This book presents a rational scheme of analysis for the periodic and
quasi-periodic solution of a broad class of problems within technical
and celestial mechanics. It develops steps for the determination of
sufficiently general averaged equations of motion, which have a clear
physical interpretation and are valid for a broad class of
weak-interaction problems in mechanics. The criteria of stability
regarding stationary solutions of these equations are derived explicitly
and correspond to the extremum of a special "potential" function. Much
consideration is given to applications in vibrational technology,
electrical engineering and quantum mechanics, and a number of results
are presented that are immediately useful in engineering practice. The
book is intended for mechanical engineers, physicists, as well as
applied mathematicians specializing in the field of ordinary
differential equations.