## Abstracts & Biographies

**Date:** 9/19/2006 (Tuesday)

**Speaker:** Dr. Chris Gennings

Professor

Department of Biostatistics

Virginia Commonwealth University

**Title**: A Gestalt Index: Use Of Desirability Functions In Evaluation Of Multiple Measurements per Experimental Subject

**Abstract**: Multiple endpoints are often measured on each subject in both toxicology and clinical studies. If each endpoint is analyzed separately, the risk of claiming an effect when none exists increases. One approach to analyzing multiple endpoints in an integrated way is through the use of a composite score. The use of desirability functions is described as a way of deriving an overall score that uses information from each of the outcomes. This methodology is commonly used in the quality engineering literature but has not been applied to toxicology or clinical data. The approach is demonstrated through the analysis of a mixture of organophosphorus pesticides where a threshold was estimated when evaluating five measures of neurotoxicity. Application of the approach to patient data from a clinical study will also be illustrated.

**Bio**:Dr. Chris Gennings earned her B.A. in mathematics at Westhampton College of the University of Richmond in 1982 and her Ph.D. in biostatistics from the Medical College of Virginia of Virginia Commonwealth University in 1986. She has been on the faculty in the Department of Biostatistics at VCU since graduating from there. Her research interests include experimental design and analysis methods for toxicology data, especially as applied to the analysis of drug/chemical mixtures. She is married to Otis Fulton and they have two children - a daughter in the 6^{th} grade and a son in the 2^{nd} grade.

**Date:** 10/12/2006 (Thursday)

**Speaker:** Dr. Kyle Siegrist

Professor

Department of Mathematical Sciences

University of Alabama in Huntsville

**Title**: 1/e: How to Find the Woman (or Man) of Your Dreams

**Abstract**: There are *n* candidates, totally ordered from best to worst. The candidates arrive sequentially, in random order. Our goal is to choose the best candidate; no one less will do. Unfortunately, we cannot observe the absolute ranks of the candidates, but only relative ranks. Once rejected, a candidate is no longer available. What should our strategy be? When *n* is large, is there any hope finding the best candidate? The answers are interesting and surprising.

**Bio**:Kyle Siegrist received a PhD in mathematics from Georgia Tech in 1979 and has been on the faculty of the Department of Mathematical Sciences at UAH since 1980. His research interests are probability and stochastic processes. He is currently the editor of the Journal of Online Mathematics and its Applications.

**Date:** 10/31/2006 (Tuesday)

**Speaker:** Ms. Virginia Lewis

Lecturer

Department of Mathematics and Computer Science

Longwood University

Ph.D. Candidate in Mathematics Education at the University of Virginia

**Title**: Undergraduate Calculus Students' Definitions and Images of Function

**Abstract**: How do Longwood calculus students define the concept of function? What do these students include in their concept image of function? Is there a relationship between the level of calculus in which a student is enrolled and the student's definition and image of function? Undergraduate calculus students at Longwood University were examined using mixed methods to determine how they define function and their concept images of function. Surveys were completed in three different levels of calculus. Students were presented with a variety of graphs and asked to determine if the graphs were functions. Students were also asked to define the word function. Interviews were conducted with two students in each level of calculus. We will discuss the results of this study and how these results can inform calculus instruction.

**Bio**:Virginia Lewis graduated from Longwood College in 1992. She earned her Master's in Interdisciplinary Studies in 2003 at VCU. She is currently a doctoral candidate in mathematics education at UVA. She is married with two daughters. In her free time she loves to play the piano and cross-stitch.

**Date:** 11/30/2006 (Thursday)

**Speaker:** Mr. David McWee

Principal Information Engineer

Professional Software Engineering, Inc. (PROSOFT)

**Title**: From the Classroom to the Cubicle

**Abstract**: The transition from the classroom to the application of knowledge can seem insurmountable especially when a student is joining an enterprise level software development process. This talk will identify some of the concerns and questions students may have about this transition. This speech will be a first hand account of my transition from being a student to a Professional Software Developer. I will provide some examples including a project currently supported and maintained solely by Longwood graduates as well as several others.

**Bio**:David McWee graduated from Prince Edward County High School in 1998 and Longwood University in 2002. Since leaving Longwood he has worked as a Civil Servant for the US Navy at Naval Surface Warfare Center Dahlgren Division (NSWCDD). While at NSWCDD he worked on the Submarine Launch Ballistic Missile, and TOMAHAWK Programs as a software tester. He also worked on the AEGIS Radar Program developing the Enhanced Radar Data Display System (ERDDS) which is currently maintained by only Longwood graduates. He was recently employed by The Consulting Network Inc. (TCNI) developing pieces of the Tactical Control Software (TCS) for the Virginia Class Submarine. He is now working at the Joint Forces Command (JFCOM) for the Joint Combat Operational Analysis (JCOA)division developing the Joint Lessons Learned Information System (JLLIS). JLLIS is intended to allow different military branches to share lessons learned and improve training.

