Intermittent Synchronization in a Pair of Coupled Chaotic Pendula

Numerical simulations have been carried out for a pair of unidirectionally coupled identical pendula under the action of a common external ac torque. Both the master pendulum and the slave pendulum were in chaotic states. The only form of persistent locking appeared to be a computational artifact; otherwise the synchronization of slave to master was found to be intermittent

Intermittent Synchronization of Resistively Coupled Chaotic Josephson Junctions

Numerical simulations have been used to investigate the dynamics of a pair of resistively linked Josephson junctions with ac bias. For suitable choices of parameters, the chaotic states of the two junctions become intermittently synchronized. Intervals of synchronization are interleaved between bursts of desynchronized activity. The distributions of these laminar times and their dependence on the coupling strength are determined. The role of phase winding in the definition of synchronization intervals is considered

Inverting Chaos: Extracting System Parameters from Experimental Data

Given a set of experimental or numerical chaotic data and a set of model differential equations with several parameters, is it possible to determine the numerical values for these parameters using a least-squares approach, and thereby to test the model against the data? We explore this question (a) with simulated data from model equations for the Rossler, Lorenz, and pendulum attractors, and (b) with experimental data produced by a physical chaotic pendulum. For the systems considered in this paper, the least-squares approach provides values of model parameters that agree well with values obtained in other ways, even in the presence of modest amounts of added noise. For experimental data, the “fitted” and experimental attractors are found to have the same correlation dimension and the same positive Lyapunov exponent

Court Ordered Non-Emergency Medical Care for Infants

It has long been recognized that a privilege to act is a perfect defense to liability for a non-consensual, intentional interference with another person. This privilege is based upon self defense, defense of third persons, mistake, or various other recognized legal theories. Even a state may have a privilege to interfere with the person of a citizen, and this privilege may extend to an interference to provide an infant citizen with medical care without the consent of, or against the express wishes of, the parent or guardian

Adjustable microchip ring trap for cold atoms and molecules

We describe the design and function of a circular magnetic waveguide produced from wires on a microchip for atom interferometry using deBroglie waves. The guide is a two-dimensional magnetic minimum for trapping weak-field seeking states of atoms or molecules with a magnetic dipole moment. The design consists of seven circular wires sharing a common radius. We describe the design, the time-dependent currents of the wires and show that it is possible to form a circular waveguide with adjustable height and gradient while minimizing perturbation resulting from leads or wire crossings. This maximal area geometry is suited for rotation sensing with atom interferometry via the Sagnac effect using either cold atoms, molecules and Bose-condensed systems