This invention provides a vascular protecting agent having salt-absorption inhibitory activity with the use of alginate oligosaccharide salt absorbed by the body via degradation to an oligosaccharide, so that a patient can easily and safely ingest such agent on a routine basis. A model structure is selected and one or more reference signal values are generated for input into the system. Thus, the liner reduces the destructive cutting away of the fan case, minimizing damage to the fan case and decreasing torque loading of the fan case from rotor deflections.