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 201213 Colloquia
 Archived 201112 Colloquia
 Archived 201011 Colloquia
 Archived 200910 Colloquia
 Archived 20089 Colloquia
 Archived 20078 Colloquia
 Archived 20067 Colloquia
 Archived 20056 Colloquia
Type 
Date 
Title 
Speaker 
G  5/1/14  Greg Bard, University of Wisconsin  Stout  
U 
4/24/14  Philip Bauer, Jordan Maiers and Adam Swinney, UMD Mathematics & Statistics Undergraduate Students  
G 
4/17/14  Qingzhao Wang, Ph.D. Canidate in Mechanical Engineering, Virginia Polytechnic Institute  
U 
4/10/14  Jasmine Helgeson, Penghuan Ni, Tim Schoenheider, Philip Bauer, Jesse Schmieg and Joe Tonianato, UMD Mathematics & Statistics Undergraduate Students  
G 
4/3/14  William Keith, Assistant Professor, Mathematical Sciences, Michigan Tech University  
U 
3/27/14  Ross Garberich, Minneapolis Heart Institute Foundation, UMD Alumni  
G 
3/13/14  Thomas Cameron, UMD Alumni, Math Graduate Student  
U 
3/6/14  Karl Wimmer, Assistant Professor, Department of Mathematics, Duquesne University (UMD Graduate)  
U 
2/20/14  Xuan Li, Assistant Professor, Statistics, UMD  
U 
2/6/14 
Uwe Leck, Associate Professor, Department of Mathematics, UWS  
G 
1/30/14 *rescheduled to 2/13/14 
Steven Chiou, Assistant Professor, Statistics, UMD  
U 
12/12/13  Kyle Krueger and Brett Bozyk, UMD Graduates  
U 
11/21/13  Lucas Gloege, Inne Singgih and Ondrej Zjevik, Graduate Students, UMD  
U 
11/15/13  Ken Stanley, Director, Dubois Project of Oberlin College  
G 
11/14/13  Steve Butler, Department of Mathematics, Iowa State University  
U 
11/7/13  Richard Green, Department of Mathematics, UMD  
G 
10/31/13  Brian Hinderliter, Department of Mechanical and Industrial Engineering, UMD  
U 
10/24/13  Ron Regal, Department of Mathematics, UMD; William Salmon, Department of Linguistics, UMD 

G 
10/17/13  David Clark, Department of Mathematics, UMTC  
U 
10/10/13  Math Majors and Information Security in a Digital Age: Any Connection? 
Dr. William Krossner 
G 
10/3/13  Families of Infinite Series With Interesting Limiting Structure 
John Greene, Department of Mathematics, UMD 
U 
9/20/13  Joseph Gallian, Department of Mathematics, UMD  
G 
9/19/13  Michael Dorff, Department of Mathematics, Brigham Young University  
U 
9/19/13  Michael Dorff, Department of Mathematics, Brigham Young University 
Breaking Codes by Solving Polynomials: Algebraic Cryptoanalysis
by
Gregory Bard
University of Wisconsin  Stout
Abstract:
Algebraic cryptanalysis is the process of turning a cipher into a system of polynomial equations, and then solving the equations to obtain the secret key of the cipher. First, it is interesting to see how alldigital circuits, but especially hardware ciphers, can be encoded as polynomial systems of equations mod 2. Second, it also exciting to see a specific example, and so I will discuss my dissertation work on breaking the cipher Keeloq, which is used in nearly all automobiles with remote keyless entry. I will briefly touch on work done upon some other ciphers, and other noncryptographic applications.
Time: Thursday, May 1, 2014, 3:00PM
Location: SCC 130
OutofClass Mathematics Experiences
by
Philip Bauer, Jordan Maiers and Adam Swinney
Abstract:
In this colloquium two UMD students will describe their honors projects and a third will discuss his internship. Philip Bauer explored some properties of continued fractions; Jordan Maiers investigated the behavior of the Mandelbrot set; and Adam Swinney was a Travelers Insurance, oil and gas actuarial summer student.