**Date:** 1/30/2007 (Tuesday)

**Speaker:** Dr. Danny Cline

Assistant Professor

Department of Mathematics

Lynchburg College

**Title**: Self-Contradiction-or- I Am Lying To You

**Abstract**: Mathematicians and philosophers have long been fascinated by paradox. Some of the earliest known and most troubling paradoxes for mathematicians are variations on the self-contradictory statement: "I am lying to you." In the early part of the 20^{th} century, Bertrand Russell found instances of these sorts of statements in mathematics and set out to find a way to eliminate them. In the process he hoped also to grant a wish of mathematician David Hilbert, a program to list a complete set of axioms capable of generating all of mathematics. Russell and his colleague Alfred North Whitehead made an attempt at this with their *Principia Mathematica*; however, the same flaws crept in. In 1931, logician Kurt Gödel used a clever proof to show that these same sort of self-contradictory statements could be generated within Russell's system of axioms. He showed also that this contradiction cannot be removed from such a system and thus that there can be no hope of ever completing mathematics and granting Hilbert's wish. In this talk, I will discuss the interconnected histories of Russell's paradox and Gödel's Incompleteness Theorem. I will also discuss how the same self-contradictory statements that Russell hoped to remove from mathematics remained regardless of his efforts and undid the rest of his project.

**Bio**:Danny Cline was born in West Virginia and received two B.S. degrees from West Virginia University, one in Mathematics and one in Chemical Engineering. He went on to study mathematics at the graduate level at Virginia Tech, earning his M.S. in Mathematics and, in 2004, his Doctorate in Number Theory. Since the fall of 2005, he has been an Assistant Professor of Mathematics at Lynchburg College. His mathematical interests are primarily in number theory and the philosophy of mathematics.

**Date:** 2/8/2007 (Thursday)

**Speaker:** Dr. Gretchen Koch

Assistant Professor

Mathematics and Computer Science Department

Goucher College

Baltimore, Maryland

**Title**: E. Coli and Taylor Series: My Journey Through Biomathematics

**Abstract**:In this talk, Dr. Koch will describe the unusual journey she took to becoming a math-biologist. She will also detail what it is like to work with scientists in other disciplines. Finally, she will present two computer models of cell division in E. coli depicting the minCDE system that decides where the middle of the cell lies. One is a Markov model, and the other is a Monte Carlo simulation. Both models have answered important questions about the MinCDE system while presenting many more.

**Bio**:Gretchen Koch has been an assistant professor of mathematics and computer science at Goucher College since August 2005. She completed her Ph.D. in Mathematics at Rensselaer Polytechnic Institute in Troy, New York in August 2005. She also completed her M.S. in Applied Mathematics at RPI in December 2002. Her B.S. in Mathematics was completed at St. Lawrence University in Canton, NY in May 2001. As an applied mathematician, she uses math to model real phenomena. As a teacher, she tries to relate the topics in lecture to things that happen in our world. Her research can be categorized as biomathematics. Recently she created two computer models of cell division in E. coli depicting the system that decides where the middle of the cell lies. This system, the MinCDE system, is a fascinating interplay of oscillating polymers. One of the aspects of her research she enjoys the most is that it is interdisciplinary, and thus she has the opportunity to work with biochemists and see her work come to life in the laboratory.

**Date:** 3/1/2007 (Thursday)

**Speaker:** Mr. Robert M. Marmorstein

Ph.D. Candidate in Computer Science

College of William and Mary

**Title**: Multiway Decision Diagrams

**Abstract**: Multiway decision diagrams (MDDs) are a convenient way to store large sets of multi-field data. Unlike arrays and linked lists, MDDs take advantage of similarities between data items. In this talk, we will present an algorithm for constructing an MDD, describe several important MDD operations, and illustrate the application of MDDs to a simple security filter. We will also discuss when it is appropriate to use an MDD in place of other storage techniques.

**Bio**: Robert Marmorstein is a Ph.D. Candidate in Computer Science at the College of William and Mary. His research concentrates on the visualization, analysis, and repair of firewall policies. He has an M.S. in Computer Science from William and Mary and a B.A. in Computer Science and Mathematics from Washington and Lee University. In addition to being a teaching assistant and a technical assistant at William and Mary, he has also worked at NASA Langley Research Center.

**Date:** 3/8/2007 (Thursday)

**Speaker:** Dr. John Augustine

Visiting Assistant Professor

Computer Science Department

Colby College

**Title**: Resource Allocation in Computer Systems: Pandas and Tetris

**Abstract**: Resource allocation in computer systems leads to optimization problems that often have elegant solutions. In many cases, the problems are modeled mathematically and the solutions are analyzed rigorously. We will discuss two problems and solutions in a manner that highlights this research process.

