Abstract. Starting from a recently developed energetic space-time weak formulation of boundary integral equations related to wave propagation problems defined on single and multidomains, a coupling algorithm is presented, which allows a flexible use of finite and boundary element methods as local discretization techniques, in order to efficiently treat unbounded multilayered media. Partial diff...

The task of probing a medium for an inclusion is cast as a signal detection problem. A sufficient statistic is developed for determining the existence and location of an inclusion. The analysis shows the human limitationsof palpationwhen using a probe and the limitations imposed by a haptic display either when emulating such an environment or when relaying related information in a teleoperated ...

We present a straightforward method to solve gas damping problems for perforated structures in two dimensions (2D) utilising a Perforation Profile Reynolds (PPR) solver. The PPR equation is an extended Reynolds equation that includes additional terms modelling the leakage flow through the perforations, and variable diffusivity and compressibility profiles. The solution method consists of two ph...

In this paper, the second order boundary value problem −∇·(A(x, y)∇u) = f is discretized by the Finite Element Method using piecewise polynomial functions of degree p on a triangular mesh. On the reference element, we define integrated Jacobi polynomials as interior ansatz functions. If A is a constant function on each triangle and each triangle has straight edges, we prove that the element sti...

FEM performance enhancement achieved by use of r.f. prebunching of the e-beam in the FEM developed at TAU was investigated theoretically and experimentally. For FEM operation as an oscillator, use of e-beam prebunching enables stable, coherent, high output power throughout the r.f. output pulse at any selected oscillator eigenfrequency for which the net gain is above unity. Prebunching enables ...

Hybrid FEM/MoM methods combine the finite element method (FEM) and the method of moments (MoM) to model inhomogeneous unbounded problems. These two methods are coupled by enforcing the continuity of tangential fields on the boundary that separates the FEM and MoM regions. When modeling complex geometries with many elements on the boundary, the MoM part of the problem is the bottleneck of the hy...

Robotic grasping of deformable objects is difficult and under-researched not simply due to the high computational cost of modeling. More fundamentally, several issues arise with the deformation of an object being grasped: a changing wrench space, (generally) growing finger contact areas, and pointwise varying contact modes inside these areas. Consequently, constraints needed for deformable mode...

This paper considers an approach to improving outcomes for neurosurgery patients by enhancing intraoperative navigation and guidance. Currently, intraoperative navigation systems do not accurately account for brain shift or tissue resection. We describe how preoperative images can be incrementally updated to take into account any type of brain tissue deformation that may occur during surgery, a...

The finite element method (FEM) is one of the most successful computational techniques for obtaining approximate solutions to the partial differential equations that arise in many scientific and engineering applications. Finite Element Method Magnetics (FEMM) is a software package for solving electromagnetic problems using FEM. The program addresses 2D planar and 3D axisymmetric linear and nonl...

The Switched Reluctance Machine (SRM) is ideal for safety critical applications (aerospace, automotive, defense, medical, etc.) where it is desirable that the electrical drive system to be fault tolerant. During the design of a fault tolerant electrical drive system it is indispensable to use advanced simulation techniques. Finite elements method (FEM) based magnetic field computation programs ...