A new procedure for accelerating the convergence of mixed finite element approximations of the eigenpairs and of the biharmonic operator is proposed. It is based on a postprocessing technique that involves an additional solution of a source problem on an augmented finite element space. This space could be obtained either by substantially refining the grid, the two-grid method, or by using the s...

a new modified adomian decomposition method (adm) is utilized to obtain an analytical solution for buckling of the nanocantilever actuators immersed in liquid electrolytes. the nanoactuators in electrolytes are subject to different nonlinear forces including ionic concentration, van der waals, external voltage and electrochemical forces. the duan–rach modified adomian decomposition method is ut...

A UK-based grid computing project that merges two earthquake data modeling methods is one of the latest tools in earthquake prediction. The new technique provides a 2D data map of tectonic structures by combining a macro modeling method based on surface deformation measurements from satellite imagery with a micro method based on finite element analysis and simulation within local geophysical co...

A multilevel homotopic adaptive finite element method is presented in this paper for convection dominated problems. By the homotopic method with respect to the diffusion parameter, the grids are iteratively adapted to better approximate the solution. Some new theoretic results and practical techniques for the grid adaptation are presented. Numerical experiments show that a standard finite eleme...

1. Abstract In this paper, we implement the extended finite element method (X-FEM) combined with the level set method to solve structural shape and topology optimization problems. Numerical comparisons with the conventional finite element method in a fixed grid show that the X-FEM leads to more accurate results without increasing the mesh density and the degrees of freedom. Furthermore, the mes...

an enhamced scheme is introduced for the solution of two dimensional umsteady euler equations. the finite- volume method of jameson et al. is modified by devicing a pnessune sensor in cell flux calculations. then the discretized gorerning equations ane relaxed in time until na steady state is reached. an appropriate model for the artificial dissipation was also employed. several tests wene cond...

Flip Chip Ball Grid Array (FCBGA) package has been introduced in recent years to address the needs in the microelectronic packaging industry for increasing performance and I/O density, which offers a cost effective solution with smaller form factor. Furthermore, Cu interconnects with low-k dielectric material were also introduced to reduce power consumption and further enhance device performanc...

Full wave equation 2D modeling and migration using a new finite difference scheme based on the Galerkin method (FDGM) for irregular grids are presented. Since these involve semi-discretization by the finite element method (FEM) in the depth direction with the linear element, spatially irregular grids can be used to compute the wavefield in modeling and reverse-time migration. The mesh can be ma...

We study the solution of linear systems that typically arise in discretizations of boundary value problems on a domain with geometrical symmetries. If the discretization is done in an appropriate way, then such a system commutes with a group of permutation matrices. Recently, algorithms have been developed that exploit this special structure, however these methods are limited to the case that t...

This paper is devoted to the construction of nonconforming finite elements for the discretization of fourth order elliptic partial differential operators in three spatial dimensions. The newly constructed elements include two nonconforming tetrahedral finite elements and one quasi-conforming tetrahedral element. These elements are proved to be convergent for a model biharmonic equation in three...