Complete enumeration of two-Level orthogonal arrays of strength $d$ with $d+2$ constraints

TL;DR

This paper completely enumerates nonisomorphic two-level orthogonal arrays of a given strength with specific constraints, providing both counts and explicit constructions using advanced theoretical methods.

Contribution

It offers a complete enumeration and construction method for two-level orthogonal arrays of strength d with d+2 constraints, expanding the understanding of their classification.

Findings

Number of nonisomorphic arrays for given parameters

Explicit construction methods for these arrays

Application of J-characteristics theory to orthogonal arrays

Abstract

Enumerating nonisomorphic orthogonal arrays is an important, yet very difficult, problem. Although orthogonal arrays with a specified set of parameters have been enumerated in a number of cases, general results are extremely rare. In this paper, we provide a complete solution to enumerating nonisomorphic two-level orthogonal arrays of strength $d$ with $d+2$ constraints for any $d$ and any run size $n=\lambda2^d$. Our results not only give the number of nonisomorphic orthogonal arrays for given $d$ and $n$, but also provide a systematic way of explicitly constructing these arrays. Our approach to the problem is to make use of the recently developed theory of $J$-characteristics for fractional factorial designs. Besides the general theoretical results, the paper presents some results from applications of the theory to orthogonal arrays of strength two, three and four.