Recently, several proposals for the generalization of Young’s SOR method to the saddle point problem or the augmented system has been presented. One of the most practical versions is the SOR-like method given by Golub et al., [(2001). SOR-like methods for augmented systems. BIT, 41, 71–85.], where the convergence and the determination of its optimum parameters were given. In this article, a ful...

The development of fast numerical methods for multilevel radiative transfer (RT) applications often leads to important breakthroughs in astrophysics, because they allow the investigation of problems that could not be properly tackled using the methods previously available. Probably, the most familiar example is the so-called Multilevel Accelerated Λ-Iteration (MALI) technique of Rybicki & Humme...

Network community detection—the problem of dividing a network of interest into clusters for intelligent analysis—has recently attracted significant attention in diverse fields of research. To discover intrinsic community structure a quantitative measure called modularity has been widely adopted as an optimization objective. Unfortunately, modularity is inherently NP-hard to optimize and approxi...

The finite difference discretization of the Poisson equation with Dirichlet boundary conditions leads to a large, sparse system of linear equations for the solution values at the interior mesh points. This problem is a popular and useful model problem for performance comparisons of iterative methods for the solution of linear systems. To use the successive overrelaxation (SOR) method in these c...

In this paper, we analyze the potential of using weights for block-asynchronous relaxation methods on GPUs. For this purpose, we introduce different weighting techniques similar to those applied in blocksmoothers for multigrid methods. For test matrices taken from the University of Florida Matrix Collection we report the convergence behavior and the total runtime for the different techniques. A...

The Euclidean division of two formal series in one variable produces a sequence of series that we obtain explicitly, remarking that the case where one of the two initial series is 1 is sufficiently generic. As an application, we define a Wronskian of symmetric functions. The Euclidean division of two polynomials P (z), Q(z), in one variable z, of consecutive degrees, produces a sequence of line...

In this report, we review the construction of polar codes and we briefly present the main results that lead to the conclusion that polar codes are capacity achieving over binaryinput discrete memoryless channels. Moreover, we discuss a more sophisticated variant of successive cancellation decoding, namely list successive cancellation decoding, that aims to improve the finite-length performance ...

In this paper, the successive overrelaxation iteration and the variation of parameters formula are used to discuss the stability of linear and nonlinear Volterra integrodifferential equations. Some sufficient conditions are obtained, such that the trivial solution of the Volterra integrodifferential equations is asymptotically stable; these stability conditions are given directly from the coeff...

This paper looks at the SSOR algorithm and shows that, under certain conditions, we can generate an approximation to the SSOR preconditioner using only one triangular solve. We show that this approximation can result in slightly increased iterations to convergence, but increased solution eeciency when used as a preconditioner for non-symmetric, indeenite systems of equations. The paper analyzes...

In this paper we generalize the Aitken-like acceleration method of the additive Schwarz algorithm for elliptic problems to the additive Schwarz waveform relaxation for the heat equation. The domain decomposition is in space and time. The standard Schwarz waveform relaxation algorithm has a linear rate of convergence and low numerical efficiency. This algorithm is, however, friendly to cache use...