http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 A stabilized mixed finite element method for the biharmonic equation based on biorthogonal systems http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12470 We propose a stabilized finite element method for the approximation of the biharmonic equation with a clamped boundary condition. The mixed formulation of the biharmonic equation is obtained by introducing the gradient of the solution and a Lagrange multiplier as new unknowns. Working with a pair of bases forming a biorthogonal system, we can easily eliminate the gradient of the solution and the Lagrange multiplier from the saddle point system leading to a positive definite formulation. Using a superconvergence property of a gradient recovery operator, we prove an optimal a priori estimate for the finite element discretization for a class of meshes. 2013-01-23T00:50:03.764Z ]]> A mixed finite element method for the biharmonic problem using biorthogonal or quasi-biorthogonal systems http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12445 We consider a finite element method based on biorthogonal or quasi-biorthogonal systems for the biharmonic problem. The method is based on the primal mixed finite element method due to Ciarlet and Raviart for the biharmonic equation. Using different finite element spaces for the stream function and vorticity, this approach leads to a formulation only based on the stream function. We prove optimal a priori estimates for both stream function and vorticity, and present numerical results to demonstrate the efficiency of the approach. 2013-01-22T00:30:04.153Z ]]> A gradient recovery operator based on an oblique projection http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11284 We present a construction of a gradient recovery operator based on an oblique projection, where the basis functions of two involved spaces satisfy a condition of biorthogonality. The biorthogonality condition guarantees that the recovery operator is local. 2012-08-15T00:31:05.433Z ]]>