Each semester the Department of Mathematics offers colloquium talks on a variety of mathematical topics. The department also hosts the Advanced Research Initiative series, featuring a distinguished guest speaker giving two talks. For upcoming Math Colloquia please see the Department of Mathematics Events Calendar.
- 2020 Spring
2020 Spring Math Colloquia
February 19 Smith Hall 516, 4:00pm
Alaa Elkadry (Marshall University) Inference when Data Sources Uncertain
Abstract: Data with uncertain sources are available all around us. Specifically, we’re talking about the cases where each observation has a probability distribution. Randomized response data and assessing possible landing disparity are among the application areas of such data.
In this talk, examples of some application areas are further discussed, and illustrative examples are provided to demonstrate the calculations for each case discussed.
- 2019 Fall
2019 Fall Math Colloquia
September 18 Smith Hall 516, 4:00pm
Faith Hensley (Marshall University) Extremal Numbrix Puzzles
Abstract: Numbrix is a puzzle in Parade magazine. The player is given a 9 × 9 grid with some integers between 1 and 81 filled in. The player then needs to fill in the rest of the integers between 1 and 81 so that consecutive integers appear in adjacent cells of the grid. Generalizing this puzzle we consider m × n grids with the entries being the integers between 1 and mn. We say that a set of clues defines a puzzle if there exists a unique solution given those clues. In 2018 Hanson and Nash find the maximum number of clues that fail to define an m × n puzzle for all m and n. I present our work on their conjecture concerning the minimum number of clues necessary to define a puzzle. This research is joint work Ashley Peper conducted as part of the 2019 REU program at Grand Valley State University.
Chloe’ Marcum (Marshall University) Extended Schur Functions
Abstract: The set of quasisymmetric functions homogeneous of degree n form a polynomial vector space, QSym, with multiple bases. Many of these bases can be generated combinatorially using tableaux with various rules. The bases of QSym we are interested in are the quasisymmetric Schur functions and the extended Schur functions. Both generalize the symmetric Schur functions. A common question in linear algebra is how to transition from one basis to another. We have an expansion of extended Schur functions into quasisymmetric Schur functions for a family of indexing compositions. We prove this expansion combinatorially by using a tree whose leaves indicate the polynomials that appear in our expansion.
October 16 Smith Hall 516, 4:00pm
Logan Rose (Marshall University) Modeling Malaria with Controls
Abstract: Malaria is a deadly parasitic disease that has been a major threat to public health for centuries, particularly in Sub Saharan Africa and South Asia. Although there are still 200 million cases reported yearly according to the CDC, there have been renewed efforts in recent decades to combat this illness. Mathematicians have created various models using differential equations to simulate the spread of malaria and to determine which control strategies are most effective in reducing the number of new infections. Many of these consider the interactions between humans and the Anopheles mosquito, the primary vector of the disease. This project considers the effectiveness of two popular malaria control strategies: using bednets and releasing sterile mosquitoes. We used an eight-equation model that combines an SEIR (Susceptible-Exposed-Infected-Recovered) model for the human population, an SEI (Susceptible-Exposed-Infected) model for the vector population, and an additional equation for the sterile mosquito population. In addition, we applied the Next Generation Matrix method to our model to derive a formula for the basic reproduction number for infectious disease. Finally, we apply optimal control theory to find the optimal releasing strategies, and numerical simulations are presented for various cases.
Michael Waldeck (Marshall University) Generalizing the Classical Construction for Complete Sets of Mutually Orthogonal Latin Squares
Abstract: Latin squares are a well established topic of study in Mathematics. A latin square of size n is an n by n square where each number from 1 to n appears exactly once in each row and in each column. Two latin squares are orthogonal mates if, when the squares are superimposed, every possible ordered pair of entries appears in the superimposed square. In the 18th century, Leonhard Euler studied the question of finding a complete set of mutually orthogonal latin squares (MOLS) of a given size. Euler proved that for each n, a set of n by n MOLS can have no more than n – 1 squares. It has also been proved that, where n is a prime power, this upper bound is achieved through the classical construction. The classical construction for a complete set of MOLS of size n by n can be given by a formula M(i, j) = i + cj, where c is a nonzero element in the finite field of order n. We study the number of orthogonal mates and the graph of the mate relationship between a family of latin squares based on a generalization of that formula. That is, when q is prime, we study the set of latin squares of size q by q that can be given by a formula S(s, c)(i, j) = s(i) + cj, where s mapping the finite field of order q to itself is a permutation of the field, c is a nonzero element in the finite field of order q, and the addition and multiplication are carried out in the finite field.
