X−1-balance of some partially balanced experimental designs with particular emphasis on block and row-column designs

This paper considers block designs and row-column designs where the information matrix C has two different nonzero eigenvalues, one of multiplicity 1 and the other of multiplicity h−1, where h is the rank of the matrix C. It was found that for each such design there exists a diagonal positive definite matrix X such that the design is X ⁻¹-balanced.