数学物理学报(英文版)

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THE EXISTENCE OF OVERLARGE SETS OF IDEMPOTENT QUASIGROUPS

常彦勋,雷建国   

  1. Department of Mathematics, Beijing Jiaotong University, Beijing 100044, China Department of Mathematics, Hebei Normal University, Shijiazhuang 050091, China
  • 出版日期:2004-07-20 发布日期:2004-07-20
  • 基金资助:

    Supported by NSFC grant No. 10371002 (Y. Chang) and
    No. 19901008 (J. Lei)

THE EXISTENCE OF OVERLARGE SETS OF IDEMPOTENT QUASIGROUPS

 CHANG Pan-Xun, LEI Jian-Guo   

  • Online:2004-07-20 Published:2004-07-20
  • Supported by:

    Supported by NSFC grant No. 10371002 (Y. Chang) and
    No. 19901008 (J. Lei)

摘要:

A idempotent quasigroup (Q, ?) of order n is equivalent to an n(n − 1) × 3
partial orthogonal array in which all of rows consist of 3 distinct elements. Let X be a
(n + 1)-set. Denote by T(n + 1) the set of (n + 1)n(n − 1) ordered triples of X with the
property that the 3 coordinates of each ordered triple are distinct. An overlarge set of
idempotent quasigroups of order n is a partition of T(n+1) into n+1 n(n−1)×3 partial
orthogonal arrays Ax, x ∈ X based on X \ {x}. This article gives an almost complete
solution of overlarge sets of idempotent quasigroups.

Abstract:

A idempotent quasigroup (Q, ?) of order n is equivalent to an n(n − 1) × 3
partial orthogonal array in which all of rows consist of 3 distinct elements. Let X be a
(n + 1)-set. Denote by T(n + 1) the set of (n + 1)n(n − 1) ordered triples of X with the
property that the 3 coordinates of each ordered triple are distinct. An overlarge set of
idempotent quasigroups of order n is a partition of T(n+1) into n+1 n(n−1)×3 partial
orthogonal arrays Ax, x ∈ X based on X \ {x}. This article gives an almost complete
solution of overlarge sets of idempotent quasigroups.

Key words: Pairwise balanced design, conjugate invariant subgroup, overlarge set of idempotent quasigroups

中图分类号: 

  • 05B