English

D-optimal matrices of orders 118, 138, 150, 154 and 174

Combinatorics 2017-10-12 v2

Abstract

We construct supplementary difference sets (SDS) with parameters (59;28,22;21)(59;28,22;21), (69;31,27;24)(69;31,27;24), (75;36,29;28)(75;36,29;28), (77;34,31;27)(77;34,31;27) and (87;38,36;31)(87;38,36;31). These SDSs give D-optimal designs (DO-designs) of two-circulant type of orders 118,138,150,154 and 174. Until now, no DO-designs of orders 138,154 and 174 were known. While a DO-design (not of two-circulant type) of order 150 was constructed previously by Holzmann and Kharaghani, no such design of two-circulant type was known. The smallest undecided order for DO-designs is now 198. We use a novel property of the compression map to speed up some computations.

Keywords

Cite

@article{arxiv.1408.6116,
  title  = {D-optimal matrices of orders 118, 138, 150, 154 and 174},
  author = {Dragomir Z. Djokovic and Ilias S. Kotsireas},
  journal= {arXiv preprint arXiv:1408.6116},
  year   = {2017}
}

Comments

14 pages. arXiv admin note: substantial text overlap with arXiv:1409.5969