Structure-Preserving Model Reductions using a Krylov Subspace Projection Formulation

A general framework for structure-preserving model reductions by Krylov subspace projection methods is developed. It not only matches as many moments as possible but also preserves substructures of importance in the coefficient matrices L,G,C, and B that define a dynamical system prescribed by the transfer function of the form H(s) = L∗(G+sC)−1B. Many existing structure-preserving model-order reduction methods for linear and secondorder dynamical systems can be derived under this general framework. Furthermore, it also offers insights to the development of new structure-preserving model reduction methods.