A detailed mathematical analysis is performed to understand the anode potential oscillations observed experimentally in a proton exchange membrane fuel cell ~PEMFC! with H2 /CO feed ~Ref. 9!. Temperature and anode flow rate are found to be key bifurcation parameters. The time dependence of all the key surface species must be accounted for in order for the model to predict the oscillatory behavi...

In this paper we consider the numerical solution of delay diierential equations (DDEs) undergoing a Hopf bifurcation. The aim is to understand what will happen when simple standard numerical methods are used to obtain an approximate solution. We present three distinctive and complementary approaches to the analysis which together provide us with the result that # methods applied to a DDE will r...

A discrete-time financial system is proposed by using forward Euler scheme. Based on explicit Neimark-Sacker bifurcation also called Hopf bifurcation for map criterion, normal form method and center manifold theory, the system’s existence, stability and direction of Neimark-Sacker bifurcation are studied. Numerical simulations are employed to validate the main results of this work. Some compari...

| The paper is devoted to nding the most dangerous (critical) changes of parameters which put the power system on either a saddle node or Hopf bifurcation boundary. The corresponding vectors in the space of system parameters provide information about stability margins, give a measure of and locally optimal ways to improve power system security, indicate parameters which badly aaect stability. T...

In this paper, a three dimensional autonomous chaotic system is considered. The existence of Hopf bifurcation is investigated by choosing the appropriate bifurcation parameter. Furthermore, formulas for determining the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions are derived with the help of normal form theory. Finally, a numerical example is given. Keyw...

We study dendritic growth numerically with a phase field model. Tip oscillation and regular side-branching are observed in a parameter region where the anisotropies of the surface tension and the kinetic effect compete. The transition from a needle pattern to a dendritic pattern is conjectured to be a supercritical Hopf bifurcation.

In this paper, a delayed SIR epidemic model with modified saturated incidence rate is proposed. The local stability and the existence of Hopf bifurcation are established. Also some numerical simulations are given to illustrate the theoretical analysis.

In this paper, a nonlinear delay population model is investigated. Choosing the delay as a bifurcation parameter, we demonstrate that Hopf bifurcation will occur when the delay exceeds a critical value. Global existence of bifurcating periodic solutions is established. Numerical simulations supporting the theoretical findings are included. Keywords—Population model; Stability; Hopf bifurcation;...

The phenomenon of vibrational resonance (VR) in the classical Morse oscillator influenced by narrow band and wide band, frequency modulated signals is numerically studied. Vibrational resonance was found to occur when the amplitudes f and g and frequencies ω and Ω of the signals were varied. The dynamics of the system is studied in the presence of both signals separately. Vibrational resonance ...

Abstract: In this paper, a delayed ratio-dependent eco-epidemiological model with Holling type III functional response and two time delays is investigated.By regarding the delay as the bifurcation parameter, local stability of each equilibrium is discussed at the endemic equilibrium. By analyzing the corresponding characteristic equations, the conditions for existence of Hopf bifurcation for th...