Grade Filtration of Linear Functional Systems

Grade filtration of linear functional systems

The grade filtration of a finitely generated left module M over an Auslander regular ring D is a built-in classification of the elements of M in terms of their grades (or their (co)dimensions if D is also a Cohen-Macaulay ring). In this paper, we show how grade filtration can be explicitly characterized by means of elementary methods of homological algebra. Our approach avoids the use of sophis...

Equivalences of linear functional systems

On the Approximation of Pseudo Linear Systems by Linear Time Varying Systems (RESEARCH NOTE)

This paper presents a modified method for approximating nonlinear systems by a sequence of linear time varying systems. The convergence proof is outlined and the potential of this methodology is discussed. Simulation results are used to show the effectiveness of the proposed method.

Serre's Reduction of Linear Functional Systems

Serre’s reduction aims at reducing the number of unknowns and equations of a linear functional system (e.g., system of partial differential equations, system of differential time-delay equations, system of difference equations). Finding an equivalent representation of a linear functional system containing fewer equations and fewer unknowns generally simplifies the study of its structural proper...

On Algebraic Simplifications of Linear Functional Systems

In this paper, we show how to conjointly use module theory and constructive homological algebra to obtain general conditions for a matrix R of functional operators (e.g., differential/shift/time-delay operators) to be equivalent to a block-triangular or block-diagonal matrix R (i.e., conditions for the existence of unimodular matrices V and W satisfying that R = V R W ). These results allow us ...