Abstract
In many modeling problems, the system matrices have a number of fixed zero entries determined by the physical structure of the system while the remaining entries are a priori known functions of the, free (physical) parameters. Then, from input-output data (e.g. transfer function), can we uniquely determine the unknown free, parameters? This problem introduced the concept of structural identifiability (abbreviated to SI).
This paper discusses SI of the system whose parametrization is affine. Firstly we remark the relation between SI and the structural controllability (and observability), and give new algebraic equivalent conditions for SI. Based upon these results, secondly, we obtain all the SI structured systems the indeterminate entries of that are unrelated, and it is made clear how SI of compartmental systems is influenced by the way of connection among its subsystems.
