Model reduction with balanced realization: A new interpretation

A new interpretation has been given to model reduction by the method of balanced realizations, which shows that it can be regarded as a type of aggregation method. This enables a user to retain the conceptual advantage of balanced realization, as well as those of aggregation. Thus, an important advantage of the latter, that the eigenvalues placed by feeding back the states of the reduced model are retained for the original system, can be fully exploited with the balanced matrix method as well.