TITLE:
Explicit Iterative Methods of Second Order and Approximate Inverse Preconditioners for Solving Complex Computational Problems
AUTHORS:
Anastasia-Dimitra Lipitakis
KEYWORDS:
Approximate Inverse Preconditioners, Iterative Methods, Second Order Iterative Schemes, Exact Inverse Methods, Approximate Inverse, Explicit Preconditioning, Conjugate Gradients, Convergence Analysis
JOURNAL NAME:
Applied Mathematics,
Vol.11 No.4,
April
22,
2020
ABSTRACT: Explicit Exact and Approximate Inverse Preconditioners for solving complex linear systems are introduced. A class of general iterative methods of second order is presented and the selection of iterative parameters is discussed. The second order iterative methods behave quite similar to first order methods and the development of efficient preconditioners for solving the original linear system is a decisive factor for making the second order iterative methods superior to the first order iterative methods. Adaptive preconditioned Conjugate Gradient methods using explicit approximate preconditioners for solving efficiently large sparse systems of algebraic equations are also presented. The generalized Approximate Inverse Matrix techniques can be efficiently used in conjunction with explicit iterative schemes leading to effective composite semi-direct solution methods for solving large linear systems of algebraic equations.