A balanced design is always optimal for any criterion based on the information matrix, although there are many values of (v,b,k) for which no balanced design exists. One way to construct an incomplete ...

A necessary condition for the α-resolvability of an incomplete block design is obtained. Further, a necessary and sufficient condition for an α-resolvable incomplete block design to be affine ...

For a portfolio of N obligors, standard methods usually require O(N2) calculations to get one random sample. In many applications, the correlation matrix has a block structure that, as we show, can be ...