## The Annals of Mathematical Statistics

### Duals of Partially Balanced Incomplete Block Designs and some Nonexistence Theorems

Damaraju Raghavarao

#### Abstract

In this note, we give simpler proofs of results obtained, regarding the necessary conditions for existence of certain unsymmetrical PBIB designs having group divisible, triangular and $L_i$ association schemes, in [5]. We also give simpler proofs of the necessary conditions for the existence of affine $\alpha$-resolvable $GD(m, n), T(n), L_i(s)$ and BIB designs obtained in [6]. We follow the notation of these two papers throughout this note. We finally obtain necessary conditions for the dual of a design $D$, to be a specified design $E$.

#### Article information

Source
Ann. Math. Statist. Volume 37, Number 4 (1966), 1048-1052.

Dates
First available: 27 April 2007

http://projecteuclid.org/euclid.aoms/1177699387

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