The Department of Mathematics and Statistics offers a weekly colloquium series on Thursdays. Most colloquia begin between 3:00 and 3:30. Seminars alternate between those aimed at Undergraduate (type U) and Graduate (type G) audiences.

- Archived 2012-13 Colloquia
- Archived 2011-12 Colloquia
- Archived 2010-11 Colloquia
- Archived 2009-10 Colloquia
- Archived 2008-9 Colloquia
- Archived 2007-8 Colloquia
- Archived 2006-7 Colloquia
- Archived 2005-6 Colloquia

Type | Date | Title | Speaker |

G | 5/21/10 | Application of Gap Statistics to Penalized Model-Based Clustering | Wencheng Geng, MS Candidate: Program in Applied and Computational Mathematics |

G | 5/20/10 | Random walk on WordNet to measure semantic relatedness |
Yanbo Xu, MS Candidate: Program in Applied and Computational Mathematics |

G | 5/13/10 | A Comparison Study of Estimation Methods for Non-regular Distributions | Nan Zhang, MS Candidate: Program in Applied and Computational Mathematics |

G | 5/12/10 | Sensitivity Analysis of Hierarchical Decision Models from the Pair-Wise Comparison Judgment |
Jingrui Li, MS Candidate: Program in Applied and Computational Mathematics |

U | 5/6/10 | Undergraduate Honors | Leah Tollefson, Hanna Froehlich, Jenalyn Wright, Barb Brandt |

U | 4/29/10 | Undergraduate Honors | Aaron Potvien, Jacob Yunker, Brett Bozyk |

U | 4/22/10 | Using permutation tests to uncover patterns in how female baboons handle the infants of other females | Tom Moore, Department of Mathematics, Grinnell College |

U | 4/20/10 | How to understand the shape of growing leaves and flowers through Mathematical Analysis and Geometry |
Marta Lewicka, University of Minnesota Twin Cities |

G | 4/15/10 | Research Topics | Faculty of UMD Department of Mathematics and Statistics |

U | 4/8/10 | The Statistics of Religion | Dick Green, Department of Mathematics and Statistics, UMD |

U | 4/5/10 | Mathematics that swings: the math behind golf | Douglas N. Arnold, McKnight Presidential Professor, School of Mathematics, University of Minnesota |

G | 4/1/10 | Research Topics | Faculty of UMD Department of Mathematics and Statistics |

U | 3/31/10 | Mathematical Contest in Modeling 2010 | UMD Undergraduate Students: Brian Christner, Matt Holst, Aaron Potvien, Abhinav Devireddy, Ashley Epperly, James McKeown |

U | 3/25/10 | Ingenix Consulting | Shawn Walwick |

G | 3/11/10 | Euler's Method: How bad can it be? | Dr. Bruce Peckham, Department of Mathematics and Statistics |

U | 3/4/10 | Hard Problems: The Road to the World's Toughest Math Contest |
documentary film |

U | 2/25/10 | The Great Pi/e Debate |
film |

U | 2/18/10 | The Making of the 2003 and 2010 Math Awareness Month Posters | Joe Gallian, Department of Mathematics and Statistics |

G | 2/11/10 | Scheduling Round Robin Tournaments | Mariusz Meszka, AGH University of Science and Technology, Kraków, Poland |

U | 2/4/10 | The Probabilities of Winning a Particular Carnival Game | Dr. Ron Regal, Department of Mathematics and Statistics |

G | 1/28/10 | Research Topics | Faculty of UMD Department of Mathematics and Statistics |

G | 12/10/09 | Development and use of physiologically-based toxicokinetic models for fish | Dr. John Nicholds, EPA & Department of Physiology, UMD |

U | 11/19/09 | My experience as a GK-12 Fellow and as a secondary mathematics teacher | Bryan Freyberg, Math Teacher, Marshall School, Duluth |

G | 11/10/09 | Monte Carlo Simulation of the Degradation of Composite Films | Brian Hinderliter, Ph.D, CHP, Coatings and Polymeric Materials Department, North Dakota State University |

U | 11/05/09 | Hanna and Leah Studied Abroad Spring, 2009 | Hanna Froehlich and Leah Tollefson, UMD Undergraduate Mathematics Majors |

G | 10/29/09 | Mathematical issues in stability of viscoelastic flows | Michael Renardy, Professor, Department of Mathematics, Virginia Tech |

