Events for 02/20/2018 from all calendars
Numerical Analysis Seminar
Time: 3:00PM - 4:00PM
Location: BLOC 220
Speaker: Dmitri Kuzmin, Dortmund University of Technology
Title: Bounds-preserving limiters for continuous high-order finite element discretizations of hyperbolic conservation laws
Abstract: In this talk, we constrain high-order finite element approximations to hyperbolic conservation laws using localized corrections to enforce discrete maximum principles. The use of Bernstein basis functions ensures that numerical solutions stay in the admissible range. The design of accuracy-preserving FCT schemes for high-order Bernstein finite elements requires a major revision of algorithms designed for low-order Lagrange elements. In this talk, we discretize the linear advection equation using an element-based FCT algorithm which features: (i) a new discrete upwinding strategy leading to variation diminishing low-order approximations with compact stencils, (ii) a high-order stabilization operator based on the divergence of the difference between two gradient approximations, (iii) localized limiters for antidiffusive element contributions, and (iv) an accuracy-preserving smoothness indicator that allows violations of strict maximum principles at smooth peaks. Additionally, we present limiters that constrain artificial diffusion coefficients or the difference between finite element basis functions corresponding to high-order and piecewise-linear approximations. Extensions of FCT to hyperbolic systems will also be discussed. This is joint work with C. Lohmann, J.N. Shadid, S. Mabuza, and Manuel Quezada de Luna
Analysis/PDE Reading Seminar
Time: 4:00PM - 5:00PM
Location: BLOC 624
Speaker: Parker Duncan, TAMU
Title: A study of uniform infinite planar triangulations II
Abstract: We study the convergence of the weak limit of uniform measures on rooted triangulations of the sphere and prove the one endedness of the UIPT.