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...

The goal of our report is to compare a number of algorithms for computing a large number of eigenvectors of the generalized eigenvalue problem arising from a modal analysis of elastic structures using preconditioned iterative methods. The shift-invert Lanczos algorithm has emerged as the workhorse for the solution of this generalized eigenvalue problem; however a sparse direct method is require...

This paper presents an empirical comparison of the Landweber iterative image restoration method with the direct CLS method, with the goal of determining which is more robust against errors in the estimated point spread function. 1. Image Formation Process 2. Restoration Methods q Constrained Least Squares (direct) ( ) T T T cls H C C H H h 1 − + = a q Landweber (iterative) ) ˆ ( ˆ ˆ * 1 k k k f...

Iterative methods such as Lanczos and Jacobi-Davidson are typically used to compute a small number of eigenvalues and eigenvectors of a sparse matrix. However, these methods are not effective in certain large-scale applications, for example, “global tight binding molecular dynamics.” Such applications require all the eigenvectors of a large sparse matrix; the eigenvectors can be computed a few ...

This paper is concerned with a technique for solving Volterra integral equations in the reproducing kernel Hilbert space. In contrast with the conventional reproducing kernel method, the Gram-Schmidt process is omitted here and satisfactory results are obtained.The analytical solution is represented in the form of series.An iterative method is given to obtain the approximate solution.The conver...

This paper is concerned with a technique for solving Volterra integro-dierential equationsin the reproducing kernel Hilbert space. In contrast with the conventional reproducing kernelmethod, the Gram-Schmidt process is omitted here and satisfactory results are obtained.The analytical solution is represented in the form of series. An iterative method is given toobtain the...

PAD&APPROXIMANTS FOR THE SOLUTION OF A SYTEM OF NONLINEAR EQUATIONS ANNIE Cm-T? and PAUL VAN DER CRUYSSEN University of Antwerp, Department of Mathematics, Universiteitsplein 1, B-2610 Wihijk, Belgium (Receioed January 1981; and in revised form May 1982) Communicated by J. F. Traub Abstract-Let F: R4 *R’ and let x* be a simple root of the system of nonlinear equations F(x) = 0. We will construc...

Parallel sparse direct solvers are now able to solve efficiently real-life three-dimensional problems having in the order of several millions of equations. They are, however, constrained by prohibitive memory requirements. Iterative methods on the other hand require much less memory, but they often fail to solve ill-conditioned systems. We propose an hybrid direct-iterative method which aims at...

in this paper, downlink resource allocation for a sparse code multiple access (scma) based heterogeneous  cellular networks (hcn) is investigated. the main aim of this paper is to obtain joint power allocation and codebook assignment to achieve the least total system transmit power. in this regard, the proposed objective function is formulated as total transmit power subject to users minimum ra...