Download or read book A Massively Parallel Adaptive Finite Element Method with Dynamic Load Balancing written by and published by . This book was released on 1993 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: We construct massively parallel, adaptive finite element methods for the solution of hyperbolic conservation laws in one and two dimensions. Spatial discretization is performed by a discontinuous Galerkin finite element method using a basis of piecewise Legendre polynomials. Temporal discretization utilizes a Runge-Kutta method. Dissipative fluxes and projection limiting prevent oscillations near solution discontinuities. The resulting method is of high order and may be parallelized efficiently on MIMD computers. We demonstrate parallel efficiency through computations on a 1024-processor nCUBE/2 hypercube. We also present results using adaptive p-refinement to reduce the computational cost of the method. We describe tiling, a dynamic, element-based data migration system. Tiling dynamically maintains global load balance in the adaptive method by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. We demonstrate the effectiveness of the dynamic load balancing with adaptive p-refinement examples.

Download or read book An Adaptive HP finite Element Method with Dynamic Load Balancing for the Solution of Hyperbolic Conservation Laws on Massively Parallel Computers written by Karen Marie Dragon Devine and published by . This book was released on 1994 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experience with Automatic Dynamic Load Balancing and Adaptive Finite Element Computation written by and published by . This book was released on 1993 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed memory, Massively Parallel (MP), MIMD technology has enabled the development of applications requiring computational resources previously unobtainable. Structural mechanics and fluid dynamics applications, for example, are often solved by finite element methods (FEMs) requiring, millions of degrees of freedom to accurately simulate physical phenomenon. Adaptive methods, which automatically refine or coarsen meshes and vary the order of accuracy of the numerical solution, offer greater robustness and computational efficiency than traditional FEMs by reducing the amount of computation required away from physical structures such as shock waves and boundary layers. On MP computers, FEMs frequently result in distributed processor load imbalances. To overcome load imbalance, many MP FEMs use static load balancing as a preprocessor to the finite element calculation. Adaptive methods complicate the load imbalance problem since the work per element is not uniform across the solution domain and changes as the computation proceeds. Therefore, dynamic load balancing is required to maintain global load balance. We describe a dynamic, fine-grained, element-based data migration system that maintains global load balance and is effective in the presence of changing work loads. Global load balance is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method utilizes an automatic element management system library to which a programmer integrates the application's computational description. The library's flexibility supports a large class of finite element and finite difference based applications.

Download or read book Proceedings of the Seventh SIAM Conference on Parallel Processing for Scientific Computing written by David H. Bailey and published by SIAM. This book was released on 1995-01-01 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings -- Parallel Computing.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parallel 3D Finite Element Particle in Cell Simulations with Pic3P written by and published by . This book was released on 2009 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic Particle-In-Cell code Pic3P. Designed for simulations of beam-cavity interactions dominated by space charge effects, Pic3P solves the complete set of Maxwell-Lorentz equations self-consistently and includes space-charge, retardation and boundary effects from first principles. Higher-order Finite Element methods with adaptive refinement on conformal unstructured meshes lead to highly efficient use of computational resources. Massively parallel processing with dynamic load balancing enables large-scale modeling of photoinjectors with unprecedented accuracy, aiding the design and operation of next-generation accelerator facilities. Applications include the LCLS RF gun and the BNL polarized SRF gun.

Download or read book Progress in Computer Research written by Frank H. Columbus and published by Nova Publishers. This book was released on 2001 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains 17 papers written by an international group of academic and industrial specialists in computer science. Some of the topics addressed include the design and implementation of video servers in video-on-demand systems; a framework for the development of globally convergent adaptive learning rate algorithms; a vector-based approach to analysis of file space properties; load balancing for unstructured mesh applications; musical composition based on genetic algorithms and fuzzy transformations of traditional Greek music patterns; and frequency-adaptive join for shared nothing machines. Most papers consist of an abstract, key words, an introduction, discussion, conclusions, suggestions for future research, and references. Several contributions are printed in a rather dark, compacted font that is difficult to read. c. Book News Inc.

Download or read book Journal of Research of the National Institute of Standards and Technology written by and published by . This book was released on 1998 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reports NIST research and development in the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Emphasis on measurement methodology and the basic technology underlying standardization.

Download or read book Graph Partitioning and Graph Clustering written by David A. Bader and published by American Mathematical Soc.. This book was released on 2013-03-18 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graph partitioning and graph clustering are ubiquitous subtasks in many applications where graphs play an important role. Generally speaking, both techniques aim at the identification of vertex subsets with many internal and few external edges. To name only a few, problems addressed by graph partitioning and graph clustering algorithms are: What are the communities within an (online) social network? How do I speed up a numerical simulation by mapping it efficiently onto a parallel computer? How must components be organized on a computer chip such that they can communicate efficiently with each other? What are the segments of a digital image? Which functions are certain genes (most likely) responsible for? The 10th DIMACS Implementation Challenge Workshop was devoted to determining realistic performance of algorithms where worst case analysis is overly pessimistic and probabilistic models are too unrealistic. Articles in the volume describe and analyze various experimental data with the goal of getting insight into realistic algorithm performance in situations where analysis fails.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1994 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Discontinuous Galerkin Methods written by Bernardo Cockburn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of finite element methods, the Discontinuous Galerkin Methods (DGM), has been under rapid development recently and has found its use very quickly in such diverse applications as aeroacoustics, semi-conductor device simula tion, turbomachinery, turbulent flows, materials processing, MHD and plasma simulations, and image processing. While there has been a lot of interest from mathematicians, physicists and engineers in DGM, only scattered information is available and there has been no prior effort in organizing and publishing the existing volume of knowledge on this subject. In May 24-26, 1999 we organized in Newport (Rhode Island, USA), the first international symposium on DGM with equal emphasis on the theory, numerical implementation, and applications. Eighteen invited speakers, lead ers in the field, and thirty-two contributors presented various aspects and addressed open issues on DGM. In this volume we include forty-nine papers presented in the Symposium as well as a survey paper written by the organiz ers. All papers were peer-reviewed. A summary of these papers is included in the survey paper, which also provides a historical perspective of the evolution of DGM and its relation to other numerical methods. We hope this volume will become a major reference in this topic. It is intended for students and researchers who work in theory and application of numerical solution of convection dominated partial differential equations. The papers were written with the assumption that the reader has some knowledge of classical finite elements and finite volume methods.

