Shared Memory Pipelined Parareal
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Finite Difference and Discontinuous Galerkin Methods for Wave Equations
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1522 Finite Difference and Discontinuous Galerkin Methods for Wave Equations SIYANG WANG ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-554-9927-3 UPPSALA urn:nbn:se:uu:diva-320614 2017 Dissertation presented at Uppsala University to be publicly examined in Room 2446, Polacksbacken, Lägerhyddsvägen 2, Uppsala, Tuesday, 13 June 2017 at 10:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Thomas Hagstrom (Department of Mathematics, Southern Methodist University). Abstract Wang, S. 2017. Finite Difference and Discontinuous Galerkin Methods for Wave Equations. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1522. 53 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9927-3. Wave propagation problems can be modeled by partial differential equations. In this thesis, we study wave propagation in fluids and in solids, modeled by the acoustic wave equation and the elastic wave equation, respectively. In real-world applications, waves often propagate in heterogeneous media with complex geometries, which makes it impossible to derive exact solutions to the governing equations. Alternatively, we seek approximated solutions by constructing numerical methods and implementing on modern computers. An efficient numerical method produces accurate approximations at low computational cost. There are many choices of numerical methods for solving partial differential equations. Which method is more efficient than the others depends on the particular problem we consider. In this thesis, we study two numerical methods: the finite difference method and the discontinuous Galerkin method. -
MPI–Openmp Algorithms for the Parallel Space–Time Solution of Time Dependent Pdes
MPI–OpenMP algorithms for the parallel space–time solution of Time Dependent PDEs Ronald D. Haynes1 and Benjamin W. Ong2 1 Introduction Modern high performance computers offer hundreds of thousands of processors that can be leveraged, in parallel, to compute numerical solutions to time dependent par- tial differential equations (PDEs). For grid-based solutions to these PDEs, domain decomposition (DD) is often employed to add spatial parallelism [19]. Parallelism in the time variable is more difficult to exploit due to the inherent causality. Recently, researchers have explored this issue as a means to improve the scalability of existing parallel spatial solvers applied to time dependent problems. There are several general approaches to combine temporal parallelism with spatial parallelism. Waveform relaxation [15] is an example of a “parallel across the prob- lem” method. The “parallel across the time domain” approaches include the parareal method [11, 17, 16]. The parareal method decomposes a time domain into smaller temporal subdomains and alternates between applying a coarse (relatively fast) se- quential solver to compute an approximate (not very accurate) solution, and apply- ing a fine (expensive) solver on each temporal subdomain in parallel. Alternatively, one can consider “parallel across the step” methods. Examples of such approaches include the computation of intermediate Runge–Kutta stage values in parallel [18], and Revisionist Integral Deferred Correction (RIDC) methods, which are the family of parallel time integrators considered in this paper. Parallel across the step meth- ods allow for “small scale” parallelism in time. Specifically, we will show that if a DD implementation scales to Nx processors, a RIDC-DD parallelism will scale to Nt × Nx processors, where Nt < 12 in practice. -
Metric Analysis Solvers April 2018
