
Pauline van den Driessche
Mon Apr 18, 2016
4:00 pm
Spatial heterogeneity of both humans and water may influence the spread of cholera, which is an infectious disease caused by an aquatic bacterium. To incorporate spatial effects, two models of cholera spread are proposed that both include direct (rapid) and indirect (environmental/water) transmission. The first is a multigroup model and the...

Alex Townsend
Mon Apr 11, 2016
4:00 pm
We synthesize the double Fourier sphere method and
low rank function techniques to develop a collection of
fast numerical algorithms for computing with functions based
on the fast Fourier transform. Furthermore, by imposing certain
partial regularity conditions on the solutions of PDEs we derive
optimal...

Albert Chern
Mon Apr 4, 2016
4:00 pm
Simulation of incompressible fluids is widely used for studies of fluid mechanics and for visual effects in computer graphics. One major challenge is to capture dynamics of thin vortices in finite grid resolution. We describe a new approach to the simulation of incompressible fluids in 3D. In it, the fluid state is represented by complexvalued...

Shidong Jiang
Mon Mar 28, 2016
4:00 pm
We present a second kind integral equation (SKIE) formulation
for calculating the electromagnetic modes of optical waveguides,
where the unknowns are only on material interfaces. The resulting numerical
algorithm can handle optical waveguides with a large number of inclusions of
arbitrary irregular cross section. It is capable of finding the...

Cheng Wang
Tue Mar 15, 2016
3:00 pm
A second order energy stable numerical scheme is presented for the two and three dimensional CahnHilliard equation, with Fourier pseudospectral approximation in space. The convex splitting nature assures its unique solvability and unconditional energy stability. Meanwhile, the implicit treatment of the nonlinear term makes a direct nonlinear...

Richard Peng
Mon Mar 14, 2016
4:00 pm
We introduce the sparsified Cholesky and sparsified multigrid
algorithms for solving systems of linear equations. These algorithms
accelerate Gaussian elimination by sparsifying the nonzero matrix
entries created by the elimination process.
We use these new algorithms to derive the first nearly linear time
algorithms for solving systems of...

Oleg Igoshin
Mon Feb 29, 2016
4:00 pm
Gene regulatory networks controlling cellular differentiation must sense changes in environmental conditions and coordinate gene expression with celldivision cycles. However, the mechanisms of sensing and integrating different signals remain elusive even for the best studied model systems. Here we uncover a simple solution to this complicated...