Department of Mathematics and Statistics Calendar
February 14 - 20, 2005

Monday, February 14, 2005


Tuesday, February 15, 2005

10:45 AM    MATH 115 Instructors Meeting   400 MSc


Wednesday, February 16, 2005

10:30 AM    Algebra Seminar   400 MSc
             Dr. Corneliu HOFFMAN, BGSU
             "Flips for Algebraic Groups, II"

11:30 AM    Statistics Seminar   **140 MSc** *note location change*
	    Dr. N. BALAKRISHNAN, Visiting Lukacs Professor
             "Progressive Censoring V: Goodness-of-Fit Tests"

12:30 PM    Calculus Seminar   459 MSc
             TBA

3:30 PM     Analysis Seminar   400 MSc
             Dr. Juan BES, BGSU
             "TBA"

**3:30 PM  Statistics Candidate Colloquium**   459 MSc
             "Robust Estimation via Measurement Error Model
	    Likelihoods with Applications to Location-Scale Models"


Thursday, February 17, 2005

**3:30 PM Statistics Candidate Colloquium**   459 MSc
            "Diagnostic Measures and Selection Criteria for
             Mixed Models Based on Kullback-Leibler Information"
ABSTRACT:  This talk consists of two parts. In the first part, a
diagnostic defined in terms of the Kullback-Leibler directed divergence
is developed for identifying cases which impact the prediction of the
random effects in a mixed model. The diagnostic compares two 
conditional densities governing the prediction of the random effects: 
one based on
parameter estimates computed using the full data set; the other based 
on parameter estimates computed using a case-deleted data set. We 
present
the definition of the diagnostic and a computational formula for its
evaluation.  We illustrate the effectiveness of the measure using a
simulated data set. The performance of the measure is also investigated
in an application where exam scores are modeled using a mixed model
containing a fixed exam effect and a random subject effect.
      In the second part, we extend the results of Shibata (1997) to
propose five bootstrap-corrected variants of AIC, denoted by AICb1-AICb5,
for the purpose of small-sample mixed model selection. These variants 
are asymptotically equivalent, and provide asymptotically unbiased 
estimators
of the expected Kullback-Leibler discrepancy between the true model and a
fitted candidate model. The performance of the criteria is investigated in
a simulation study where the random effects and the errors for the true
model are generated from a Gaussian distribution. Parametric,
semiparametric, and nonparametric bootstrapping are employed. Our 
results indicate that under parametric bootstrapping, the variants 
exhibit the best overall bias properties. For correctly specified or 
overfit models, the criterion originally introduced by Efron (1983, 
1986), AICb1, provides a
less biased estimator of the expected discrepancy than AIC and the 
other proposed variants. The criterion originally introduced by 
Cavanaugh and
Shumway (1997), AICb2, exhibits a higher success rate in identifying the
correct model than AIC and the other variants. Overall, the bootstrap 
AIC variants appear to serve as effective tools for selecting a mixed 
model of appropriate dimension.


Friday, February 18, 2005

**12:00 PM  Calendar Information due to Cyndi
           for inclusion in next week's calendar listing**

**1:30 PM Director of Service Mathematics Candidate Colloquium**
             459 MSc
	    "Wavelets, Multiscale Analysis and Their Applications"
ABSTRACT:  We begin with a brief overview of wavelet analysis. We then
compare wavelet transforms with Fourier transforms and state their
properties. Multiresolution analysis provides a natural framework of 
the construction of wavelets. We describe its insight by an 
illustration from a coarse approximation to a higher resolution 
approximation. The computational efficiency and accuracy of the 
multiscale methods have allowed us to make improvements in many 
applications.  Several wavelet based multiscale computational methods 
will be introduced. Applications on image processing
and numerical solutions of partial differential equations will be mentioned.


Saturday, February 19, 2005


Sunday, February 20, 2005

A list of mathematics seminars by subject and other seminars at BGSU is available  here.

If you have comments or material for the calendar, send e-mail to Cyndi Patterson,

If you wish to be placed on the e-mail distribution list, send e-mail to Craig Zirbel,

Previous calendars are available individually or in one single file for searching.

Return to Math & Stat Home Page / BGSU Welcome Page

/ / Disclaimer