U | 10/22/09 | Bioinformatics: opportunities and challenges | Marshall Hampton, Department of Mathematics and Statistics |

U | 10/20/09 | Securian Financial Group | Natasha Farooq, Brian Hinkle, and Leah Tollefson, UMD Undergraduate Students |

G | 10/15/09 | Jacobians of Polynomial Mappings | Steve Rosenberg, Associate Professor, Department of Mathematics and Computer Science, University of Wisconsin-Superior |

U | 10/8/09 | AVERAGES | Dick Green, Department of Mathematics and Statistics, UMD |

U | 10/2/09 | Lessons Learned in My Career | Michael Hafeman |

U | 9/24/09 | Using Mathematics to Think Clearly about Sustainable Harvesting of Natural Resources | John Pastor, Professor of Biology, UMD |

**Using Mathematics to Think Clearly about Sustainable Harvesting of Natural Resources**

John Pastor

Professor of Biology

University of Minnesota Duluth

**Abstract:**

There is much discussion about sustainability of natural resources and whether we are approaching so-called tipping points where systems change abruptly and become unsustainable. Mathematics can help us think more clearly about these problems. The mathematical ideas underlying "sustainability" and "tipping points" are equilibrium, stability, and bifurcations. I will show how these help us understand whether different harvesting policies of a population are sustainable. The unharvested population will be described by a logistic growth curve, from which we will subtract various functions representing different harvesting
strategies. Different equilibria with different stabilities result. Various bifurcations happen at particular levels of harvesting where populations may go extinct or collapse to low levels. The underlying theory makes use of differential equations, but I will demonstrate the
basic ideas graphically.

**Time: ** Thursday, September 24, 2009 3:00PM -- 4:00PM

** Location: ** 130 Solon Campus Center

**Lessons Learned in My Career**

Michael Hafeman

**Abstract:**

I will provide an overview of my varied career as an actuary. I will begin with a description of my current activities as an independent consultant on financial sector regulatory issues. This will be followed by a discussion of the path taken to get there and some lessons learned along the way. An example will be used to illustrate how these lessons apply to a specific current activity--participation on the
Public Interest Oversight Board.
The objectives of the session will be to provide some insight on the range of opportunities available to actuaries and some ideas on factors that can contribute to career success.
There will be opportunity for questions and discussion.
Michael Hafeman is a 1974 graduate of UMD with degrees in mathematics and economics. He has assessed the insurance sectors of several countries for the International Monetary Fund and managed the development of comprehensive training materials on insurance supervision for the World Bank. He previously directed the Specialist Support Sector experts in Accounting and Financial Information, Actuarial, Capital, Capital Markets, Compliance, Credit Risk and Financial Services Technology, and oversaw the Office of the Chief Actuary, at the Office of the Superintendent of Financial Institutions Canada.
He will be inducted into the Swenson College of Science & Engineering Academy of Science & Engineering while on campus.

**Time: ** Friday, October 2, 2009 3:00PM -- 4:00PM

** Location: ** LSBE 118

**AVERAGES**

Dick Green

Department of Mathematics and Statistics

**Abstract:**

An average is one number that stands for a bunch of other numbers when one is doing something with them. There are many kinds of averages. Not only do different numbers produce different averages, but the same numbers produce different averages when different things are being done with then. Various kinds of averages will be illustrated with examples including the
rate of tuition increase at UMD, family size, generation time and the Ortega hypothesis about scientific productivity. This talk will be accessible to anyone who has had a basic course in statistics.]

** Time: ** Thursday, October 8, 2009 3:00PM -- 4:00PM

** Location: ** 130 Solon Campus Center

**Jacobians of Polynomial Mappings**

Steve Rosenberg

Associate Professor, Department of Mathematics and Computer Science, University of Wisconsin-Superior

**Abstract:**

Usually introduced in second-year calculus, the Jacobian
determinant associated with a smooth mapping carries much
information about the mapping. In this introductory talk, we will
explore polynomial mappings f : C[x1,...,xn] --> C[x1,...,xn] and
investigate what the Jacobian J(f) tells us about f; e.g., when is f
injective? Surjective? In the process, we will survey some basic
results in commutative algebra and algebraic geometry.

