• 한국항공우주학회지
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• 제34권7호
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• pp.28-34
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• 2006

일반적인 엔지니어링 문제에 대한 최적화는 최적의 설계변수를 구하는 문제이다. 이는 설계변수의 총합을 얼마로 하며, 총합을 설계변수들이 어떠한 비율로 차지하는 것이 최적인가를 판단하는 문제가 된다. 즉, 혼합물 총량법의 개념에 맞추어 문제를 재구성할 수 있다. 혼합물 총량법의 목적은 각 성분의 혼합비율과 혼합물의 총량을 동시에 고려하여 반응면을 구하는 것이다. 항공기 동체 최적화 문제에 혼합물 총량법과 유전자 알고리즘을 적용하였다. 이번 연구를 통해서 항공기 구조물 최적화 문제에 대한 혼합물 총량법의 유용성을 확인하였다. 또한 본 연구에서 제시된 혼합물 총량법은 D-optimal에서는 불가능한 설계변수 12개 이상의 최적화 문제에도 적용이 가능하다.

• 한국식품과학회지
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• 제53권2호
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• pp.174-180
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• 2021

본 연구는 국내산 복분자와 오디의 활용도를 높이고 고품질의 환을 개발하기 위해 복분자 가루, 오디 가루, 비타민 C 세 가지 재료가 복분자-오디 환의 항산화 특성에 미치는 영향을 조사하기 위해 혼합물 설계법 중 D-optimal mixture design을 이용하였다. 독립변수인 복분자 가루, 오디 가루 및 비타민 C 함량에 따라 복분자-오디 환의 총 페놀 및 플라보노이드 함량, FRAP이 linear 모델, DPPH 라디컬 소거활성은 quadratic 모델로 결정되었으며 회귀식은 p-value의 값이 각각 0.0481, <0.0001, <0.0001 및 0.0387로 유의성이 인정되었다. 총 페놀 함량은 비타민 C 첨가량에 영향을 크게 받았지만 복분자 가루 및 오디 가루 첨가량이 부정적인 영향을 주지 않는 것으로 나타났다. 총 플라보노이드 함량은 복분자 가루의 함량이 증가할수록 크게 높아지는 것으로 나타났다. DPPH 라디컬 소거활성은 비타민 C 첨가량이 높을수록 증가하였으며, 복분자 가루의 첨가량이 너무 낮아지면 감소하는 것으로 나타났다. FRAP 활성은 비타민 C와 오디가루 첨가량이 긍정적인 영향을 주는 것으로 드러났다. 이러한 결과와 desirability를 바탕으로 두 개의 복분자-오디 환 배합비가 가능할 것으로 도출되었지만 이 둘 중에서 Formulation 1 (복분자 가루 35%, 오디가루 10%, 비타민 C 10%)이 desirability가 0.8 이상으로 제품 품질이 적합하고 우수하여 최적 배합 비율로 설정하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.129-134
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• 2000

Hardening agent has been the traditional material for surface soil stabilization a sat ground This study aims at determining optimal mixture ratio of hardening agent in accordance with the required design specificutions. Hardening agent is properly mixed with Fly ash, Gyosum, Slag and Cement for the etmmngite hydrates which is dective for early stabilization of unconsoliokrred soil. \ulcornerhe treated soil is the clay tint is widely found here and there in Koresz In this study, preliminary tests were performed to get optirml mixture ratio of stabilizer ingredient, and mrvine clay in Jin-Hae was used to get physid and Md properties. Labomtory tests of 50 stabilized soil were performed to get optimal mixture mtio for 16-stabilizer merial a 6 types, a d stabilizer mixing was determined

• 산업기술연구
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• 제22권A호
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• pp.83-87
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• 2002

Many industrial products such as paints, ink and adhesives are composed of the ingredients of a mixture. In mixture experiments, the characteristics of quality(response) depends only on the proportions of the ingredients and does not depend on the total amount of the mixture. This article discusses the constrained mixture experimental design, the data analysis, and the optimum formulation of ingredients based on the two quality characteristics - taste and flavor. It IS shown that efficient designs can be constructed from D-optimal criterion. Special cubic models were selected as the final mixture response surfaces for both reponses. The desirability function was used for the optimization of the two responses.

