15 Liapunov's "second method" eliminates this drawback and leads to accurate conclusions regarding the stability of well-defined families of systems. This method made it natural to introduce the new notion of "absolute stability" whose origin can be traced to a work of . A. I. Lur'e and V. N. Post- nikov [1]. The results of the many investigations effected to date in the field of absolute stability have been presented in a number of monographs, from...