Download or read book The Method of Conjugate Gradients for the Numerical Solution of Large Body Electromagnetic Scattering Problems written by A. F. Peterson and published by . This book was released on 1985 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, many techniques have been developed for the numerical solution of integral equations representing electromagnetic scattering problems. However, a majority of these techniques are limited to electrically small scatterers, i.e., below the resonance range. This is primarily because the amount of CPU computer time and storage requirements become prohibitive for large body scatterers. Recent work indicates that a procedure based on the iterative conjugate gradient method can be incorporated into conventional numerical methods in order to extend the range of application of the techniques to larger geometries. In this paper we discuss the conjugate gradient method and illustrate several ways in which it can be applied to electromagnetic scattering problems. The discussion includes mention of the method as compared to conventional approaches as well as some of its limitations. In many practical scattering problems of interest at optical wavelengths, the method can provide a convenient means of treating problems which are electrically more than an order of magnitude larger than can be handied by other techniques. Keywords: Electromagnetic scattering; Method of moments; Conjugate gradient method; Spectral iterative technique; Numerical electromagnetics. (Author).
Download or read book Electromagnetic Modelling and Measurements for Analysis and Synthesis Problems written by B. de Neumann and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this volume is presented the proceedings of a NATO Advanced Study Institute (ASI) on the theme of Electromagnetic Modelling and Measurements for Analysis and Synthesis Problems. The ASI was held at 11 Ciocco, Castelvecchio Pascoli, Tuscany, Italy, August 10th - 21st, 1987. It has been my good fortune to act as co-director of two of Jozef's previous ASIs, and so I am well acquainted with the JKS format for ASIs. As participants will realise, I did not attend this ASI, and so I only have a partial appreciation of the programme. In particular it has not been possible to include transcripts of any panel discussions which may have taken place. Readers may recall that such transcripts have formed a most interesting and useful part of previous ASI proceedings edited by Jozef Skwirzynski, and helped to convey the spirit of the meetings. Unfortunately it has proved impossible to locate the tapes, despite the best efforts of Jozef's assistant, Barry Stuart. A further dificulty has arisen through the untimely death of Jozef's former deputy and colleague at GEC Research, Ed Pacello, who assisted Jozef with the organisation of the precursor of this ASI. The following is taken from original material relating to the aims of the Advanced Study Institute: "PURPOSE OF THE INSTITUTE This Institute is concerned with computer modelling and with experimental measurements as two complementary tools for both analysis and synthesis of electromagnetics (EM), infra-red (IR) and optical problems.
Download or read book Efficient Solution for Electromagnetic Scattering Using the Dual surface Magnetic field Integral Equation for Bodies of Revolution written by James L. Schmitz and published by . This book was released on 1995 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Techniques in Electromagnetics Second Edition written by Matthew N.O. Sadiku and published by CRC Press. This book was released on 2000-07-12 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the availability of powerful computer resources has grown over the last three decades, the art of computation of electromagnetic (EM) problems has also grown - exponentially. Despite this dramatic growth, however, the EM community lacked a comprehensive text on the computational techniques used to solve EM problems. The first edition of Numerical Techniques in Electromagnetics filled that gap and became the reference of choice for thousands of engineers, researchers, and students. The Second Edition of this bestselling text reflects the continuing increase in awareness and use of numerical techniques and incorporates advances and refinements made in recent years. Most notable among these are the improvements made to the standard algorithm for the finite difference time domain (FDTD) method and treatment of absorbing boundary conditions in FDTD, finite element, and transmission-line-matrix methods. The author also added a chapter on the method of lines. Numerical Techniques in Electromagnetics continues to teach readers how to pose, numerically analyze, and solve EM problems, give them the ability to expand their problem-solving skills using a variety of methods, and prepare them for research in electromagnetism. Now the Second Edition goes even further toward providing a comprehensive resource that addresses all of the most useful computation methods for EM problems.
