Cost estimates for simulations of full QCD with n f = 2 Wilson fermions by hybrid Monte Carlo are presented. The extrapolations are based on the average number of iterations, Nit, of the iterative solver within the fermionic part of the HMC molecular dynamics, which is closely related to the minimal eigenvalue of M † M. The cost formula is determined as a product of the scaling functions of ite...

We developed a fast iterative solver for computing time-harmonic acoustic waves scattered by an elastic object in layered media. The discretization of the problem was performed using a finite element method with linear elements based on a locally body-fitted uniform triangulation. We used a domain decomposition preconditioner in the iterative solution of the resulting system of linear equations...

In this paper, we introduce the truncated primal-infeasible dual-feasible interior point algorithm for linear programming and describe an implementation of this algorithm for solving the minimum cost network flow problem. In each iteration, the linear system that determines the search direction is computed inexactly, and the norm of the resulting residual vector is used in the stopping criteria...

Resilience is a major challenge for large-scale systems. It is particularly important for iterative linear solvers, since they take much of the time of many scientific applications. We show that single bit flip errors in the Flexible GMRES iterative linear solver can lead to high computational overhead or even failure to converge to the right answer. Informed by these results, we design and eva...

In this paper we describe an embedded iterative scheme based on the GMRES method and implemented in combination with the Fast Multipole Method for the solution of large electromagnetic scattering problems expressed in an integral formulation. In our scheme, we use a Frobenius-norm minimization preconditioner to speed-up the inner iterations, and the M-V products within the inner and the outer s...

This paper presents an analysis of electrically large antennas using the adaptive integral method (AIM). The arbitrarily shaped perfectly conducting surfaces are modeled using triangular patches and the associated electric field integral equation (EFIE) is solved for computing the radiation patterns of these antennas. The method of moments (MoM) is used to discretize the integral equations and ...

the aim of this research paper is the introduction of a novel mathematical approach to improvethe accuracy of the results of air pollution dispersion models based on the calibration of input backgroundconcentrations. using the dunkirk area of the city of nottingham in the uk as a case study, an air pollutionmodel in adms-roads was created for developing the mathematical approach. the iterative ...

Traditional large sparse linear solvers are not suited in a grid computing environment as they require a large amount of synchronization and communication penalizing the performance on this architecture. This paper presents some features of the solver designed during the current GREMLINS (GRid Efficient Method for LINear Systems) project. The GREMLINS solver limits the amount of communication a...

Finite element discretization of fully-coupled, incompressible flow problems with the classic mixed velocity-pressure interpolation produces matrix systems that render the best and most robust iterative solvers and preconditioners ineffective. The indefinite nature of the discretized continuity equation is the root cause and is one reason for the advancement of pressure penalty formulations, le...

Much e ort has gone into the development of implicit methods for electromagnetic kinetic plasma simulation. One such implicit method is the implicit moment method [1]. The maximum allowable time step in this method has often been found to be governed by the iterative elliptic eld solver, and not the implicit moment method itself [2]. In ref. [2] it was shown, in one dimension, that by using a d...