Search for Time accuracy: A Variable Time-stepping Algorithm for Computational Fluid Dynamics

Speaker: Wenlong Pei (OSU) Dates: 2022/12/01 Abstract: Dahlquist, Liniger, and Nevanlinna proposed a two-step time-stepping scheme for systems of ordinary differential equations (ODEs) in 1983. The little-explored variable time-stepping scheme has advantages in numerical simulations for its fine properties such…

Investigating Stability for Implicit-Explicit Discontinuous Galerkin Methods (IMEX-DG) on the Linear Convection-Dispersion Equation

Speaker: Joseph Hunter (OSU) Dates: 2022/10/20 Abstract: In this talk we will introduce the Local Discontinuous Galerkin for a linear convection-dispersion PDE. The stability of this method when paired with an Implicit-Explicit Runge-Kutta time-stepping method will be investigated using the…

Bayesian Radar Image Formation

Speaker: Victor Churchill (OSU) Dates: 2022/10/27 Abstract: In this talk, I will present a Bayesian approach to the inverse problem of radar image formation. We will formulate a posterior distribution that has desirable properties with respect to specifics of radar…

Butterfly Factorization and Butterfly-Net: from Numerical Linear Algebra to Machine Learning

Speaker: Zhongshu Xu (OSU) Dates: 2022/10/06 Abstract: Butterfly Factorization is a data-sparse nearly optimal approximation for the discrete Fourier Integral Operator (FIO) matrices. It is constructed based on interpolative low-rank approximations of the complementary low-rank matrix. For an N √óN…

Runge-Kutta discontinuous Galerkin(RKDG) methods and cRKDG

Speaker: Qifan Chen (OSU) Dates: 2022/09/29 Abstract: Discontinuous Galerkin methods (DG methods) form a class of numerical methods for solving differential equations. They combine features of the finite element and the finite volume framework and have been successfully applied to…

Interface Problems and Immersed Finite Element Methods

Speaker: Yuan Chen (OSU) Dates: 2022/09/22 Abstract: In this talk, we introduce PDE interface problems and their applications. A brief picture of Immersed Finite Element Method (IFEM) for interface problems will be sketched. Upon sharing the basic ideas and theoretical…