Eingereicht von Dipl.-Ing. Christoph Hofer, BSc. Angefertigt am Doktoratskolleg “Computational Mathematics” Betreuer und Erstbeurteiler O. Univ.-Prof. Dipl.-Ing. Dr. Ulrich Langer Fast Multipatch Isogeo- Zweitbeurteiler Prof. Dr. Giancarlo Sangalli metric Analysis Solvers April 2018 Dissertation zur Erlangung des akademischen Grades Doktor der technischen Wissenschaften im Doktoratsstudium Technische Wissenschaften JOHANNES KEPLER UNIVERSITAT¨ LINZ Altenbergerstraße 69 4040 Linz, Osterreich¨ www.jku.at DVR 0093696 2 Abstract This thesis is devoted to the generalization of the Dual-Primal Finite Element Tearing and Interconnecting (FETI-DP) method to linear algebraic systems arising from the Isogemetric Analysis (IgA) of linear elliptic boundary value problems, like stationary diffusion or heat conduction problems. This IgA version of the FETI-DP method is called Dual-Primal Isogeometric Tearing and Interconnect (IETI-DP) method. The FETI-DP method is well established as parallel solver for large-scale systems of finite element equations, especially, in the case of heterogeneous coefficients having jumps across subdomain interfaces. These methods belong to the class of non-overlapping domain decomposition methods. In practise, a complicated domain can often not be represented by a single patch, instead a collection of patches is used to represent the computational domain, called multi-patch domains. Regarding the solver, it is a natural idea to use this already available decomposition into patches directly for the construction of a robust and parallel solver. We investigate the cases where the IgA spaces are continuous or even discontinuous across the patch interfaces, but smooth within the patches. In the latter case, a stable formulation is obtained by means of discontinuous Galerkin (dG) techniques. -
Numerical Investigation of Parallel-In-Time Methods for Dominantly Hyperbolic Equations
Numerical Investigation of Parallel-in-Time Methods for Dominantly Hyperbolic Equations Vom Fachbereich Maschinenbau an der Technischen Universität Darmstadt zur Erlangung des akademischen Grades eines Doktor-Ingenieurs (Dr.-Ing.) genehmigte Dissertation vorgelegt von Andreas Schmitt, M.Sc. aus Düsseldorf Berichterstatter: Prof. Dr. rer. nat. Michael Schäfer Mitberichterstatter: Prof. Dr. rer. nat. Sebastian Schöps Tag der Einreichung: 23.07.2018 Tag der mündlichen Prüfung: 10.10.2018 Darmstadt 2019 D 17 Schmitt, Andreas Numerical Investigation of Parallel-in-Time Methods for Dominantly Hyperbolic Equations Technische Universität Darmstadt Tag der mündlichen Prüfung: 10.10.2018 Jahr der Veröffentlichung auf TUprints: 2019 URN: urn:nbn:de:tuda-tuprints-83286 Veröffentlicht unter CC BY-NC-ND 4.0 International https://creativecommons.org/licences/by-nc-nd/4.0/ Vorwort Die vorliegende Arbeit “Numerical Investigation of Parallel-in-Time Methods for Dominantly Hyperbolic Equations” ist mein Beitrag zum Forschungsgebiet der zeitparallelen Methoden. Diese Dissertation wurde als Abschlussarbeit meines Promotionsvorhabens an der Technischen Universität Darmstadt am Fachgebiet für Numerische Berechnungsverfahren im Maschinenbau und der Graduiertenschule Computational Engineering verfasst. Mit den Inhalten der Dissertation habe ich mich von Mai 2015 bis Juli 2018 beschäftigt. Ich möchte mich bei Prof. Michael Schäfer für die Möglichkeit zur Pro- motion, den Vorschlag des spannenden Themengebietes und die Betreuung bedanken. Insbesondere danke ich Ihm auch für die gegebenen Freiheiten, so dass ich das Thema nach meinen Interessen erforschen konnte. Des Weiteren danke ich Prof. Sebastian Schöps für die Übernahme der Mitberichterstatter- schaft und die konstruktiven Gespräche. Für viele konstruktive Gespräche möchte ich mich auch bei den Mitentwick- lern von SWEET bedanken. -
A Parareal Algorithm for Optimality Systems Martin Gander, Félix Kwok, Julien Salomon
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Archive Ouverte en Sciences de l'Information et de la Communication PARAOPT: A parareal algorithm for optimality systems Martin Gander, Félix Kwok, Julien Salomon To cite this version: Martin Gander, Félix Kwok, Julien Salomon. PARAOPT: A parareal algorithm for optimality systems. 2019. hal-02346535 HAL Id: hal-02346535 https://hal.archives-ouvertes.fr/hal-02346535 Submitted on 5 Nov 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. PARAOPT: A PARAREAL ALGORITHM FOR OPTIMALITY SYSTEMS MARTIN J. GANDER, FELIX KWOK, AND JULIEN SALOMON Abstract. The time parallel solution of optimality systems arising in PDE constraint optimization could be achieved by simply applying any time paral- lel algorithm, such as Parareal, to solve the forward and backward evolution problems arising in the optimization loop. We propose here a different strat- egy by devising directly a new time parallel algorithm, which we call ParaOpt, for the coupled forward and backward non-linear partial differential equations. ParaOpt is inspired by the Parareal algorithm for evolution equations, and thus is automatically a two-level method. -
