We have studied experimentally a chaotic cryptosystem, which is based on the inverse system approach. We applied this method to a second order nonlinear circuit (master circuit), which is described by a Duffing equation. We present the implementation of the slave circuit with the inverse system approach and we demonstrate the decryption when the information signal has several forms (sinusoidal ...

Consider the stochastic Duffing-van der Pol equation ẍ = −ω2x− Ax −Bx2ẋ + εβẋ + εσxẆt with A ≥ 0 and B > 0. If β/2 + σ/8ω > 0 then for small enough ε > 0 the system (x, ẋ) is positive recurrent in R \ {0}. Let λ̃ε denote the top Lyapunov exponent for the linearization of this equation along trajectories. The main result asserts that λ̃ε ∼ ελ̃ as ε → 0 where λ̃ is the top Lyapunov exponent along tra...

The issue of synchronization has been analyzed from many points of view since it was first described in 17th century. Nowadays the theory that stands behind it is so developed, it might be difficult to understand where it all comes from. This paper reminds the key concepts of synchronization by examination of two coupled Duffing oscillators. It describes also the origins of Duffing equation and...

We investigate the hard nonresonant excitation of the forced Duffing equation with a positive damping parameter E. Using the symbolic manipulation system MACSYMA, a computer algebra system. we derive the two term perturbation expansion by the method of multiple time scales. The resulting approximate solution is valid for small values of the coefficient e As the damping parameter e increases, th...

We study the periodic solutions of the following kind of non-autonomous Duffing differential equation ÿ+ay− εy = εh(t, y, ẏ), with a > 0, ε a small parameter and h a C2 function in its variables.

By using Mawhin–Manásevich continuation theorem, some new sufficient conditions for the existence and uniqueness of periodic solutions of Duffing type p-Laplacian differential equation are established, which are complement of previously known results. © 2007 Elsevier Inc. All rights reserved.