Interpolatory Weighted-H2 Model Reduction
  This paper introduces an interpolation framework for the weighted-H2 model reduction problem. We obtain a new representation of the weighted-H2 norm of SISO systems that provides new interpolatory first order necessary conditions for an optimal reduced-order model. The H2 norm representation also provides an error expression that motivates a new weighted-H2 model reduction algorithm. Several numerical examples illustrate the effectiveness of the proposed approach. 
Branimir Anic, Christopher A. Beattie, Serkan Gugercin, Athanasios C.   Antoulas
math.NA cs.SY math.DS math.OC