Computers and Mathematics with Applications the Method of Lines For
Computers and Mathematics with Applications 56 (2008) 2175–2188 Contents lists available at ScienceDirect Computers and Mathematics with Applications journal homepage: www.elsevier.com/locate/camwa The method of lines for solution of the one-dimensional wave equation subject to an integral conservation condition Fatemeh Shakeri, Mehdi Dehghan ∗ Department of Applied Mathematics, Faculty of Mathematics and Computer Sciences, Amirkabir University of Technology, No. 424, Hafez Avenue, Tehran 15914, Iran article info a b s t r a c t Article history: Hyperbolic partial differential equations with an integral condition serve as models in Received 14 November 2007 many branches of physics and technology. Recently, much attention has been expended Received in revised form 22 March 2008 in studying these equations and there has been a considerable mathematical interest in Accepted 25 March 2008 them. In this work, the solution of the one-dimensional nonlocal hyperbolic equation is presented by the method of lines. The method of lines (MOL) is a general way of viewing Keywords: a partial differential equation as a system of ordinary differential equations. The partial Hyperbolic partial differential equation derivatives with respect to the space variables are discretized to obtain a system of ODEs Non-classic boundary condition Method of lines in the time variable and then a proper initial value software can be used to solve this ODE System of ordinary differential equations system. We propose two forms of MOL for solving the described problem. Several numerical Integral conservation condition examples and also some comparisons with finite difference methods will be investigated to confirm the efficiency of this procedure. -
The Method of Lines for Solution of the Two- Dimensional Elliptic Equation
ANNALS of Faculty Engineering Hunedoara – International Journal of Engineering Tome XIV [2016] – Fascicule 1 [February] ISSN: 1584-2665 [print; online] ISSN: 1584-2673 [CD-Rom; online] a free-access multidisciplinary publication of the Faculty of Engineering Hunedoara 1. G.V. PATEL, 2. K.B. PATEL THE METHOD OF LINES FOR SOLUTION OF THE TWO- DIMENSIONAL ELLIPTIC EQUATION 1-2. Department of Mathematics, Veer Narmad South Gujarat University, Surat, Gujarat, INDIA ABSTACT: The solution of the two-dimensional elliptic equation is presented by the method of lines. The method of lines (MOL) is a general way of viewing a partial differential equation as a system of ordinary differential equations. The partial derivatives with respect to the one dimension spatial variable is discretized to obtain a system of ODEs in the second dimension spatial variable and then using analytic method with eigenvalues and eigenvectors to solve this ODEs system. Keywords: Elliptic equation, Method of lines, Eigenvalues and Eigenvectors 1. INTRODUCTION Over the last few years, it has become increasingly apparent that many physical phenomena can be described in terms of elliptic partial differential equations with the classical boundary condition [3,13,14].Growing attention is being paid to the development, analysis and implementation of numerical methods for the solution of these problems[1,2,3].Elliptic boundary value problems in two dimensions that have been studied by several authors [5 - 10].This equation have been solved directly by various numerical methods such as Adomain decomposition method, Finite volume method, Finite difference method, Finite element method and etc. In this research, we consider the following problem of this family of equations ∂ 2 u ∂ 2 u + = 0, ∂x 2 ∂y2 (1) u = u(x, y),0 ≤ x ≤ a,0 ≤ y ≤ b with Direchlet boundary conditions u(0, y) = f1(y) (2) u(a, y) = f2 (y) (3) u(x,0) = g1(x) (4) u(x,b) = g2 (x) (5) where f1(y),f2 (y),g1(x) and g2 (x)are known functions. -
Appendix H: an OUTLINE of MSA HISTORY
