Some series of proper generalized neighbor designs

Neighbor balanced designs are used to remove the neighbor effects but most of these designs require a large number of blocks. To neutralize the neighbor effects in such situations, GN2-designs are most desirable. This article deals with the (i) refinement of some series of GN2-designs constructed by Zafaryab et al. (2010) and (ii) construction of some new series of GN2-designs in circular blocks of equal size.