The effect of artificial diffusion schemes on the convergence of an implicit method is investigated. A multigrid code using a symmetric limited positive scheme in conjunction with a lowerupper symmetric-Gauss-Seidel method is developed for viscous compressible flows. The present numerical method is shown to be an effective multigrid driver in three-dimensions. Despite its reasonably fast conver...

The problem of reconstructing an unknown electric conductivity from boundary measurements has applications in medical imaging, geophysics, and nondestructive testing. A. Nachman [Ann. of Math. 143 (1996)] proved global uniqueness for the 2-D inverse conductivity problem using a constructive method of proof. Based on this proof, Siltanen, Mueller and Isaacson [Inverse Problems 16 (2000), pp.681-...

An algorithm for reducing a symmetric dense matrix into a symmetric semiseparable one by orthogonal similarity transformations and an efficient implementation of the QR–method for symmetric semiseparable matrices have been recently proposed. In this paper, exploiting the properties of the latter algorithms, an algorithm for computing the rank revealing factorization of symmetric matrices is con...

We propose a method to construct a 3-dimensional symmetric function that is radially symmetric, using two symmetric 2-copulas, with one of them being also radially symmetric. We study the properties of the presented construction in some specific cases and provide several examples for different families of copulas.

Efficient mode shape extraction of fluid-structure systems is of particular interest in engineering. An efficient modified version of unsymmetric Lanczos method is proposed in this paper. The original unsymmetric Lanczos method was applied to general form of unsymmetric matrices, while the proposed method is developed particularly for the fluid-structure matrices. The method provides us with si...

We consider the problem of decomposing a real-valued symmetric tensor as the sum of outer products of real-valued, pairwise orthogonal vectors. Such decompositions do not generally exist, but we show that some symmetric tensor decomposition problems can be converted to orthogonal problems following the whitening procedure proposed by Anandkumar et al. (2012). If an orthogonal decomposition of a...

A new algorithm for the computation of the spectral expansion of the eigenvalues and eigenvectors of a random non-symmetric matrix is proposed. The algorithm extends the deterministic inverse power method using a spectral discretization approach. The convergence and accuracy of the algorithm is studied for both symmetric and non-symmetric matrices. The method turns out to be efficient and robus...

let be a set and let be the set of subsets of . the pair in which is a collection of elements of (blocks) is called a design if every element of appears in , times. is called a symmetric design if . in a symmetric design, each element of appears times in blocks of . a mapping between two designs and is an isomorphism if is a one-to-one correspondence and . every isomorphism of a design, , to it...

The first infinite families of symmetric designswere obtained fromfinite projective geometries, Hadamardmatrices, and difference sets. In this paper we describe two general methods of constructing symmetric designs that give rise to the parameters of all other known infinite families of symmetric designs. The method of global decomposition produces an incidence matrix of a symmetric design as a...