Time: Thursday, April 24, 2014, 3:004:00PM
Location: MoH 203
Computational Investigations of Boundary Effects on CFD Simulations of Thermoacoustic Instabilities
by
Qingzhao Wang
Abstract:
The increasing awareness of environmental issues has been challenging gas turbine designers since early 90s. Lean premixed combustion is one of the strategies to achieve low NOx emission, and has been widely applied in gas turbines. However, near the leancombustion limit, the gas turbines are more susceptible to thermoacoustic instabilities, which may cause loud noise, violent vibration, structural destruction, and time and economic cost. Thus, it is desirable and essential to predict and control the occurrence of thermoacoustic instabilities. Many studies have been focusing on the Computational Fluid Dynamics (CFD) simulations to explore this phenomenon, but they either made simplifications and ignore some complex but important mechanisms, or required impractically long time for computations. In this talk, I will first present the key issues in simulating the coupling process of heat release rate and pressure fluctuations involved in thermoacoustic instability phenomenon. Then I will talk about the potential sensitivity analysis approaches that are applicable to investigations of boundary condition effects on thermoacoustic instabilities. The focus is on the formulation of Continuous Sensitivity Equation (CSE) method applied to the Direct Numerical Simulation (DNS) of thermoacoustic instability problems. This proposed sensitivity analysis approach only requires a single run of the CFD simulation. Moreover, the sensitivities of field variables, pressure, velocity and temperature to boundarycondition parameters are directly obtained from the solution to sensitivity equations. Thermoacoustic instability is predicted by the Rayleigh criterion and indicated by Rayleigh index. The sensitivity of Rayleigh index is computed utilizing the sensitivities of field variables. This approach is validated through the 1D thermally induced acoustics problem.
Time: Thursday, April 17, 2014, 3:00PM
Location: SCC 130
Mathematical Contest in Modeling 2014
by
Jasmine Helgeson, Penghuan Ni, Tim Schoenheider, Philip Bauer, Jesse Schmieg and Joe Toninato
UMD Mathematics & Statistics Undergraduate Students
Abstract:
Each February, a nationwide international Mathematical Contest in Modeling (MCM) is held. Contestants have 96 hours to select from one of two problems and submit a solution. This year, two teams represented UMD. One team selected PROBLEM A: The KeepRightExceptToPass Rule, to develop a model to determine whether this is an effective rule in promoting better traffic flow, or whether some other rule might be better. The other team selected PROBLEM B: College Coaching Legends, to build a mathematical model to choose the best college coach or coaches from among either male or female coaches in such sports as college hockey, field hockey, football, baseball, basketball, or soccer.
The teams will discuss the contest problems, their proposed solutions, and their overall experience with the competition.
Time: Thursday, April 10,2014, 3:004:00PM
Location: MoH 203
mregular partitions and etafunction symmetries
by
William Keith
Abstract:
A famous result in partition theory is Ramanujan's congruences, that the number of partitions of 5n+4 is divisible by 5, those of 7n+5 divisible by 7, and those of 11n+6 divisible by 11. These are now understood as members of an infinite family of such congruences, unified by the symmetries of modular forms. More recent work has been devoted to finding congruences for the mregular partitions, those in which parts may not be divisible by m. These are now numerous, but we do not yet have a similar unifying structure. This talk will outline each of these ideas, demonstrate that it is now fairly easy to prove many conjectured congruences with current techniques, and lay out a few ideas, tentative as yet, for constructing such general theorems.
Time: Thursday, April 3,2014, 3:00PM
Location: SCC 130
The Role of Statisticians in Medical Reserach
by
Ross Garberich
Abstract:
Statisticians play a critical role in medical research. They help design studies, validate and analyze data and write abstracts, manuscripts and reports for publication. Additionally, as hospitals and healthcare systems face continued pressure to reduce costs and improve patient outcomes, the roles statisticians’ play continues to expand, Aided by the implementation of electronic health records, statisticians are beginning to play key roles in reporting realtime analytics and predictive modeling for patients who are still admitted to the hospital.
The presentation gives a brief overview of the varying roles that statisticians play in the field of medicine, the different types of business that hire statisticians, and some examples of different projects on which I have worked.
Time: Thursday, March 27 ,2014, 3:004:00PM
Location: MoH 203
NonLinear Eigenvalue Problems
by
Thomas Cameron
Abstract:
The standard linear eigenvalue problem Av = λ v and the generalized linear eigenvalue problem Av = λBv are introduced in the latter part of undergraduate school and become well known in graduate school.
