Nonlinear vibration of parabolic springs employed in suspension system of a freight car has been studied in this paper. First, dynamical behavior of the springs is investigated by using finite element method and the obtained results are then used in vibration analysis of a railway freight car. For this purpose, dynamics of a parabolic spring subjected to a cyclic excitation has been studied ...

Health systems research aims to understand the governance of health systems (i.e. how health systems function and perform and how their actors interact with each other). This can be achieved by applying innovative methodologies and concepts that are going to capture the complexity and dynamics of health systems when they are affected by shocks. The capacity of health systems to adapt to shocks ...

‎In this paper, we investigate the chaotic behaviors of the fractional-order permanent magnet synchronous motor (PMSM) system. The necessary condition for the existence of chaos in the fractional-order PMSM system is deduced and an active controller is developed based on the stability theory for fractional systems. The presented control scheme  is simple and flexible, and it is suitable both fo...