Download or read book Numerical Methods for Solving the Problem of Electromagnetic Scattering from Large Bodies written by Albert Hoon Chang and published by . This book was released on 1988 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conjugate Gradient Type Methods for Ill Posed Problems written by Martin Hanke and published by CRC Press. This book was released on 2017-11-22 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The conjugate gradient method is a powerful tool for the iterative solution of self-adjoint operator equations in Hilbert space.This volume summarizes and extends the developments of the past decade concerning the applicability of the conjugate gradient method (and some of its variants) to ill posed problems and their regularization. Such problems occur in applications from almost all natural and technical sciences, including astronomical and geophysical imaging, signal analysis, computerized tomography, inverse heat transfer problems, and many more This Research Note presents a unifying analysis of an entire family of conjugate gradient type methods. Most of the results are as yet unpublished, or obscured in the Russian literature. Beginning with the original results by Nemirovskii and others for minimal residual type methods, equally sharp convergence results are then derived with a different technique for the classical Hestenes-Stiefel algorithm. In the final chapter some of these results are extended to selfadjoint indefinite operator equations. The main tool for the analysis is the connection of conjugate gradient type methods to real orthogonal polynomials, and elementary properties of these polynomials. These prerequisites are provided in a first chapter. Applications to image reconstruction and inverse heat transfer problems are pointed out, and exemplarily numerical results are shown for these applications.
Download or read book Application of Conjugate Gradient Method to Electromagnetics and Signal Analysis written by Tapan K. Sarkar and published by Elsevier Science & Technology. This book was released on 1991 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scattering of Electromagnetic Waves written by Leung Tsang and published by John Wiley & Sons. This book was released on 2004-04-07 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: A timely and authoritative guide to the state of the art of wave scattering Scattering of Electromagnetic Waves offers in three volumes a complete and up-to-date treatment of wave scattering by random discrete scatterers and rough surfaces. Written by leading scientists who have made important contributions to wave scattering over three decades, this new work explains the principles, methods, and applications of this rapidly expanding, interdisciplinary field. It covers both introductory and advanced material and provides students and researchers in remote sensing as well as imaging, optics, and electromagnetic theory with a one-stop reference to a wealth of current research results. Plus, Scattering of Electromagnetic Waves contains detailed discussions of both analytical and numerical methods, including cutting-edge techniques for the recovery of earth/land parametric information. The three volumes are entitled respectively Theories and Applications, Numerical Simulation, and Advanced Topics. In the second volume, Numerical Simulations, Leung Tsang (University of Washington) Jin Au Kong (MIT), Kung-Hau Ding (Air Force Research Lab), and Chi On Ao (MIT) cover: * Layered media simulations * Rough surface and volume scattering simulations * Dense media models and simulations * Electromagnetic scattering by discrete scatterers and a buried object * Scattering by vertical cylinders above a surface * Electromagnetic waves scattering by vegetation * Computational methods and programs used for performing various simulations
Download or read book Parallel Computing Works written by Geoffrey C. Fox and published by Elsevier. This book was released on 2014-06-28 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt: A clear illustration of how parallel computers can be successfully appliedto large-scale scientific computations. This book demonstrates how avariety of applications in physics, biology, mathematics and other scienceswere implemented on real parallel computers to produce new scientificresults. It investigates issues of fine-grained parallelism relevant forfuture supercomputers with particular emphasis on hypercube architecture. The authors describe how they used an experimental approach to configuredifferent massively parallel machines, design and implement basic systemsoftware, and develop algorithms for frequently used mathematicalcomputations. They also devise performance models, measure the performancecharacteristics of several computers, and create a high-performancecomputing facility based exclusively on parallel computers. By addressingall issues involved in scientific problem solving, Parallel ComputingWorks! provides valuable insight into computational science for large-scaleparallel architectures. For those in the sciences, the findings reveal theusefulness of an important experimental tool. Anyone in supercomputing andrelated computational fields will gain a new perspective on the potentialcontributions of parallelism. Includes over 30 full-color illustrations.
