5,922 research outputs found
Synchronization of chaotic modulated time delay networks in presence of noise
We study the constructive role of noises in a Lorenz system with functional
delay. The effect of delay can change the dynamics of the system to a chaotic
one from its steady state. Induced synchronization with white and colored (red
and green) noises are observed between two identical uncoupled systems and
enhancement of synchrony is also observed with unidirectional coupling. We
investigate both the phenomena in a globally coupled network in the presence of
white and color noises.Comment: 10 pages, 7 figure
Estimation of communication-delays through adaptive synchronization of chaos
This paper deals with adaptive synchronization of chaos in the presence of
time-varying communication-delays. We consider two bidirectionally coupled
systems that seek to synchronize through a signal that each system sends to the
other one and is transmitted with an unknown time-varying delay. We show that
an appropriate adaptive strategy can be devised that is successful in
dynamically identifying the time-varying delay and in synchronizing the two
systems. The performance of our strategy with respect to the choice of the
initial conditions and the presence of noise in the communication channels is
tested by using numerical simulations. Another advantage of our approach is
that in addition to estimating the communication-delay, the adaptive strategy
could be used to simultaneously identify other parameters, such as e.g., the
unknown time-varying amplitude of the received signal.Comment: Accepted for publication in Chaos, Solitons & Fractal
Langevin approach to synchronization of hyperchaotic time-delay dynamics
In this paper, we characterize the synchronization phenomenon of hyperchaotic
scalar non-linear delay dynamics in a fully-developed chaos regime. Our results
rely on the observation that, in that regime, the stationary statistical
properties of a class of hyperchaotic attractors can be reproduced with a
linear Langevin equation, defined by replacing the non-linear delay force by a
delta-correlated noise. Therefore, the synchronization phenomenon can be
analytically characterized by a set of coupled Langevin equations. We apply
this formalism to study anticipated synchronization dynamics subject to
external noise fluctuations as well as for characterizing the effects of
parameter mismatch in a hyperchaotic communication scheme. The same procedure
is applied to second order differential delay equations associated to
synchronization in electro-optical devices. In all cases, the departure with
respect to perfect synchronization is measured through a similarity function.
Numerical simulations in discrete maps associated to the hyperchaotic dynamics
support the formalism.Comment: 12 pages, 6 figure
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