(Link to CAM seminar talks in Spring, 2007)
(Link to CAM seminar talks in Fall, 2006)
(Link to CAM seminar talks in other years.)
(Link to Numerical Analysis Group Webpage)
| August 29 | Organizational Meeting
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| September 5 |
Hongguo Xu
University of Kansas An eigenvalue approach to a Riccati equation from transport theory Abstract We consider the entrywise least positive solution of a nonsymmetric Riccati equation that is from an integro-differential equation in transport theory. We formulate the solution in terms of the eigenvalues of an associated structured matrix. With the formulas we provide some new properties of the solution. We also give a numerical method that computes the solution with high accuracy. This talk is based on a joint work with Volker Mehrmann. | |||||||||||||||||||||||||||||
| September 12 |
None Scheduled
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September 19 |
Mike Jolly
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Indiana University Averaged bounds on moments for the 2D Navier-Stokes equation Abstract Upper and lower bounds for the ensemble averages of energy, enstrophy, and palinstrophy (the first three moments of the 2D, periodic, Navier-Stokes equations) are derived both in the general case, and in the case where the energy spectrum for fully developed turbulence holds. In the turbulent case, the bounds are sharp, up to a logarithm, and provide a new lower bound on the Landau-Lifschitz degrees of freedom. A key Sobolev-type estimate of the inertial term is shown to be sharp on a significant portion of the global attractor.
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September 26 |
Aslihan Demirkaya
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University of Kansas The Existence of a Global Attractor for Kuramoto-Sivashinsky Equation Abstract
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October 3 | Milena Stanislavova
| University of Kansas On the Kuramoto-Sivashinsky equation in $R^1$ and $R^2$ Abstract We consider the Kuramoto-Sivashinsky equation in finite domains of the form $[-L,L]^d$. Our first result deals with the two dimensional model and provides an explicit criteria for (eventual) blow-up in terms of its $L^2$ norm. Our other result provides refined Gevrey estimates for the solutions of the 1 D differentiated KS, which in turn imply new estimates for higher Sobolev norms of the solutions in terms of powers of $L$. The common underlying idea in both results is that {\it a priori} control of the $L^2$ norm is enough in order to conclude higher order regularity.
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October 17 |
Weishi Liu
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University of Kansas Viscous standing asymptotic states of isentropic compressible flows through a nozzle Abstract In this talk, we will discuss some results on a well-know one-dimensional model for isentropic viscous compressible flows through a nozzle. More precisely, a complete characterization for the existence and multiplicity of standing asymptotic states will be given for a special type of nozzles. As an application of the geometric singular perturbation theory, we also show that all the standing asymptotic states admit viscous profiles. The talk is based on a joint work with J. Hong and C.-H. Hsu.
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October 24 |
Jude Kastens
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Kansas Applied Remote Sensing Program Floodplain Identification Using Gridded Elevation Data Abstract Floodplain identification using elevation data is complicated by (1) local topographic variability, and (2) the gradual downhill trajectory of the stream course. Traditional methods for floodplain delineation require the parametrization and numerical solving (optimization) of a system of coupled, 1-D flow equations along a series of floodplain cross sections. Such models suffer three shortcomings: (1) the required approximation of stream geometry does not fully utilize the available topographic information; (2) acquisition/estimation of the many required inputs can be prohibitive; and (3) professional experience is required for manual, iterative model adjustment until an acceptable, physically reasonable result is obtained. We introduce a deterministic, two-parameter algorithm for floodplain identification using gridded elevation data. The method is time independent and is based on simple, pixel-level surface flow properties. It alleviates the three problems listed above, yet produces reasonable results.
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October 31 |
No talk scheduled
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November 7 |
No talk scheduled
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November 14 |
No talk scheduled
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November 28 |
No talk scheduled
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December 5 |
Speaker 12
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