A boundary element method-based cortical potential imaging technique has been developed to directly link the scalp potentials with the cortical potentials with the aid of magnetic resonance images of the subjects. First, computer simulations were conducted to evaluate the new approach in a concentric three-sphere inhomogeneous head model. Second, the corresponding cortical potentials were estim...

The numerical solution of the free boundary Bernoulli problem is addressed. An iterative method based on a level-set formulation and boundary element method is proposed. Issues related to the implementation, the accuracy and the generality of the method are discussed. The efficiency of the approach is illustrated by numerical results.

Abstract We extend the preconditioning approach of Glowinski and Pironneau, and of Peisker to the case of mixed finite element general fourth-order elliptic problems. We show that H−1/2-preconditioning on the boundary leads to mesh-independent performance of iterative solvers of Krylov subspace type. In particular, we show that the field of values of the boundary Schur complement preconditioned...

A new meshless method for solving nonlinear boundary value problems, based on the local boundary integral equation (LBIE) method and the moving least squares approximation, is proposed in the present paper. The total formulation and a rate formulation are developed for the implementation of the present method. The present method does not need domain and boundary elements to deal with the volume...

Attract-Integral ~uations are derived for the ~p~~nta~~on of in-plane as well as transverse displacements of shallow shells undergoing small, quasi-static or dynamic deformations. A combined boundary/interior element method for static stress, free-vibration, and transient response analyses of shallow shells, based on these integral equations, is derived. Numerical results are presented to demon...

In this paper we discuss a combined a-priori a-posteriori approach to mesh reenement in nite element methods for two-and three-dimensional elliptic boundary value problems containing boundary singularities. We review rst both techniques of a-priori mesh grading around singularities and a-posteriori mesh reenement controlled by local error indicators. In examples of two-and three-dimensional bou...

In this study, the natural frequencies and mode shapes of beams without cracks and cracked Timoshenko beams is calculated with different boundary conditions using finite element method. The energy method is used to solve the equations. Hardness and softness matrices for Timoshenko beam without crack are obtained by solving the potential and kinetic energy equations. Then for investigation of cr...

A hierarchical multilevel preconditioner is constructed for an efficient solution of a first kind boundary integral equation with the single layer potential operator discretized by a boundary element method. This technique is based on a hierarchical clustering of all boundary elements as used in fast boundary element methods. This hierarchy is applied to define a sequence of nested boundary ele...