Combining differing solution approaches by means of solver portfolios has proven as a highly effective technique for boosting solver performance. We consider the problem of generating parallel SAT solver portfolios. Our approach is based on a recently introduced sequential SAT solver portfolio that excelled at the last SAT competition. We show how the approach can be generalized for the paralle...

This manuscript presents results relative to the optimization of 3D impedance tomography reconstruction algorithms for execution on multi–core computing platforms. Speed–ups obtainable by the use of modern computing architectures and by an optimized implementation allow the use of much finer FEM meshes in the forward model, leading ultimately to a better image quality. We formulate the reconstr...

Gas turbine design, development, monitoring and maintenance are widely based on numerical simulations of the steady and transient engine performance. Most of the equations that are solved in the simulation programs involve the thermodynamic properties of the fluid flowing through the engine. These properties depend on temperature, pressure, humidity and fuel dosage. As the solution of chemical ...

A neural network may be considered as an adaptive system that progressively self-organizes in order to approximate the solution, making the problem solver free from the need to accurately and unambiguously specify the steps towards the solution. Moreover, Evolutionary Artificial Neural Networks (EANNs) have the ability to progressively improve their performance on a given task by executing lear...

In this paper we present a simulator designed to handle multibody systems with changing constraints, wherein the equations of motion for each of its constraint configurations are formulated in minimal ODE form with constraints embedded before they are passed to an ODE solver. The constraint-embedded equations are formulated symbolically according to a re-combination of terms of the unconstraine...

In this paper we examine a collection of related incremental constraint-posting algorithms for temporal planning and for planning with continuous processes. The basis for these algorithms is an incremental version of the Bellman-Ford single-source shortest-path algorithm for consistency checking Simple Temporal Networks (STNs). We extend an existing incremental algorithm for STNs and then proce...

For iterative solvers, besides convergence proofs that may state qualitative results for some classes of problems, straight-forward methods to compute (bounds for) convergence rates are of particular interest. A widelyused straight-forward method to analyze the convergence of numerical methods for solving discretized systems of partial differential equations (PDEs) is local Fourier analysis (or...

We propose a new cooperative concurrent search for solving the constraint satisfaction problem. Our approach consists in running independently many solvers (each one being associated with a process). These solvers exploit the algorithm Forward-Checking with Nogood Recording and they differ from each other in the heuristics they use for ordering variables and values. The cooperation is then base...

For iterative solvers, besides convergence proofs that may state qualitative results for some classes of problems, straight-forward methods to compute (bounds for) convergence rates are of particular interest. A widelyused straight-forward method to analyze the convergence of numerical methods for solving discretized systems of partial differential equations (PDEs) is local Fourier analysis (or...

Several parallel algorithms have been proposed for the solution of triangular systems. The stability of four of them is analysed here: a fan-in algorithm, a block elimination method, a method based on a factorized power series expansion of the matrix inverse, and a method based on a divide and conquer matrix inversion technique. New forward error and residual bounds are derived, including an im...