CS 455/CSE 411/MATH 455: Final Guide, Spring 2008

Final Exam, Wednesday, May 7th, 2008, 7 - 10 PM, in 1302 Siebel Center

General Advice: The exam will consist of questions over Sections 2.1 - 4.9, 6.1 - 6.6 of Morton & Mayers; Sections II.1 - II.8, IV.1 - IV.4, V.1, V.6 of Braess; General PDE Notes; Parts 1 - 6 of the Morton & Mayers Finite Difference Notes; Parts 1 - 6 of the Braess Finite Element Notes. To help you study, a list of specific key topics is listed below.

[1] General Introduction to PDEs

  • Classification of first order PDEs
    Linear vs. Quasilinear vs. Nonlinear
  • Classification of second order PDEs
    Linear vs. Quasilinear vs. Nonlinear
    Elliptic vs. Parabolic vs. Hyperbolic
    Time dependent vs. independent
    Steady State vs. No Steady State
  • Example PDEs:
    Advection Equation, Laplace Equation
    Heat Equation, Wave Equation
  • Definitions:
    Well Posed
    Characteristic
    Domain of Dependence
    Range of Influence
  • How to Compute:
    Characteristics of a first-order PDE
    Characteristics for the wave equation

[2] M&M Parabolic in 1D

  • Heat Equation:
    Exact solution
  • Finite Differences:
    Forward vs. Backward vs. Centered
    Accuracy using Taylor Series
  • Numerical Methods:
    Explicit Method, Implicit Method
    Theta Method, Crank Nicolson
    Method of Lines
  • Error and Stability Analysis:
    Truncation Error
    Fourier Analysis
    Maximum Principle
    Global error vs. Truncation Error
  • Boundary Conditions:
    Dirichlet, Neumann, Robin
  • More general Parabolic problems:
    Setup explicit/implicit methods
    Cost of each timestep
    Upwind scheme
  • How to compute:
    Stability using Fourier
    Convergence using maximum principle
    One step with an explicit method

[3] M&M Parabolic in higher dimensions

  • Stability of Methods:
    Explicit vs. Crank Nicolson vs. ADI
  • Accuracy of Methods:
    Explicit vs. Crank Nicolson vs. ADI
  • Cost of Methods:
    Explicit vs. Crank Nicolson vs. ADI
  • More general boundaries:
    Dirichlet on a curved boundary
  • How to Compute:
    Stability using Fourier
    One step with an explicit method
    Discrete equations at curved boundary

[4] M&M Hyperbolic Problems

  • Stability:
    Characteristics
    Courant-Friedrich-Lewy (CFL)
    Domain of Dependence
  • Fourier Analysis:
    Upwind Method
    Centered Difference
  • Existence and Uniqueness
    Crossing of Characteristics
    Conservation form
    Weak solution in conservation form
    Shock speed from conservation form
  • Numerical method properties:
    Upwind Method, Lax-Wendroff
  • Know how to compute:
    One step with an explicit method
    Stability using Fourier
    Crossing time of characteristics
    Conservation form
    Shock speed

[6] M&M Elliptic Problems

  • Discretization:
    Centered difference scheme
    Sparse structure of equations
    Local order of accuracy
  • Global convergence:
    Comparison function
    Conditions for Theorem 6.1
    Result for curved boundaries
    Result for Neumann boundary conditions

[B1] Weak Formulation I

  • Definitions:
    Functional
    Vector space
    Inner Product
    Norm
    Cauchy Sequence
    Complete Vector Space
    Hilbert Space
    L2 space
    Cauchy-Schwarz inequality
    Weak Derivative
    Sobolev spaces
    Poincare-Friedrichs inequality
    Quadratic Functional
    Directional Derivative
    Stationary Point
  • Concept of Completion:
    Is C(k) complete?
    Is H(k) complete?
  • Riesz Representation Theorem:
    Statement and Conditions
  • Lax-Milgram Lemma:
    Statement and Conditions

[B2] Weak Formulation II

  • Euler-Lagrange Equations:
    Derive from a quadratic functional
    Strong Form vs. Weak Form
    Derivation in 1d/2d/3d
    Gauss divergence Theorem
    Integration by parts in 2d/3d
    Sobolev Spaces in 2d/3d
    Possibility of singular functions
    Lipschitz domain
    Poincare-Friedrichs in 2d/3d
    Trace Theorem
    Cone Condition
  • Boundary Conditions:
    Natural vs. Essential Boundary conditions
    How to impose boundary conditions in minimization form

[B3] Ritz-Galerkin Method

  • Problem formulation:
    Derive minimization form from a(u,v) = G(v)
    Derive a(u,v) = G(v) from strong form
    Derive discrete equations from a(u,v) = G(v)
  • Triangular Finite Element mesh:
    Piecewise linear basis functions
    Mapping to standard triangle
    Assembly of linear system
    When is numerical quadrature necessary?
    Midpoint quadrature rule
    Non-homogeneous Boundary Conditions

[B4] Error Estimates

  • Definitions:
    C(k) finite elements
    Conforming Mesh
    Element diameter
    Mesh diameter
    Shape regular
    Uniform mesh
  • Theorems:
    How smooth are H(k) functions?
    Finite element approximation is bounded
    Céa's Lemma
  • Higher-Order Finite Elements:
    Nodal basis
    Interpolation error for H(k) in L2-norm

[B5] Iterative Methods

  • Nonlinear Problems:
    Nonlinear weak form
    Linearized bilinear form
    Newton's method
  • Solving linear systems:
    Fixed point theorem
    Jacobi Iteration
    Gauss Seidel Iteration
    Diagonally Dominant
    Reducible
    Properties of CG

[B6] Multigrid

  • Multigrid V-Cycle:
    Frequency of Error on Grids
    Restriction
    Prolongation
    Definition of Coarse Problem

Last Updated: 27-Apr-08
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