Delta}P$) increased from 1atm to 2atm and 3atm, permeation fluxes of 40ppm feed concentration increased by 66% and 152% of permeation rate at 1atm respectively. However, concentrations of humic acid in permeate side increased from 0.5ppm to 1.5ppm and 3.5ppm. RSM showed that the optimum condition of system variables is 38.5~40ppm of humic acid concentration in feed stream, 30~30.7cc/min of feed flow rate, and 2atm of pressure difference.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.557-564
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• 2019

The characteristics of the torque and torque ripple of Interior Permanent Magnet Synchronous Motor(IPMSM) are influenced by the size and position of the rotor magnet and the size of the stator slot. This paper deals with the optimal design method for improving torque and torque ripplerate for IPMSM using Response Surface Methodology(RSM). Two objective functions of torque output and torque ripple were derived from the sensitivity analysis by Plackett-Burmann(PB) for the characteristic variables affecting torque and torque ripple. Secondary characteristic variables were selected from the derived objective function and RSM secondary regression model function was estimated by the experiment schedule and analysis results according to the Central Composite Design (CCD). The reliability of the secondary regression model was verified using ANOVA table. The analysis according to the experimental schedule was verified by JMAG(Ver. 18.0) which is Finite Element Method(FEM) software. The torque output of IPMSM applied with final characteristic variables was increased torque output by 11.5 % and the torque ripplerate was reduced by 9.1 %.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.123-132
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• 2018

The purpose of this study was to evaluate the reduction effect of non point source (NPS) pollution in Haean highland agricultural catchment ($62.8km^2$) for 13 BMP scenarios under RCP (Representative Concentration Pathway) 4.5 and 8.5 scenarios. Under the present climate condition, the BMP (best management practices) reduction efficiency of SS (suspended solid), T-N (total nitrogen), and T-P (total phosphorus) showed +25.7%, +4.2%, and +16.1% for VFS (vegetative filter strip), +0.1%, +15.6%, and +5.7% for FC (fertilizer control), and +6.3%, -2.9%, and +3.9% for RSM (rice straw mulching) respectively. In general, effective was the best for SS and T-P reductions, and the FC was the best for T-N reduction. The negative effect of T-N on RSM was induced by increase in infiltration and solute transport to baseflow. Under the future climate change scenarios, the SS, T-N, and T-P reduction efficiency showed the range of +1.9~+11.6%, -1.9~+0.2%, and +5.3~+11.9% respectively. The 3 BMPs (VFS, FC, and RSM) application in the future showed negative and little differences (-0.5~+1.6%) for SS and T-N reduction efficiencies while T-P reduction efficiency showed +0.3~+7.6% comparing with the baseline period. To achieve an increase in the reduction efficiency of future SS and T-N by +2~+10%, the combined application of more than two BMPs is necessary.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.957-963
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• 1999

Effects of cryoprotectants on protein denaturation of soybean curd, tofu, during frozen storage were examined. A whole-coagulated non-press tofu was prepared by adding 2% of isolated soybean protein to soy milk in order to prevent loss of added cryoprotectants. The cryoprotectants added were glocose, glycerol, sorbitol, propylene glycol, and tripolyphosphate. The texture characteristics of soybean curds before and after frozen storage were measured by sensory evaluation and Texture analyzer, and the results were evaluated by response surface methodology (RSM). Glucose, glycerol, sorbitol, and sodium tripolyphosphate were effective as single cryoprotectant, and the mixtures of glucose and sodium tripolyphosphate, and sorbitol and propylene glycol were also effective in minimizing textural change during freezing. Overall, the mixture of cryoprotectants were more effective than single cryoprotectant. According to the RSM, the maximum effect of cryoprotectants in minimizing textural changes during freezing was obtained with the mixture of 2.1% glucose, 6.7% glycerol, 2.1% sorbitol, 0.4% propylene glycol, and 0.3% sodium tripolyphosphate. However, considering the sensory acceptability, the optimum use of cryoprotectants in frozen tofu was 1% glucose, 2% glycerol, 1% sorbitol, 0.2% propylene glycol, and 0.5% sodium tripolyphosphate.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.21-27
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• 2002

Angiotensin I converting enzyme inhibitory activities of shelled krill (Euphausia superba) hydrolysates by autolysis and by hydrolysis with commercial proteases were analyzed. Among the proteases, Alcalase was the most effective protease for the hydrolysis of krill considering the degree of hydrolysis $(87.5\%)$ and the ACE inhibitory activity $(60\%)$. Four hour hydrolysis suggested as the most suitable and economic. In order to establish the optimum hydrolysis condition of krill, degree of hydrolysis and ACE inhibitory activity as affected by Alcalase concentration and water amount added were statistically analyzed by response surface methodology (RSM). The optimum hydrolysis condition was $2.0\%$ Alcalase hydrolysis in 2 volumes (v/w) of water at $55\% for 4 hr. The hydrolysate prepared from the optimum hydrolysis condition was fractionated by molecular weight. The lower molecular weight fraction showed the higher ACE inhibitory activity. $IC_{50}$ of the fraction under 500 Da was 0.57mg protein/mL.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.414.1_415.1
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• 2009

This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor (FSM) using RSM & FEM. The focus of this paper is to find a design solution through the comparison of torque density and torque ripple according to rotor shape variations. And then, a central composite design(CCD) mixed resolution is introduced, and analysis of variance (ANOVA) is conducted to determine the significance of the fitted regression model.