Given a vector eld X on the real plane, we study the innuence of the curvature of the orbits of _ x = X ? (x) in the stability of those of the system _ x = X(x). We pay special attention to the case in which this curvature is negative in the whole plane. Under this assumption, we classify the possible critical points and give a criterion for a point to be globally asymptotically stable. In the ...

dynamically stable biped robots mimicking human locomotion have received significant attention over the last few decades. formerly, the existence of stable periodic gaits for straight walking of passive biped walkers was well known and investigated as the notion of passive dynamic walking. this study is aimed to elaborate this notion in the case of three dimensional (3d) walking and extend it f...

In this paper, we focuses on stability, asymptotical stability and finite-time stability for a class of differential inclusions governed by a nonconvex superpotential. This problem is known by "evolution hemivariational inequalities". After proposing an existence result of solutions, we give the stability results in terms of smooth Lyapunov functions subjected to some conditions described in te...

This paper deals with the stability of nonlinear fractional differential systems equipped with the Caputo derivative. At first, a sufficient condition on asymptotical stability is established by using a Lyapunov-like function. Then, the fractional differential inequalities and comparison method are applied to the analysis of the stability of fractional differential systems. In addition, some ot...