We consider a radially symmetric free boundary problem with logistic nonlinear term. The spatial environment is assumed to be asymptotically periodic at infinity in the radial direction. For such a free boundary problem, it is known from [7] that a spreading-vanishing dichotomy holds. However, when spreading occurs, only upper and lower bounds are obtained in [7] for the asymptotic spreading sp...

This paper reports an experimental investigation of the effect of two specific errors on a class of model based controllers for the low-speed maneuvering of fully actuated underwater vehicles. First, we review previously reported studies and a commonly accepted simplified plant model that has been experimentally validated for this class of vehicles. Second, we review a family of associated mode...

In the work, there have been investigated the optical power limiting effects which occur in the nonlinear photonic crystals possessing saturable Kerr nonlinearity. The method is proposed which allows exact determination of the parameters of the structure as well as the radiation parameters which provide the limiting effect.

This paper studies the nonlinear vibration analysis of a simply supported Euler-Bernoulli beam resting on a nonlinear elastic foundation under compressive axial load using nonlinear normal modes concept in the case of three-to-one (3:1) internal resonance. The beam’s governing nonlinear PDE of motion and also its boundary conditions are derived and then solved using the method of Multiple Time ...

The nonlinear optical properties of carbon nanotubes (CNTs) have been studied by using the Z-scan technique. Experiments are performed by CW second harmonic of Nd-YAG laser at 532 nm wavelength with a power of 40 mW. The samples are synthesized by the chemical vapor deposition (CVD) method in the presence of Nickel and Nickel-Cobalt catalysts. In this work, for the first time, effect of the typ...

in the present study, the onset of double diffusive reaction-convection in a uid layer with viscous fluid, heated and salted from below subject to chemical equilibrium on the boundaries, has been investigated. linear and nonlinear stability analysis have been performed. for linear analysis normal mode technique is used and for nonlinear analysis minimal representation of truncated fourier serie...

We describe a methodology for optimizing a threshold detection-based biosurveillance system. The goal is to maximize the system-wide probability of detecting an ‘‘event of interest” against a noisy background, subject to a constraint on the expected number of false signals. We use nonlinear programming to appropriately set detection thresholds taking into account the probability of an event of ...

Submitted for the MAR06 Meeting of The American Physical Society Geometrically induced nonlinear dynamics in one-dimensional lattices MERLE D. HAMILTON, O.F. DE ALCANTARA BONFIM, University of Portland — We present a lattice model consisting of a single one-dimensional chain, where the masses are interconnected by linear springs and allowed to move in a horizontal direction only, as in a monora...

This paper presents a finite element formulation for the dynamics analysis of the steady and transient states of a nonlinear piezoelectric beam. A piezoelectric beam with damping is studied under harmonic excitation. A numerical method is used for this analysis. In the paper, the central difference formula of four order is used and compared with the central difference formula of two order in th...