November 20 Smith Hall 530, 4:00pm
Carl Mummert (Marshall University) How to Multiply Big Natural Numbers
Abstract: Big natural numbers are all around. They keep your data private on the internet, and scientists use them for high precision simulations. Adding big numbers is not very hard, but multiplying them is much more challenging. The problem of multiplying numbers efficiently is at the border between mathematics and computer science.
I will introduce several multiplication algorithms currently used in state of the art software. Then I will describe a breakthrough announced by two researchers in March 2019. They produced an algorithm that can multiply two natural numbers – of any size – with an efficiency we think is optimal. This talk is aimed at anyone with a background of college algebra or higher.
- 2019 Spring
2019 Spring Math Colloquia
March 20 Jiyoon Jung (Marshall University) Enumeration of Fuss-Schroder paths by types and connected components Smith Hall 516, 4:00pm
Abstract: Catalan numbers form a sequence of natural numbers that occur in various important counting problems in Combinatorics. Dyck paths are one of the problems that engaged Catalan numbers. In this talk, the applications of Dyck paths are introduced by considering types of paths, connected blocks, Schroder paths, and Fuss analogues.
April 17 Michael Schroeder (Marshall University) Putting Numbers in Grids: Theory and Applications Smith Hall 516, 4:00pm
Abstract: There are many games that involve putting numbers in a grid, like Sudoku, but there are equally many theoretical and practical applications for putting numbers in a grid. Grids with certain conditions met, like no numbers repeated in a row or column, have uses in cryptography, statistics, and experimental testing.
In this talk, we begin with an introduction to Latin squares (a grid of numbers meeting certain Sudoku-like conditions) and discuss a few of their many applications. We then look at some embedding problems (completely filling a partially filled grid with certain conditions) and discuss some recently published results in this area.
You may not improve your Sudoku-solving skills by attending this talk, but you should gain some appreciation for why such games can be useful in the real world!
This is a talk for a general audience! Tell your friends!
- 2018 Fall
2018 Fall Math Colloquia
September 19 Elizabeth Niese (Marshall University) The RSK algorithm and applications Smith Hall 516, 4:00pm
Abstract: The Robinson-Schensted-Knuth (RSK) algorithm is a classical algorithm in algebraic combinatorics. It is a bijection between words and pairs of tableaux which has many interesting combinatorial properties. There are a number of distinct constructions equivalent to this algorithm, including the jeu-de-taquin and Viennot’s shadow lines construction. We will look at several of these constructions and their use in proofs of algebraic formulas.
October 17 Chloé Marcum (Marshall University) Using polynomials to study knots Smith Hall 516, 4:00pm
Abstract: A knot is any closed loop in space. Two knots may be the same knot even though they appear to be different. A local move is a change to a small portion of a knot and the rest of the knot is assumed to stay the same. A local move may or may not change the knot. An invariant is a characteristic of a knot that help us tell the difference between knots. In our research, we studied certain polynomials that are knot invariants. We studied the effect of certain local moves on Homflypt and Kauffman polynomials. As a consequence, we discovered some new properties of these invariants.
This research was completed in summer 2018 as part of a Research Experience for Undergraduates (REU) at St Mary’s College of Maryland. At the end of the talk, I will share general information about REUs as well as my experience at St. Mary’s.
Knot theory is an area of math that is understandable without a lot of math background. All students interested in math are encouraged to attend.
November 28 Raid Al-Aqtash (Marshall University) Market Basket Analysis Smith Hall 516, 4:00pm
Abstract: Market basket analysis is a data mining technique based upon using association rules to uncover the purchasing trends in large transaction datasets. The key factor here is to determine possible lists of items that are frequently sold together. In this talk, I will speak about association rules and how they can be used by large retail companies in market basket analysis. A real dataset will be provided in an application of association rules.
Keywords and phrases: data mining, basket analysis, beer and diapers, association rules, support, confidence, lift.
This will be a general audience talk, using a bit of information about proportions and percentages.
