B0463
Title: Egde designs from skew-symmetric supplementary difference sets
Authors: Stelios Georgiou - RMIT University (Australia) [presenting]
Abstract: The purpose of screening experiments is to identify the dominant variables from a set of many potentially active variables which may affect some characteristic y. Edge designs were introduced in the literature, are constructed by using conference matrices and were proved to be robust designs. We introduce a class of edge designs which are constructed from skew-symmetric supplementary difference sets. These designs are particularly useful since they can be applied for experiments with an even number of factors, and they may exist for orders where conference matrices do not exist. Using this methodology, examples of edge designs for 6, 14, 22, 26, 38, 42, 46, 58, and 62 factors are constructed. Of special interest are the edge designs for studying 22 and 58 factors because edge designs with these parameters have not been constructed in the literature, as conference matrices of the corresponding order do not exist. The suggested edge designs achieve the same model robustness as the traditional edge designs. We also suggest the use of a mirror edge method as a test for the linearity of the true underlying model. We give the details of the methodology and provide some illustrating examples for this new approach. We also show that the new designs have good D-efficiencies when applied to first-order models.
