In this paper, a class of Hessenberg matrices is presented for adoption as test matrices. The Moore-Penrose inverse and the Drazin inverse for each member of this class are determined explicitly.

In this paper we prove that the simplest band representations of unitary operators on a Hilbert space are five-diagonal. Orthogonal polynomials on the unit circle play an essential role in the development of this result, and also provide a parametrization of such five-diagonal representations which shows specially simple and interesting decomposition and factorization properties. As an applicat...

The aim of this paper is to present the structure of a class of matrices that enables explicit inverse to be obtained. Starting from an already known class of matrices, we construct a Hadamard product that derives the class under consideration. The latter are defined by 4n − 2 parameters, analytic expressions of which provide the elements of the lower Hessenberg form inverse. Recursion formulae...

The low protein barley (Hordeum vulgare L.) cultivar ;Karl' is deficient in hordeins, the major storage protein fraction, but has normal levels of other endosperm protein fractions. We compared hordein gene expression in Karl with that in ;Traill,' a related cultivar that contains normal amounts of hordein. In plants grown in controlled environmental conditions, hordein accumulation in Karl was...