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...

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...

The biorthogonal Lanczos and the biconjugate gradient methods have been proposed as iterative methods to approximate the solution of nonsymmetric and indefinite linear systems. Sonneveld (1989) obtained the conjugate gradient squared by squaring the matrix polynomials of the biconjugate gradient method. Here we square the unsymmetric (or biorthogonal) Lanczos method for computing the eigenvalue...

Fast algorithms, based on the unsymmetric look-ahead Lanczos and the Arnoldi process, are developed for the estimation of the functional (f)= uf(A)v for xed u; v and A, where A∈Rn×n is a largescale unsymmetric matrix. Numerical results are presented which validate the comparable accuracy of both approaches. Although the Arnoldi process reaches convergence more quickly in some cases, it has grea...

For most unsymmetric matrices it is difficult to compute many accurate eigenvalues using the primitive form of the unsymmetric Lanczos algorithm (ULA). In this paper we propose a modification of the ULA. It is related to ideas used in [J. Chem. Phys. 122 (2005), 244107 (11 pages)] to compute resonance lifetimes. Using the refined ULA we suggest, the calculation of accurate extremal and interior...

First several algorithms based on the unsymmetric Lanczos process are surveyed the biorthog onalization BO algorithm for constructing a tridiagonal matrix T similar to a given matrix A whose ex treme spectrum is sought typically the BOBC algorithm which generates directly the LU factors of T the Biores Lanczos Orthores Biomin Lanczos Orthomin or biconjugate gradient BCG and the Biodir Lanczos O...

A new version of the unsymmetric Lanczos algorithm without look-ahead is described combining elements of numerical stability and parallel algorithm design. Firstly, stability is obtained by a coupled two-term procedure that generates Lanczos vectors scaled to unit length. Secondly, the algorithm is derived by making all inner products of a single iteration step independent such that global sync...

For the solutions of linear systems of equations with unsymmetric coeecient matrices, we propose an improved version of the quasi-minimal residual (IQMR) method by using the Lanczos process as a major component combining elements of numerical stability and parallel algorithm design. For Lanczos process, stability is obtained by a coupled two-term procedure that generates Lanczos vectors normali...