Bi-State Math Colloquium
Spring 2011

Loras College and the University of Wisconsin - Platteville

All talks begin at 4PM unless otherwise noted. To carpool to Platteville from Loras, meet outside Hennessy 210 by 3:15 on the afternoon of the talk.

If you would like to give a talk at Loras or have questions regarding the colloquium, contact Angela Kohlhaas. Last semester's schedule can be viewed here.

Schedule

Date Location Speaker Title
Thursday
February 10
UW-Platteville
Ottensman 144
Ki-Bong Nam
UW-Whitewater
Generalized Euler φ-function
Wednesday
February 16
Loras College
Hennessy 350
Joe Eichholz
University of Iowa
An Introduction to
Bioluminescence Tomography
Thursday
February 24
UW-Platteville
Ottensman 144
Jonas Meyer
UWP
Mathematical Truth:
History and Perspectives
Friday
March 4
Loras College
Hennessy 350
Megan Patnott
Univ. of Notre Dame
Symmetry, Wallpaper Patterns,
and M.C. Escher
Friday
March 11
Loras College
Hennessy 350
TJ Hitchman
Univ. of Northern Iowa
Counting and Dividing:
m-ary partition sequences
Thursday
March 24
UW-Platteville
Ottensman 144
Clem Jeske
UWP
A Theorem about Incircles
Wednesday
March 30
Loras College
Hennessy 350
Erik Insko
University of Iowa
Flipping Coins, Drunken Walks,
and Wallis' Formula for π
Wednesday
April 6
Loras College
Hennessy 350
Chad Vidden
Iowa State University
Trading Cookies
in a Gambler's Ruin Scenario
Thursday
April 14
UW-Platteville
Ottensman 144
Pam Peters
UWP
Go Ask Alice:
The Mathematics of Lewis Carroll
Thursday
April 28
UW-Platteville
Ottensman 144
Kevin Haertzen
UWP
Polynomial Splines
Friday
May 6
Loras College
Hennessy 350
Amanda Matson
Clarke University
Did She Say, "Monoid"?

Abstracts

February 10, 2011, at Platteville

Speaker
Dr. Ki-Bong Nam
Title
Generalized Euler φ-function
Abstract

We define a generalized Euler φ-function. We also characterize the Euler φ-function differently from the classical definition. We find some properties of the generalized Euler φ-function. We will also discuss some basic number theory which is related to the generalized Euler φ-function. The results of this work are the result of undergraduate research with my students at UW-W, so this talk will also be appropriate to general audiences.

Ki-Bong Nam earned his Ph.D. in 1998 at the University of Wisconsin-Madison, in the field of Algebra. He has taught at the University of Wisconsin-Whitewater since 1999. He has authored and co-authored over 75 papers, and has earned the Award for Outstanding Research and the research award in the College of Letters and Sciences at UW-W. He lives in Madison with his wife and two children.

February 16, 2011, at Loras

Speaker
Joe Eichholz
Title
An Introduction to Bioluminescence Tomography and Associated Problems
Abstract

Bioluminescence tomography (BLT) is an emerging medical imaging technique in which we aim to reconstruct the position of light sources inside a biological medium. The BLT has several challenging mathematical aspects, one of which is efficiently solving the radiative transfer equation. In this talk, we will introduce the BLT problem in an accessible manner, and focus on the difficulty of solving the associated RTE. We will proceed give to an efficient algorithm for solving a simplified version of the RTE developed by undergraduate students at the University of Iowa Summer REU in 2010.

Joe Eichholz is a graduate student at the University of Iowa.

February 24, 2011, at Platteville

Speaker
Dr. Jonas Meyer
Title
Mathematical Truth: History and Perspectives
Abstract

A fairly informal survey will be given of some of the ideas concerning truth in mathematics, the history of the development of these ideas, and some of the diverse perspectives of mathematicians and philosophers through the ages. Topics will include a comparison between mathematical truth and truth in the physical sciences; the role of abstraction and deduction; relative versus absolute truth of foundational principles (axioms), especially in geometry and arithmetic; and independence results concerning the (set theoretic) notion of infinity.

Jonas Meyer is a mathematics lecturer at the University of Wisconsin-Platteville. He earned his Ph.D. in mathematics from the University of Iowa in 2010, working primarily in functional analysis. Reading about the history of mathematics is one of his hobbies.