Download or read book Numerical Methods to Solve the Problem of Scattering from Electrically Large Bodies written by A. Chang and published by . This book was released on 1988 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: An alternative to directly inverting the large MoM matrix is to recast the problem in a form that is suitable for solution via iterative schemes. Although the use of iterative methods may enable one to treat scatterers that are an order of magnitude larger electrically, a close examination of them shows that most of them are not well-suited for handling multiple excitations in an efficient manner. In this report some variational-iteration schemes based on the use of prechosen entire domain basis functions that are suitable not only for treating larger bodies but for handling multiple incident angles as well are suggested. It is shown that, for this type of variational iteration schemes, the choice of an initial guess plays an important role in achieving a rapid convergence. Also, in an effort to further improve the convergence, a hybrid technique, where the method of moments is utilized to generate better gradient vectors in the iterative procedure, is developed. A simple case of scattering from a perfectly conducting or resistively-loaded strip is use to demonstrate the effectiveness of the methods. Keywords: Electromagnetic scattering, Iterative methods, Radar cross sections, and Resistive strips. (KR).
Download or read book The CG FFT Method written by Manuel F. Cátedra and published by Artech House Publishers. This book was released on 1995 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a comprehensive description of the basic principles and practical application of the conjugate gradient method in combination with fast Fourier transform (CG-FFT). It provides extensive fundamental analyses of basic spectral methods and conjugate gradient methods. The presentation details the relationship between applied electromagnetics and linear system theory for the analysis of radiation and scattering from: two-dimensional and three-dimensional bodies with arbitrary geometry and material composition; plane, multilayer or volumetric periodic structures; and metallic pateches defined over body of revolution (BOR) surfaces.
Download or read book Handbook of Microstrip Antennas written by James R. James and published by IET. This book was released on 1989 with total page 1384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews developments in the following fields:circular microstrip antennas; microstrip patch antennas; circular polarisation and bandwidth; microstrip dipoles; multilayer and parasitic configurations; wideband flat dipole and short-circuit microstrip patch elements and arrays; numerical analysis; multiport network approach; transmission-line model; rectangular microstrip antennas; low-cost printed antennas; printed phased-array antennas; circularly polarised antenna arrays; microstrip antenna feeds; substrate technology; computer-aided design of microstrip and triplate circuits; resonant microstrip antenna elements and arrays for aerospace applications; mobile and satellite systems; conical conformal microstrip tracking antenna; and microstrip field diagnostics.
Download or read book Scientific Computing in Electrical Engineering written by Angelo Marcello Anile and published by Springer Science & Business Media. This book was released on 2007-01-10 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of papers presented at the last Scientific Computing in Electrical Engineering (SCEE) Conference, held in Sicily, in 2004. The series of SCEE conferences aims at addressing mathematical problems which have a relevancy to industry. The areas covered at SCEE-2004 were: Electromagnetism, Circuit Simulation, Coupled Problems and General mathematical and computational methods.
Download or read book Electromagnetic Scattering by Numerical Methods Applicable for Large Structures written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is to develop numerical methods for general and efficient solutions to the linear systems obtained using the integral equations arising from electromagnetic scattering problems involving electrically large structures. In the process, the prior art in this area is reviewed. Then, the integral equations and their solutions by the method of moments (MoM) are derived. The progressive numerical method (PNM) and the projection iterative method (PIM) are analysed, including formulations, operation counts, stopping criteria, and their connection. In practice, the PNM is successful in calculation of two-dimensional scattering problems. The iterative PNM and a special case of the PNM, the modified spatial decomposition technique (SDT), are applied to the problems and compared with the PNM. Examples show that the PNM can depress internal resonances. The PIM is implemented in the two-dimensional TE case and convergent solutions are obtained. In order to overcome the difficulties with three-dimensional scattering problems, the PIM is implemented to solve the matrix equation obtained by MoM. Convergent results are observed in all examples being calculated for two- and three-dimensional objects. The PIM's iteration process can be accelerated by appropriate relaxation factors. The dependence of optimum relaxation factors on various parameters are investigated. Approximate results of large objects are obtained by the PIM with much less computation effort than the direct method. By allowing certain smaller elements in a coefficient matrix to be zero, the PIM can be further sped up, while still getting good far field results. This technique was found to be object dependent, providing better results for spheres than other objects.
Download or read book Electromagnetic Scattering by Numerical Methods Applicable for Large Structures written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
