Second Order Slope Rotatable Designs of Second Type Utilizing Balanced Incomplete Block Designs
B. Re. Victorbabu
Department of Statistics, Acharya Nagarjuna University, Guntur-522510, India.
B. Venkata Ravikumar *
Department of Statistics, Acharya Nagarjuna University, Guntur-522510, India and Department of Mathematics, Siddhartha Academy of Higher Education (SAHE) Deemed to be University, Kanuru, Vijayawada, India.
*Author to whom correspondence should be addressed.
Abstract
Kim (2002) proposed second order rotatable designs (SORD) of second type utilizing Central composite design (CCD), wherein the two digits denotes the position of star points. Kim and Ko (2004) introduced second order slope rotatable designs (SOSRD) of second type utilizing CCD, wherein the two digits denotes the position of star points. In this study, we propose SOSRD of second type utilizing balanced incomplete block designs (BIBD) for 3≤v≤16 (v-stands for number of factors). In specific cases, the recommended procedure results in fewer number of design points than SOSRD of second type acquired utilizing CCD of Kim and Ko (2004), Ravikumar and Victorbabu (2022a), Pairwise balanced designs (PBD) of Ravikumar and Victorbabu (2022c), Symmetrical unequal block arrangements (SUBA) with two unequal block sizes of Ravikumar and Victorbabu (2024) and BIBD with unequal block sizes of Ravikumar and Victorbabu (2025). The variance of the estimated response of first order partial derivative of SOSRD of second type using BIBD for different factors 3≤v≤16 are also obtained.
Keywords: Response surface designs, second order slope rotatable designs, second order slope rotatable designs of second type