Pole assignment constitutes one of the fundamental problems of control as it aims at shaping the desired system response by assigning a closed-loop pole structure. The pole structure assignment techniques belong to the basic tools for the controller design. It's special cases are also of great practical interes. In particular, the case when just a finite pole structure is assigned to the system results in the elimination of the so called system impulsive behavior. The assignment of the infinite eigenvalue to the closed-loop system is important, too. Consider for example the design of perfect observers.