The geometry of some two-character sets

@article{Cossidente2008TheGO,
  title={The geometry of some two-character sets},
  author={Antonio Cossidente and Nicola Durante and Giuseppe Marino and Tim Penttila and Alessandro Siciliano},
  journal={Designs, Codes and Cryptography},
  year={2008},
  volume={46},
  pages={231-241}
}
A projective (n, d, w1, w2)q set (or a two-character set for short) is a set $${\mathcal{S}}$$ of n points of PG(d − 1, q) with the properties that the set generates PG(d − 1, q) and that every hyperplane meets the set in either n − w1 or n − w2 points. Here geometric constructions of some two-character sets are given. The constructions mainly involve commuting polarities, symplectic polarities and normal line-spreads of projective spaces. Some information about the automorphism groups of such… 
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