Moreover, we have successful numerical algorithms for finding both the eigenvalue λ and the eigenvector v, specifically the QR, QZ, and Francis algorithm to name only a few.
However, when it comes to nonlinear eigenvalue problems, for example
(Aλ^{2} + Bλ + C)v = 0
it is rare for a student to come across this problem in their course studies, even at the graduate level. Truthfully, the best numerical algorithms of the day, perhaps in defeat, simply linearize the problem and refer to our old friends, QR, QZ, and Francis.
We will take a look at some general properties of nonlinear eigenvalue problems, a brief history of the numerical methods for solving the linear eigenvalue problem, some nonlinear methods, and a Gersgorin like theorem for the bounds of the eigenvalues with some practical results.
Time: Thursday, March 13 ,2014, 3:004:00PM
Location: SCC 130
What is Theoretical Computer Science
by
Karl Wimmer
Abstract:
In this talk, we will give a survey of various areas of theoretical computer science and the role that mathematics plays in these areas. We will discuss some applications such as machine learning and voting theory, as well as some theoretical topics. We will also discuss some realworld problems (that we would really like to be able to solve), which appear to be computationally hard not only to solve exactly, but also to solve approximately.
The material presented in the talk will be heavily influenced by the problems studied during the ``Real Analysis in Computer Science'' program (which the speaker attended as a Research Fellow) held during Fall 2013 at the Simons Institute for the Theory of Computing at the University of CaliforniaBerkeley.
Time: Thursday, March 6,2014, 3:004:00PM
Location: MoH 203
Xuan Li
Abstract:
Regression is a statistical approach to investigating the relationship between variables. Regression techniques have been widely used in almost every field.
This talk will be given by STAT 5511 Regression Analysis students (2013 Fall semester) based on their class projects:
 Estimation of Risk Rates using Arbitrage Pricing Theory (Michal Hrabia)
 Lake Superior  clear and cold, almost good enough to drink (Tim Cyr, Yvette Ibrahim, Dave Ongaro, Kelly Peterson, Andrea Samuelson, Miranda Steinmetz)
 Effects of Minimum Wage on Inflation (Katherine Borchert, Shinjini Kar, Cole Mathson)
 Cases of Infectious Diseases: Determinants of the Number of Deaths due to Tuberculosis across Nations (Matthew Arthur, Jasmine Helgeson, Xiao Li, Penghuan Ni, Kyle Vezina, Zichao Wang)
Time: Thursday, February 20,2014, 3:004:00PM
Location: MoH 203
Combinatorial Problems Motivated by Databases
by
Uwe Leck
Abstract:
Some combinatorial problems and results will be discussed that arise in the context of restoration of lost information in distributed databases. Consider a set T of lattice points in a k x k grid and call it a configuration. You can think of the points in T as faulty nodes that need to be repaired or decoded. Performing a step of decoding means transforming T into a new configuration T’ by removing all points belonging to some horizontal or vertical line L, under the constraint that only t points of T are on L (where t is some given number). T is decodable if it can be transformed into the empty set by an appropriate sequence of decoding steps. Examples of interesting questions in this context are: What is the largest size of a decodable configuration? Among all decodable configurations with the same given number of points, which are the hardest to decode (i.e., which require the most decoding steps)? What are the smallest decodable configurations that require some given number of decoding steps? How does all this generalize to higher dimensional grids?
Time: Thursday, February 6,2014, 3:004:00PM
Location: MoH 203
Recent Advances in Rankbased Inference for Accelerated Failure Time
by
Steven Chiou
Abstract:
Semiparametric accelerated failure time (AFT) models have not been used as frequently as Cox relative risk models in such settings due to lack of efficient and reliable computing routines for inferences. The challenge roots in the nonsmoothness of the rankbased estimating functions. The recently proposed induced smoothing approach, which provides fast and accurate rankbased inferences for AFT models. The induced smoothing approach is generalized to incorporate weights to accommodate different rank weights and additional weights from missing data and various sampling schemes. The variances are estimated with an efficient resampling approach that avoids solving estimating equations repeatedly. I will demonstrate the methods in a numerical study. As expected, the proposed estimators were obtained much faster without loosing accuracy in comparison to those from nonsmooth estimating equations, and the variance estimators provided good approximation of the variation in estimation.
