• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.1033-1038
• /
• 1995

NC 공작기계의 contour 운동 오차를 측정하기 위하여 사용되는 Ball-Bar에 의한 원호 보간 시험 데이터를 이용하여 NC controller의 성능을 평가 할 수 있는 S/W에 의한 방법을 제시한다. 본 논문에서 지금까지는 분석이 어려웠던 Masrer-Slave Changeover의 분석을 가능하게 하였으며, Ball-Bar로 부터 얻어지는 데이터를 Weighted Residual Method에 의한 종합적인 분석을 하였으며, 오차 원인별 비교를 위해 Eztra Sum of Squares Method를 도입하였다. 본 연구의 실제 적용을 위한 측정 및 분석 S/W를 개발하였으며, 결과적으로 NC controller의 성능평가에 유용함을 알 수 있었다. 무부하 조건에서의 Ball-Bar에 의한 분석 데이터와의 비교를 위하여 원형 시편을 가공하고, 진원도 측정 및 분석을 통하여 유사한 오차 pattern을 가짐을 알 수 있었다.

• Journal of the Korean Data and Information Science Society
• /
• v.21 no.5
• /
• pp.901-908
• /
• 2010

A geometrical description method is proposed to represent the process of the forward selection and backward elimination methods among many variable selection methods for multiple regression models. This graphical method shows the process of the forward selection and backward elimination on the first and second quadrants, respectively, of half circle with a unit radius. At each step, the SSR is represented by the norm of vector and the extra SSR or partial determinant coefficient is represented by the angle between two vectors. Some lines are dotted when the partial F test results are statistically significant, so that statistical analysis could be explored. This geometrical description can be obtained the final regression models based on the forward selection and backward elimination methods. And the goodness-of-fit for the model could be explored.

• Journal of Korean Society of Forest Science
• /
• v.88 no.4
• /
• pp.446-453
• /
• 1999

In this study, the effects of stand planting density on parameters of stand height and basal area growth models were investigated. We used the Korf equation as the base model in estimating the parameters of the growth models for cryptomeria plantation forest stands. Then, in order to investigate the effects of the change in plantation density on the parameter estimates, the "extra sums of square" principle, which provided a reasonable statistical procedure for a performance test, was used. The results of the test coincide with the understandings that stand height growth is not affected significantly by the planting density and the growth curves of stand basal area approaches a common asymptote regardless of the stand density for a given site. However, the shapes of the basal area growth curves were affected significantly by the planting density. Based on the results of the test, we developed a basal area growth model to account for the effects of initial planting density in cryptomeria plantation forest stands.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.24 no.8
• /
• pp.1197-1208
• /
• 2000

The purpose of this study was to find out the effects of the accord between consumers benefit factors and attribute factors of brand image on brand attitude. This study was based on Kellers conceptualizing model of brand image. The subjects were 605 working women in their twenties living in Seoul, Korea. The data were analyzed by Euclidian distance model, ANOVA of repeated measures, regression, F-test by Extra Sum of Squares Principle. The results were as follows. 1. There were significant differences among the brands and among the segmented groups in the accord between benefit factors and attribute factors of brand image and in the brand preference. Moreover there were significant interactions between the brands and the segmented groups in the accord between benefit factors and attribute factors of brand image and in the brand preference. 2. There were significant effects of the accord between benefit factors and attribute factor of brand image on brand attitude. 3. There were significantly different effects of the accord between benefit factors and attribute factors of brand image on brand attitude among the segmented groups.