On λ-designs
نویسندگان
چکیده
منابع مشابه
(3, Λ)-group Divisible Covering Designs
Let U, g, k and A be positive integers with u :::: k. A (k, A)-grOUp divisible covering design ((k, A)-GDCD) with type gU is a A-cover of pairs by k-tuples of a gu-set X with u holes of size g, which are disjoint and spanning. The covering number, C(k, A; gil), is the minimum number of blocks in a (k, A)-GDCD of type gUo In this paper, the detennination ofllie fimction C(3, A; gil) begun by [6]...
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The basic necessary conditions for the existence of a (v, k, λ)-perfect Mendelsohn design (briefly (v, k, λ)-PMD) are v ≥ k and λv(v− 1) ≡ 0 (mod k). These conditions are known to be sufficient in most cases, but certainly not in all. For k = 3, 4, 5, 7, very extensive investigations of (v, k, λ)-PMDs have resulted in some fairly conclusive results. However, for k = 6 the results have been far ...
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There is one nontrivial regular configuration on two paths of three vertices, and one on three paths. Path designs which are resolvable into copies of these configurations are shown to exist whenever basic numerical conditions are met, with a few possible exceptions.
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The existence of pairwise additive balanced incomplete block (BIB) designs and pairwise additive cyclic BIB designs with λ = 1 has been discussed through direct and recursive constructions in the literature. This paper takes BIB designs with 1-rotational automorphisms and then the existence of pairwise additive 1-rotational BIB designs is investigated for λ = 1. Finally, it is shown that there ...
متن کاملBalanced arrays of strength two and nested (r,λ)-designs
An (r,λ)-design with mutually balanced nested subdesigns ( for brevity, (r,λ)-design with MBN ) is introduced firstly in this paper. It is shown that an (r,λ)design with MBN is equivalent to a balanced array of strength 2 with s symbols. By the use of a nested design and an orthogonal array, a construction of an (r,λ)design with MBN is given. A direct construction of such an (r,λ)-design, based...
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series A
سال: 1974
ISSN: 0097-3165
DOI: 10.1016/0097-3165(74)90072-7