- 2018 Spring
2018 Spring Math Colloquia
February 21 Michael Otunuga (Marshall University) Global stability for a (2n+1)-dimensional HIV/AIDS epidemic model with treatments Smith Hall 518, 4:00pm
Abstract: In this work, we derive and analyze a (2n+1)-dimensional deterministic differential equation modeling the transmission and treatment of HIV (Human Immunodeficiency Virus) disease. The model is extended to a stochastic differential equation by introducing noise in the transmission rate of the disease. A theoretical treatment strategy of regular HIV testing and immediate treatment with Antiretroviral Therapy (ART) is investigated in the presence and absence of noise. By defining R(0,n), R(t,n) and R(t,n) as the deterministic basic reproduction number in the absence of ART treatments, deterministic basic reproduction number in the presence of ART treatments and stochastic reproduction number in the presence of ART treatment, respectively, we discuss the stability of the infection-free and endemic equilibrium in the presence and absence of treatments by first deriving the closed form expression for R(0,n), R(t,n) and R(t,n). We show that there is enough treatment to avoid persistence of infection in the endemic equilibrium state if R(t,n)=1. We further show by studying the effect of noise in the transmission rate of the disease that transient epidemic invasion can still occur even if R(t,n)<1. This happens due to the presence of noise (with high intensity) in the transmission rate, causing R(t,n)>1. A threshold criterion for epidemic invasion in the presence and absence of noise is derived. Numerical simulation is presented for validation.
April 19 Carl Mummert (Marshall University) The number TREE(3), and counting down in base infinity Smith Hall 518, 4:00pm
Abstract: The motivation of this talk is a peculiar situation from computer science. In some cases, we know that a program will eventually stop, but we have no way to concretely describe or even bound the number of steps the program will take. For one such program, the number of steps is a number TREE(3) so large that there is no concrete way to describe it or bound it from above.
This talk will introduce TREE(3) and the related result known as Kruskal’s theorem. We will look at some simpler versions of the theorem, leading us to a “base infinity” number system. This system is like base ten, but each digit can be arbitrarily large. We will see that counting down to 1 from a base infinity number is not as easy as it sounds.
The work on base infinity numbers is joint research with mathematics major Samantha Colbert.
- 2017 Fall
2017 Fall Math Colloquia
September 20 Matt Davis (Muskingum University) Non-transitive dice: Constructions, Complications, and Questions Smith Hall 509, 4:00pm
Abstract: Non-transitive dice have been a source of fascination for mathematicians for over 50 years. We are given a set of dice which are numbered in strange ways. Each player chooses a die, rolls it, and the higher roll wins. Our intuition suggests that in any set of dice, one is the “best”. However, it turns out that it is relatively easy to construct a set of dice which are non-transitive – where most dice are strong against some opponents and weak against others. In this talk we will look at lots of examples of these fascinating objects, aiming for a goal of a single construction that allows us to create a set of dice in any desired configuration. We will also talk briefly about the much harder problem of finding the most efficient way to create such a set of dice.
October 18 Skye Smith (Service Pump & Supply, Huntington WV) Three Things I Wish I Had Known When I Was a Math Major Smith Hall 509, 4:00pm
Abstract: Since graduating from Marshall University with an applied mathematics degree in 2014, I have used my degree in several various business roles. Each position has provided a new way to use my mathematics degree in a business setting and each role brought new lessons I wished I had considered throughout my time as an undergraduate student. In this presentation, I will discuss the three things I wish I had known while I was a mathematics major at Marshall University. Addressing these three observations will help guide mathematics students who are hoping to use their skill set in a business setting at a time when math minds are more important than ever to companies undergoing digital transformations and embracing the era of big data.
November 15 Avishek Mallick (Marshall University) Statistical Modeling of Discrete/Count Data
Abstract: In this talk, I will introduce the idea of Statistical modeling, especially in context of count data. We will look at different facets of data fitting like estimation techniques and criterion for assessing goodness-of-fit. A substantial part of the talk will be about modeling inflated count data. We will be looking at lots of real world examples. This talk is intended for a general audience and thus should be appropriate for Mathematics undergraduate and graduate students.
- 2017 Spring
2017 Spring Math Colloquia
January 16 Carl Mummert (Marshall University) Mathematical Induction: Through Infinity and Beyond
February 16 John Asplund (Dalton State University) Vertex Colouring Degeneracy and the Limits of Edge-Colouring Techniques
- 2016 Fall
2016 Fall Math Colloquia
September 21 Michael Schroeder (Marshall University) A Survey of Graph Decompositions
October 24 Elizabeth Niese (Marshall University) The combinatorics of symmetric polynomials
November 16 Scott Sarra (Marshall University) Radial Basis Functions Methods and their Implementation
November 30 JiYoon Jung (Marshall University)
- 2016 Spring
2016 Spring Math Colloquia
January 26 Avishek Mallick (Marshall University) A Look at Permuatation (a.k.a. Randomization) Tests
February 24 Carl Mummert (Marshall University) Incompleteness in mathematics
March 7 Shubhabrata Mukherjee (University of Washington, Seattle) Introduction to Genetic Epidemiology in GWAS era
March 8 Shubhabrata Mukherjee (University of Washington, Seattle) Genetic analyses of late-onset Alzheimer’s Disease
April 6 Anna Mummert (Marshall University)
- 2015 Fall
2015 Fall Math Colloquia
September 2 Michael Schroeder (Marshall University) Tournaments: Scheduling Them Fairly and More!
