We consider a dynamical systems formulation for models with an exponential scalar field and matter linear equation of state in spatially flat isotropic spacetime. In contrast to earlier work, which only considered hyperbolic fixed point analysis, we do center manifold analysis the non-hyperbolic points associated bifurcations. More importantly though, construct monotonic functions Dulac functio...

Analysis of nonlinear autonomous systems has been a popular field of study in recent decades. As an interesting nonlinear behavior, chaotic dynamics has been intensively investigated since Lorenz discovered the first physical evidence of chaos in his famous equations. Although many chaotic systems have been ever reported in the literature, a systematic and qualitative approach for chaos generat...

This paper presents an indirect adaptive system based on neuro-fuzzy approximators for the speed control of induction motors. The uncertainty including parametric variations, the external load disturbance and unmodeled dynamics is estimated and compensated by designing neuro-fuzzy systems. The contribution of this paper is presenting a stability analysis for neuro-fuzzy speed control of inducti...