A Study of Second Order Slope Rotatable Designs under Intra-class Correlated Structure of Errors Using Partially Balanced Incomplete Block Type Designs
B. Sulochana *
Department of Statistics, Acharya Nagarjuna University, Guntur, 522510, India.
B. Re. Victorbabu
Department of Statistics, Acharya Nagarjuna University, Guntur, 522510, India.
*Author to whom correspondence should be addressed.
Abstract
In this paper, a study of second order slope rotatable designs under intra-class correlated structure of errors using partially balanced incomplete block type designs is suggested. Further, we study the variance function of the estimated slopes for different values of intra-class correlated coefficient ( ) and distance from centre (d) for 6 ≤ v ≤ 12 (number of factors) are also suggested. We note the new method sometimes leads to designs with fewer number of design points.
Keywords: Second order response surface designs, slope rotatability, intra-class correlated errors