## Abstract This article looks at (5,Ξ») GDDs and (__v__,5,Ξ») pair packing and pair covering designs. For packing designs, we solve the (4__t__,5,3) class with two possible exceptions, solve 16 open cases with Ξ» odd, and improve the maximum number of blocks in some (__v__, 5, Ξ») packings when __v__
Kirkman packing and covering designs with spanned holes of size 2
β Scribed by Jianxing Yin
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 120 KB
- Volume
- 13
- Category
- Article
- ISSN
- 1063-8539
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
A Kirkman holey packing (resp. covering) design, denoted by KHPD(g^u^) (resp. KHCD(g^u^)), is a resolvable (gu, 3, 1) packing (resp. covering) design of pairs with u disjoint holes of size g, which has the maximum (resp. minimum) possible number of parallel classes. Each parallel class contains one block of size Ξ΄, while other blocks have size 3. Here Ξ΄ is equal to 2, 3, and 4 when guββ‘β2, 3, and 4 (mod 3) in turn. In this paper, the existence problem of a KHPD(2^u^) and a KHCD(2^u^) is solved with one possible exception of a KHPD(2^8^). Β© 2004 Wiley Periodicals, Inc.
π SIMILAR VOLUMES
## Abstract In this paper, we determine the number of the orbits of 7βsubsets of $X= {\rm GF}(2^n)\cup\{\infty\}$ with a fixed orbit length under the action of PSL(2, 2^__n__^). As a consequence, we determine the distribution of Ξ» for which there exists a simple 3β(2^__n__^β+β1, 7, Ξ») design with P
We consider direct constructions due to R. J. R. Abel and
## Abstract We determine the distribution of 3βdesigns among the orbits of 4β and 5βelement subsets under the action of PSL(2,2^__n__^) on the projective line. Thus we give complete information on all KramerβMesner matrices for the action of PSL(2,2^__n__^) on 3βsets versus 4β and 5βsets. As a cons
## Abstract Large sets of disjoint groupβdivisible designs with block size three and type 2^__n__^4^1^ have been studied by Schellenberg, Chen, Lindner and Stinson. These large sets have applications in cryptography in the construction of perfect threshold schemes. It is known that such large sets
This paper contains a discussion of cocyclic Hadamard matrices, their associated relative difference sets, and regular group actions. Nearly all central extensions of the elementary abelian 2-groups by Z 2 are shown to act regularly on the associated group divisible design of the Sylvester Hadamard