2 Abstract Recent advances in Kalman filtering to estimate system state and parameters in nonlinear systems has offered the potential to apply such approaches to spatiotemporal nonlinear systems. We here adapt the nonlinear method of unscented Kalman filtering to observe the state and estimate parameters in a computational spatiotemporal excitable system that serves as a model of cerebral corte...

Nanocomposite materials, including noble metal nanoparticles embedded in a dielectric host medium, are interesting because of their optical properties linked to surface plasmon resonance phenomena. For studding of nonlinear optical properties and/or energy transfer process, these materials may be excited by ultrashort pulse laser with a temporal width varying from some femtoseconds to some hund...

Two large clinical trials of drugs that exhibited significant antiarrhythmic properties in single cells were found to increase the rate of sudden cardiac death in patients by two to three fold over untreated patients. We hypothesized that premature excitation within the drug-altered vulnerable region, a region that trails each excitation wave, might be one mechanism for initiating re-entrant ta...

The biological information extracted from various excitable tissues can be obtained by intracellular as well as by extra-cellular recordings, the latest one being easier and noninvasive method with many applications in medicine testing. Electrophysiological recording of the eye excitability is analyzed in the following computational study dedicated to the diagnosis of the type of dynamics gover...

We analyze the properties of a nonlinear metamaterial formed by integrating nonlinear components or materials into the capacitive regions of metamaterial elements. A straightforward homogenization procedure leads to general expressions for the nonlinear susceptibilities of the composite metamaterial medium. The expressions are convenient, as they enable an inhomogeneous system of scattering ele...

We analyze the existence and stability of nonlinear localized waves in a periodic medium described by the Kronig-Penney model with a nonlinear defect. We demonstrate the existence of a novel type of stable nonlinear band-gap localized state, and also reveal a generic physical mechanism of the oscillatory wave instabilities associated with the band-gap resonances.

In this paper we present an exact calculation of the transfer function associated with the nonlinear Fabry-Perot resonator. While our exact result cannot be evaluated in terms of elementary functions, it does permit us to obtain a number of simple approximate expressions of various orders of accuracy. In addition, our derivation yields criteria of validity for the approximate formulae. Our appr...

The equations of motion and the nonlinear constitutive theory of fluid-filled poroelastic media are derived from the fundamental equations of elasticity and fluid mechanics for the constituents. A two-scale spatial expansion and the method of homogenization are employed. Explicit equations are obtained for the special case of a medium consisting of alternating solid and fluid layers. The linear...

A simple but highly efficient approach for dealing with the problem of cylindrical electromagnetic waves propagation in a nonlinear medium is proposed based on an exact solution proposed recently. We derive an analytical explicit formula, which exhibiting rich interesting nonlinear effects, to describe the propagation of any amount of cylindrical electromagnetic waves in a nonlinear medium. The...

Using high-resolution, two-dimensional hydrodynamic simulations, we investigate nonlinear gravitational responses of gas to, and the resulting drag force on, a very massive perturber Mp moving at velocity Vp through a uniform gaseous medium of adiabatic sound speed a∞. We model the perturber as a Plummer potential with softening radius rs, and run various models with differing A = GMp/(a 2 ∞rs)...