The formal classification of linear difference operators

AbstractA Jordan canonical form for formal difference operators, like the one in [7], is derived in a way inspired by [3], [4]. This yields a classification of meromorphic difference operators in a neighbourhood of infinity, up to formal equivalence

Linear homogeneous relations for the hypergeometric function. I. Mixed difference-differential relations

No abstract

Sufficient conditions for BIBO robust stabilization : given by the gap metric

A relation between coprlme fractions and the gap metric is presented. Using this result we provide some sufficient conditions for BIBO robust stabilization for a very wide class of systems. These conditions allow the plant and compensator to be disturbed simultaneously. Keywords: Robust stabllization; Gap metric; Coprime fraction

A new method for computing a column reduced polynomial matrix

A new algorithm is presented for computing a column reduced form of a given full column rank polynomial matrix. The method is based on reformulating the problem as a problem of constructing a minimal basis for the right nullspace of a polynomial matrix closely related to the original one. The latter problem can easily be solved in a numerically reliable way. Two examples illustrating the method are included. Keywords: Polynomial matrix, column reduced, minimal polynomial basis, numerical method