*Steve Rosenberg has published results in number theory, discrete
mathematics, and cryptographic protocol security. His current
research interests include complex algebraic geometry, kswappable
graphs, and diophantine approximation. *

** Time: ** Thursday, October 15, 2009 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

**Securian Financial Group**

Natasha Farooq, Brian Hinkle, and Leah Tollefson

UMD Department of Mathematics and Statistics

**Abstract:**

This colloquium will include three parts: A synopsis of Securian Financial Group and their internship program by Natasha Farooq, a personal account of Securian?s internship program in actuarial science by Leah Tollefson, and a discussion of the day-to-day activities of an actuary at Securian by Brian Hinkle. Questions to be answered: What does an actuary do? How do I become an actuary? How should I begin applying for internships and jobs in theactuarial sciences? What does Securian do?

**Time: ** Tuesday, October 20, 2009 3:00PM -- 5:00PM

** Location: ** 130 Solon Campus Center

** Bioinformatics: opportunities and challenges**

Marshall Hampton

UMD Department of Mathematics and Statistics

**Abstract:**

Biological data has been growing exponentially for the last
few decades. The resulting wealth of data requires new mathematical,
statistical, and computational methods. This talk will survey some of
these methods, highlighting recent developments in sequencing
mammalian genomes, the structure of the HIV virus, and the recent H1N1
swine-flu pandemic

**Time: ** Thursday, October 22, 2009 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Mathematical issues in stability of viscoelastic flows**

Michael Renardy

Professor, Department of Mathematics, Virginia Tech

**Abstract:**

"Traditional" hydrodynamic stability studies infer stability of a flow
from a computation of eigenvalues of the linearized system. While this
is well justified for the Navier-Stokes equations, no rigorous result
along these lines is known for general systems of partial differential
equations; indeed there are counterexamples for lower order
perturbations of the wave equations. This lecture will discuss how
recent results on "advective" equations can be applied to creeping
flows of viscoelastic fluids of Maxwell or Oldroyd type. For spatially
periodic flows, stability can be reduced to the study of a) the
eigenvalues, and b) a system of non-autonomous ordinary differential
equations that arises from a geometric optics approximation for short
waves. A more complete result for the upper convected Maxwell model
will also be discussed.

Michael Renardy has published 4 books, 164 research journal papers, 40
conference proceeding papers, and 24 papers on problem solving. He is
a winner of several awards, like Presidential Young Investigator Award
(1985), Virginia Tech Alumni Award for Research Excellence (1993), and
Class of 1950 Professor, Department of Mathematics, Virginia
Polytechnic Institute and State University

** Time: ** Thursday, October 29, 2009 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Hanna and Leah Studied Abroad Spring, 2009**

Hanna Froehlich and Leah Tollefson

UMD Department of Mathematics and Statistics

**Abstract:**

UMD mathematics majors Hanna Froehlich and Leah Tollefson
will tell of their experiences studying abroad last spring semester.
Hanna Froehlich, who studied at Loughborough University in
Loughborough, England, took Fourier analysis, partial differential
equations, calculus of variations, statistical modeling, numerical
methods and complex variables. Leah Tollefson, who studied at the
Norwegian University of Science and Technology in Trondheim, Norway,
took partial differential equations, political economy, Norwegian
ethnography, and Norwegian language. Each will describe her exchange
program, course work, classroom culture and student behavior, making
friends and holiday travel. They will answer questions, give advice
and encourage others to also study abroad.

** Time: ** Thursday, November 5, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Monte Carlo Simulation of the Degradation of Composite Films**

Brian Hinderliter, Ph.D, CHP

Coatings and Polymeric Materials Department, North Dakota State University

**Abstract:**

Coatings cover most metal and wood surfaces exposed to environmental
weathering, both to protect the underlying material, from corrosion
for example, and offer aesthetic improvements. Insights into coating
degradation have been achieved first through Monte Carlo simulations,
then through the recognition that many of the property changes are due
to the statistical accumulation of vast numbers of small random
events, allowing the central limit theorem (CLT) to be used to predict
topological roughness distribution as a function of time.

Simulation of coatings and other composite material degradation continues to be productive, not only in generating functional quantitative relationships of measurable properties with time, but also in helping to direct research to improve the technology. The modeling process payoffs include practical benefits such as the ability to interpolate measurements and smooth noisy data based on physically based fitting functions and extrapolate measured data for lifetime prediction or service/maintenance scheduling. Modeling is vital in more fundamental improvements of composite systems such as understanding the physical processes and composite constituents that are impacting measurement leads to better design of coatings (Occam?s razor ? know what is important for the property of interest), separating various degradation processes (chemistry from topography), and detecting changes in the dominant cause of measurement (for example detecting coating crack initiation in the paint).

