ON THE NUMBER OF BLOCKS IN A PERFECT COVERING OF v POINTS

نویسندگان

  • Rolf REES
  • R. Rees
  • D. R. Stinson
چکیده

A perfect covering of a v-set X is a set of subsets of X (called blocks), such that every pair of elements of X (points) occurs in a unique block. A perfect covering is also referred to in the literature as a pairwise balanced design or a finite linear space. The quantity of g’“‘(v) is defined to be the minimum number of blocks in a perfect covering of a v-set, in which the longest block has size k (where (2skGv). There has been considerable interest in the last several years in the determination of g’“‘(v). Several lower bounds on g’“‘(v) have been given, by Woodall, Stanton and Kalbfleisch, Stinson, and Rees. For future reference, we now state these lower bounds, in approximate chronological order. The earliest bound (W) was proved by Woodall [12]; it is

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تاریخ انتشار 2001