We consider the problem of multiuser detection for DSCDMA in doubly-selective (timeand frequency-selective) channels, and propose a time-varying multiuser detector (TVMUD) to solve this problem. Using a basis expansion model (BEM) to model the doubly-selective channel and the TVMUD, we derive a closed-form expression for the BEM coefficients of the TV-MUD as a function of the BEM coefficients o...

the bem is applied to the solution of the torsion problem of non-homogeneous anisotropic non-circular prismatic bars. the problem is formulated in terms of the warping function. this formulation leads to a second order partial differential equation with variable coefficients, subjected to a generalized neumann type boundary condition. the problem is solved using the analog equation method (aem)...

Multimodality NIR spectroscopy systems offer the possibility of region-based vascular and molecular characterization of tissue in vivo. However, computationally efficient 3D image reconstruction algorithms specific to these image-guided systems currently do not exist. Image reconstruction is often based on finite-element methods (FEMs), which require volume discretization. Here, a boundary elem...

An advanced boundary element method (BEM) is developed in this paper for analyzing thin layered structures, such as thin films and coatings, under the thermal loading. The boundary integral equation (BIE) formulation for steady-state thermoelasticity is reviewed and a special case, that is, the BIE for a uniform distribution of the temperature change, is presented. The new nearly-singular integ...

Objectives: We used a 3-compartment boundary element method (BEM) model from an averaged magnetic resonance image (MRI) data set (Montreal Neurological Institute) in order to provide simple access to realistically shaped volume conductor models for source reconstruction, as compared to individually derived models. The electrode positions were transformed into the model’s coordinate system, and ...

A diagonal form fast multipole boundary element method (BEM) is presented in this paper for solving 3-D acoustic wave problems based on the Burton–Miller boundary integral equation (BIE) formulation. Analytical expressions of the moments in the diagonal fast multipole BEM are derived for constant elements, which are shown to be more accurate, stable and efficient than those using direct numeric...

In the analysis of an acoustic radiation mode of a baffled plate, Rayleigh integral with free space Green’s function is involved. The boundary element method (BEM) is one of the approaches to compute its modes and radiation efficiencies. In this paper a fast multipole BEM in conjunction with an iterative solver based on the implicit restart Arnold method is proposed to efficiently and accuratel...

In this paper, we introduce a flexible box erecting machine (BEM) that swiftly and automatically transforms cardboard into a three dimensional box. Recently, the parcel service and home-shopping industries have grown rapidly, and there is an increasing need for various box types to ship various products. However, workers cannot fold thousands of boxes manually in a day. As such, automatic BEMs ...

This article studies the problem of limited feedback design for heterogeneous multiuser (MU) transmissions over timeand frequency-selective (doubly selective) multiple-input multiple-output downlink channels. Under a doubly selective propagation condition, a basis expansion model (BEM) is deployed as a fitting parametric model for capturing the time-variation of the MU downlink channels and for...