Recent works in the boundary element method (BEM) community have been devoted to derivation of fast techniques perform matrix-vector product needed iterative solver. Fast BEMs are now very mature. However, it has shown that number iterations can significantly hinder overall efficiency BEMs. The robust preconditioners is inevitable increase size problems be considered. Analytical offer a interes...

precise geoid determination on islands suffers from the lack of accurate gravity data on the open seas. nowadays, sub-microgal accuracy for the land gravity observations is obtainable. but the sea gravity data which are collected via shipborne techniques, due to the measuring environment at sea area, are usually highly noisy and are contaminated with various systematic errors. on the other hand...

in this article, we study the new streamline diffusion finite element for treating the linear second order hyperbolic initial-boundary value problem. we prove a posteriori $ l^2(l^2)$ and error estimates for this method under minimal regularity hypothesis. test problem of an application of the wave equation in the laser is presented to verify the efficiency and accuracy of the method.

‎In this paper‎, ‎we study the Neumann boundary value problem of a class of nonlinear divergence type diffusion equations‎. ‎By a priori estimates‎, ‎difference and variation techniques‎, ‎we establish the existence and uniqueness of weak solutions of this problem.

We modify and extend proofs of Serrin’s symmetry result for overdetermined boundary value problems from the Laplace-operator to a general quasilinear operator and remove a strong ellipticity assumption in [9] and a growth assumption in [5] on the diffusion coefficient A, as well as a starshapedness assumption on Ω in [4]. Mathematics Subject Classification (2000). 35J65, 35B35