H An Outline of MSA History H–1 Appendix H: AN OUTLINE OF MSA HISTORY TABLE OF CONTENTS Page §H.1. INTRODUCTION H–3 §H.2. Background and Terminology H–4 §H.3. Prolog - Victorian Artifacts: 1858-1930 H–6 §H.4. Act I - Gestation and Birth: 1930-1938 H–6 §H.4.1. The Source Papers ................ H–6 §H.4.2. The MSA Source Book ............. H–7 §H.5. Interlude I - WWII Blackout: 1938-1947 H–8 §H.6. Act II - The Matrix Forest: 1947-1956 H–8 §H.6.1. Computers Become Machines ............ H–8 §H.6.2. The Matrix CFM Takes Center Stage ......... H–8 §H.6.3. The Delta Wing Challenge ............. H–9 §H.6.4. Reduction Fosters Complexity ........... H–10 §H.6.5. Two Paths Through the Forest ............ H–11 §H.6.6. Dubious Duality ................ H–12 §H.7. Interlude II - Questions: 1956-1959 H–13 §H.8. Act III - Answers: 1959-1970 H–13 §H.8.1. A Path Outside the Forest ............. H–13 §H.8.2. The Fire Spreads ................ H–14 §H.8.3. The Final Test ................. H–15 §H.9. Epilogue - Revisiting the Past: 1970-date H–16 §H.10. Concluding Remarks H–16 H–2 §H.1 INTRODUCTION A Historical Outline of Matrix Structural Analysis: A Play in Three Acts C. A. Felippa Department of Aerospace Engineering Sciences and Center for Aerospace Structures University of Colorado, Boulder, CO 80309-0429, USA Report CU-CAS-00-14, June 2000; submitted for publication in Computers & Structures Abstract The evolution of Matrix Structural Analysis (MSA) from 1930 through 1970 is outlined. -
Asynchronous Iterations of Parareal Algorithm for Option Pricing Models Frédéric Magoulès, Guillaume Gbikpi-Benissan, Qinmeng Zou
Asynchronous Iterations of Parareal Algorithm for Option Pricing Models Frédéric Magoulès, Guillaume Gbikpi-Benissan, Qinmeng Zou To cite this version: Frédéric Magoulès, Guillaume Gbikpi-Benissan, Qinmeng Zou. Asynchronous Iterations of Parareal Algorithm for Option Pricing Models. Mathematics , MDPI, 2018, 6 (4), pp.45. 10.3390/math6040045. hal-01741114v2 HAL Id: hal-01741114 https://hal.archives-ouvertes.fr/hal-01741114v2 Submitted on 27 Jun 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Asynchronous Iterations of Parareal Algorithm for Option Pricing Models Frédéric Magoulès∗ Guillaume Gbikpi-Benissany Qinmeng Zouz Abstract Spatial domain decomposition method has been largely investigated in the last several decades, while time decomposition seems against intuition, which is not as popular as the former. However, there are still many attractive methods being proposed, espe- cially the parareal algorithm, which shows both theoretical and experimental efficiency in the context of parallel computing. In this paper, we present an original model of asynchronous variant based on parareal scheme, applied to the European option pricing problem. Some numerical experiments are given to illustrate the convergence perfor- mance and computational efficiency of such method. Keywords: Parallel computing; asynchronous iterations; parareal method; European options; domain decomposition; time-dependent problems 1 Introduction Today’s dominating high-performance computer architecture is parallel. -
{FREE} Numerical Solution of Partial Differential Equations by the Finite
NUMERICAL SOLUTION OF PARTIAL DIFFERENTIAL EQUATIONS BY THE FINITE ELEMENT METHOD PDF, EPUB, EBOOK Claes Johnson | 288 pages | 27 Mar 2009 | Dover Publications Inc. | 9780486469003 | English | New York, United States Numerical Solution of Partial Differential Equations by the Finite Element Method PDF Book Adomian, G. FEA simulations provide a valuable resource as they remove multiple instances of creation and testing of hard prototypes for various high fidelity situations. Main article: Finite difference method. The nature of this failure can be seen more concretely in the case of the following PDE: for a function v x , y of two variables, consider the equation. Partial differential equation at Wikipedia's sister projects. Abstract The finite element method has established itself as an efficient numerical procedure for the solution of arbitrary-shaped field problems in space. Existence and uniqueness of the solution can also be shown. The process is often carried out by FEM software using coordinate data generated from the subdomains. November Learn how and when to remove this template message. Figure 6. Generally the higher the number of elements in a mesh, the more accurate the solution of the discretized problem. However, this procedure is restricted to even-ordered differential equations and leads to symmetric system matrices as a key property of the finite element method. JAMP Subscription. Algebra of physical space Feynman integral Quantum group Renormalization group Representation theory Spacetime algebra. Namespaces Article Talk. Please help improve this section by adding citations to reliable sources. CRC Press. The meshes on the subdomains do not match on the interface, and the equality of the solution is enforced by Lagrange multipliers, judiciously chosen to preserve the accuracy of the solution. -
