In electroencephalographic (EEG) source imaging as well as in transcranial current stimulation (TCS), it is common to model the head using either three-shell boundary element (BEM) or more accurate finite element (FEM) volume conductor models. Since building FEMs is computationally demanding and labor intensive, they are often extensively reused as templates even for subjects with mismatching a...

This paper describes a mixed direct-iterative method for boundary integral formulations of dielectric solvation models. We give an example for which a direct solution at thermal accuracy is nontrivial and for which Gauss-Seidel iteration diverges in rare but reproducible cases. This difficulty is analyzed by obtaining the eigenvalues and the spectral radius of the iteration matrix. This establi...

We present a new Boundary Discontinuous Petrov-Galerkin (BDPG) method for Computational Fluid Dynamics (CFD) simulations. The method represents a modification of the standard Hybrid Discontinuous Galerkin (HDG) scheme, and uses locally-computed optimal test functions to achieve enhanced accuracy along the domain boundaries. This leads to improved accuracy in relevant boundary outputs such as li...

the galerkin finite element method is used to solve the three dimensional continuity, momentum and energy equations for laminar newtonian and power-law model non-newtonian flow through horizontal circular tube. the governing equations are non-dimensionalized with respect to specific variables and converted into algebraic equations using appropriate elements. to accelerate convergence a combinat...

Neuroimaging studies have identified three scene-selective regions in human cortex: parahippocampal place area (PPA), retrosplenial complex (RSC), and occipital place area (OPA). However, precisely what scene information each region represents is not clear, especially for the least studied, more posterior OPA. Here we hypothesized that OPA represents local elements of scenes within two independ...

In eukaryotic cells, the DNA material is densely packed inside the nucleus in the form of a DNA-protein complex structure called chromatin. Since the actual conformation of the chromatin fiber defines the possible regulatory interactions between genes and their regulatory elements, it is very important to understand the mechanisms governing folding of chromatin. In this paper, we show that supe...

Abstract Generalized impedance boundary conditions are effective approximate that describe scattering of waves in situations where the wave interaction with material involves multiple scales. In particular, this includes materials a thin coating (with thickness as small scale) and strongly absorbing materials. For acoustic from generalized conditions, approach taken here first determines Dirich...

in recent year, the evolutionary structural optimization (eso) method, has been applied as an effective tool for structures design. the concept of eso method is to use the finite element  results in each iteration of process and removal of inefficient material based on these results. in this method there are several experimental parameters such as rejection rate and evolutionary rate that are e...

In this paper, the extended finite element method (XFEM) is employed to investigate the statics and vibration problems of cracked isotropic bars and beams. Three kinds of elements namely the standard, the blended and the enriched elements are utilized to discretize the structure and model cracks. Two techniques referred as the increase of the number of Gauss integration points and the rectangle...