• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.144-150
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• 2008

In this study, the PVDF (polyvinylidene fluoride) piero-film sensor was applied to measure the internal quality of apple. The developed sensor detected the response signal through apple after mechanical impact on the surface of apple. The acoustical parameters at time domain such as rise time (RT), ring down count (RC), energy (EN), event duration (ED) and peak amplitude (PA) and acoustical parameter at frequency domain such as spectral density (SE) were analyzed. The size of waveform decreased as storage time of apple increased. The frequency at maximum magnitude was shifted to lower frequency band according to the storage time. The acoustical parameters showed strong relationship with storage time. The multiple linear regression equation was developed to estimate storage time of apple using the acoustical parameters at time domain and its coefficient of determination was 0.97. The internal quality of apple according to storage time is predictable using developed PVDF sensor and acoustical parameters defined in this study.

• 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.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.233-236
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• 2000

The acoustical response of fish depends on size and physical structure na, most important, on the presence or absence of a swimbladder. Acoustic scattering models for swimbladdered fish represent a fish by an ideal pressure-release surface having the size and shape as the swimbladder. Target strength experiments of red seabream (Chrysophrys major) have been conducted using 38 (split-beam), 120 (split-beam) and 200kHz (dual-beam) frequencies. At each start of each experiment, the live fish are placed in the cage at the surface, then the cage is lowed to about $4{\cal}m$ depth where it remains during the measurements. To test the acoustic models, predictions of target strength based on swimbladder morphometries of 10 red seabream offish total length from $103{\cal}mm{\;}to{\;}349{\cal}mm$ ($3 <$TL/\lambda$ < 45)are compared with conventional target strength measurements on the same, shock-frozen immediately after caged experiments. X-ray was projected along dorsal aspect to know the morphological construction of swimbladder. and fish body. At high frequencies, Helmholtz-kirchhoff(HK) approximation would greatly enhance swimbladdered fish modeling. Sound scattering model [HK-ray approximation model] for comparison to experimental target strength data was used to model backscatter measurements from individual fish. The scattering data can be used in the inverse method along with multiple frequency sonar systems to investigate the adequacy of classification and identification of fish

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1968-1976
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• 2006

Recombinant E. coli ACV 1003 (recA:: lacZ) was used to measure low concentrations of DNA-damaging chemicals, which produce $\beta$-galactosidase via an SOS regulon system. Very low $\beta$-galactosidase activities of less than 0.01 unit/ml, $\beta$-galactosidase produced through an SOS response corresponding to the 10 ng/ml (ppb) of DNA damaging chemicals in the environment, can be rapidly determined by using an alternative interferometric biosensor with optically flat thin films of porous silicon rather than by the conventional time-consuming Miller's enzyme assay as well as the ELISA method. fu order to enhance the sensitivity in the interferometry, it needs to obtain more uniform distribution and higher biolinking efficiency, whereas interferometric sensing is rapid, cheap, and advantageous in high throughput by using a multiple-well-type chip. In this study, pore size adjusted to 60 nm for the target enzyme $\beta$-galactosidase to be bound on both walls of a Si pore and a calyx crown derivative was apllied as a more efficient biolinker. Furthermore, anti-$\beta$-galactosidase was previously functionalized with the biolinker for the target $\beta$-galactosidase to be specifically bound. When anti-$\beta$-galactosidase was bound to the calyx-crown derivative-linked surface, the effective optical thickness was found to be three times as high as that obtained without using anti-$\beta$-galactosidase. The resolution obtained was very similar to that afforded by the time-consuming ELISA method; however, the reproducibility was still unsatisfactory, below 1 unit $\beta$-galactosidase/ml, owing to the microscopic non-uniform distribution of the pores in the etched silicon surface.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.113-125
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• 2017

In spite of bulk literature about the tuning of TMD, the effectiveness of TMD in reducing the seismic response of engineering structures is still in a row. This paper deals with the optimum tuning parameters of a passive TMD and simulated on MATLAB with a ten-story numerical shear building. A weighted multi-objective optimization method based on computer experiment consisting of coupled with central composite design(CCD) central composite design and response surface methodology(RSM) was applied to find out the optimum tuning parameters of TMD. After the optimization, the so-conceived TMD turns out to be optimal with respect to the specific seismic event, hence allowing for an optimum reduction in seismic response. The method was employed on above structure by assuming first the El Centro seismic input as a sort of benchmark excitation, and then additional recent strong-motion earthquakes. It is found that the RSM based weighted multi-objective optimized damper improves frequency responses and root mean square displacements of the structure without TMD by 31.6% and 82.3% under El Centro earthquake, respectively, and has an equal or higher performance than the conventionally designed dampers with respect to frequency responses and root mean square displacements and when applied to earthquakes.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.568-576
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• 2018