March 4, 2011, at Loras

Speaker
Megan Patnott
Title
Symmetry, Wallpaper Groups, and M.C. Escher
Abstract

We often see repeating patterns used in decoration. All of these patterns remain unchanged if we shift them in the correct direction, but some of them can also be rotated or reflected over a line without the pattern changing. We call these shifts, rotations, and reflections symmetries of the pattern. If we are mainly interested in the symmetries of the patterns, then it turns out that there are only a very small number of types of patterns. We'll discuss four types of symmetry, the wallpaper patterns they lead to, and a variation on the classical wallpaper patterns.

Megan Patnott is a graduate student at the University of Notre Dame.

March 11, 2011, at Loras

Speaker
Dr. TJ Hitchman
Title
Counting and Dividing: m-ary partition sequences
Abstract

m-ary partition sequences count the number of ways to divide a set of size n into subsets whose sizes are powers of m. These things have neat divisibility properties that occur in a rich self-similar pattern. We will explore the pattern and maybe talk about a recent advance in understanding involving generating functions.

TJ Hitchman is an Assistant Professor of Mathematics at the University of Northern Iowa.

March 24, 2011, at Platteville

Speaker
Dr. Clem Jeske
Title
A Theorem about Incircles
Abstract

An n-sided polygon inscribed in a circle can be triangulated using n - 2 triangles. Each of these n - 2 triangles has an incircle and an inradius. What can be said of the sum of the inradii?

Clem Jeske has been a member of the math faculty at the University of Wisconsin- Platteville since 1984. He completed his Ph.D. in mathematics from the University of Wisconsin-Madison in 1989 under the direction of Don Passman.

March 30, 2011, at Loras

Speaker
Erik Insko
Title
Flipping coins, drunken walks, and a simple proof of Wallis' product formula for π.
Abstract

We discuss the ties between the combinatorics of coin flipping problems, drunken walks, and the elementary geometric proof of Wallis' product formula for π due to Johan Wastlund. This talk is motivated by a lecture given by Donald Knuth at Bowdoin College, Wastlund's article in The American Mathematical Monthly, and a personal correspondence with aBa Mbirika.

Erik Insko is a graduate student at the University of Iowa and a Loras College alum.

April 6, 2011, at Loras

Speaker
Chad Vidden
Title
Trading Cookies in a Gambler's Ruin Scenario
Abstract

We consider several variations of a probabilistic game between a "buyer" and a "seller", whose major component is a random walk of the buyer on an interval of integers. We assume a gambler’s ruin scenario, where in contrast to the classical version the walker (buyer) has the option of consuming "cookies", which when used, increase the probability of moving in the desired direction for the next step. The cookies are supplied to the buyer by the second player ("seller"). We determine the equilibrium price policy for the seller and the optimal "cookie store" location. An initial motivation for this question is provided by the popular model of "cookie" or "excited" random walks.

Chad Vidden is a graduate student at Iowa State University.

April 14, 2011, at Platteville

Speaker
Dr. Pam Peters
Title
Go Ask Alice: The Mathematics of Lewis Carroll
Abstract

While many of us are familiar with "Alice in Wonderland" as a children's story or Burton film, we aren’t quite as familiar with Charles Dodgson, Carroll’s real name, a mathematician. I will be discussing Dodgson’s more major works, specifically his algorithm for computing the day of the week and the condensation method for evaluating determinants, but also looking a bit at how he used Alice and other literary works in criticizing the more "modern" mathematicians of his time. It should be a good time to "Remember what the doormouse said, 'Feed your head'."

Pam Peters is a pure mathematician with a PhD in Algebraic Topology from Colorado State University. She has been teaching at UW-Platteville for almost 4 years now and has finally learned to find Green Bay on a map (among other Wisconsin priorities). Beyond algebra, number theory, and combinatorics, she has an interest in the history of math, as you meet such fascinating people there. And she is still in search of the winged pigs.

April 28, 2011, at Platteville

Speaker
Dr. Kevin Haertzen
Title
Polynomial Splines
Abstract

What’s a spline, and why do we care about them? Wolfram Math World defines a spline as “A piecewise polynomial function that can have a locally very simple form, yet at the same time be globally flexible and smooth. Splines are very useful for modeling arbitrary functions, and are used extensively in computer graphics.” We will explore how to produce simple splines, and see some of the advantages of this approach to approximating functions.

Kevin Haertzen has been a member of Mathematics Department since Fall 2003. He has a Ph.D. in Mathematics from Northern Illinois University, under the direction of Dr. Hongyou Wu.

May 6, 2011, at Loras

Speaker
Dr. Amanda Matson
Title
Did She Say, "Monoid"?
Abstract

If you've ever kept track of a score in a sporting event, you've used a monoid! We will be exploring some common monoids as well as the concepts of reducibility and factoring.

Amanda Matson is an Assistant Professor of Mathematics at Clarke University.