Registered Data

[CT094]

[02520] A direct method for solving a structured Sylvester equation

  • Session Date & Time : 2D (Aug.22, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : In this talk, we will present a pseudospectral method for 2D advection operators. After discretizing the 2D advection operator by the Legendre-Gauss-Lobatto pseudospectral methods, we obtain a Sylvester equation. The Sylvester equation is equivalent to a block tridiagonal liner system of equations. We propose a URV approach to solve the linear system.
  • Classification : 65F05, 65N35
  • Author(s) :
    • Yung-Ta Li (Fu Jen Catholic University)

[01042] Preconditioners of Reduced Dimension for Vector Field Problems

  • Session Date & Time : 2D (Aug.22, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : When designing preconditioners based on domain decomposition methods, the coarse space plays a key role. In order to keep the scalability, the coarse space of low computational complexity is essential. We introduce a new coarse space of reduced dimension for vector field problems. Numerical results for the problems in three dimensions are also presented.
  • Classification : 65F08, 65F10, 65N30, 65N55
  • Author(s) :
    • Duk-Soon Oh (Chungnam National University)

[01183] Development of algebraic preconditioners based on multiscale domain decomposition methods

  • Session Date & Time : 2D (Aug.22, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : This work presents a new algebraic formulation for the Multiscale Robin Coupled Method - MRCM. This domain decomposition method generalizes other mixed multiscale methods by imposing Robin-type boundary conditions on the local problems. The MRCM is flexible and accurate, obtaining near-optimal scalability up to billions of unknowns in high-performance simulations. We propose a new algebraic formulation, allowing the construction of multiscale-based preconditioners for solving non-symmetric linear systems with Krylov subspace methods, such as GMRES.
  • Classification : 65F08, 65N55, 65N08, 76S05
  • Author(s) :
    • Fabricio Simeoni de Sousa (University of Sao Paulo)
    • Franciane F. Rocha (Wikki Brazil)
    • Luca Meacci (Università degli Studi di Firenze)
    • Rafael T. Guiraldello (Piri Technologies LLC)
    • Roberto F. Ausas (University of Sao Paulo)
    • Gustavo C. Buscaglia (University of Sao Paulo)
    • Felipe Pereira (The University of Texas at Dallas)

[00544] Quantification of Entangled Bipartite Systems

  • Session Date & Time : 2D (Aug.22, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : Gauging the distance between a mixed state and its nearest separable state is important but challenging in the quantum mechanical system. We, in this talk, propose a dynamical system approach to tackle low-rank approximation of entangled bipartite systems, which has several advantages, including 1) A gradient dynamics in the complex space can be described in a fairly concise way; 2) The global convergence from any starting point to a local solution is guaranteed; 3) The requirement that the combination coefficients of pure states must be a probability distribution can be ensured; 4) The rank can be dynamically adjusted. The theory, algorithms, and some numerical experiments will be presented in this talk.
  • Classification : 65F10, 15A24, 65H10, 15A72, 58D19
  • Author(s) :
    • Matthew M. Lin (National Cheng Kung University)
    • Moody T. Chu (North Carolina State University)

[00734] PARALLEL-IN-TIME SOLVER FOR THE ALL-AT-ONCE RUNGE-KUTTA DISCRETIZATION

  • Session Date & Time : 2D (Aug.22, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : We present a fully parallelizable preconditioner for the all-at-once linear system arising when an implicit Runge-Kutta method is employed for the time discretization of evolutionary PDEs. The triangular preconditioner for the resulting $2 \times 2$ block linear system entails a block-diagonal solve for all the stages and for all the time-steps, and a Schur complement in which a new block-preconditioner for the stage solver, based on the SVD of the RK coefficient matrix, is introduced.
  • Classification : 65F10, 65M22, 65Y05
  • Author(s) :
    • Luca Bergamaschi (University of Padua)