The construction of geometry models of heart-torso is critical for solving the forward and inverse problems of magnetoand electro-cardiography (MCG/ECG). Boundary element method (BEM) is a commonly used numerical approach for the solution of these problems and it requires the modeling of interfaces between various tissue regions. In this study, a new BEM (h-adaptive type) has been applied to th...

H-Matrix LU-decomposition based preconditioners for BEM

The main objective of this paper is to contribute to the development of a reconstruction method for the electrical impedance tomography (EIT) problem using the boundary element method (BEM). The idea is to adopt BEM to improve the performance of the solution of the direct problem. The EIT problem is generally formulated as an inverse problem and the approach to its solution consists in minimizi...

The self-noise generated by a sharp-edged strut immersed in low Mach number flow is predicted using a hybrid computational fluid dynamics (CFD) boundary element method (BEM) technique. The fluctuating flow field is obtained using an incompressible CFD solver. A high-order reconstruction scheme is used to extract acoustic sources based on Lighthill’s analogy from the flow field data. Acoustic wa...

For many engineers and acousticians, the boundary element method (BEM) provides an invaluable tool in the analysis of complex problems. It is particularly well suited for the examination of acoustical problems within large domains. Unsurprisingly, the widespread application of the BEM continues to produce an academic interest in the methodology. New algorithms and techniques are still being pro...

The spherical head model has been used in magnetoencephalography (MEG) as a simple forward model for calculating the external magnetic fields resulting from neural activity. For more realistic head shapes, the boundary element method (BEM) or similar numerical methods are used, but at greatly increased computational cost. We introduce a sensor-weighted overlapping-sphere (OS) head model for rap...

We demonstrate quantitative functional imaging using image-guided near-infrared spectroscopy (IG-NIRS) implemented with the boundary element method (BEM) for reconstructing 3-D optical property estimates in breast tissue in vivo. A multimodality MRI-NIR system was used to collect measurements of light reflectance from breast tissue. The BEM was used to model light propagation in 3-D based only ...

In this paper, the problem of adaptive MAP symbol detection in the uncoded transmission as well as the problem of adaptive APP demodulation in the coded transmission of data symbols over the frequency-selective Rayleigh fading channel are explored within the framework of the Bayesian expectationmaximization (BEM) algorithm. In particular, two novel versions of the BEM-based detection and demodu...

Polygonal meshes are especially suited for the discretization of boundary value problems in adaptive mesh refinement strategies. Such meshes are very flexible and incorporate hanging nodes naturally. But only a few approaches are available that handle polygonal discretizations in this context. The BEM-based Finite Element Method (FEM) and a residual based error estimate are reviewed in the pres...