Alvaro L. G. A. Coutinho

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This work presents optimization techniques for the sparse matrix-vector multiplication needed in the conjugate gradient solution of nite element systems of equations on unstructured grids composed by triangles or tetrahedra. The optimization techniques are based on the transition from a conventional element-by-element to an edge-by-edge data structure.(More)
Large-scale experiments in computational science are complex to manage. Due to its exploratory nature, several iterations evaluate a large space of parameter combinations. Scientists analyze partial results and dynamically interfere on the next steps of the simulation. Scientific workflow management systems can execute those experiments by providing process(More)
One of the main advantages of using a scientific workflow management system (SWfMS) to orchestrate data flows among scientific activities is to control and register the whole workflow execution. The execution of activities within a workflow with high performance computing (HPC) presents challenges in SWfMS execution control. Current solutions leave the(More)
SUMMARY Several performance improvements for finite-element edge-based sparse matrix–vector multiplication algorithms on unstructured grids are presented and tested. Edge data structures for tetrahedral meshes and triangular interface elements are treated, focusing on nodal and edges renumbering strategies for improving processor and memory hierarchy use.(More)
SUMMARY A distance field is a representation of the closest distance from a point to a given surface. Distance fields are widely used in applications ranging from computer vision, physics and computer graphics and have been the subject of research of many authors in the last decade. Most of the methods for computing distance fields are devoted to Cartesian(More)
The finite element discretization of the incompressible steady-state Navier-Stokes equations yields a non-linear problem, due to the convective terms in the momentum equations. Several methods may be used to solve this non-linear problem. In this work we study Inexact Newton-type methods, associated with the SUPG/PSPG stabilized finite element formulation.(More)
The parallel edge-based solution of 3D incompressible Navier-Stokes equations is presented. The governing partial differential equations are discretized using the SUPG/PSPG stabilized finite element method [5] on unstructured grids. The resulting fully coupled nonlinear system of equations is solved by the inexact Newton-Krylov method [1]. Matrix-vector(More)
In this paper we present new preconditioners for implicit edge-based computations inspired on the concept of clustered element-by-element preconditioners. These new globally deened preconditioners employ product decompositions of clusters of edges matrices obtained from the grouping of edges into superedges. A performance study of these new preconditioners(More)