The Department of Scientific Computing
at Florida State University presents
SCOTT MCKINLEY
Department of Mathematics
University of Florida
"Sensing and Decision-making in Random Search"
Thursday, April 18, 2013 2:00 P.M.
499 Dirac Science Library
Abstract
Many organisms locate resources in environments in which sensory signals
are rare, noisy, and lack directional information. Recent studies of search in
such environments model search behavior using random walks (e.g., Levy walks)
that match empirical movement distributions. We extend this modeling approach
to include searcher responses to noisy sensory data. The results of numerical
simulation show that including even a simple response to noisy sensory data
can dominate other features of random search, resulting in lower mean search
times and decreased risk of long intervals between target encounters. In particular,
we show that a lack of signal is not a lack of information. Searchers that receive no
signal can quickly abandon target-poor regions. On the other hand, receiving a
strong signal leads a searcher to concentrate search effort near targets. These
responses cause simulated searchers to exhibit an emergent area-restricted
search behavior similar to that observed of many organisms in nature.
The Department of Scientific Computing
at Florida State University presents
HYUNG-CHUN LEE
Director, Center for Applied Analysis and Scientific Computations
Professor, Department of Mathematics
Ajou University, Korea
"A sparse collocation method for an optimal control problem of SPDE"
Thursday, January 31, 2013 3:30 P.M.
499 Dirac Science Library
Abstract
In this talk, we propose and analyze a stochastic collocation method for
solving optimal control problems for elliptic partial differential equations
with random coefficients and forcing terms. These input data are assumed
to depend on a finite number of random variables. We prove existence
of optimal solution and derive an optimality system. In the method, we use
a Galerkin approximation in space and a sparse grid collocation in the
probability space. We provide error estimates for fully discrete solution
using an appropriate norm and analyze the computational efficiency.
Computational evidence complements the present theory and shows the
effectiveness of the sparse grid stochastic collocation method.