54,617 research outputs found
Computational Methods for the Construction of a Class of Noetherian Operators
This paper presents some algorithmic techniques to compute explicitly the
noetherian operators associated to a class of ideals and modules over a
polynomial ring. The procedures we include in this work can be easily encoded
in computer algebra packages such as CoCoA and Singular
Ideals generated by quadrics
Our purpose is to study the cohomological properties of the Rees algebras of
a class of ideals generated by quadrics. For all such ideals we give the precise value of depth and decide whether the
corresponding rational maps are birational. In the case of dimension , when , we give structure theorems for all ideals of
codimension minimally generated by quadrics. For
arbitrary fields , we prove a polarized version
A Geometric Index Reduction Method for Implicit Systems of Differential Algebraic Equations
This paper deals with the index reduction problem for the class of
quasi-regular DAE systems. It is shown that any of these systems can be
transformed to a generically equivalent first order DAE system consisting of a
single purely algebraic (polynomial) equation plus an under-determined ODE
(that is, a semi-explicit DAE system of differentiation index 1) in as many
variables as the order of the input system. This can be done by means of a
Kronecker-type algorithm with bounded complexity
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