Success in understanding and predicting coating?s properties has been achieved with surface degradation in homogenized materials, both using statistical equations and Monte Carlo simulations. Many aspects of a coatings performance are impacted the surface topology, and with the temporal response function of the surface roughness based on CLT approximation, closed functional forms can the evolution of the surface reflectance as a function of wavelength, the surface energy and the probability of cracks developing in the coating.

** Time: Tuesday**, November 10, 2:45PM -- 4:00PM (Note: this is not the usual day)

** Location: ** 130 Solon Campus Center

** My experience as a GK-12 Fellow and as a secondary mathematics teacher.**

Bryan Freyberg

Math Teacher, Marshall School, Duluth

**Abstract:**

Fifty percent of new teachers walk away from the job within the
first five years. I just needed a break. This talk is aimed at
undergraduate and graduate students who may be considering a career in
secondary education or applying for the NSF GK-12 Fellowship offered at
UMD. I did both and lived to tell about it. I'll share some stories about
teaching, information about the GK-12 program, and leave plenty of time
for questions.

** Time: ** Thursday, November 19, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Development and use of physiologically-based toxicokinetic models for fish**

Dr. John Nicols

EPA & Department of Physiology, UMD

**Abstract:**

Kinetic models of chemical uptake and accumulation by fish are used extensively in ecological risk assessments for toxic chemicals to diagnose likely causes of impairment and predict effects of different management options. Different models are used for different applications. In this presentation I will describe the development and use of physiologically-based toxicokinetic (PBTK) models for fish. PBTK models are developed from knowledge of an organism’s anatomy, physiology, and biochemistry as well as attributes of the chemical in question. Because they are based on a mechanistic understanding of the processes that underlie observed chemical kinetics, these models can be used to extrapolate limited knowledge to a much wider range of untested chemicals, species, and exposure scenarios.

** Time: ** Thursday, December 10, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Research Topics**

Faculty of the UMD Department of Mathematics and Statistics

**Abstract:**

Members of the UMD Department of Mathematics and Statistics will present some of the many interesting aspects of their research. Get a better understanding of faculty member's research interests and perhaps find a topic that could become the basis for your thesis/project research.

** Time: ** Thursday, January 28, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** The Probabilities of Winning a Particular Carnival Game**

Dr. Ron Regal, UMD Department of Mathematics and Statistics

**Abstract:**

In the 1970's the State of Minnesota prosecuted the operator of a Midway game at the Minnesota State Fair for fraud. When the attorney general's office was investigating the game at the fair, they saw one fair-goer lose $800 and another lose $1400. Players at times begged the operator to hold their places in line so they could go home to get more money and pick up where they left off.

In this talk I will tell how the game worked and how to compute probabilities of winning the game. I will also explain why the charge of fraud was chosen. This talk will be aimed at students who have taken Stat 3611. Some ideas in common with Stat 5531, Probability Models, will be used, but the basic concepts can be understood after taking Stat 3611.

** Time: ** Thursday, February 4, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** Scheduling Round Robin Tournaments**

Mariusz Meszka

AGH University of Science and Technology, Kraków, Poland

**Abstract:**

Many sport competitions, in which every game is a meeting of two players, are based on round robin tournaments. A *round *is a collection of games in which every team plays at most one game and all these games are arranged in the same period. A *round robin tournament of n teams *is a tournament in which each team meets every other team exactly once and all games are split into *m *rounds.

Very often schedules have to meet additional rules and requirements,

appropriate for specific competitions. Particular solutions are results of using advanced software packages. Algorithms applied therein base both on graph theoretical and optimization methods.

** Time: ** Thursday, February 11, 2:45PM -- 4:00PM

** Location: ** 130 Solon Campus Center

** The Making of the 2003 and 2010 Math Awareness Month Posters**

Joe Gallian

UMD Department of Mathematics and Statistics

**Abstract:**

In this talk I discuss the how Mathematics Awareness Month has been observed over the years. Particular attention will be paid to how the selection of themes for Mathematics Awareness Month 2003 and 2010 were made and how the images for those years were created.

** Time: ** Thursday, February 18, 2:45PM -- 4:00PM

** Location: ** 150 Chemistry