• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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• pp.513-516
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• 2004

Evolutionary operation is useful to improve on-line full-scale manufacturing processes by systematically changing the levels of the process variables while meeting production schedule. Evolutionary operation was developed using two or three process variables for process operators who are not good at statistics. Recently, when a product is developed, it is very important for the engineers to make the production line stable as soon as possible. And there are many causes which have influences to the product performance. This paper presents an evolutionary operation procedure with many process variables using saturated two level fractional factorial designs including Plackett-Burman design.

• Journal of Welding and Joining
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• 제6권2호
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• pp.47-55
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• 1988

This paper reports on a study of the influence of welding variables on the weld shape of Al-7020 in pulse-GMA welding. Five variables, i.e., wire feed rate, peak pulse current, welding speed, welding votage, and pulse frequency were investigated for their effects on the weld shape. From the results of the 2$^{n-1}$ fractional factorial design, quantitative effects of each variable and the interaction of two variables were obtained, and consequently wire feed rate, welding voltage, and welding speed were determined as the main welding variables. Supplementary experiment was performed for ivestigating the detailed relationship between the main variables nd the seld shape. In this experiment, the penetation of the seldment increased when the wire feed rate was raised, nad the bead width increased when the welding voltage was raised or the welding speed was reduced.d.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.279-284
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• 2000

The object of this paper is to evaluate the chip breakability using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. L$\sub$9/(3$^4$) orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. The evaluation of chip breakability is used the chip breaking index(C$\sub$B/), non-dimensional parameter. And the analysis of variance (ANOYA)-test has been used to check the significance of cutting parameters. Using the result of ANOYA-test, the experimental equation of chip breakability, which consists of significant cutting parameters, has been developed. The coefficient of determination of this equation is 0.866.

• 응용통계연구
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• 제7권2호
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• pp.201-211
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• 1994

다구찌에 의해서 개발된 파라미터 설계법에서는 교호작용효과를 무시하고 직교배열을 이용하여 실험을 분석하는 것이 일반적인 방법으로 사용되고 있다. 본 논문에서는 직교배열과 거의 유사한 통계적 성질을 가지면서 최소의 실험횟수로 2인자 교호작용까지 분석할 수 있는 실험계획을 제시하고, 이러한 계획법에 의해 파라미터 설계법을 분석하고 유의적인 2인자 교호작용까지 검출하는 방법을 제시하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.26-28
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• 2007

This research is concerned with a study of failure strength evaluation on heat element gap at resistance welding. The failure strength of resistance welded joint is changed by welding factor like as current(power level), welding time(total energy), pressure etc. and another heat element factor like as number of element line, element gap etc. Tensile-shear tests were carried out with the single-lap specimen using polypropylene(PP). The failure mechanism and optimization of gap was discussed in order to explain the tensile-shear strength evaluation on heat element gap at resistance welding. Orthogonal array was used by fractional factorial design for efficient experiments.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2004년도 정기학술대회
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• pp.129-137
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• 2004

This paper presents an accelerated life test for burnout of tungsten filament of incandescent lamp. From failure analyses of field samples, it is shown that their root causes are local heating or hot sports in the filament caused by tungsten evaporation and wire sag. Finite element analysis is performed to evaluate the effect of vibration and impact for burnout, but any points of stress concentration or structural weakness are not found in the sample. To estimate the burnout life of lamp, an accelerated life test is planned by using quality function deployment and fractional factorial design, where voltage, vibration, and temperature are selected as accelerating variables. We assumed that Weibull lifetime distribution and a generalized linear model of life-stress relationship hold through goodness of fit test and test for common shape parameter of the distribution. Using accelerated life testing software, we estimated the common shape parameter of Weibull distribution, life-stress relationship, and accelerating factor.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1410-1415
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• 2006

Media components, including date juice, sodium acetate, peptone, and $K_{2}HPO_4$, which were screened by Plackett-Burman fractional factorial design, were optimized for lactic acid production from date juice using the response surface method (RSM). Sodium acetate, peptone (p<0.0001), and $K_{2}HPO_4$ (p=0.0029) were highly significant in influencing the lactic acid production. Close correlationship between predicted and experimental values was observed. When the optimum values of the parameters obtained through RSM (25.0 g/l date sugar, 15.0 g/l sodium acetate, 19.1 g/l peptone, and 4.7 g/l $K_{2}HPO_4$) were applied, lactic acid production (22.7 g/l) increased by 50.33%, compared with unoptimized media (15.1 g/l). The subsequent validation experiments confirmed the validity of the statistical model.

• 동아시아식생활학회지
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• 제17권1호
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• pp.103-109
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• 2007

The optimum conditions for springiness of polymannuronate acorn mook, in which polymannuronate was added to acorn powder, was investigated by the response-surface method(RSM). The fractional factorial design with three variables, i.e. polymannuronate addition, water addition and boiling time, and with three levels revealed that the range of acorn springiness was $0.804{\sim}0.987$. The governing equation was also partially differentiated for boiling time, showing that the optimum manufacturing condition for $90^{\circ}C$ is addition of 2% polymannuronate, addition of 120 mL of water, and 60 minutes of boiling time.

• 산업경영시스템학회지
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• 제36권3호
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• pp.17-24
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• 2013

Release planning in a software product line (SPL) is to select and assign the features of the multiple software products in the SPL in sequence of releases along a specified planning horizon satisfying the numerous constraints regarding technical precedence, conflicting priorities for features, and available resources. A greedy genetic algorithm is designed to solve the problems of release planning in SPL which is formulated as a precedence-constrained multiple 0-1 knapsack problem. To be guaranteed to obtain feasible solutions after the crossover and mutation operation, a greedy-like heuristic is developed as a repair operator and reflected into the genetic algorithm. The performance of the proposed solution methodology in this research is tested using a fractional factorial experimental design as well as compared with the performance of a genetic algorithm developed for the software release planning. The comparison shows that the solution approach proposed in this research yields better result than the genetic algorithm.

• Journal of Ginseng Research
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• 제18권1호
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• pp.53-59
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• 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.