Sixth-Order Combined Compact Finite Difference Scheme for the Numerical Solution of One-Dimensional Advection-Diffusion Equation with Variable Parameters
mathematics Article Sixth-Order Combined Compact Finite Difference Scheme for the Numerical Solution of One-Dimensional Advection-Diffusion Equation with Variable Parameters Gurhan Gurarslan Department of Civil Engineering, Pamukkale University, Denizli 20160, Turkey; [email protected] Abstract: A high-accuracy numerical method based on a sixth-order combined compact difference scheme and the method of lines approach is proposed for the advection–diffusion transport equa- tion with variable parameters. In this approach, the partial differential equation representing the advection-diffusion equation is converted into many ordinary differential equations. These time- dependent ordinary differential equations are then solved using an explicit fourth order Runge–Kutta method. Three test problems are studied to demonstrate the accuracy of the present methods. Nu- merical solutions obtained by the proposed method are compared with the analytical solutions and the available numerical solutions given in the literature. In addition to requiring less CPU time, the proposed method produces more accurate and more stable results than the numerical methods given in the literature. Keywords: advection–diffusion; variable parameters; solute transport; combined compact difference scheme; method of lines; Runge–Kutta scheme Citation: Gurarslan, G. Sixth-Order Combined Compact Finite Difference Scheme for the Numerical Solution of One-Dimensional 1. Introduction Advection-Diffusion Equation with The transport of solutes by water takes place in a large variety of environmental, Variable Parameters. Mathematics agricultural, and industrial conditions. An accurate prediction of the pollutant transport is 2021, 9, 1027. https://doi.org/ crucial to the effective management of these systems [1]. In the deterministic approach with 10.3390/math9091027 constant transport parameters with respect to time and position the advection–diffusion equation (ADE) is linear and explicit closed-form solutions can generally be derived. -
Time Parallel Time Integration
Time Parallel Time Integration Martin J. Gander November 27, 2018 Contents 1 Introduction 3 1.1 Weather Prediction as an Example . .5 1.2 Ordinary Differential Equations (ODEs) . .6 1.3 Partial Differential Equations (PDEs) . 10 1.4 Historical Overview . 27 1.5 Problems . 36 2 Multiple Shooting Type Methods 39 2.1 Idea of Nievergelt in 1964 . 40 2.2 Multiple Shooting Methods in Time . 43 2.3 The Parareal Algorithm . 46 2.4 Problems . 72 3 Waveform Relaxation and Domain Decomposition 75 3.1 Method of Successive Approximations . 76 3.2 Classical Waveform Relaxation . 78 3.3 Problems . 85 1 Preface These lecture notes are an introduction to the emerging field of time parallel time integration. They correspond to a course taught by the author at the University of Geneva in fall 2018. The goal of the course was to introduce graduate students to this exciting field of research, and the notes are unique in three aspects: 1. they treat the four main classes of time parallel methods, namely shoot- ing type methods, waveform relaxation methods, time parallel multigrid methods and direct time parallel methods. 2. For each of the method classes, their historical development is carefully traced, and a complete convergence proof is given for one of the most modern variants of the methods. 3. The notes contain also runnable Matlab codes for the most representative methods. These notes should be useful to other teachers, because they allow the material to be taught with very little preparation, and all arguments are self contained. It is also possible to study the material independently and individually from these notes, without taking a course.