Smallest defining sets for 2-(9, 4, 3) and 3-(10, 5, 3) designs
نویسنده
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.
منابع مشابه
On Minimal Defining Sets of Full Designs and Self-Complementary Designs, and a New Algorithm for Finding Defining Sets of t-Designs
A defining set of a t-(v, k, λ) design is a partial design which is contained in a unique t-design with the given parameters. A minimal defining set is a defining set, none of whose proper partial designs is a defining set. This paper proposes a new and more efficient algorithm that finds all non-isomorphic minimal defining sets of a given t-design. The complete list of minimal defining sets of...
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ورودعنوان ژورنال:
- Australasian J. Combinatorics
دوره 10 شماره
صفحات -
تاریخ انتشار 1994