• 응용통계연구
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• 제28권1호
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• pp.93-102
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• 2015

D-최적 등을 위시한 최적실험은 비선형모형인 경우 추정을 하여야할 모수에 의존하는 문제점이 존재한다. 따라서 기본적으로 문헌에서는 모수추정을 위해서는 순차실험을 제안한다. 본 연구에서는 2단계 실험설계를 모수추정의 사례를 포함한 다양한 환경 하에서의 사용방법을 알아보았다. 본 연구에서 제안한 내용은 단계의 수나 구체적인 실험기준의 숫자에 상관없이 적용되는 범용적인 기준이다. 본 연구는 2단계 실험에서 3개 이상의 실험목적을 가지고 있는 경우 하이브리드(hybrid)방법을 제안하였다. 모든 실험은 근사실험설계의 형태로 논의되었다.

• 응용통계연구
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• 제20권2호
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• pp.267-280
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• 2007

혼합물 성분들의 비율의 상한과 하한에 대한제한조건이 부과된 제한된 혼합물 실험 공간 R에서의 혼합물 실험을 위한 최적 설계를 찾는 데에 D-, G-, V- 최적기준 등과 같은 다양한 최적 설계 기준이 사용된다. 각각의 실험 설계는 선택된 최적 기준에 대해서는 최적이지만, 제한된 혼합물 실험 공간에서의 예측력에 대해서는 만족스럽지 못하다는 것은 잘 알려진 사실이다. (Vining 등, 1993; Khuri 등, 1999). 우리의 관심사는 2차 혼합물 반응표면모형을 가정한 경우에 제한된 혼합물 공간에서의 효율적인 실험 설계를 찾는 것이다. 이 논문에서는 꼭지점, 선중심점, 면중심점, 중앙점과 내부점으로 구성된 확장된 후보 실험점 그룹을 구성한 다음에, D-최적기준, G-최적기준, V-최적기준과 실험점들 간의 거리에 근거한 U-최적기준에 강건한 실험 설계를 제안한다. Khuri 등(1999)에서 분석된 비료 혼합물 실험과Vining과 Cornell(1993)이 분석한 조명탄 혼합물 실험의 사례에서 강건한 실험설계들과 두 논문에서 추천된 실험 설계들에 대한 예측치의 표준화된 분산의 분위수의 그림(SVPQP)을 비교한 결과 강건한 설계가 상대적으로 우월함이 판명되었다.

• 한국조리학회지
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• 제23권7호
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• pp.20-30
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• 2017

This study was conducted for the optimization of ingredients in salad dressing using Hwangdo peach (Prunus persica L. Batsch). The experiment was designed according to the D-optimal design of mixture design, which included 14 experimental points with 4 replicates for three independent variables (olive oil 40~65%, peach puree 27~50%, vinegar 8~20%). The linear regression models for pH, viscosity and color value and the quadratic regression models for emulsion stability, all sensory evaluation of the products were proven to be valid by the F-test for the overall significance of the regression model at a 5% level. Viscosity and pH of the products increased as olive oil content. Color value, viscosity and pH of the products increased as peach puree content. pH, viscosity, redness, and yellowness of the products decreased as vinegar content. Sensory evaluation result of the products showed that general preference for the products were increasingly affected by the increases in contents then decreased as they exceeded the optimum levels. In consequence, according to result from the first stage of the experiment, the optimum ingredients ratios of the raw materials were set in olive oil 52.43%, peach puree 35.07%, and vinegar 13.91% for ingredients of apricot dressing. These results provided the possibility that peach can be applied to the preparation of a dressing, and thereby present baseline data for the development of new dressings. This is also presumed to meet demands of customers who are always in pursuit of new products.

