Aliasing Strings for Some Nonregular Designs with Generalized Minimum Aberration

• Activity Number: 294
• Type: Contributed
• Date/Time: Tuesday, July 31, 2007 : 10:30 AM to 12:20 PM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Debra Ingram*+ and Alison L. Wiley
• Companies: Arkansas State University and Arkansas State University
• Keywords: fractional factorial design ; generalized resolution ; Hadamard matrix ; nonregular design ; partial aliasing ; projection

Abstract

Nonregular designs of 20, 24, and 28 runs help fill the gap in available run sizes between the 16-run and the 32-run regular 2^(k-p) fractional factorials, and provide experimenters flexibility in run size. For several values of k, the nonregular designs offer higher generalized resolution than their regular counterparts. These nonregular designs exhibit better projection properties and may provide advantages in satiability of effects through partial (instead of full) aliasing. The aliasing structures for the regular 2^(k-p) designs are straightforward and can be summarized by a defining relation. The aliasing structures for nonregular designs, on the other hand, are more complex. This paper provides the aliasing strings for some nonregular designs, specifically those that are viewed as attractive alternatives to the 16-run and 32-run regular designs.