• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.185-190
• /
• 2005

This work presents a numerical procedure to optimize the elliptic-shaped pin fin arrays to enhance turbulent heat transfer. The response surface method is used as an optimization technique with Reynolds-averaged Navier Stokes analysis of flow and heat transfer. Shear stress transport (SST) turbulence model is used as a turbulence closure. Computational results for average heat transfer rate show a reasonable agreement with the experimental data. Four variables including major axis length, minor axis length, pitch and the pin fin length nondimensionalized by duct height are chosen as design variables. The objective function is defined as a linear combination of heat transfer and friction-loss related terms with weighting factor. D-optimal design is used to reduce the data points, and, with only 28 points, reliable response surface is obtained. Optimum shapes of the pin-fin arrays have been obtained in the range from 0.0 to 0.1 of weighting factor.

• The KSFM Journal of Fluid Machinery
• /
• v.11 no.2
• /
• pp.38-45
• /
• 2008

This study presents a numerical procedure to optimize the compressor design to increase the surge margin of compressor with response surface method (RSM). The Box-Behnken design method is used to reduce the number of calculation for fitting the second-order response surface. In order to consider the increase of surge margin during numerical optimization without any calculation at the surge point, the slope of compressor characteristic curve at the design point is suggested as an objective function in the present optimization problem. Mean line performance analysis method is used to get the design and off-design characteristic curves of centrifugal compressor. The impeller exit angle, impeller exit height and impeller radius are chosen as design variables. The optimum shapes show the increase of surge margin for the surge margin optimization and increase of efficiency for the efficiency optimization in comparison with an initial shape.

• The KSFM Journal of Fluid Machinery
• /
• v.7 no.6 s.27
• /
• pp.55-61
• /
• 2004

A numerical procedure for optimizing the shape of three-dimensional sedimentation tank is presented to maximize its sedimentation efficiency. The response surface based optimization is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis for multi-phase flow. Standard $k-{\epsilon}$ model is used as a turbulence closure. Three design variables such as, tank height to center feed wall diameter ratio, blockage ratio of center feed wall and angle of distributor are chosen as design variables. Sedimentation efficiency is defined as an objective function. Full-factorial method is used to determine the training points as a means of design of experiment. Sensitivity of each design variable on the objective function has been evaluated. And, optimal values of the design variables have been obtained.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.3
• /
• pp.427-433
• /
• 1995

The optimal condition for hydrolysis of oyster was evaluated with proteases using response surface methodology(RSM). Among 11 commerical proteases, APLTM 440 was selected as the suitable protease for producing oyster hydrolysate on the basis of cost per unit enzyme activity. The effect of autolysis on degree of hydrolysis in oyster was negligible comparing to that of APL 440 protease treatment. From RSM and ridge analysis, the conditions favoring the highest degree of hydrolysis were pH 9.95, 61.1$^{\circ}C$, 2.64 hr reaction time, 49.2% substrate, and 0.35% enzyme/substrate ratio. Oyster hydrolysate prepared under optimal conditions shwoed virtually 51.98% of hydrolysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.10a
• /
• pp.87-88
• /
• 2014

The Coastal sediment is highly contaminated due to ship transportation, industries discharges and urban sources. Various contaminants release into seawater and settle in marine sediment and it significantly affect marine eco system. In the present study evaluated the optimization of slow release biostimulant ball (BSB) in coastal sediment in busan. The effective variables like BSB size, distance and month variables on VS reduction was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of VS was 0.9369 and maximum reduction of VS was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective VS reduction in coastal sediment.

• Steel and Composite Structures
• /
• v.13 no.2
• /
• pp.109-122
• /
• 2012

An efficient and accurate algorithm is proposed to evaluate the reliability of cable-stayed bridges accounting for soil-pile interaction. The proposed algorithm integrates the finite-element method and the response surface method. The finite-element method is used to model the cable-stayed bridge including soil-pile interaction. The reliability index is evaluated based on the response surface method. Uncertainties in the superstructure, the substructure and load parameters are incorporated in the proposed algorithm. A long span steel cable-stayed bridge with a main span length of 1088 m built in China is considered as an illustrative example. The reliability of the bridge is evaluated for the strength and serviceability performance functions. Results of the study show that when strength limit states for both girder and tower are considered, soil-pile interaction has significant effects on the reliability of steel cable-stayed bridges. Further, a detailed sensitivity study shows that the modulus of subgrade reaction is the most important soil-pile interaction-related parameter influencing the reliability of steel cable-stayed bridges.

• Journal of Life Science
• /
• v.10 no.2
• /
• pp.196-201
• /
• 2000

The production of tetrodotoxin (TTX) using Vibrio sp. YE-101, a novel marine microorganism isolated from the intestine of pufferfish, was investigated. Culture condition was optimized for the enhanced production of TTX using response surface methodology. The experimental sets of environmental conditions including pH, temperature and NaCl concentration were designed using central composite experimental design. The optimal conditions of pH, temperature and NaCl concentration were determined to be 8.1, 29.2℃, and 2.6% (w/v) respectively. The relative growth extent could be enhanced up to 80%, and final mouse unit (MU) value of TTX was also enhanced up to 87% by response surface optimization.

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

• Earthquakes and Structures
• /
• v.8 no.5
• /
• pp.1241-1254
• /
• 2015

Spatially variable ground motions can be significant on the seismic response of a structure due to the incoherency of the incident wave. Incoherence of the incident wave is resulted from wave passage and wave scattering. In this study, wave passage effect on the response spectrum of a building structure built on a soft soil layer was investigated utilizing a finite element program of P3DASS (Pseudo 3-dimensional Dynamic Analysis of a Structure-soil System). P3DASS was developed for the axisymmetric problem in the cylindrical coordinate, but it is modified to apply anti-symmetric input earthquake motions. Study results were compared with the experimental results to verify the reliability of P3DASS program for the shear wave velocity of 250 m/s and the apparent shear wave velocities of 2000-3500 m/s. Studied transfer functions of input motions between surface mat foundation and free ground surface were well-agreed to the experimental ones with a small difference in all frequency ranges, showing some reductions of the transfer function in the high frequency range. Also wave passage effect on the elastic response spectrum reduced the elastic seismic response of a SDOF system somewhat in the short period range.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.8 no.3
• /
• pp.46-53
• /
• 2009

To find the working condition is one of the important factors in precision machining. In this study, we analyzed maximum working temperature by infra-red camera and surface roughness in side wall end milling using design of experiment (DOE): RSM(response surface methodology), ANOM(analysis of means) and ANOVA(analysis of variance) by table of orthogonal array. ANOM and ANOVA are well adapted to select sensitivity of design variables for maximum working temperature and surface roughness. The effective design variables and their levels should be determined using ANOM, ANOVA. RSM is presented 2nd order approximation polynomial of maximum working temperature and surface roughness is composed with design variables. Therefore, it is expected that the proposed procedure using design of experiment : table of orthogonal array, ANOM, ANOVA and RSM can be easily utilized to solve the problem of working condition.