The monotone convergence of a class of parallel nonlinear relaxation methods for nonlinear complementarity problems

We set up a class of parallel nonlinear multisplitting AOR methods by directly multisplitting the nonlinear mapping involved in the nonlinear complementarity problems. The different choices of the relaxation parameters can yield all the known and a lot of new relaxation methods, as well as a lot of new relaxed parallel nonlinear multisplitting methods for solving the nonlinear complementarity problems. The two-sided approximation properties and the influences on the convergence rates from the relaxation parameters about our new methods are shown, and sufficient conditions guaranteeing the methods to converge globally are discussed. Finally, a lot of numerical results show that our new methods are feasible and efficient.     

Asynchronous multisplitting relaxation methods for linear complementarity problems

To solve the linear complementarity problems efficiently on the high-speed multiprocessor systems, we set up a class of asynchronous parallel matrix multisplitting accelerated over-relaxation (AOR) method by technical combination of the matrix multisplitting and the accelerated overrelaxation techniques. The convergence theory of this new method is thoroughly established under the condition that the system matrix of the linear complementarity problem is an H-matrix with positive diagonal elements. At last, we also make multi-parameter extension for this new asynchronous multisplitting AOR method, and investigate the convergence property of the resulted asynchronous multisplitting unsymmetric AOR method. Thereby, an extensive sequence of asynchronous parallel relaxed iteration methods in the sense of multisplitting is presented for solving the large scale linear complementarity problems in the asynchronous parallel computing environments. This not only affords various choices, but also presents systematic convergence theories about the asynchronous parallel relaxation methods for solving the linear complementarity problems.     

A monotone Newton multisplitting method for the nonlinear complementarity problem with a nonlinear source term

In this paper, we develop a Newton multisplitting method for the nonlinear complementarity problem with a nonlinear source term in which the multisplitting method is used as secondary iterations to approximate the solutions for the resulting linearized subproblems. We prove the monotone convergence theorem for the proposed method under proper conditions.     

A unified framework for the construction of various matrix multisplitting iterative methods for large sparse system of linear equations

A unified framework for the construction of various synchronous and asynchronous parallel matrix multisplitting iterative methods, suitable to the SIMD and MIMD multiprocessor systems, respectively, is presented, and its convergence theory is established under rather weak conditions. These afford general method models and systematical convergence criterions for studying the parallel iterations in the sense of matrix multisplitting. In addition, how the known parallel matrix multisplitting iterative methods can be classified into this new framework, and what novel ones can be generated by it are shown in detail.     

A multiplicative multisplitting method for solving the linear complementarity problem

The convergence of the multiplicative multisplitting-type method for solving the linear complementarity problem with an H-matrix is discussed using classical and new results from the theory of splitting. This directly results in a sufficient condition for guaranteeing the convergence of the multiplicative multisplitting method. Moreover, the multiplicative multisplitting method is applied to the H-compatible splitting and the multiplicative Schwarz method, separately. Finally, we establish the monotone convergence of the multiplicative multisplitting method under appropriate conditions.     

Convergence analysis of the two-stage¶multisplitting method

An example is given which shows that the asymptotic convergence rate of the two-stage multisplitting method (see D.B. Szyld and M.T. Jones, SIAM J. Matrix Anal. Appl. 13, 671–679 (1992)) with one inner iteration is, generally, either faster or slower than that with many inner iterations. When the coefficient matrix is an H-matrix and a monotone matrix, respectively, we formulate the convergence as well as the monotone convergence theories for this two-stage multisplitting method under suitable constraints on the two-stage multisplitting. Furthermore, the corresponding comparison theorem in the sense of monotonicity for this method is established and several concrete applications are discussed. Received: April 1996 / Accepted: April 1998     

An acceleration of preconditioned generalized accelerated over relaxation methods for systems of linear equations

In this paper, a new type of preconditioners are proposed to accelerate the preconditioned generalized accelerated over relaxation methods presented by Zhou et al. [Preconditioned GAOR methods for solving weighted linear least squares problems, J. Comput. Appl. Math. 224 (2009), pp. 242–249] for the linear system of the generalized least-squares problem. The convergence and comparison results are obtained. The comparison results show that the convergence rates of the proposed methods are better than those of the original methods. Finally, numerical experiments are provided to confirm the results obtained in this paper.     

Relaxed parallel two-stage multisplitting methods ∗

Two classes of relaxed parallel two-stage multisplitting methods based on extrapolated and AOR methods are studied for the solution of nonsingular linear systems, which are called outer relaxed or inner relaxed parallel two-stage multisplitting methods. Convergence of these methods is studied for H-matrix. Furthermore, computational results about these methods on a shared memory multiprocessor are presented. The results show that the methods we proposed are better than the corresponding existed parallel (two-stage) multisplitting methods.     

Relaxed parallel two-stage multisplitting methods II: Asynchronous version

Two classes of asynchronous relaxed parallel two-stage multisplitting methods based on extrapolated and AOR methods are studied for the solution of nonsingular linear systems, which are called asynchronous outer relaxed or inner relaxed parallel two-stage multisplitting methods. Convergence of these methods is studied for H-matrix. Almost all methods seen in literatures can be viewed as special cases of our methods.     

Comparison results on the preconditioned GAOR method for generalized least squares problems

Recently, Zhou et al. [Preconditioned GAOR methods for solving weighted linear least squares problems, J. Comput. Appl. Math. 224 (2009), pp. 242–249] have proposed the preconditioned generalized accelerated over relaxation (GAOR) methods for solving generalized least squares problems and studied their convergence rates. In this paper, we propose a new type of preconditioners and study the convergence rates of the new preconditioned GAOR methods for solving generalized least squares problems. Comparison results show that the convergence rates of the new preconditioned GAOR methods are better than those of the preconditioned GAOR methods presented by Zhou et al. whenever these methods are convergent. Lastly, numerical experiments are provided in order to confirm the theoretical results studied in this paper.