Search for: [Abstract = "This paper focuses on the model order reduction problem of second\-order form models. The aim is to provide a reduction procedure which guarantees the preservation of the physical structural conditions of second\-order form models. To solve this problem, a new approach has been developed to transform a second\-order form model from a state\-space realization which ensures the preservation of the structural conditions. This new approach is designed for controllable single\-input state\-space realizations with real matrices and has been applied to reduce a single\-input second\-order form model by balanced truncation and modal truncation."]