In recent years, encryption technology has been developed rapidly the chaos based cryptographic algorithms. Chaos owns certain critical properties such as sensitive dependence on initial condition, random-like behavior, and continuous broadband power spectrum, which match the confusion, diffusion, and key sensitivity requirements for cryptography. Chaos based cryptographic offer sundry features...

Control of chaos in the single-mode optically pumped far-infrared NH3 laser is experimentally demonstrated using continuous time-delay control. Both the Lorenz spiral chaos and the detuned period-doubling chaos exhibited by the laser have been controlled. While the laser is in the Lorenz spiral chaos regime the chaos has been controlled both such that the laser output is cw, with corrections of...

We consider quantum systems with a chaotic classical limit that are perturbed by a point-like scatterer. The spectral form factor K(τ) for these systems is evaluated semiclassically in terms of periodic and diffractive orbits. It is shown for order τ 2 and τ 3 that off-diagonal contributions to the form factor which involve diffractive orbits cancel exactly the diagonal contributions from diffr...

E Abstract The study of complex adaptive systems, a subset of nonlinear dynamical systems, has recently become a major focus of interdisciplinary research in the social and natural sciences. Nonlinear systems are ubiquitous; as mathematician Stanislaw Ulam observed, to speak of "nonlinear science" is like calling zoology the study of "nonelephant animals" (quoted in Campbell et al. 1985, p. 374...

Correspondence: Dr. Anca Berescu e-mail: ancaberescu@ yahoo.com Congenital high airway obstruction syndrome (CHAOS) is a rare disorder defined as any fetal abnormality that obstructs the larynx or trachea. Most cases are sporadic with an unknown incidence. We report a case that was diagnosed prenatally at 21 gestational weeks, which showed a typical CHAOS pattern with expanded hyperechogenic lu...

In a variety of studies of dynamical systems, the edge of order and chaos has been singled out as a region of complexity. It was suggested by Wolfram, on the basis of qualitative behaviour of cellular automata, that the computational basis for modeling this region is the Universal Turing Machine. In this paper, following a suggestion of Crutchfield, we try to show that the Turing machine model ...

The most exciting recent development in nonlinear dynamics is realization that chaos can be useful. One application involves "Secure Communication". Two piecewise linear systems with switching nonlinearities have been taken as chaos generators. In the present work the phenomenon of secure communication with chaos masking has been investigated experimentally. In this investigation chaos which is...

While applying linear models to human systems and their elements has improved our understanding of their structure and function, such models often fall short of explaining experimental results or predicting future abnormalities in complex nonlinear systems. Starting from the fact that the periodontium is a complex system in the body, this paper demonstrates possible reflection of chaos theory a...

We derive semiclassical approximations for wavefunctions, Green’s functions and expectation values for classically chaotic quantum systems. Our method consists of applying singular and regular perturbations to quantum Hamiltonians. The wavefunctions, Green’s functions and expectation values of the unperturbed Hamiltonian are expressed in terms of the spectral determinant of the perturbed Hamilt...

This paper studies the performance of selected chaos-based systems which share their frequency bands with conventional spread-spectrum systems. Such a scenario may occur in normal practice when chaos-based systems are introduced while the conventional systems are still in operation. The particular chaos-based systems under study are the coherent chaosshift-keying (CSK) system and the non-cohere...