Download or read book Adaptive Atmospheric Modeling written by Jörn Behrens and published by Springer Science & Business Media. This book was released on 2007-06-25 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an overview of the development of adaptive techniques for atmospheric modeling. Written in an educational style, it functions as a starting point for readers interested in adaptive modeling, in atmospheric sciences and beyond. Coverage includes paradigms of adaptive techniques, such as error estimation and adaptation criteria. Mesh generation methods are presented for triangular/tetrahedral and quadrilateral/hexahedral meshes, with a special section on initial meshes for the sphere.

Download or read book The Local Discontinuous Galerkin Method for Time Dependent Convection Diffusion Systems written by Bernardo Cockburn and published by . This book was released on 1997 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we study the Local Discontinuous Galerkin methods for non-linear, time-dependent convection-diffusion systems. These methods are an extension of the Runge-Kutta Discontinuous Galerkin methods for purely hyperbolic systems to convection-diffusion systems and share with those methods their high parallelizability, their high-order formal accuracy, and their easy handling of complicated geometries, for convection dominated problems. It is proven that for scalar equations, the Local Discontinuous Galerkin methods are L2-stable in the nonlinear case. Moreover, in the linear case, it is shown that if polynomials of degree k are used, the methods are k-th order accurate for general triangulations; although this order of convergence is suboptimal, it is sharp for the LDG methods. Preliminary numerical examples displaying the performance of the method are shown.

Download or read book Flow Simulation with High Performance Computers II written by Ernst Heinrich Hirschel and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Der Band enthält den Abschlußbericht des DFG-Schwerpunktprogramms "Flußsimulation mit Höchstleistungsrechnern". Es führt die Arbeiten fort, die schon als Band 38 in der Reihe "Notes on Numerical Fluid Mechanics" erschienen sind.Work is reported, which was sponsored by the Deutsche Forschungsgemeinschaft from 1993 to 1995. Scientists from numerical mathematics, fluid mechanics, aerodynamics, and turbomachinery present their work on flow simulation with massively parallel systems, on the direct and large-eddy simulation of turbulence, and on mathematical foundations, general solution techniques and applications. Results are reported from benchmark computations of laminar flow around a cylinder, in which seventeen groups participated.

Download or read book Parallel Algorithms for Irregularly Structured Problems written by Afonso Ferreira and published by Springer Science & Business Media. This book was released on 1995-08-25 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings -- Parallel Computing.

Download or read book Computational Fluid Dynamics on Parallel Systems written by Siegfried Wagner and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the DFG -Schwerpunktprogramm "Stromungssimulation mit Hochleistungsrechnern" and within the activities of the French-German cooperation of CNRS and DFG a DFG symposium on "Computational Fluid Dynamics (CFD) on Parallel Systems" was organized at the Institut fur Aerodynamik and Gasdynamik of the Stuttgart University, 9-10 December 1993. This symposium was attended by 37 scientists. The scientific program consisted of 18 papers that considered finite element, finite volume and a two step Taylor Galerkin algorithm for the numerical solution of the Euler and Navier-Stokes equations on massively parallel computers with MIMD and SIMD architecture and on work station clusters. Incompressible and compressible, steady and unsteady flows were considered including turbu lent combustion with complex chemistry. Structured and unstructured grids were used. High numerical efficiency was demonstrated by multiplicative, additive and multigrid methods. Shared memory, virtual shared memory and distributed memory systems were investigated, in some cases based on an automatic grid partitioning technique. Various methods for domain decomposition were investigated. The key point of these methods is the resolution of the inter face problem because the matrix involved can be block dense. Multilevel decomposition can be very efficient using multifrontal algorithm. The numerical methods include explicit and implicit schemes. In the latter case the system of equations is often solved by a Gauss -Seidel line re laxation technique.

Download or read book Parallel Solution Methods in Computational Mechanics written by Manolis Papadrakakis and published by . This book was released on 1997-04-17 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book follows the previously published title, Solving Large-scale Problems in Mechanics, edited by M. Papadrakakis. This first volume to be published in the Wiley Series in Solving Large-scale Problems in Mechanics is devoted to high-performance computing using the new generation of computers with parallel and distributed computing capabilities. Parallel and distributed processing is a rapidly growing area of high technology where engineering applications lagged behind hardware advances. New algorithms and codes are required in order to exploit effectively modern computer architectures, as programs suitable for conventional computers achieve very modest performances on these new machines. There is therefore an urgent need to develop and test powerful solution and data handling techniques capable of exploiting the potential of modern computers and of accomplishing the solution of complex engineering problems in an acceptable computing time. This volume intends capturing the latest developments in the field and to serve as an essential reference book on the subject. It comprises a comprehensive state-of-the-art treatment of theory and practice, illustrated by extensive numerical examples.