September 28 Nick Loehr (Virginia Tech) Rook Theory 101
September 29 Nick Loehr (Virginia Tech) Sweep Maps and Bounce Paths
October 21 Micheal Otunuga (Marshall University) Stochastic Modeling of Energy Commodity Spot Price Processes
November 4 Martha Yip (University of Kentucky) Coloring: the Algebraic Way
- 2015 Spring
2015 Spring Math Colloquia
February 4 Elizabeth Niese (Marshall University) What do trigonometry and combinatorics have to do with each other?
February 17 David Cusick (Marshall University) 350 Years of Service … and Then Pffft!
March 4 Gregory Moses (Ohio University) Clustering and Stability of Cyclic Solutions in the Cell Division Cycle of Yeast
March 27–28 MAA Ohio Section Meeting at Marshall University
April 14 Judy Day (University of Tennessee) Modeling the host response to inhalation anthrax to uncover the mechanisms driving risk of disease.
April 15 Judy Day (University of Tennessee) Determining the what, when, and how of therapeutic intervention strategies for controlling complex immune responses.
- 2014 Fall
2014 Fall Math Colloquia
September 3 Carl Mummert (Marshall University) Is that a Prime Number?
September 17 Laura Adkins (Marshall University) Interactive Regression Models with Centering
October 1 Michael Schroeder (Marshall University) Latin squares and their completions
October 15 Xue Gong (Ohio University) Clustering and Noise-Induced Dispersion in Cell Cycle Dynamics (No Link to Abstract)
November 5 Richard Brualdi (University of Wisconsin–Madison) The Gale-Berlekamp Light-Switching Problem and a Permutation Variation
November 6 Richard Brualdi (University of Wisconsin–Madison) All Things Bruhat: Matrix Bruhat Decomposition, Complete Flags, Bruhat Order of Permutations, (0,1) and Integral Matrices, and Tournaments
November 19 Bismark Oduro (Ohio University) Designing Optimal Spraying Strategies for Controlling Re-infestation by Chagas Vectors
- 2014 Spring
2014 Spring Math Colloquia
March 10 Jeffry L. Hirst (Appalachian State University) Alan and Ada’s Theoretical Machines
March 11 Jeffry L. Hirst (Appalachian State University) Reverse Mathematics, Graphs, and Matchings
April 9 JiYoon Jung (Marshall University) The topology of chain selected complexes of a poset PDF
April 11 Lingxing Yao (Case Western Reserve University) Mathematical Modeling and Simulation for Biological Applications
April 14 Stephen Flood (University of Connecticut – Waterbury) Path, trees, and the computational strength of a packed Ramsey’s theorem
- 2013 Fall
2013 Fall Math Colloquia
October 2 Lynne Yengulalp (University of Dayton) Topological completeness
October 30 Roger Estep (Marshall University) Filtered leapfrog time integration with enhanced stability properties Robert Hughes (Marshall) Agent-based modelin of pandemic influenza
November 18 Thomas Mathew (University of Maryland-Baltimore County) The Assessment of Bioequivalence: A Statistical Overview
November 19 Thomas Mathew (University of Maryland-Baltimore County) Methodology and Some Applications
- 2013 Spring
- 2012 Fall
2012 Fall Math Colloquia
October 3 John Drost (Marshall) What is Strategic Voting and What Can Be Done About It?
