Northeastern Section of the MAA (NES/MAA)

Fall 2003 MEETING

November 21-22, 2003

Wellesley College in Wellesley, MA

 

 

The schedule of student papers is below followed immediately by the abstracts for the student papers.

 

 

Student Papers: Schedule

 

 

 

Speaker and Title

Time

Room

Brian D. Ginsberg, Yale University

The Nearly Secret Theorem of E. Midy  An Extension after 165   Years

5:00-5:10

270

Elizabeth Bellenot, Wellesley College

 Effects of Biological Invasions on Ecological Communities

5:15-5:25

270

Jessica S. Lee, Wellesley College

 Mersenne Primes

5:30-5:40

270

Michael J. Coleman, Boston University and Sidharth Rupani, WPI

Modeling iBOT Belt Dynamics

5:45-5:55

270

Seila Selimovic, Wellesley College

Who Wins: The Mathematician or The Physicist?  The Dirac Delta function and Its Use in Quantum Mechanics

6:00-6:10

270

 

 

 

Iuli Pascu, Wellesley College

A Graphical Interpretation for Complementary Sequences

5:00-5:10

274

Karin Steece, Wellesley College

The Chinese Postman Problem

5:15-5:25

274

XinXin Du, Wellesley College

Monte Carlo Simulations on One Electron Per Site, Two-Dimensional Square Lattices

5:30-5:40

274

Paula F. Popescu, Wellesley College

Games with Hats

5:45-5:55

274

Kathleen Leahy, College of the Holy Cross

Enigma  The Code that Changed History

6:00-6:10

274

 

Charlie Rossetti and Matthew Angelucci, Bentley College

Dynamica

5:00-5:10

278

Brandon Dwyer, Bentley College

A Student’s Look at the First Actuarial Exam

5:15-5:25

278

Jenny Kirouac, Westfield State College

Naming Really Large Numbers

5:30-5:40

278

Kari Lock, Williams College

Making Best Approximates Appear Through Magical Intervals

5:45-5:55

278

Neil Hoffman, Williams College

Double Bubbles in Other Universes

6:00-6:10

278

 

Speaker and Title

Time

Room

Kathleen Smith, Norwich University

Vertex Total Magic Labelings

5:00-5:10

392

Jerzy Wieczorek, Olin College

Solving ‘Rubik’s Polyhedra’ Using Three-Cycles,

5:15-5:25

392

Joelle Arnold, Olin College

The Assignment Problem and Optimizing Registration

5:30-5:40

392

Janet Tsai, Olin College

You Can Make Anything with One Straight Cut

5:45-5:55

392

Ben Kraines and Siddartha Rao, Middlebury College

Extreme Points and Lipschitz Conditions for Functions in a Certain Zygmund Class

6:00-6:10

392

 

 

 

Matthew Stephen Palmacci, Framingham State College

The Golden Ratio

5:00-5:10

396

Alison Fish, Merrimack College

The Golden Ratio and Three-Dimensional Geometry

5:15-5:25

396

Kaitlyn ONeil, Merrimack College

Pretzel Knots and Colorability

5:30-5:40

396

Kevin Roberge, University of Maine

Algebraic Topology and Elementary Circuits

5:45-5:55

396

Michael A. Burr, Tufts University

Simplicial Depth: An Improved Definition, Analysis, and Efficiency for the Finite Sample Case

6:00-6:10

396


Student Papers: Abstracts

 

Matthew Angelucci, Bentley College                                                                     5:00-5:10, room 278

Dynamica                    

            In this talk we present Dynamica, a software package running under Mathematica that helps researchers gain insight into the behavior of dynamical systems. The various features of the software are demonstrated on a biological model of Lyme disease described by a difference equation.

 

Joelle Arnold, Olin College                                                                                    5:30-5:40, room 392

The Assignment Problem and Optimizing Registration

Consider the arranged marriages of a fixed and finite number of heterosexual couples. Suppose that each woman gets to make a list of her preferred husbands, but that the men have no say. We will discuss the conditions under which each woman can be paired with a suitable husband - this is Hall’s marriage problem. The Assignment Problem is any scenario in which a group of people or other entities are to be matched to another group of people or entities, and in which both groups have the same number of members. By either one group or both groups ranking preferences, an optimization can be found. We arrange the data in a matrix and by using the Hungarian Method, may make the best matches. This procedure is used to solve job training, hypothetical marriage and shipping route problems. We will investigate using these two methods to optimize the registration process here at Olin. In this manner, we should be able to maximize student satisfaction with spring schedules.

 

Elizabeth Bellenot, Wellesley College                                                                    5:15-5:25, room 270

Effects of Biological Invasions on Ecological Communities                                                                      

In an ecological community with n distinct species, what happens when an invader species is introduced?  By studying food webs using matrix analysis and simple graph theory, we examine cases where we can predict which resident species will increase, decrease, or has no change in population. We also look at cases where the outcome is ambiguous.

 

Michael A. Burr, Tufts University                                                                          6:00-6:10, room 396

Simplicial Depth: An Improved Definition, Analysis, and Efficiency for the Finite Sample Case

As proposed by Liu (1990) the simplicial depth of a point  with respect to a probability distribution  on  is the probability that  belongs to a random simplex in . The simplicial depth of  with respect to a data set  in  is the fraction of the closed simplices given by  of the data points containing the point . We propose an alternative definition for simplicial depth which continues to remain valid over a continuous probability field, but also fixes some of the problems for the finite sample case, including those discussed by Zuo and Serfling (2000). Additionally, we discuss the effect of the revised definition on the efficiency of previously developed algorithms and prove tight bounds on the value of the simplicial depth based on the half-space depth.

