We construct supplementary difference sets (SDS) with parameters
(59;28,22;21), (69;31,27;24), (75;36,29;28), (77;34,31;27) and
(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.Comment: 14 pages. arXiv admin note: substantial text overlap with
arXiv:1409.596