- 2012 Spring
2012 Spring Math Colloquia
January 25 Michael Schroeder (Marshall) Cyclic Matching Sequencibility of Graphs
Feburary 22 Anna Mummert (Marshall) Studying the recovery procedure for the time-dependent transmission rate in epidemic models
March 7 Matthew Sedlock (Johns Hopkins University) Percolation models
March 9 Avishek Mallick (University of New Hampshire) Inferential procedures based on samples with nondetects from normal and related distributions
March 12 Myung Soon Song (University of Pittsburgh) An unconventional approach to likelihood of correlation matrices
April 2 Sharad Silwal (Kansas State University) Image quality assessment methods
April 6 JiYoon Jung (University of Kentucky) The topology of restricted partition posets PDF
- 2011 Fall
2011 Fall Math Colloquia
November 8 Carl Mummert (Marshall) Two examples from infinitary combinatorics
- 2011 Spring
2011 Spring Math Colloquia
April 5 Suman Sanyal (Marshall) Stochastic Dynamic Equations
April 8 Elizabeth Niese (Virginia Tech) Macdonald polynomials and the hook-length formula for standard Young tableaux
April 15 Andrew Oster (École Normale Supérieure) A laminar model for the development of the primary visual cortex
April 18 Michael Schroeder (University of Wisconsin-Madison) Phi-symmetric Hailton cycle decompositions of graphs
April 20 Remy Friends Ndangali (University of Florida) Bound states in the radiation continuum and nonlinear effects in photonic structures
April 22. Paul Shafer (Cornell) Coding arithmetic in the Medvedev degrees and its substructures
- 2010 Fall
2010 Fall Math Colloquia
September 8 Anna Mummert (Marshall) Get the News Out Loudly and Quickly: Modeling the Influence of the Media on Limiting Infectious Disease Outbreaks
October 13 Carl Mummert (Marshall) The axiom of choice in mathematics and computability
November 9 Suman Sanyal (Marshall) Stochastic Process Indexed by Time Scale
- 2010 Spring
2010 Spring Math Colloquia
February 10 Anna Mummert (Marshall) Parameter sensitivity analysis for mathematical modeling
April 14 Suman Sanyal (Marshall) Stochastic dynamic equations and their applications
April 21 John Drost (Marshall) Inheritance, bankruptcy, and the Talmud
- 2009 Fall
2009 Fall Math Colloquia
September 16 Carl Mummert (Marshall) Gaming around with topology
October 15 Sydney Thembinkosi Mkhatshwa (Marshall) Super-spreading events
November 11 Duane Farnsworth (Marshall) Approximation Numbers and Ideals of Operators
- 2006 Fall
2006 Fall Math Colloquia
October 19 Peter Saveliev (Marshall) Low level vision through topological glasses
- 2005 Spring
2005 Spring Math Colloquia
February 22 Norah Esty (University of California – Berkeley) Topological Properties of Orbit Sets for Groups of Homeomorphisms
February 24 Elmas Irmak (Michigan State University) Mapping Class Groups
March 3 Akhtar Khan (Michigan Technological University) An inverse problem in elasticity
April 8 Judith Silver Conics in Projective Geometry
April 22 Bonnie Shook Topological Approaches to Fingerprint Identification Nathan Cantrell Cubical Homology in Medical Imaging
April 29 Arthur Porter (Professor Emeritus, University of Toronto) Manchester University’s Contributions to Analog and Digital Computing
- 2004 Fall
2004 Fall Math Colloquia
September 24 Alfred Akinsete The winning probability and ranking models for teams in soccer tournaments
October 8 Ralph Oberste-Vorth From Chaos to Stability: Dynamic Equations Parameterized by Time Scales PDF
October 22 John L. Drost What is the opposite of a prime number?
November 5 Elizabeth Duke and Kelli Hall Time Scale Calculus and Dynamical Systems
November 19 Christopher Johnson and Peter Saveliev Topological Proteomics: Pure Mathematics in Life Sciences
- 2004 Spring
2004 Spring Math Colloquia
January 23 Yulia Dementieva Statistical approaches to gene mapping
February 6 Linda Hamilton Robotics of the Mars Station Program
February 19 Basant Karna (Baylor University) Eigenvalue Comparison for Multipoint Boundary Value Problems
February 24 John (Matt) Matthews (Duke University) Granular Materials: An Introduction & Application to Hopper Flows
February 27 Mohamed Elhamdadi (University of South Florida) On knot invariants
March 5 Scott Sarra Scattered Data Approximation with Radial Basis Functions
April 2 John L. Drost Arrow’s Theorem or Why we all just can’t get along
- 2003 Fall
2003 Fall Math Colloquia
September 26 John L. Drost Addition Chains
October 10 Peter Saveliev From slot machines to topology through calculus
October 24 Kelli Hall Escher’s Tilings and Ribbons
November 7 Judith Silver The Spherical Metric Project
December 5 Bonita Lawrence Time Scales: A Snappy Link between Continuous Processes and Discrete Processes