Brown University Joint Seminar
Department of Neuroscience, Division of Biology and Medicine and
Division of Applied Mathematics
***Dr. Crook is a candidate for a faculty position in the Department of Neuroscience and the Division of Applied Mathematics. If you wish to meet with Dr. Crook contact Susan Troy at X3-9524. Please send written comments to: J. Donoghue, Theoretical Search Committee, Box 1953, John_Donoghue@brown.edu |
Lefschetz Center for Dynamical Systems Seminar
Abstract: What semiconductor laser theory, fiber optics, surface water waves and acoustic waves have in common? Although these systems are seemingly disconnected and have quite different physical nature, they can be viewed as complex systems composed out of interacting particles or waves. There is a general theoretical framework for their statistical description, called weak turbulence theory. One can obtain a closed equation describing the time evolution of such systems, called kinetic equation. I will explain what classes of stationary solutions kinetic equation has, and how understanding of surface water waves can lead to better design of semiconductor lasers.
***NEW ANNOUNCEMENT ***
LEMS and Pattern Analysis Seminar
Abstract: Aligning experimental data into a standard coordinate system (SCS) is of great interest to neuroimaging science, and a necessary tool in support of genomics efforts for gene expression. Multimodality imaging, noisy data and transformations are frequent difficulties. Geometric based alignments carry across-multimodalities, yet have to be well structured to handle the noisy/occluded data. In this work, we introduce a non-iterative geometric-based method to align 3D brain surfaces into standard coordinate system (SCS), which is based on a novel set of surface landmarks (e.g., planar embilical points, zero torsion points, etc..), which are intrinsic and are computed from the differential geometry of the surface. This is in contrast to existing methods that depend on anatomical landmarks that require expert intervention to locate -- a very hard task. The landmarks are local, and are preserved under affine transformations. To reduce the sensitivity of the landmarks to noise, we use a B-Spline surface representation that smoothed out the surface prior to the computation of the landmarks. The alignment is driven by establishing correspondences between the landmarks after a conformal sorting based on derived absolute invariants (volumes confined between parallelepipeds spanned by sets of the landmark point quadruplets). The method is tested for intra- and inter-brain alignments while entertaining cubic nonlinear transformations.
Brown University Center for Statistical Sciences Seminar
No Seminar This Week
Brown University Joint Seminar,
Department of Neuroscience, Division of Biology and Medicine and Division of Applied Mathematics
***Dr. Reinagel is a candidate for a faculty position in the Department of Neuroscience. If you wish to meet with Dr. Reinagel contact Susan Troy at X3-9524. Please send written comments to: J. Donoghue, Theoretical Search Committee, Box 1953, John_Donoghue@brown.edu |
Brown University, Applied Mathematics Pattern Theory and Vision Seminar
Special PDE Seminar
Brown Analysis Seminar
*** NEW ANNOUNCEMENT ***
Scientific Computing Seminar
Abstract: A new type of multigrid methods, the so-called Cascadic Multigrid is presented. It performs only iterations on each grid space and requires no coarse grid corrections at all that may be viewed as a one-way multigrid. The convergence accuracy as well as the computational complexity will be discussed for various conforming or nonconforming finite element discretizations and for different iterative smoothers.
Scientific Computing Seminar
Abstract: In this talk, we will review some recent studies of turbulence physics using numerical simulation data bases. In particular, we will study the fundamental measurements of turbulence, such as the energy spectra, transfer functions, interacting scales, and isotropy. Special attention will be focused on the response of small scale turbulence to large scale anisotropy forcing and the development of quasi-two dimensional turbulence for strongly rotating flows. We will demonstrate that the knowledge of detailed energy transfer will be helpful in the subgrid modeling efforts for large-eddy simulations.
PDE Seminar
Department of Mathematics Colloquium
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