The problem of powering down is encountered when any energy intensive system goes through an idle period of time. I will present several models and algorithms that are increasingly more accurate in capturing the essence of this problem.

The second problem is encountered while scheduling jobs in a Field Programmable Gate Array (FPGA). Simply put, an FPGA is a mesh of computing elements that can be reconfigured in run-time. Our goal is to schedule an input set of jobs in a manner that minimizes the completion time of all jobs.

I will conclude with a summary of other previous work and plans for future research. In particular, I will describe how I plan to collaborate with undergraduate students.

**Bio**:Dr. Augustine has a Ph.D. in Information and Computer Science from the University of California at Irvine, a M.S. in Electrical and Computer Engineering and an M.S. in Systems Science, both from Louisiana State University. His undergraduate degree was a B.E. in Computer Science and Engineering from the University of Madras in India. When he finds himself with some time to kill, he likes to ride his road bike, photograph, and hike.

**Date:** 3/22/2007 (Thursday)

**Speaker:** Dr. Laura Taalman

Associate Professor of Mathematics

Department of Mathematics and Statistics

James Madison University

**Title**: Sudoku Variations and Research

**Abstract**: Sudoku puzzles and their variants are linked to many mathematical problems involving combinatorics, Latin squares, magic squares, polyominos, symmetries, computer algorithms, the rook problem, knight tours, graph colorings, and permutation group theory. In this talk we will explore variations of Sudoku and the many open problems and new results in this new field of recreational mathematics. Many of the problems we will discuss are suitable for undergraduate research projects. Puzzle handouts will be available for all to enjoy!

**Bio**:Laura Taalman is an Associate Professor of Mathematics at James Madison University. She received her Ph.D in mathematics from Duke University, and did her undergraduate work at the University of Chicago. Her research includes singular algebraic geometry, knot theory, and the mathematics of puzzles. She is the author of a textbook that combines calculus, pre-calculus, and algebra into one course, and one of the organizers of the Shenandoah Undergraduate Mathematics and Statistics (SUMS) Conference at JMU. Her awards include the MAA Trevor Evans award for her jointly written article "Simplicity is not Simple: Tesselations and Modular Architecture", and the MAA Alder Award for Distinguished Teaching.

**Date:** 4/5/2007 (Thursday)

**Speaker:** Dr. Deborah L. Gochenaur

Assistant Professor of Mathematics

Department of Mathematical Sciences

Elizabethtown College

Elizabethtown, Pennsylvania

**Title**: Evaluating STEM Intervention Programs

**Abstract**: As the United States science, technology, engineering, and mathematics (STEM) workforce continues to grow faster than the overall workforce, the need for college-trained STEM workers continues to increase. While African Americans comprise 11.3 percent of the US population 18 years or older, they hold just 4.4 percent of the STEM degreed-workforce positions. Numerous intervention programs, geared towards increasing the number of underrepresented minorities in STEM, were developed to increase undergraduate retention and attainment rates, graduate degree attainment rates, and the rate at which students were entering the STEM workforce. Although many of these programs have conducted small self-studies, few have undergone extensive external program evaluation. As millions of dollars continue to pour into these programs, evaluation of their effectiveness at increasing the numbers of African Americans in STEM needs to be addressed. An evaluation model that uses qualitative analysis to build upon a quantitative analysis base, utilizing logistic regression, will be explored.

**Bio**: Dr. Gochenaur is currently an Assistant Professor in the Department of Mathematical Sciences at Elizabethtown College in Elizabethtown, PA. In addition to teaching duties in the Department she serves as Program Director for Mathematics Education by overseeing pre-service teachers as they complete their academic programs and then supervising them in their professional semester. Dr. Gochenaur has done research into underrepresented minorities for several years and is currently working to procure funding to increase the number of underrepresented minorities entering the teaching workforce from Elizabethtown College. Dr. Gochenaur brings a variety of life experiences to her roles at the college; she was a non-traditional returning student, first raising a family and going the route of butcher, baker, candlestick maker. Receiving her Ph.D. from American University in 2005, she was selected as a MAA Project NExT National Fellow.

**Date:** 4/19/2007 (Thursday)

**Speaker:** Dr. Ling Xu

Assistant Professor

Department of Mathematics and Statistics

James Madison University

**Title**: Detecting Multimodality in Ecological Data

**Abstract**:

Body size is one of the most important features of any animal. Ecologists are interested in understanding the processes that determine whether distributions of body size are multimodal. Several broad classes of methods have been devised to assess modality. This talk will focus on non-parametric inference with kernel estimates and a Bayesian approach with mixture models, and the utility of these methods on body size distributions of boreal forest birds and mammals.

**Bio**:Ling Xu earned her Ph.D. in statistics from The University of New Mexico in 2005. Ling Xu is currently an Assistant Professor at James Madison University.