11,965 research outputs found
Synchronization of Heterogeneous Kuramoto Oscillators with Arbitrary Topology
We study synchronization of coupled Kuramoto oscillators with heterogeneous
inherent frequencies and general underlying connectivity. We provide conditions
on the coupling strength and the initial phases which guarantee the existence
of a Positively Invariant Set (PIS) and lead to synchronization. Unlike
previous works that focus only on analytical bounds, here we introduce an
optimization approach to provide a computational-analytical bound that can
further exploit the particular features of each individual system such as
topology and frequency distribution. Examples are provided to illustrate our
results as well as the improvement over previous existing bounds
Zero delay synchronization of chaos in coupled map lattices
We show that two coupled map lattices that are mutually coupled to one
another with a delay can display zero delay synchronization if they are driven
by a third coupled map lattice. We analytically estimate the parametric regimes
that lead to synchronization and show that the presence of mutual delays
enhances synchronization to some extent. The zero delay or isochronal
synchronization is reasonably robust against mismatches in the internal
parameters of the coupled map lattices and we analytically estimate the
synchronization error bounds.Comment: 9 pages, 9 figures ; To appear in Phys. Rev.
Synchronization in complex networks
Synchronization processes in populations of locally interacting elements are
in the focus of intense research in physical, biological, chemical,
technological and social systems. The many efforts devoted to understand
synchronization phenomena in natural systems take now advantage of the recent
theory of complex networks. In this review, we report the advances in the
comprehension of synchronization phenomena when oscillating elements are
constrained to interact in a complex network topology. We also overview the new
emergent features coming out from the interplay between the structure and the
function of the underlying pattern of connections. Extensive numerical work as
well as analytical approaches to the problem are presented. Finally, we review
several applications of synchronization in complex networks to different
disciplines: biological systems and neuroscience, engineering and computer
science, and economy and social sciences.Comment: Final version published in Physics Reports. More information
available at http://synchronets.googlepages.com
Fast Desynchronization For Decentralized Multichannel Medium Access Control
Distributed desynchronization algorithms are key to wireless sensor networks
as they allow for medium access control in a decentralized manner. In this
paper, we view desynchronization primitives as iterative methods that solve
optimization problems. In particular, by formalizing a well established
desynchronization algorithm as a gradient descent method, we establish novel
upper bounds on the number of iterations required to reach convergence.
Moreover, by using Nesterov's accelerated gradient method, we propose a novel
desynchronization primitive that provides for faster convergence to the steady
state. Importantly, we propose a novel algorithm that leads to decentralized
time-synchronous multichannel TDMA coordination by formulating this task as an
optimization problem. Our simulations and experiments on a densely-connected
IEEE 802.15.4-based wireless sensor network demonstrate that our scheme
provides for faster convergence to the steady state, robustness to hidden
nodes, higher network throughput and comparable power dissipation with respect
to the recently standardized IEEE 802.15.4e-2012 time-synchronized channel
hopping (TSCH) scheme.Comment: to appear in IEEE Transactions on Communication
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