• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.225.1-225
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• 2003

잣을 이용한 쌀가루즉석죽 제조조건의 최적화와 제조조건에 따른 관능적 특성을 4차원 반응표면분석에 의하여 모니터링 하였다. 죽의 제조에 이용되는 잣은 가루같이 으깬 것을 첨가하는 것이 바람직하였다. 관능적 특성에 의한 잣죽의 점성에 대한 최적조건은 주입액의 양과 잣의 첨가비율이 각각 쌀가루 무게의 15.52배, 16%, 가열조리시간 7.79 분이었으며 이때 $R^2$는 0.9518, 관능평점은 7.45, 임계점은 maximum point였다. 색상에 대한 최적조건은 19.09배, 45%, 2.16분($R^2$=0.7917)이었고 관능평점은 5.44, saddle point였으며, 맛에 대한 최적조건은 12.90배, 22%, 11.40분($R^2$=0.9361), 관능평점은 7.11, maximum point였고, 향에 대한 최적조건은 15.06배, 20%, 4.9분($R^2$=0.8372), 관능평점은 6.16, saddle point였다. 관능적 특성을 모두 만족시켜주는 최적조건은 주입액의 양과 잣의 첨가비율이 각각 쌀가루무게의 16.86배와 15%, 가열조리시간 5.48분이었고 이때 $R^2$는 0.9738, 관능적 평점은 7.69, 임계점은 maximum point였다. 관능적 특성 중 점성은 맛과 전반적기호도에 큰 영향을 주었으며 상관계수는 각각 0.8173($R^2$=0.0001), 0.7878($R^2$=0.0002)이었고 맛은 향과 전반적인 기호도와 밀접한 관계가 있으며 상관계수는 각각 0.5196($R^2$=0.0325)과 0.7004($R^2$=0.0017)이었다.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.78-83
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• 2010

In the present paper, a flap was optimized to maximize the lift. A 2-element fowler flap system was utilized for optimization with an initial shape of general aviation airfoil and a flap shape designed by Wentz. Response surface method and Hicks-Henne shape function were implemented for optimization. 2-D Navier-Stokes method was used to solve flow field around aGA(W)-1 airfoil with a fowler flap. Commercial programs including Visual-Doc, Gambit/Tgridand Fluent were used. Upper surface shape and the flap gap were optimized and lift for landing condition was improved considerably. The original and optimized flaps were tested in the KARI's 1-m low speed wind tunnel to examine changes in aerodynamic characteristics. For optimized flap tests, the similar trend to prediction could be seen but stall angle of attack was lower than what was expected. Also, less gap than optimized design delayed stall and produced better lift characteristics. This is believed to be the effect of turbulence model.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.497-503
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• 2016

This study aimed to optimize the culture conditions of recombinant Escherichia coli expressing otsBA using crude glycerol for the enhanced production of trehalose. The effects of culture temperature and isopropyl ${\beta}$-D-1-thiogalactopyranoside (IPTG)-induction were investigated. Trehalose production and cell growth were highest when cells were cultured at $37^{\circ}C$ and induced with IPTG. The concentrations of IPTG, validamycin A, and NaCl were optimized using Box-Behnken design. Statistical analyses of the experimental data revealed that the concentrations of IPTG and NaCl had significant effects on trehalose production, but that of validamycin A did not. Contour plot analysis and model calculation showed that the highest amount of trehalose could be produced at 298 mM NaCl and 0.1 mM IPTG. Under these optimal conditions, the optical density at 600 nm and trehalose production were $5.4{\pm}0.2$ and $304{\pm}15mg/l$, respectively.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.655-661
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• 1989

Optimal drying conditions consisting of air temperature and relative humidity were searched by the simulation-optimization technique for minimizing quality changes in red pepper drying. Optimized drying conditions were analysed in the viewpoint of quality change kinetics and effects of control variables on the state variables. Optimal drying conditions were nearly same in both cases for carotenoid maximization and browning minimization. In two staged optimized drying, relative humidity took a lower search limit of about 10%, and air temperature in the first stage was near the lower limit of $50^{\circ}C$ and in second stage increased to a higher temperature varying with total drying time and stage changing time. Response surface analysis of time invariable drying confirmed the location of the optimal point lying on the vertex of lower limit humidity and a lowest drying temperature which ensures to attain target moisture of 0.2g water/g dry solid. Two stage drying can attain the higher objective function of quality by 3-5% than time invariable drying for shorter total drying times.

