Massam, Helene; Muller, Jochen - In: Journal of Multivariate Analysis 16 (1985) 2, pp. 253-259
The purpose of this paper is to give a characterization of the nonnegative MINQUE estimate for variance components. A similar characterization has been given by Pukelsheim but only in some special cases. The proof presented here uses results from convex programming and emphasizes certain...