김완세 교수

We prove the existence and multiplicity of periodic solutions for nonlinear Lienard System of the type urn:x-wiley:01611712:media:ijmm962802:ijmm962802-math-0001 under various conditions upon the functions g , h and e .

The multiplicity if periodic sloutions of semilinear dissipative hyperbolic equations is treated

In this paper, we establish a multiple existence result of T-periodic solutions for the semilinear parabolic boundary value problem with sublinear growth nonlinearities. We adapt sub-supersolution scheme and topological argument based on variational structure of functionals.

A condition on forcing term insuring the multiplicity of Dirichlet-periodic solutions of nonlinear dissipative hyperbolic equations is discussed. The nonlinear term is assumed to have co- ercive growth.

We establish multiple extence of positive solutions for parameterized nonhomogeneous elliptic equations involving critical Sobolev exponent. The approach to the problem is variational method.

Abstract. Multiplicity of nonlinear second order nonlinear ordinary differential equa-tions will be discussed 1.