Pair covering designs with block size 5

被引:6
|
作者
Abel, R. Julian R. [1 ]
Assaf, Ahmed
Bennett, Frank E.
Bluskov, Iliya
Greig, Malcolm
机构
[1] Univ New S Wales, Sch Math & Stat, Sydney, NSW 2052, Australia
[2] Cent Michigan Univ, Dept Math, Mt Pleasant, MI 48859 USA
[3] Mt St Vincent Univ, Dept Math, Halifax, NS B3M 2J6, Canada
[4] Univ No British Columbia, Dept Math & Comp Sci, Prince George, BC V2N 4Z9, Canada
[5] Greig Consulting, N Vancouver, BC V7L 4R3, Canada
关键词
covering design; SBCD; ISBCD; GDD; PBD; resolvable;
D O I
10.1016/j.disc.2006.09.026
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
In this article we look at pair covering designs with a block size of 5 and v = 0 (mod 4). The number of blocks in a minimum covering design is known as the covering number C (v, 5, 2). For v 24, these values are known, and all but v = 8 exceed the Schonheim bound, L(v, 5, 2) = [v/5[(v -1)/4]]. However, for all v >= 28 with v = 0 (mod 4), it seems probable that C(v, 5, 2) L(v, 5, 2). We establish this for all but 17 possible exceptional values lying in the range 40 <= v <= 280. (C) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:1776 / 1791
页数:16
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