In order to investigate the adsorption characteristics of the antibiotics trimethoprim (TMP) by activated carbon (WCAC) prepared from waste citrus peel, the effects of operating parameters on the TMP adsorption were investigated by using a response surface methodology (RSM). Batch experiments were carried out according to a four-factor Box-Behnken experimental design with four input parameters : concentration ($X_1$: 50-150 mg/L), pH ($X_2$: 4-10), temperature ($X_3$: 293-323 K), adsorbent dose ($X_4$: 0.05-0.15 g). The experimental data were fitted to a second-order polynomial equation by the multiple regression analysis and examined using statistical methods. The significance of the independent variables and their interactions was assessed by ANOVA and t-test statistical techniques. Statistical results showed that concentration of TMP was the most effective parameter in comparison with others. The adsorption process can be well described by the pseudo-second order kinetic model. The experimental data of isotherm followed the Langmuir isotherm model. The maximum adsorption amount of TMP by WCAC calculated from the Langmuir isotherm model was 144.9 mg/g at 293 K.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.88-92
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• 1991

To analyze the effects of the system parameters on the target parameters, which include the amount of water evaporation, water solubility index(WSI) and water absorption index(WAI), test trials of fractional factorial design of the three process variables at three levels were carried out for corn grit with a laboratory twin-screw extruder with three different screw configurations. The system parameters collected from the trials, such as extrusion temperature, specific mechanical energy input(SME) and mean residence time(RT), were showed the ranges of $129{\sim}182^{\circ}C$, $67{\sim}163\;kwh/ton$ and $12{\sim}34\;sec$, respectively. Within these ranges of the system parameters, the target parameters were able to be quantified by using multiple regression equations. The correlation of results with the system parameters blocked by the screw configuration as dependent variables, yield correlation coefficients above 0.90, and the correlation using the system parameters obtained from whole experiment system as the dependent variables yield correlation coefficients around 0.80. The functional relationship, which can be quantified by second order polynomial regression equation with only two system parameters within necessary degree of accuracy, can he graped in three dimensional surface response and contour diagrams.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1104-1109
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• 2003

Response surface methodology (RSM) was used to investigate the effects of the processing parameters on supercritical $CO_2\;(SC-CO_2)$. extraction of total carotenoids and ${\beta}$-cyptoxanthin from Citrus unshiu press cake. The parameters tested were $SC-CO_2$ pressure, dynamic extraction time, and concentration of ethanol added as the modifier to $CO_2$. Experimental data correlated well with the processing parameters (p<0.01), and there was a high statistically significant multiple regression relationship for the extraction of total carotenoids and ${\beta}-cyrptoxanthin$ ($R^2=0.9789$ and 0.9796, respectively). The optimal processing conditions were extraction pressure 33.4 and 37.3 MPa, extraction time 39.6 and 41.0 min, ethanol concentration 18.6 and 17.0% for total carotenoids and ${\beta}-cryptozanthin$, respectively. Maximum extraction yields predicted by RSM were 61.1 and 95.8% ppm, respectively. The extraction yield of total carotenoids increased asymptotically with the increase of the extraction pressure. It increased in proportion to extraction time and concentration of the cosolvent. The extraction yield of ${\beta}-cryptoxanthin$ increased with extraction pressure, extraction time, and concentration of the cosolvent. The extraction time and the concentration of the cosolvent, and the interaction between extraction time and the concentration of the cosolvent significantly affected the extraction yields of carotenoids from C. unshiu press cake.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.245-258
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• 2020

In this study, a data-driven response surface method using the results acquired from the numerical simulation is developed to evaluate the potential storage capacity of groundwater due to the construction of a groundwater dam. The hydraulic conductivities of alluvium and basement rock, depth and slope of the channel are considered as the natural conditions of the location for groundwater dam construction. In particular, the probability models of the hydraulic conductivities and the various types of geometry of the channel are considered to ensure the reliability of the numerical simulation and the generality of the developed estimation model. As the results of multiple simulations, it can be seen that the hydraulic conductivity of basement rock and the depth of the channel greatly influence to the groundwater storage capacity. In contrast, the slope of the channel along the groundwater flow direction shows a relatively lower impact on the storage capacity. Based on the considered natural conditions and the corresponding numerical simulation results, the storage capacity estimation model is developed applying an artificial neural network as the nonlinear regression model for training. The developed estimation model shows a high correlation coefficient (>0.9) between the simulated and the estimated storage amount. This result indicates the superiority of the developed model in evaluating the storage capacity of the potential location for groundwater dam construction without the numerical simulation. Therefore, a more objective and efficient comparison for the storage capacity between the different potential locations can be possibly made based on the developed estimation model. In line with this, the proposed method can be an effective tool to assess the optimal location of groundwater dam construction across Korea.