The principles of synchronization of chaotic systems are extended to the case where the drive signal is filtered. A feedback loop in the response system with an identical filter is used to reconstruct the original drive signal, allowing synchronization. A simple parameter switching scheme is used to send information from a drive circuit to a receiver. It is also possible to add a chaotic signal...

This paper shows how the chaotic systems theory can be applied to the modeling of speech signals, whose dynamics is highly complex. We verify that, when using a theory that is able to model nonlinear features, speech signals present a highly nonlinear behavior, which could not be inferred from a linear theory.

It is well-known that filtered chaotic signals can exhibit increases in observed fractal dimension. However, there is still insufficient knowledge regarding the underlying causes of this phenomenon. We provide further insight into this problem through the use of computer animations and three-dimensional ray-tracings. Specifically, we show that lowpass filters can induce a non-uniform convergenc...

In this paper using a negative feedback scheme we study the problem of synchronizing two systems (each of them made of n independent chaotic circuits) through the transmission of a unique signal (i.e. a scalar variable). To find the appropriate values of the feedback gains, an approach based on the design of an asymptotic observer leading to a set of linear matrix inequalities is used for piece...

In this paper we examine two couplings that produce time-shifted synchronization in a pair of chaotic oscillators. The couplings do not utilize an explicit timedelay term. We characterize the observed synchronization by determining the dependence of the time shift and cross correlation between the drive and response oscillators on a tunable parameter. Our observations agree well with estimates ...

Various phonemes are considered in terms of nonlinear dynamics. Phase portraits of the signals in the embedded space, correlation dimension estimate and the largest Lyapunov exponent are analyzed. It is shown that the speech signals have comparatively small dimension and the positive largest Lyapunov exponent

Over the past several years, there have been various proposals for communication with chaotic signals. But the issue of compensating the distortions introduced by the physical channel like noise, time varying fading and multi-path has not been fully addressed. In this paper, we first describe a noise reduction method for chaotic signals corrupted by an additive noise. The method uses the phenom...

A general approach based on the introduction of a control function for constructing amplitudecontrollable chaotic systems with quadratic nonlinearities is discussed in this paper. We consider three control regimes where the control functions are applied to different coefficients of the quadratic terms in a dynamical system. The approach is illustrated using the Lorenz system as a typical exampl...

Nonlinear dynamics has been introduced to the analysis of biological data and increasingly recognized to be functionally relevant. The aim of this study is to evaluate nonlinear and chaotic dynamics of gait signals. For this purpose, we analyzed gait data in ten healthy subjects who walked for an hour at their usual, slow and fast paces. Poincare plots, Hurst Exponents and the Lyapunov Exponent...

Complex responses, including chaotic responses, were observed through physiological experiments with biological neurons. To include these complex responses, the chaotic neuron model was proposed. Chaotic dynamical systems have been applied to logical systems, and to information and signal processing systems. In this paper, we propose a dynamic logic element with a chaotic transition region usin...