| Date (most recent first) | Title and Speaker |
| December 2005 | |
| 12/13/05 5:30 PM Bentley |
Internship Evening. Presentations by math/stat students about their internship experiences in area businesses and agencies. Click here for more information. |
| 12/10/05 12 Noon Kay Center |
To Infinity and Beyond. An original play by the Fall 2005 Honors Calculus Class. Click here for more information. |
| 12/6/05 3:35 pm |
An Introduction to Topological Quantum
Field Theory.
This event has been cancelled. Artur Elezi, AU |
| November 2005 | |
| 11/29/05 3:35 pm |
Using Business-Style cases in an Introductory Statistics Course Eduardas Valaitis, AU Most institutions of higher learning in the United States offer introductory statistics courses in a variety of flavors. Integration of the subject-specific concepts with the basic applied statistical techniques should be the primary goal of these flavored courses. Solely lecture-based traditional instruction method is not suitable to satisfying this objective. We argue for the incorporation of business-style cases into the introductory statistics curriculum using Constructivist learning theory and the notion of the "liberal arts" education. A typical business case setup is presented and its compatibility with an introductory statistics course is assessed. Finally, a sample business-style case for the application of simple linear regression is provided. |
| 11/15/05 3:35 pm |
Is Abstraction Really Necessary in Mathematics?
Ali Enayat, AU This presentation will share some favorite examples of the use of highly abstract machinery to solve concrete problems from combinatorics and number theory. It will also address, using a framework provided by mathematical logic, whether one can prove that the use of such machinery is really necessary. The talk is designed to be accessible to undergraduate mathematics majors. |
| 11/8/05 3:35 pm |
When Does Raking Converge? Jill Montaquilla, Westat and the Joint Program in Survey Methodology Raking, also called iterative proportional fitting (IPF), was proposed by Deming and Stephan (1940) as a way to ensure consistency between complete counts and sample data from the 1940 U.S. Census of population. Raking is now widely used in estimation from complex sample surveys. The raking algorithm is an iterative approach that consists of a sequence of adjustments of weighted totals to external totals on more than one dimension. The algorithm iterates until weighted totals converge to the external totals for all the dimensions (marginal distributions) simultaneously. In working with a variety of surveys that use raking at Westat, we have encountered some issues and concerns with the procedure. In this presentation, I will give an overview of raking and discuss some of the issues the procedure presents. In particular, I will describe problems with convergence. Although my application is in the area of survey sampling, this is a more general computational problem with other applications. |
| October 2005 | |
| 10/28/05 7:30pm |
Mathemagic: The Art of Mental Calculation Dr. Arthur Benjamin, Harvey Mudd College This is a special appearance by a world famous mathemagician, who will show you his secrets for calculator beating mental feats. The public performance in Ward Hall room 1 will be followed by a reception and Halloween Party in Gray Hall. Halloween costumes are encouraged. For full details click here. |
| 10/25/05 3:35 pm |
The field of Biostatistics and its shortage
in the scientific community. Misrak Gezmu, NIH The importance and demand for biostatistics expertise in Public Health and medical research has increased over the last several years. The demand for biostatisticians is rising while the number of Masters and Doctoral-level graduates remains the same. This opens lots of job opportunities for future biostatisticians. This talk also will introduce students to the field of Biostatistics and describe what biostatisticians do. Examples of clinical trials in HIV/AIDS will be discussed. |
| 10/14/05 2:00pm |
Combinational Aspects of
Moduli Spaces of Curves Dr. Carel Faber, The Royal Institute of Technology (Kungliga Tekniska Högskolan), KTH, and Johns Hopkins University Dr. Faber will give an introduction to current research on moduli spaces of curves in which combinatorics plays an important role. Dr Faber will also discuss several open problems that can be formulated in mostly elementary terms. |
| September 2005 | |
| 9/20/05 3:35 PM |
Envelopes, Ladders, and Couches: an old topic gives a new look to an old problem Dan Kalman, AU The ladder problem is to find the longest segment that can fit around a corner in a corridor. The couch problem is similar, but you have to move a rectangle instead of a segment. The first is a standard max/min problem in calculus books, and the traditional solution begins with a reversal: instead of looking for the longest segment that WILL go around the corner, we seek the shortest segment that WON'T. But there is a direct approach that is both much simpler and gives much better understanding. This direct approach uses envelopes of families of curves, a topic that was once a standard part of the undergraduate math curriculum, but which (sadly) seems to have disappeared. |
| April 2005 | |
| 4/26/05 3:35 PM |
Smoothly Truncated Stable Distributions, GARCHModels, and Option
Pricing Christian Menn, Cornell Abstract (PDF format) |
| 4/19/05 3:35 PM |
Modeling Interference in Wireless Networks with Stable Distributions Michael Souryal, NIST Abstract (PDF format) |
| 4/5/05 3:35 PM |
Metamathematics Kent Miller, American University Abstract (PDF format) |
| March 2005 | |
| 3/29/05 3:35 PM |
Finding Structure in Data Streams William Szewczyk, National Security Agency Abstract (PDF format) |
| 3/22/05 3:35 PM |
Statistics Before Your Eyes Bob Jernigan, American University Abstract (PDF format) |
| 3/1/05 3:35 PM |
Taking Products of Particles: Poincaré Symmetry and Representation
Towers Nate Harshman, American University Physics Department Abstract (PDF format) |
| February 2005 | |
| 2/22/05 3:35 PM |
