Stability of Numerical Solutions for Abel-Volterra Integral Equations of the Second Kind

We analyze the stability of convolution quadrature methods for weakly singular Volterra integral equations with respect to a linear test equation. We prove that the asymptotic behavior of the numerical solution replicates the one of the continuous problem under some restriction on the stepsize. Numerical examples illustrate the theoretical results.

AMG based on compatible weighted matching for GPUs

We describe the main issues found in the design of an efficient implementation, tailored to GPGPUs, of an Algebraic MultiGrid (AMG) preconditioner recently proposed by one of the authors and already available for CPU in the open-source BootCMatch code. The AMG method relies on a new approach for coarsening sparse symmetric positive definite matrices, which we refer as coarsening based on compatible weighted matching. It exploits maximum weight matching in the adjacency graph of the sparse matrix and the principle of compatible relaxation to define a pairwise aggregation of unknowns.

The QR Steps with Perfect Shifts

In this paper we revisit the problem of performing a QR-step on an unreduced Hessenberg matrix H when we know an "exact" eigenvalue ?0 of H. Under exact arithmetic, this eigenvalue will appear on diagonal of the transformed Hessenberg matrix H~ and will be decoupled from the remaining part of the Hessenberg matrix, thus resulting in a deflation. But it is well known that in finite precision arithmetic the so-called perfect shift can get blurred and that the eigenvalue ?0 can then not be deflated and/or is perturbed significantly.

Dirichlet-to-Neumann mappings and finite-differences for anisotropic diffusion (Reprint from AN INTERNATIONAL JOURNAL COMPUTERS AND FLUIDS)

A general methodology, which consists in deriving two-dimensional finite-difference schemes which involve numerical fluxes based on Dirichlet-to-Neumann maps (or Steklov-Poincare operators), is first recalled. Then, it is applied to several types of diffusion equations, some being weakly anisotropic, endowed with an external source. Standard finite-difference discretizations are systematically recovered, showing that in absence of any other mechanism, like e.g.

Some Remarks about the Hilbert Transform

In this poster we present some remarks about the Hilbert transform on the real line, in connection with its application in signal processing [1, 2]. References [1] M.R. Capobianco, G. Criscuolo, Convergence and stability of a new quadrature rule for evaluating Hilbert transform, Numer. Algor., 60 (2012) 579-592 [2] C. Zhou, L. Yang, Y. Liu, Z. Yang, A novel method for computing the Hilbert transform with Haar multiresolution approximation,Journal of Computational and Applied Mathematics 223 (2009), 585-597

Combining pathway identification and breast cancer survival prediction via screening-network methods

Breast cancer is one of the most common invasive tumors causing high mortality among women. It is characterized by high heterogeneity regarding its biological and clinical characteristics. Several high-throughput assays have been used to collect genome-wide information for many patients in large collaborative studies. This knowledge has improved our understanding of its biology and led to new methods of diagnosing and treating the disease. In particular, system biology has become a valid approach to obtain better insights into breast cancer biological mechanisms.

Land cover mapping capability of multispectral thermal data: The TASI-600 case study

This study shows the land cover mapping accuracy retrievable by the TASI-600 thermal airborne multispectral sensor and describes some of the classification results tested on the thermal preprocessed data for a rural area. In the paper is provided an overview of the principal TASI-600 characteristics, i.e. 32 spectral bands in the 8.0-11.5 ?m spectral range, and land cover classification performances. A full assessment of the TASI-600 spectral bands has been also obtained by ranking them in order to understanding their role in land cover classification.