An Adaptative Neuro-Fuzzy Inference System (ANFIS), new flexible tool, is applied to predict the cut-off frequencies of the symmetric and the anti-symmetric circumferential waves (Si and Ai, i=1,2) propagating around an elastic aluminum cylindrical shell of various radius ratio b/a (a: outer radius and b: inner radius). The time-frequency of WignerVille and the proper modes theory are used in t...

The hydrodynamic properties of cylindrical ~rodlike and discoidal! particles in dilute solution have been computed using the bead-shell model treatment. Previous results @Tirado and Garcı́a de la Torre, J. Chem. Phys. 71, 2581 ~1979!; 73, 1993 ~1980!# for rods with length-to-diameter ratio p .2 are now extended to short cylinders and disks down to p50.1. The intrinsic viscosity is obtained for r...

Cylindrical shells exhibit a dense frequency spectrum, especially in the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to multiple internal resonances. The aim of the present work is to investigate the dynamic behavior and st...

Reduced order models employing the Lagrange and POD reduced basis methods in numerical approximation and feedback control of systems are presented and numerically tested. The system under consideration is a thin cylindrical shell with surface-mounted piezoceramic actua-tors. Donnell-Mushtari equations, modiied to include Kelvin-Voigt damping, are used to model the system dynamics. Basis functio...

Starting from the gravitational potential of a Newtonian spheroidal shell we discuss electrically charged rotating prolate spheroidal shells in the Maxwell theory. In particular we consider two confocal charged shells which rotate oppositely in such a way that there is no magnetic field outside the outer shell. In the Einstein theory we solve the Ernst equations in the region where the long pro...

In this paper, stress and strain equations are developed for the left ventricle mainly to nd the innuence of the ventricle's shape on wall stresses. Here, the ventricle is assumed to be a thick-walled truncated conical shell and large elastic deformation theory is applied. Our model is compared to corresponding results approximating the left ventricle as a spherical shell. Clinically relevant p...

Abstract The local Casimir energy density and the global Casimir energy for a massless scalar field associated with a λδ-function potential in a 3+1 dimensional circular cylindrical geometry are considered. The global energy is examined for both weak and strong coupling, the latter being the well-studied Dirichlet cylinder case. For weak-coupling, through O(λ2), the total energy is shown to van...

We present a method for performing time domain simulations of a microphotonic system containing a four level gain medium based on the finite element method. This method includes an approximation that involves expanding the pump and probe electromagnetic fields around their respective carrier frequencies, providing a dramatic speedup of the time evolution. Finally, we present a two dimensional e...