• Journal of Life Science
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• v.30 no.12
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• pp.1101-1108
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• 2020

Tartary buckwheat is a grain with many flavonoids, such as rutin, quercetin, kaempferol, and myricetin. This study aimed to optimize extraction conditions to maximize the rutin, quercetin, and myricetin contents of tartary buckwheat sprout extracts using response surface methodology. A BoxBehnken design containing 15 experiments was employed to evaluate the effects of extraction conditions, such as temperature (X1, 50~70℃), extraction time (X2, 5~9 hr), and ethanol concentration (X3, 60~90%). The coefficients of determination (R2) for all the dependent variables (extraction temperature, extraction time, and extraction ethanol concentration) were determined to be over 0.95, indicating significance. The p-value of the model in lack of fit was over 0.1 than means, indicating that the model was well predicted. The optimal extraction conditions for rutin, quercetin, and myricetin contents were obtained at X1 = 51.03, X2 = 6.62, and X3 = 69.16, respectively. Under these optimal conditions, the predicted rutin, quercetin, and myricetin contents were 808.467 ㎍/ml, 193.296 ㎍/ml, and 37.360 ㎍/ml, respectively. For the validation of the model, ten experiments were performed and the experimental rutin and quercetin contents were measured at 802.84±8.49 ㎍/ml, 193.76±2.80 ㎍/ml, and 34.84±0.43 ㎍/ml, respectively. The experimental rutin and quercetin contents were similar to the predicted contents, but the experimental myricetin content was lower than predicted.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.47-50
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• 2005

본 연구의 목적은 차세대 대체에너지로 각광받는 풍력발전 중에서 육상발전보다 여러 가지 이점이 있는 해상에서의 한국형 풍력터빈 블레이드의 최적 형상을 위 한 알고리즘을 구현하는 것이다. 풍력터빈 블레이드에서 깃익형의 공기 역학적 특성은 매우 중요한 사항이다. 이를 위해서 익형 성능예측에 층류에서 난류로의 천이과정을 포함하는 XFOIL을 이용하여 블레이드 익형 단면의 양력과 항력 분포를 해석하였다. 첫 번째 수준의 설계변수는 운용범위내의 바람의 속도와 블레이드 지름, 축 회전수이며, 각 단면에서의 비틀림각과 시위길이는 두 번째 수준의 설계 변수이다. 운용범위 내의 각 설계점에서 익형의 공력 변수들과 최소에 너지손실 조건을 이용하여 시위길이와 피치각 분포를 최적화하였다. 각각의 설계점에서 결과를 바탕으로 풍력발전의 설계 운용범위에서 반응면을 구성하고 구배최적화 기법을 통해 요구동력의 제약함수를 만족하고 효율을 최대로 하는 블레이드 형상을 구현하였다. 최적형상에 대해 탈설계점 해석을 수행하여 그 성능을 구하였다.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.272-279
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• 2004

The process for the preparation of fungicide propineb starting with 1,2-diaminopropane was studied on the optimal condition base. Side reaction producing toxic material 1,2-propylenethiourea could be ieduced effectively by using phase transfer catalyst and the product was noticed to show a great improvement in yield and purity. Especially when the phase transfer catalyst tetraphenylphosphonium bromide is used, the yield and the purity of the product were found to be best with up to 95 and 96% respectively and the byproduct content was shown within 1.7%. Also, the contents of wetting agent AES and dispersing agent APS were optimally chosen $3.1\sim4.0%$ and $4.0%\sim5.0%$ respectively for the improvement of suspensibility and wettability of Propineb WP.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.21-27
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• 2018

In this paper the laminate design parameters are researched to maximize the performance index of a composite pressure vessel. To maximize the performance index, the three design variables that the thickness of each of helical and hoop layers and the length of hoop layer are considered under the assumption of fixed internal space. To optimize the variables, the response surface method is introduced for construction of the surrogate model and the ANOVA(analysis of variance) is performed to evaluate the effects of the variables. The optimization problem is formulated to maximize performance index under the burst pressure constraint. To verify the effectiveness of the research, numerical analyses are performed for the optimum model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.106-113
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• 2002

In spacecraft system, structure subsystem has the mission of supporting all the components safely under various space environmental conditions. The safety of spacecraft structure is finally verified from the coupled load analysis, which is a branch of load analysis which combines the launch vehicle and satellite. This study introduces the optimization algorithm to reduce the weight of spacecraft structure under launch environmental conditions directly. The acceleration responses are obtained by the introduction of coupled load analysis, which lead to check the failure of spacecraft structural members. The results show a 12% saving of structural weight and this saving is mainly driven by the thickness of honeycomb core, which strongly affects the natural frequencies of platforms and panels.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.439-452
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• 1994

A method to optimize the cost of R/C frames and an algorithm of the optimal limit state design for R/C frames subjected to dynamic loads are presented. The modal superposition method was used to find the dynamic responses of the frames. Each member of R/C frame is made up of more than two elements and the stiffness matrix and consistent mass matrix of three d.o.f in the node of each element was used to include axial, shear and flexural effects. The objective function to be minimized formulated the cost of materials, steel and concrete, and optimised to satisfy the behaviors of R/C frame and each constraint imposed by the limit state requirements. Both objective function and each constraint are derived in terms of design variables which include the effective depth, beam width, compression and tension steel area, and column shear steel area. A few applications are presented which demonstrate the feasibility, the validity and efficiency of the algorithm for automated optimum design of R/C frames where dynamic behavior is to be considered.