Dissertation for the degree of Doctor of Technology to be presented with due permission for public examination and debate in Auditorium F1 at Helsinki University of Technology (Espoo, Finland) on the 27th of April, 2000, at 12 o'clock noon.

Introduction Magnetic Resonance Imaging (MRI) scanners are popular medical diagnostic devices providing useful information about patients in a noninvasive manner. However, a disadvantage of MRI is the high level of acoustic noise generated during scanning, which is caused by the Lorentz forces acting on the gradient coils bound within an epoxy resin cylinder. As the gradient current switches di...

(2001) A coupled Element Free Galerkin / Boundary Element method for stress analysis of two-dimensional solids. Abstract Element Free Galerkin (EFG) method is a newly developed meshless method for solving partial differential equations using Moving Least Squares interpolants. It is, however, computationally expensive for many problems. A coupled EFG/Boundary Element (BE) method is proposed in t...

Homotopy perturbation method HPM and boundary element method BEM for calculating the exact and numerical solutions of Poisson equation with appropriate boundary and initial conditions are presented. Exact solutions of electrostatic potential problems defined by Poisson equation are found using HPM given boundary and initial conditions. The same problems are also solved using the BEM. The cell i...

this paper describes a contra-rotating propeller (crp) system to calculate the hydrodynamic characteristics and then design the optimum operational condition to be installed on two different large bulk carriers and vlcc. the method is based on boundary element method (bem) to obtain the hydrodynamic performance of any complicated configuration such as crp system, and then the optimum propeller ...

the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) was used to predict the barrier insertion loss. the results of rigid and with absorptive coverage were also calculated for comparisons. using qrd on the top surface and faces of all vertical profil...

We propose a semiautomated seeded boundary extraction algorithm that delineates diffuse region boundaries by finding and plugging their leaks. The algorithm not only extracts boundaries that are partially diffuse, but in the process finds and quantifies those parts of the boundary that are diffuse, computing local sharpness measurements for possible use in computer-aided diagnosis. The method t...

The alternating iterative algorithm proposed by Kozlov et al. [An iterative method for solving the Cauchy problem for elliptic equations. USSR Comput Math Math Phys 1991;31:45–52] for obtaining approximate solutions to the Cauchy problem in twodimensional anisotropic elasticity is analysed and numerically implemented using the boundary element method (BEM). The illposedness of this inverse boun...

The Galerkin finite element method is used to solve the three dimensional continuity, momentum and energy equations for laminar Newtonian and power-law model non-Newtonian flow through horizontal circular tube. The governing equations are non-dimensionalized with respect to specific variables and converted into algebraic equations using appropriate elements. To accelerate convergence a combinat...