In this paper, the problem of constructing optimal blocked regular fractional factorial designs is considered. The concept of minimum aberration due to Fries and Hunter is a well-accepted criterion ...

Let L be a finite-dimensional Lie algebra over a field k of characteristic zero, and U(L) its universal enveloping algebra. We show that the semicenter of U(L) is a UFD. More generally, the same ...

I HAVE recently 1 been investigating certain probability distributions arising from points possessing one of k colours or characters arranged on a line or in the form of a rectangular lattice. In the ...