Summer Research Showcase Come find out about opportunities for students to do research at AU this summer - and get paid! |
| 2/17/05 10:15 AM |
Tests for Bimodality (Note special time and location: Gray Hall
104) Eduartas Valaitis, Yale University When a frequency distribution exhibits multimodality, there is a lack of universally accepted hypothesis tests that can be used to evaluate whether the modes are due to chance. A bimodality criterion is proposed and serves as a basis for partitioning a plane into a region of bimodality and a region of unimodality. No unbiased test exists for this bimodality boundary shape. Nevertheless, two synthetic tests for detecting bimodality in a mixture of two normal components with equal variances are presented. These proposed tests are less biased than the maximum likelihood ratio test. |
| 2/15/05 3:35 PM |
Meta-Analytic Approaches in Statistical Genomics John Stevens, Purdue University It is becoming increasingly common for multiple laboratories to use microarray technology to study the genetic basis of the same disease or condition of interest in the same organism. With this technology, a laboratory can seek to identify which genes are differentially expressed between conditions. Differences in experimental results can arise from chance variation and fundamental differences between experiments. Estimates of each gene's magnitude of differential expression from multiple experiments in the same laboratory may not be independent. In order to effectively combine results from different laboratories to achieve a clearer understanding of each gene's true relationship to the condition of interest, it is necessary to account for these differences and dependencies. A meta-analytic approach to combine results from the Affymetrix platform is developed, focusing on the use of covariate and covariance information. Fixed effects, random effects, and hierarchical Bayes frameworks are presented. A minimum variance threshold approach is proposed to blend the notions of biological relevance and statistical significance. The traditional univariate Affymetrix approach to quantifying differential expression via the signal log ratio is extended to the multivariate case to allow for covariance estimation. This new approach is demonstrated using both data from a simple simulation model and experimental data from a mouse model for multiple sclerosis. The results of this approach are compared with those of other alternative and previously proposed approaches to combine results from multiple microarray experiments. |
| 2/10/05 10:15 AM |
Exploring goodness-of-fit and spatial correlation using components
of Tango's index of spatial clustering (Note special time and location:
Gray Hall 104) Monica Jackson, Emory University The ability to detect anomalies as clustering in data sets plays an important role in spatial data analysis. Tango (1995) developed a statistic that can be used to detect clusters in data sets. Rogerson (1999) observed that Tango's index may be decomposed into the summation of two distinct statistics, the first part a test of goodness-of-fit (GOF), and the second part an index of spatial autocorrelation (SA) similar to Moran's I. In this talk we investigate the effectiveness of Rogerson's expression of Tango's statistic in separating GOF from SA in data sets containing clusters. We simulate data under the null hypothesis of no clustering as well as two alternative hypotheses. The first alternative hypothesis induces a poor fit from the null hypothesis while maintaining independent observations and the second alternative hypothesis induces spatial autocorrelation while maintaining fit. Using Rogerson's decomposition and leukemia incidence data from New York, we show graphically one is unable to statistically distinguish poor fit from autocorrelation. |
| 2/1/05 1:30 PM |
Nonstandard Analysis: Calculus without ε and δ (Note
special time) Jeff Adler, The University of Akron Abstract (PDF format) |
| 2/1/05 3:35 PM |
Artin L-functions and the Dedekind Conjecture. (Note special location:
Gray 104) Josh Lansky, American University Abstract (PDF format) |
| January 2005 | |
| 1/25/05 3:45 PM |
A Tour: Part A. Shaping a Trigonometric Curve to Hear a Sound Part B. Separation of Sounds: Voice Prints, Methods of Independent Component Analysis. (Note special location: McKinley 108) I Lok Chang, American University Abstract (PDF format) |
| November 2004 | |
| 11/09/04 3:35 PM |
Automorphism groups of curves and codes Amy Ksir, US Naval Academy Abstract : There is a type of code called an AG code that can be built out of the points and functions on an algebraic curve. If the curve has a finite group of symmetries, these will induce a group of permutations of the code words. I will discuss the structure of this group representation, and a result on when permutations of the code can induce symmetries of the curve itself. |
| October 2004 | |
| 10/26/04 3:35 PM |
The Absolute Galois Group and Dessins d'Enfants Melanie Wood, Princeton University The absolute Galois group of the algebraic numbers over the rationals is one of the most important yet one of the most mysterious objects in number theory--so mysterious that we can only even write down two of its infinitely many elements. Grothendieck proposed a method of studying the absolute Galois group by considering its action on certain maps between algebraic curves. It turns out that these maps can be described completely combinatorially, and absolute Galois group acts faithfully on a set of objects so simple that Grothendieck called them "children's drawings." These combinatorial objects allow us to say some concrete things about the absolute Galois group and this action, and they also provide a simple way of seeing how much we still don't know about the absolute Galois group. |
10/26/04 8 PM |
Math and Creativity - a special evening presentation by Ms. Woods for the general public. Note special location: Ward Building, Room 1. |
| 10/19/04 | Charles Davies and the Mathematics Education Business Amy Ackerberg-Hastings Abstract (PDF format) |
| September 2004 | |
| 9/14/04 | Quantum Dots Andrew Shabaev, U. S. Naval Research Labs Abstract (PDF format) |
