Smallest defining sets for 2-(9, 4, 3) and 3-(10, 5, 3) designs

نویسنده

  • Tony Moran
چکیده

A set of blocks which can be completed to exactly one t-(v, k, A) design is called a defining set of that design. A known algorithm is used to determine all smallest defining sets of the 11 non-isomorphic 2-(9,4,3) designs. Nine of the designs have smallest defining sets of eight blocks each; the other two have smallest defining sets of six blocks each. Various methods are then used to find all smallest de£ning sets of the seven non-isomorphic 3-(10,5,3) designs, all of which are extensions of 2(9,4,3) designs. Four of the 3-(10,5,3) designs have smallest defining sets of eight blocks each; the other three have smallest defining sets of six blocks each. Whereas in previous computations of sizes of smallest defining sets of classes of non-isomorphic designs with the same parameters, the size of smallest defining sets was found to be non-decreasing as automorphism group order increases, both of these classes of designs provide cases which show that this is not a universal rule.

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عنوان ژورنال:
  • Australasian J. Combinatorics

دوره 10  شماره 

صفحات  -

تاریخ انتشار 1994