In this paper the most suitable algorithms for unconstrained optimization now available applied to an identi®cation inverse problem in elasticity using the boundary element method (BEM) are compared. Advantage is taken of the analytical derivative of the whole integral equation of the BEM with respect to the variation of the geometry, direct differentiation, which can be used to obtain the grad...

Green’s functions represent the scattering behaviour of a particular geometry and are required to propagate acoustic disturbances through complex geometries using integral methods. The versatility of existing integral methods of acoustic propagation may be greatly increased by using numerical Green’s functions computed for more general geometries. We investigate the use of the Sinc-Galerkin met...

In continuum approaches to molecular electrostatics, the boundary element method (BEM) can provide accurate solutions to the Poisson-Boltzmann equation. However, the numerical aspects of this method pose significant problems. We describe our approach, applying an alpha shape-based method to generate a high-quality mesh, which represents the shape and topology of the molecule precisely. We also ...

In VLSI circuits with deep sub-micron, the parasitic capacitance from interconnect is a very important factor determining circuit performances such as power and time-delay. The Boundary Element Method(BEM) is an effective tool for solving Laplacian’s equation applied in the parasitic capacitance extraction. In this paper, a hierarchical h-adaptive BEM is presented . It constructs a 3-D linear h...

In this paper, an adaptive mesh scheme in boundary element computations for solving the propagation of oblique incident wave passing a breakwater is developed. The purpose is to demonstrate cost savings engendered through adaptivity. The computation is performed on meshes of constant boundary elements, and are adapted to the solution by locally changing element sizes (h-version). Two error indi...

In this paper, the iterative algorithm proposed by Kozlov et al. [Comput. Maths. Math. Phys. 31 (1991) 45] for obtaining approximate solutions to the ill-posed Cauchy problem for the Helmholtz equation is analysed. The technique is then numerically implemented using the boundary element method (BEM). The numerical results confirm that the iterative BEM produces a convergent and stable numerical...

In this paper, we introduce a domain decomposition method with non-matching grids for solving Dirichlet exterior boundary problems by coupling of finite element method (FEM) and natural boundary element method(BEM). We first derive the optimal energy error estimate of the nonconforming approximation generated by this method. Then we apply a Dirichlet-Neumann(D-N) alternating algorithm to solve ...

The direct electro/magnetoencephalographic (E/MEG) problem consists of simulating the electromagnetic field produced by neuronal sources on the cortex. We compare two different methods for the resolution of this problem, from the point of view of computational complexity and accuracy. First, the finite element method (FEM), based on the discretization of the PDE in the entire head volume. Secon...

finite element and boundary methods in structural finite element and boundary methods in structural finite element and boundary methods in structural finite element and boundary methods in structural finite element and boundary methods in structural finite element and boundary methods in structural finite element and boundary methods in structural introduction to finite element vibration analys...

Free surface modeling plays an important role in some ocean structures design, especially in Oscillating Water Column (OWC) devices. Boundary element method (BEM) is a suitable method for free surface modeling due to its simplicity, quick solving, and low data storage requirement. In this paper, BEM was used for free surface modeling in OWC chamber and out of it. Linear kinematic and dynamic bo...