“School of Mathematics”

Back to Papers Home
Back to Papers of School of Mathematics

Paper   IPM / M / 153
School of Mathematics
  Title:   Trading signed designs and some new 4-(12,5,4) designs
1.  G. B. Khosrovshahi
2.  A. Nowzari-Dalini
3.  R. Torabi
  Status:   Published
  Journal: Des. Codes Cryptogr.
  Vol.:  11
  Year:  1997
  Pages:   279-288
  Supported by:  IPM
Variations of the trade-off method exist in the literature of design theory and have been utilized by some authors to produce some t-designs with or without repeated blocks. In this paper we explore a new version of this algorithmic method (i) to produce 20 nonisomorphic and rigid 4-(12,5,4) designs, (ii) to study the spectrum of support sizes of 4-(12,5,4) designs. Along these, we also present a new design invariant for testing isomorphism among designs and a new way of representing t-designs.

Download TeX format
back to top
scroll left or right