This article points out that the differential quadrature (DQ) and differential cubature (DC) methods, due to their global domain property, are more efficient for nonlinear problems than the traditional numerical techniques such as finite element and finite difference methods. By introducing the Hadamard product of matrices, we obtain an explicit matrix formulation for the DQ and DC solutions of...

Assume that ? and ? are two independent random variables with distribution functions F? F?, respectively. The of a variable ??, denoted by F??F?, is called the product-convolution F?. It proved F??F? generalized subexponential if belongs to class distributions nonnegative not degenerated at zero.

Arithmetic convolution rings provide a general and unified treatment of many rings that have been called arithmetic; the best known examples are rings of complex valued functions with domain in the set of non-negative integers and multiplication the Cauchy product or the Dirichlet product. The emphasis here is on factorization and related properties of such rings which necessitates prior result...

1 Hadamard matrices in Space Communications One hundred years ago, in 1893, Jacques Hadamard 21] found square matrices of orders 12 and 20, with entries 1, which had all their rows (and columns) orthogonal. These matrices, X = (x ij), satissed the equality of the following inequality jdet Xj 2 n i=1 n X j=1 jx ij j 2 and had maximal determinant. Hadamard actually asked the question of matrices ...