 

Michael J. Coleman, Boston University                                                                 5:45-5:55, room 270

Modeling iBOT Belt Dynamics

The iBOT, a revolutionary personal mobility device developed by DEKA Research and Development Corporation, contains several belts that transfer mechanical power through the system. The dynamic characteristics of the belts are obviously important to the operation of the iBOT. Our task is to create a mathematical model of some aspects of the belt dynamics. Partial and ordinary differential equations and Lagrangian dynamics are employed to understand the elements of this electro-mechanical system.  Ultimately, finite difference numerical methods are applied to solve the rather complicated system of governing equations developed. The results from our mathematical model are compared with those from actual experiments.

 

XinXin Du, Wellesley College                                                                                 5:30-5:40, room 274

Monte Carlo Simulations on One Electron Per Site, Two-Dimensional Square Lattices

I used Monte Carlo methods to do random walks through configuration space on two-dimensional, square lattices, computing the energy and the magnetism of the system, and finding the ground state of the system.  Using the Metropolis algorithm, I simulated a situation where the system sits at a particular temperature and looked at its thermodynamic behavior.  The Metropolis algorithm also allowed me to overcome the problem of arriving at metastable states instead of the ground state in some cases.

 

Brandon Dwyer, Bentley College                                                                            5:15-5:25, room 278

A Student’s Look at the First Actuarial Exam

If a student is looking seriously into a career as an actuary, they should begin the exam process while still in college.  The Course I exam contains problems relating to calculus and probability (both discrete and continuous).  This presentation will look at how to prepare for the exam including strategies for studying.  Two typical exam questions will also be presented.

 

Alison Fish, Merrimack College                                                                             5:15-5:25, room 396

The Golden Ratio and Three-Dimensional Geometry

The golden ratio, represented by  (phi) is found in many areas of mathematics. This talk will discuss the golden ratio and how it can be found in three-dimensional geometric shapes such as polyhedra.  Golden rectangles, which exhibit this ratio, exist within the polyhedra. Also the coordinates of the vertices of the polyhedra and the relationship of the edges include the golden ratio.

 

Brian D. Ginsberg, Yale University                                                                        5:00-5:10, room 270

The Nearly Secret Theorem of E. Midy  An Extension after 165 Years

This work extends Midy’s theorem  a curious, old number theory result about parts of decimals of even periodto a wider class of fractions whose period need not be even. Avenues for further extension are also explored.

 

Neil Hoffman, Williams College                                                                              6:00-6:10, room 278

Double Bubbles in Other Universes

The recently proved Double Bubble Conjecture says that the familiar double soap bubble is the least-area way to enclose and separate two regions of prescribed volumes in . We report on extensions to other three-dimensional universes.

 

Jenny Kirouac, Westfield State College                                                                  5:30-5:40, room 278

Naming Really Large Numbers

You know thousand, and million, and billion, and trillion. Ten thousand, ten million, ten billion, and ten trillion, but do you recall the numbers that come after them all? Shouldn`t we have names for bigger and bigger numbers? And what exactly is a zillion? This talk will delve into a system of naming numbers that not only exceeds our traditional system, but also allows us to keep naming larger and larger numbers without limit. Of course, we will also mention some of the famous numbers and say how they can be alternatively named in this new system: large numbers like the perplexing Googolplex number, the merciful Mersenne primes, and the invigorating Vinogradov`s number. After experiencing this talk you will know lots of amazingly large numbers AND you will be able to name any number you come across.


Ben Kraines, Middlebury College                                                                          6:00-6:10, room 392

Extreme Points and Lipschitz Conditions for Functions in a Certain Zygmund Class

The Tagakivan der Waerden function is an important example of a continuous nowheredifferentiable function.  Although it is nowhere differentiable, it is possible to define an analogue to the derivative via the “dyadic difference quotient” sequence. This paper concerns functions whose dyadic difference quotients have modulus one.  We use the dyadic difference quotient to investigate Lipschitz points and extreme points for such functions in a way that parallels the use of the derivative in studying extreme points and Lipschitz behavior in real variable calculus.

 

Kathleen Leahy, College of the Holy Cross                                                           6:00-6:10, room 274

Enigma  The Code that Changed History

In this talk we will give a brief history of the Enigma code used by the Germans in World War II. We will describe the machine used to encode and decode as well as some of the mathematics involved. We will also discuss the connection between the breaking of the Enigma code and the creation of the first digital computer. 

 

Jessica S. Lee, Wellesley College                                                                           5:30-5:40, room 270

Mersenne Primes

As early as 300 B.C., Euclid studied prime numbers, which are numbers divisible only by one and themselves.  Until 1536, mathematicians believed that all numbers of the form  were prime for all primes .  While this conjecture is false, many people now have joined the search for primes of that form, now dubbed Mersenne Primes after the Frenchman who studied them at great length.  This talk briefly outlines the history of these rare primes, the current on-going search for them, as well as providing an introduction to some of the unsolved mysteries surrounding Mersennes.

 

Kari Lock, Williams College                                                                                   5:45-5:55, room 278

Making Best Approximates Appear Through Magical Intervals

Let  be a real, irrational number. Given a positive integer q, an important question in diophantine approximation is: how do we determine exactly when q is the denominator of a “best rational approximate” to ? Using the theory of continued fractions and their convergents, I show that if the continued fraction expansion of  has the form , then a positive integer q is a denominator of a best approximate to  if and only if the interval