The purpose of this paper is to review and unify certain types of functional inequalities which
claim their origin to the following

We consider the nonlinear one-dimensional wave equation (0.1) uzz--att--Zxu,-azl= &u3+ b.

Publisher Summary This chapter discusses analytic methods for the approximate solution of
elliptic free boundary value problems (BVPs). It discusses the application of perturbation …

In this paper we extend results obtained previously [2] for positive solutions (that is, solutions
in K) of (1) and (2); here we consider solutions which are not necessarily in K. Specifically, …

… This justifies rigorously a formal scheme derived previously by Fleishman … BA FLEISHMAN
AND TJ MAHAR, Analytic methods for … BA FLEISHMAN AND TJ MAHAR, On the existence of …

Several aspects of the theory of forced oscillatios of piecewise-linear systems are considered.
First of all, the general problem of determining such periodic solutions is formulated and …

We find all solutions (a countable infinity) to the nonlinear boundary value problem (BVP)
and exhibit them explicitly. The extremal (maximal and minimal) solutions are seen to be the …

We derive here periodic solutions, of harmonic and subharmonic type, of a differential equation
governing the operation of a relay servomechanism which is subjected to a sinusoidal …

… BA FLEISHMAN. A generalization of the phase relations in a … BA FLEISHMAN. Harmonic
and subharmonic responses of … BENEDIKTSSON AND BA FLEISHMAN. Forced oscillations in …

Piecewise-linear systems of the type that arise in relay servomechanisms or problems
involving Coulomb friction, which are usually regarded as nonlinear, are shown here to exhibit …