Time and Location: Friday, 3:004:00PM, ACE 6.304. Special time and locations are indicated in color.
If you are interested in meeting a speaker, please contact Kui Ren (ren@math.utexas.edu)
Here are the links to the past seminars: Fall 2012, Spring 2012, Fall 2011, Spring 2011, Fall 2010, Spring 2010, Fall 2009
Dates 
Spekers 
Title and Abstract 



01/25/13 Friday 2:003:00PM 
Alessandro Munafo (Von Karman Institute, Belgium) 
Multiscale Models and Computational Methods for
Nonequilibrium Aerothermodynamics 
01/29/13 Tuesday 3:304:30PM 
Thierry E. Magin (Von Karman Institute, Belgium) 
Multicomponent transport algorithms for plasmadynamics models A new formalism for the transport properties of partially ionized plasmas is investigated from a computational point of view. Wellposedness of the transport properties is established, provided that some conditions on the kinetic data are met. The mathematical structure of the transport matrices is readily used to build transport algorithms that rely either on a direct linear solver or on convergent iterative Krylov projection methods, such as the conjugate gradient. Air and carbon dioxide mixtures in local thermodynamic equilibrium at atmospheric pressure serve as benchmark to assess the physical model and numerical methods. Superiority of the conjugate gradient method with respect to the direct solver and approximate mixture rules found in the literature is demonstrated in terms of accuracy and computational cost. 
03/04/13 Monday 2:003:00PM RLM 11.176 
Fons ten Kroode (Shell Global Solutions International BV, The Netherlands) 
A WaveEquationBased Kirchhoff Operator In this talk, I will study a Kirchhofftype integral, which can be seen as a linear operator mapping angle–azimuthdependent reflection coefficients along a reflector into reflection data for the acoustic wave equation. I will show that a minor adaptation of a construction of angle–azimuthdependent images as proposed by Sava and Fomel leads to a left inverse of this operator, which maps primary reflection data to angle–azimuthdependent reflection coefficients. The new construction naturally leads to a reformulation of the Kirchhoff operator, acting on spaceshiftextended images, which can be implemented completely in terms of the fundamental solutions of the wave equation. I will study the composition of this new waveequationbased Kirchhoff operator with an operator forming spaceshiftextended images from data. I will show that these operators are partial inverses of each other, with their compositions being pseudodifferential operators that reconstruct suitably microlocalized versions of primary reflection data and extended images focused at spaceshift zero. 
03/29/13 Friday 
Jose Rodriguez (UC Berkeley) 
Numerical Algebraic Geometry in Statistics Maximum likelihood estimation is a fundamental computational task in statistics and involves beautiful geometry. We discuss this task for determinantal varieties (matrices with rank constraints) and show how numerical algebraic geometry can be used to maximize the likelihood function. Our computational results with the software Bertini led to surprising conjectures and duality theorems. This is joint work with Jan Draisma, Jon Hauenstein, and Bernd Sturmfels. 



04/12/2013 Friday 
Yuri Kuznetsov (University of Houston) 
Mixed Finite Element Method with Piecewise Constant Fluxes In this presentation, we consider a new mixed finite element method for diffusion equations on general polygonal/polyhedral meshes. Originally the method was invented in 2007.Then it was used in a number of projects supported by ExxonMobil URC. The main idea of the method is based on the approximation of the fluxes by piecewise constant vector functions (PWCF).The normal components of the approximate vector functions are continuous on the interfaces between polyhedral mesh sells. In the interior of mesh cells these vector functions are discontinuous. The error estimates for the special type of meshes are derived. We discuss applications of the PWCFmethod in geosciences as well as numerical results. 



04/26/13 Friday 
Ammar Hakim Princeton Plasma Physics Laboratory 
Aspects of Discontinuous Galerkin Schemes for Fluid
and Kinetic Simulations of Plasmas 




















