• 품질경영학회지
• /
• 제40권1호
• /
• pp.15-24
• /
• 2012

For the construction of fractional factorial designs, the various arrays can be widely used. In this paper we review the statistical properties of fractional designs constructed by two arrays such as orthogonal array and partially balanced array, and develop a quick and easy method for analyzing unreplicated saturated designs. The proposed method can be characterized that we control the error rate by experiment-wise way and exploit the multivariate Student $t$-distribution. Especially the proposed method can be used efficiently together with some exploratory analysis methods, such as half normal probability plot method.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제13권1호
• /
• pp.55-72
• /
• 2009

A misclassified size-biased modified power series distribution (MSBMPSD) where some of the observations corresponding to x = c + 1 are misclassified as x = c with probability $\alpha$, is defined. We obtain its recurrence relations among the raw moments, the central moments and the factorial moments. Discussion of the effect of the misclassification on the variance is considered. To illustrate the situation under consideration some of its particular cases like the size-biased generalized negative binomial (SBGNB), the size-biased generalized Poisson (SBGP) and sizebiased Borel distributions are included. Finally, an example is presented for the size-biased generalized Poisson distribution to illustrate the results.

• Korean Journal of Mathematics
• /
• 제21권3호
• /
• pp.319-323
• /
• 2013

Let D be a principal ideal domain, X be an indeterminate over D, D[X] be the polynomial ring over D, and $R_n=D[X]/(X^n)$ for an integer $n{\geq}1$. Clearly, $R_n$ is a commutative Noetherian ring with identity, and hence each nonzero nonunit of $R_n$ can be written as a finite product of irreducible elements. In this paper, we show that every irreducible element of $R_n$ is a primary element, and thus every nonunit element of $R_n$ can be written as a finite product of primary elements.

• Journal of Microbiology and Biotechnology
• /
• 제21권12호
• /
• pp.1250-1256
• /
• 2011

In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

• 한국산학기술학회논문지
• /
• 제9권5호
• /
• pp.1249-1254
• /
• 2008

그래프 모델에서 가장 중요한 부분은 관찰 데이터가 주어진 상황에서 은닉 변수와 더불어 파라미터의 사후확률 분포의 계산이다. 이 논문에서는 가우시안 혼합 모델에 대한 변분 베이지안 방법의 구현과 변분 근사화 분포의 분해 유도를 제안한다. 이 방법은 정보 검색이나 데이터 시각화와 같은 데이터 분석 등에 적용이 가능하다.

• 대한안전경영과학회지
• /
• 제10권3호
• /
• pp.237-243
• /
• 2008

The present study proposes two normality tests using nonparametric rank measures for small sample such as modified normal probability paper(NPP) tests and modified Ryan-Joiner Test. This research also reviews various normality tests such as $X^2$ test, and Kullback-Leibler test. The proposed normality tests can be efficiently applied to the sparsity tests of factor effect or contrast using saturated design in $k^n$ factorial and fractional factorial design.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.862-865
• /
• 2000

The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ 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. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.393-396
• /
• 1997

High-speed machining is one of the most effective technologies to improve productivity. Because of the high speed and high feed rate, high-speed machining can give great advantages for the machining of dies and molds. This paper describes on the improvement of machining accuracy in high-speed machining. Depth of cut and feed rate are control factors. The effect of the control factors on machining accuracy is investigated using two-way factorial design.

• 한국기계가공학회지
• /
• 제6권4호
• /
• pp.65-70
• /
• 2007

In this study, we analyzed about that after design form manufacture master pattern in Rapid Prototyping-RP through design program, processes to manufacture prototype using Vacuum Casting. In Rapid Prototyping-RP, there is an en-or by shrinkage of resin and, in Vacuum Casting, there is an error by shrinkage of silicon. To select condition which shrinkage become the minimum of each process, manufactured prototype after using Full Factorial Design of Design of Experiments, We could confirm shrinkage using reverse engineering and that result came into effect ANOVA 2-way. We applied errors of each process to master pattern, and then presented the method to improve flood control precision of prototype of Vacuum Casting.

• 동력기계공학회지
• /
• 제20권3호
• /
• pp.51-56
• /
• 2016

In this study, the tensile tests and hardness tests were carried out for the joints characteristics in friction stir welds of Al 5052 alloy. Three way factorial design was applied to optimal welding conditions, whose control factors were shoulder diameter, rotation speed and welding speed of tool. From the results of this study, the optimum condition for maximum yield strength was predicted as the shoulder diameter of 15 mm, welding speed of 500mm/min and rotating speed of 1000 rpm. And the presumed optimal yield strength was estimated to be $167.36{\pm}7.82MPa$ with 99% reliability. In addition the increaser rotation speed of tool and the decreaser welding speed, the decreaser the hardness at welding part.