Division of Applied Mathematics

Seminars for Nov 15 - Nov 19, 1999

---

• Monday, November 15, 1999
  
  

  Special PDE Seminar

  Speaker:	Cedric Villani, ENS & Georgia Tech
  Title:	On the Trend to Equilibrium for Space-Dependent, Entropy-Dissipating Systems
  Time/Place:	3:00 p.m., 182 George Street Room 110

  Lefschetz Center for Dynamical Systems Seminar

  Speaker:	Jeffrey Weiss, University of Colorado
  Title:	Coherent Structures in Geophysical Turbulence
  Time/Place:	4:00 p.m., B&H 155

  Brown University Center for Statistical Sciences Seminar

  Speaker:	Xihong Lin, Associate Professor of Biostatistics, Department of Biostatistics School of Public Health, University of Michigan
  Title:	Is Correct Specification of Correlation Always the Best Strategy for Analyzing Clustered Data? Nonparametric and Semiparametric Regression
  Time/Place:	4:00 p.m., Arnold Lab, 97 Waterman Street. 4th Floor Conference Room,   (Refreshments at 167 Angell St., 2 floor conference room right after seminar.) *Sponsored by the C. V. Starr Foundation Lectureships Fund

  Abstract:   We consider nonparametric and semiparametric regression estimation for clustered data using estimating equations. The first half of the talk discusses the use of the kernel method for nonparametric regression with a single covariate. We show that it is generally the best strategy to ignore entirely the correlation structure within each cluster, and instead to pretend that all observations are independent. Correctly specifying the correlation structure in fact results in an asymptotically less efficient estimator. The second half of the talk extends nonparametric regression to semiparametric regression for clustered data where some additional covariates effects are modeled parametrically using the profile/kernel estimating equations. We show that correct specification of the correlation structure leads to inconsistent estimates of the finite dimensional parameteric parameters. Consistent estimates of both the parametric and nonparametric parameters require completely ignoring the within-cluster correlation. We apply the proposed methods to the analysis of the AIDS Costs and Services Utilization Survey. This is a joint work with Ray Carroll.

• Wednesday, November 17, 1999
  
  

  Brown Applied Mathematics Pattern Theory and Vision Seminar

  Speaker:	David Laidlaw, Computer Science Department, Brown University
  Title:	Partial Volume Classification of MR Images using Voxel Histograms
  Time/Place:	4:00 p.m., 182 George Street, Room 110

  Brown Analysis Seminar

  Speaker:	Toma Tonev, University of Montana
  Title:	Inductive Limits of Classical Uniform Algebras
  Time/Place:	4:00 p.m., Kassar 105   (Coffee at 3:30 p.m.)

• Thursday, November 18, 1999
  
  

  TURKEY TALK - Applied Mathematics Colloquium

  Speaker:	Professor Philip J. Davis, Brown University, Division of Applied Mathematics
  Title:	Four Questions About Mathematics and Society
  Time/Place:	4:30 p.m., B&H 158 - Refreshments at 4:00 p.m. in 182 George Street, Room 110

  Abstract:   The speaker will discuss four questions selected from a number submitted to him by both faculty and students. After a ten minute discussion of each question by the speaker, there will be a five minute period for audience response.

• Friday, November 19, 1999
  
  

  Scientific Computing Seminar

  Speaker:	Olga Lepsky, Brown University, Department of Mathematics
  Title:	Spectral and Pseudospectral Viscosity Method for the Nonlinear Hamilton-Jacobi Equation
  Time/Place:	11:00 a.m., 182 George Street, Room 110

  Abstract:   Hamilton-Jacobi equation arise in many areas of application, e.g. calculus of variations, control theory, differential games, image processing. Its generalized solutions are Lipschitz continuous, but may have discontinuous derivatives.

  In this talk I will present the numerical solution of the Hamilton-Jacobi initial boundary value problem by the spectral/pseudospectral viscosity method. This method may be considered as a compromise between the vanishing viscosity approximation and the usual spectral/pseudospectral method.

  I will prove that the numerical solution is formally spectral accurate and converges to the exact unique viscosity solution. I will also show some numerical simulations.

  PDE Seminar

  Speaker:	Jean-Michel Roquejoffre, Univeristy of Toulouse
  Title:	Analogy with the Porous Medium Equation in an Oblique Derivative Problem for the Heat Equation
  Time/Place:	3:00 p.m., Kassar 105

  Department of Mathematics Colloquium

  Speaker:	John Holbrook, University of Guelph, Canada
  Title:	Variations on a Theme by Von Neumann
  Time/Place:	4:30 p.m., Kassar 105

  <---   1999  Index

• Seminars and Events Page

DAM Home Page

Questions and comments to:   webmaster@dam.brown.edu