Preconditioned iterative solution methods are compared with the direct Gaussian elimination method to solve dense linear systems Ax = b which originate from crack propagation problems, modeled and discretized by boundary element (BEM) techniques. Numerical experiments are presented and compared with the direct solution method available in a commercial BEM package. The experiments show that the ...

In this work a novel method for the analysis with trimmed CAD surfaces is presented. The method involves an additional mapping step and the attraction stems from its simplicity and ease of implementation into existing Finite Element (FEM) or Boundary Element (BEM) software. The method is first verified with classical test examples in structural mechanics. Then two practical applications are pre...

The objective is to construct and discretize (to fourth-order accuracy) a hybrid model for waveguide problems, where a finite difference method for inhomogeneous layers is coupled to a boundary element method (BEM) for a set of homogeneous layers. Such a hybrid model is adequate for underwater acoustics in complicated environments. Waveguides with either plane or axial symmetry are treated, whi...

Across 7 experiments (N 3,289), we replicate the procedure of Experiments 8 and 9 from Bem (2011), which had originally demonstrated retroactive facilitation of recall. We failed to replicate that finding. We further conduct a meta-analysis of all replication attempts of these experiments and find that the average effect size (d 0.04) is no different from 0. We discuss some reasons for differen...

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...

In BEM one encounters linear system with a dense and non-symmetric square matrix which might be so large that inverting the linear system is too prohibitive in terms of cpu time and/or memory. Each usual powerful treatment (Fast Multipole Method, H-matrices) developed to deal with this issue is optimized to efficiently perform matrix vector products. This work presents a new technique to adequa...

Channel estimation for single-input multiple-output (SIMO) frequency-selective time-varying channels is considered using superimposed training. The time-varying channel is assumed to be described by a complex exponential basis expansion model (CE-BEM). A periodic (nonrandom) training sequence is arithmetically added (superimposed) at a low power to the information sequence at the transmitter be...

We present a new real-time method that can animate a moving elastic object that could collide with other objects in a virtual environment. For simulating physical motions of elastic objects, we exploit a Boundary Element Method (BEM), which can achieve efficient computations and desired deformation as opposed to spring models and a Finite Element Method. In case that real-time processes are req...