TY - JOUR

T1 - Directed covering with block size 5 and v and λ Odd

AU - AbuGhneim, Omar A.

AU - Al-Halees, Hasan A.

AU - Assaf, Ahmed M.

PY - 2008/8

Y1 - 2008/8

N2 - A directed covering design, DC(v, k, λ), is a (v, k, 2λ) covering design in which the blocks axe regarded as ordered k-tuples and in which each ordered pair of elements occurs in at least λ blocks. Let DE(v, k, λ) denote the minimum number of blocks in a DC(v, k, λ). In this paper the values of the function DE(v, k, λ) are determined for all odd integers v ≥ 5 and λ odd, with the exception of (v, λ) = (53, 1), (63, 1), (73, 1), (83, 1). Further, we provide an example of a covering design that can not be directed.

AB - A directed covering design, DC(v, k, λ), is a (v, k, 2λ) covering design in which the blocks axe regarded as ordered k-tuples and in which each ordered pair of elements occurs in at least λ blocks. Let DE(v, k, λ) denote the minimum number of blocks in a DC(v, k, λ). In this paper the values of the function DE(v, k, λ) are determined for all odd integers v ≥ 5 and λ odd, with the exception of (v, λ) = (53, 1), (63, 1), (73, 1), (83, 1). Further, we provide an example of a covering design that can not be directed.

UR - http://www.scopus.com/inward/record.url?scp=78651582963&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:78651582963

VL - 66

SP - 237

EP - 255

JO - Journal of Combinatorial Mathematics and Combinatorial Computing

JF - Journal of Combinatorial Mathematics and Combinatorial Computing

SN - 0835-3026

ER -