Dissertation > Excellent graduate degree dissertation topics show

Fast Iterative Techniques for Electromagnetic Scattering Analysis

Author: ZuoPingLiang
Tutor: ChenRuShan
School: Nanjing University of Technology and Engineering
Course: Electromagnetic Field and Microwave Technology
Keywords: Electromagnetic scattering method of moment fast Fourier Transform multilevel fast multipole method iterative solvers iterative acceleration strategies preconditioning techniques multigrid methods
CLC: TN011
Type: PhD thesis
Year: 2007
Downloads: 373
Quote: 14
Read: Download Dissertation


In this work, we consider the iterative solution of large dense complex linear systems that arise from integral equations in electromagnetic scattering applications. The goal of this study is the development of efficient acceleration strategies and robust preconditioning techniques for the Krylov subspace iterative methods.We first adapt to the dense situation the preconditioners initially developed for sparse linear systems. We compare their respective numerical scalabilities and propose an efficient perturbation technique for constructing robust incomplete factorization preconditoners. We also develop a robust sparse approximate inverse preconditioner in the fast multipole method framework.We then investigate several acceleration strategies based on generalized minimal residual method and compare their numerical behaviours respectively. This inspires us to improve the performance of an augmentation strategy with more accurate eigenvector information, resulting in the enhanced generalized minimal residual method. The eigenvector information can be evaluated by an eigensolver in a preprocessing phase or by a deflated generalized minimal residual method at run time.The performance of most existing preconditioners suffers heavily from the lack of global coupling in the sparsified matrix on which they have been constructed. To tack this problem we propose a multi-step hybrid preconditioning technique. It uses a spectral preconditioner in a multi-step manner to continuously update an existing preconditioner so as to recover the global information.Inherited from the basic idea from the multigrid methods that are fully defined by the choice of the smoother and the selection of the coarse space, we develop a robust algebraic multigrid method. We use a preconditioned Krylov iterative method to implement the smoother and the coarse space is defined by the span of the eigenvectors associated with the smallest eigenvalues close to the origin.Finally, we develop two spectral block iterative methods for the solution of a set of systems involving the same coefficient matrix but different right-hand sides. Both of these methods exploit spectral information of the coefficient system to improve the performance of traditional block GMRES iterative method.

Related Dissertations

  1. Multigrid Methods for Elliptic Partial Differential Equations with Discontinuous Coefficients,O241.82
  2. A Nonlinear Multigrid Method for the LLT Model,TP391.41
  3. Non- symmetric indefinite second order elliptic boundary value problems multigrid convergence,O175.25
  4. Two-grid Methods for the Model of 2-D Heat Conduction with Three-temperature,O241.82
  5. Block algebraic multigrid algorithm and its implementation technology in reservoir simulation software,TP391.9
  6. Study on Preconditioning Techniques for Generalized Minimal Residual Algorithm,O241.6
  7. Fast Algorithms of the Finite-element Method, Boundary Integral Method and Their Hybrid Methods for Complicated Electromagnetic Problems,O241.82
  8. Fast Electromagnetic Algorithms of Structures in Multilayered Media,O441
  9. Numerical Analysis of Finite-Difference Time-Domain and Time-Domain Finite-Element Methods in Electromagnetic Simulation,TM15
  10. Fast Electromagnetic Simulation of Microstrip Circuits and Antenna Arrays,TM159
  11. Fast Analysis for Complicated Electromagnetic Problems and the Software Implementation,TP311.52
  12. Fast Algorithms for Electromagnetic Scattering Analyses,TN951
  13. LARGE accurate modeling of complex stealth targets , and fast algorithm,TN972
  14. Electromagnetic scattering integral equation method GPU-based parallel numerical solution,O441.4
  15. The complex structure of the scattering and radiation characteristic basis function method and improved technology,O441.4
  16. Mixed metal dielectric properties of electromagnetic scattering surface integral equation analysis,O441.4
  17. Electromagnetic scattering media targets based on the new three-dimensional integral equation analysis,TN011
  18. Guide heliocentric orbit simulation Research and Improvement,O53
  19. Research and Design of Electronic Equalization Based on Most Likelihood Sequence Estimation,TN911.5
  20. Design and Research of Ultrasonic Gas Leak Detector Based on Embedded System,TP274.53

CLC: > Industrial Technology > Radio electronics, telecommunications technology > General issues > Basic theory > Radio wave propagation,the propagation mechanism
© 2012 www.DissertationTopic.Net  Mobile