• 한국환경과학회지
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• 제29권8호
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• pp.793-800
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• 2020

The conventional development of multi-component electrodes is based on the researcher's experience and is based on trial and error. Therefore, there is a need for a scientific method to reduce the time and economic losses thereof and systematize the mixing of electrode components. In this study, we use design of mixture experiments (DOME)- in particular a simplex lattice design with Design Expert^Ⓡ program- to attempt to find an optimum mixing ratio for a three-component electrode for the high RNO degradation; RNO is an indictor of OH radical formation. The experiment included 12 experimental points with 2 center replicates for 3 different independent variables (with the molar ratio of Ru, Ti, Ir). As the Prob > F value of the 'Quadratic' model is 0.0026, the secondary model was found to be suitable. Applying the molar ratio of the electrode components to the corrected response model results is an RNO removal efficiency (%) = 59.89 × [Ru] + 9.78 × [Ti] + 67.03 × [Ir] + 66.38 × [Ru] × [Ir] + 132.86 × [Ti] × [Ir]. The R² value of the equation is 0.9374 after the error term is excluded. The optimized formulation of the ternary electrode for an high RNO degradation was acquired when the molar ratio of Ru 0.100, Ti 0.200, Ir 0.700 (desirability d value, 1).

• 품질경영학회지
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• 제50권1호
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• pp.169-181
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• 2022

Purpose: This paper addresses a case study of developing a flame retardant wood-plastic composites (WPC) by adding tannic acid to the existing synthetic wood. The optimal mixing ratios of six components are explored to minimize the burning time using two mixture designs. Methods: In the preliminary experiment, six components are considered to find important components and their ranges. Seven D-optimal mixture design points are generated. Two points are removed for the balance of plastic components to be maintained, and the remaining five points are augmented with two basic compositions. Four components are selected to be considered in the main experiment. In the main experiment, pellets are extruded at the eight mixture design points. In-house testing of burning time is executed three times. Specimens made of pellets from two promising flame retardant compositions are sent to the accredited laboratories and tested. Results: The test results are as follows: 1) The best composition (Wood flour, Tannic acid, PE, Lubricant) = (25, 41, 10, 2) (wt%) shows the burning time of 1 second, which is 9-fold improvement compared to the the burning time of 9 seconds from the existing composition (58, 0, 10, 2) (wt%). 2) The second best composition (41, 25, 10, 2) (wt%) results in the burning time of 2 seconds. This composition is inferior to the best composition in terms of the flame retardancy, but more economical since it needs less tannic acid which is 100-fold expensive than the wood flour. Conclusion: Flame retardant compositions are found by adding tannic acid to the existing WPC employing optimal mixture designs. This case study will be helpful to practitioners who try to develop new products with additional physical properties with as small number of experimental trials as possible. Future research direction includes exploring conditions which satisfy both performance level and cost limitation simultaneously.

• 한국식품조리과학회지
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• 제28권1호
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• pp.67-76
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• 2012

This study examined the optimal ingredient mixing ratio for the preparation of steamed cake containing mugwort (Artemisia princeps var. orientalis) powder. After preliminary studies, the following ingredient ranges were determined; 110~129% sugar, 3~8% mugwort powder, 10~25% oil. Among the different mixture designs, the D-optimal design was chosen for analysis. The results of F-test, specific gravity, viscosity, volume and color values (L, a, b), hardness decided a linear model, while the sensory characteristics (color, taste, texture and overall acceptance) decided a quadratic model. The fitness analysis results showed that in all characteristic, the probabilities were significant within 0.05%; thus, the models were accepted as appropriate. The response surface and trace plot results showed that increasing amounts of mugwort powder decreased the brightness, and increased redness and yellowness. As the level of added oil increased, the softness of the cake increased. Cake samples received low sensory evaluation scores when sugar, mugwort powder, and oil were added above their optimal levels. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method presented as: sugar, mugwort powder, and oil at 120.7%, 5.1%, and 16.2%, respectively(flour weight basis). The above results demonstrate the feasibility of adding mugwort powder to sponge cake, and therefore, the commercialization of mugwort powder cake marketed as a functional food is deemed possible.