Computational and Applied Mathematics
Seminar
Fall 2009
Mondays 4:10 PM, 202 Carver unless otherwise
stated
Date
|
Speaker
|
Title
|
|
09/10(Thursday) |
Ornella Cominetti |
DifFUZZY: A novel fuzzy clustering algorithm for
complex data sets |
|
09/14 |
Zhijun
Wu (Mathematics, ISU) |
Solving
Distance Geometry Problems via Successive Subspace Optimization |
|
09/28 |
Alberto
Passalacqua (Department of Chemical and Biological Engineering, ISU) |
A
quadrature-based moment method for gas-particle
flows. Abstract is here |
|
10/05 |
Baskar Ganapathysubramanian
(Department
of Mechanical Engineering , ISU)
|
A
stochastic variational multiscale
framework for modeling flow through heterogeneous porous media
|
|
10/26 |
James
Evans (Department of Mathematics, and Ames
Lab) |
STATISTICAL
MECHANICAL AND MULTISCALE MODELING OF NON-EQUILIBRIUM PROCESSES AT SURFACES |
|
11/02 |
Hailiang Liu (Mathematics, ISU) |
Kinetic Models for Polymers with Inertial Effects |
|
11/20 3:30pm-4:15pm Carver 268 4:150m-5:00pm (Joint CAM & Math Colloquium) |
Tong Li (University of Iowa) Lihe Wang (University of Iowa) |
Stability of traveling waves arising
from chemotaxis Estimates
for Invariant Classes of Functions |
|
11/30 11:00am-11:50am |
Wen Zhang ( Oakland University) |
The
effect of imposing a corner condition on the evolution of two-dimensional
crystal morphologies by surface diffusion with anisotropic
surface free energies |
|
12/07 |
Wen Zhou (Mathematics, ISU) |
|
|
12/14 |
|
|
For
more information, please contact Hailiang Liu at hliu@iastate.edu or Paul Sacks at psacks@iastate.edu
Some schedules in past semesters: Spring 2008, Spring 2004 ||
Fall 2003
||CM Seminar Fall
2002
11/02
"Kinetic Models for Polymers with Inertial Effects"
Hailiang Liu
Iowa State University
Abstract: Novel kinetic models for both Dumbbell-like and rigid-rod like polymers are derived, based on the probability distribution function f(t, x, n, n' ) for a polymer molecule positioned at x to be oriented along direction n while embedded in a n' environment created by inertial effects. It is shown that the probability distribution function of the extended model, when converging, will lead to well accepted kinetic models when inertial effects are ignored such as the Doi models for rod like polymers, and the Finitely Extensible Non-linear Elastic (FENE) models for Dumbbell like polymers. Various mathematics issues involved in this area will be highlighted.
11/30
"The effect of imposing a corner condition on the
evolution of two-dimensional crystal morphologies by surface diffusion with
anisotropic surface free energies"
Wen Zhang
Oakland University
Abstract: Continuity of the chemical potential is required from
the physics of the evolution of crystal morphology by surface diffusion and in
equilibrium crystal shapes (ECS). With an anisotropic surface free energy,
multiple ECS with corners have been reported and instability developed in
computing evolution of crystal morphology. For a cornered ECS that minimizes
the total surface free energy, a corner condition is needed. Hence, in addition
to continuity of the chemical potential, we add the corner condition in the
evolution of crystal morphology and ensure the condition is satisfied in the
numerical computation of the evolving surfaces. The evolution is governed by a
nonlinear 4th order time dependent partial differential equation. By enforcing
the corner condition, we obtain better stability in the evolution, which leads toECS having lower total surface free energies than those
obtained previously without satisfying the corner condition. Our study shows
that the corner condition plays an important role for the cases of critically
and severely anisotropic surface free energies that yield surface corners and
facets.
11/20
"Stability of
traveling waves arising from chemotaxis "
Tong Li
University of Iowa
Traveling
wave (band) behavior driven by chemotaxis was
observed experimentally by Adler and was modeled by Keller and Segel. For a quasilinear
hyperbolic-parabolic system that arises as a non-diffusive limit of the Keller-Segel model with nonlinear kinetics, we establish the
existence and nonlinear stability of traveling wave solutions with large
amplitudes. The numerical simulations are performed to show the stability of
the traveling waves under various perturbations. This is a joint work with Zhi-an Wang at Vanderbilt
University.
11/20
"
Estimates for Invariant Classes of
Functions"
Lihe Wang
University
of Iowa
We
will talk about the classical DeGiorgi, Nash, Krylov and Safonov, as well as
Inverse H\"older theory from the point of view of invariant classes of
functions.