# observability

## Computation of positive stable realizations for discrete-time linear systems

Sufficient conditions for the existence of positive stable realizations for given proper transfer matrices are established. Two methods are proposed for determination of the positive stable realizations for given proper transfer matrices. The effectives of the proposed procedures is demonstrated on numerical examples.

## Reachability and observability of fractional positive electrical circuits

Necessary and sufficient conditions for the reachability and observability of fractional positive continuous-time linear electrical circuits are established. Effectiveness of the proposed conditions is demonstrated on examples of electrical circuits.