On a class of nonlinear eigenvalue problems
On a construction of fast direct solvers
Fast direct solvers for the Poisson equation with homogeneous Dirichlet and Neumann boundary conditions on special triangles and tetrahedra are constructed. The domain given is extended by symmetrization or skew symmetrization onto a rectangle or a rectangular parallelepiped and a fast direct solver is used there. All extendable domains are found. Eigenproblems are also considered.
On a devil’s staircase associated to the joint spectral radii of a family of pairs of matrices
The joint spectral radius of a finite set of real matrices is defined to be the maximum possible exponential rate of growth of products of matrices drawn from that set. In previous work with K. G. Hare and J. Theys we showed that for a certain one-parameter family of pairs of matrices, this maximum possible rate of growth is attained along Sturmian sequences with a certain characteristic ratio which depends continuously upon the parameter. In this note we answer some open questions from that paper...
On a direct method for the solution of nearly uncoupled Markov chains.
On a hierarchical basis multilevel method with nonconforming P1 elements.
On a Lyapunov type equation related to parabolic spectral dichotomy.
On a method of D. Marsal for equations with positive operators
On a modified Kovarik algorithm for symmetric matrices.
On a multilevel Krylov method for the Helmholtz equation preconditioned by shifted Laplacian.
On a New Class of Elementary Matrices.
On a non-stagnation condition for GMRES and application to saddle point matrices.
On a parallel implementation of the mortar element method
On a Parallel Implementation of the Mortar Element Method
We discuss a parallel implementation of the domain decomposition method based on the macro-hybrid formulation of a second order elliptic equation and on an approximation by the mortar element method. The discretization leads to an algebraic saddle- point problem. An iterative method with a block- diagonal preconditioner is used for solving the saddle- point problem. A parallel implementation of the method is emphasized. Finally the results of numerical experiments are presented.
On a Theorem of Stein-Rosenberg Type in Interval Analysis.
On a weighted quasi-residual minimization strategy for solving complex symmetric shifted linear systems.
On adaptive BDDC for the flow in heterogeneous porous media
We study a method based on Balancing Domain Decomposition by Constraints (BDDC) for numerical solution of a single-phase flow in heterogeneous porous media. The method solves for both flux and pressure variables. The fluxes are resolved in three steps: the coarse solve is followed by subdomain solves and last we look for a divergence-free flux correction and pressures using conjugate gradients with the BDDC preconditioner. Our main contribution is an application of the adaptive algorithm for selection...
On additive scharz preconditioners for sparse grid discretizations.
On algebraic multilevel methods for non-symmetric systems - convergence results.
On an accelerated procedure of extrapolation.
On an algorithm for testing T4 solvability of max-plus interval systems
In this paper, we shall deal with the solvability of interval systems of linear equations in max-plus algebra. Max-plus algebra is an algebraic structure in which classical addition and multiplication are replaced by and , where , . The notation represents an interval system of linear equations, where and are given interval matrix and interval vector, respectively. We can define several types of solvability of interval systems. In this paper, we define the T4 solvability and give an algorithm...