Time: Thursday, January, 30 2014, 3:004:00PM
Location: 130 SCC
Kyle Krueger and Brett Bozyk
Abstract:
The world of retail is evolving quickly. Amazon.com has forced the brickandmortar chains to evolve rapidly, and the guiding hand that steers that evolution is analytics. A retail analyst can use massive data sets within tools like SAS and Excel to answer questions about what should go on the shelves, where it should go, how much space should be allocated, and more. Metrics like exclusivity, penetration, and lift can better inform decisions made by the business on a daily basis, and ensure that a company stays relevant to its consumer base.
Time: Thursday, December 12, 2013, 3:004:00PM
Location: 150 Chemistry
Mathematics courses in various parts of the world and study abroad recommendations for UMD mathematics and statistics students
by
Lucas Gloege, Inne Singgih and Ondrej Zjevik
Abstract:
Spending a term abroad can be very expensive and it can delay a student’s progress toward graduation. However, for many students these costs are more than balanced by eyeopening and life changing experiences they have while studying in a foreign country. Planning ahead is important for reducing the negatives and increasing the positives of a semester spent abroad. This includes, in part, determining what courses to take at UMD and what courses to take abroad. Since university mathematics and statistics education is not uniform across the world, foreign course syllabi and even UMD course equivalences provide only partial information.
In this colloquium three UMD graduate students, each of whom majored in mathematics as an undergraduate, will talk about their educational experiences in three different parts of the world. Inne Singgih will talk about her bachelor’s degree program at the University of Indonesia in West Java Province and her work as a mathematics educator in Indonesia. Ondrej Zjevik will talk about his bachelor’s degree program at VSB – Technical University of Ostrava, Czech Republic and how it compares with the mathematics programs at UMD. Lucas Gloege spent a semester abroad at Waikato University in New Zealand, while earning his BS from UMD. He will talk about his preparations for studying abroad, the courses he took at Waikato U. and his experiences in New Zealand. He will also give studyabroad recommendations for UMD mathematics and statistics students.
Time: Thursday, November 21, 2013, 3:004:00PM
Location: 150 Chemistry
Making math fun for mathphobic children
by
Ken Stanley, Director, Dubois Project of Oberlin College
Abstract:
The United States lags many developing countries in educational performance, particularly in our education of children of underrepresented minorities and children from families of lower socioeconomic status. Local funding for schools is part of the problem as students from lowincome families disproportionately attend poorly funded schools, however, local funding does not explain why these children perform poorly in all schools. In Oberlin, Ohio children from all backgrounds attend the same K12 schools, yet the achievement gap persists. Motivation, especially intrinsic motivation, drives educational achievement. The Du Bois Project helps underrepresented minorities and children from low socioeconomic families achieve and maintain excellence in the Oberlin Public Schools by helping them learn to enjoy math. We will explain how we use running, music, simple psychology and motivated Oberlin College students to make math fun.
Time: Thursday, November 15, 2013, 3:004:00PM
Location: 70 Montague Hall
Hypercube orientations with degree restrictions, or what color is my hat?
by
Steve Butler, Department of Mathematics, Iowa State University
Abstract:
There are many variations of hat guessing games, which generically consist of a group of players forming a strategy about how each player will go about guessing the color of their own hat by using information gleaned from looking at the hats of other players (but not their own). Strategies in this game can be rephrased in terms of hypercube orientations with given degree restrictions. We will look at several problems in this direction and give some open problems.
Time: Thursday, November 14, 2013, 3:004:00PM
Location: 130 Solon Campus Center
Why is Tuition So High at UMD?
by
Richard Green, Department of Mathematics, UMD
Abstract:
Tuition at UMD is now 55 times as high as it was in 1960, when I was a student here. Adjusted for inflation, tuition is seven times as high as it was in 1960. In this talk I will demonstrate the fact of tuition increase and I will discuss some of its causes and consequences. I will give three reasons why tuition at UMD should be no more than onethird of what it is now. I will also discuss some recent literature on the management and funding of American higher education, including the radical, democratic idea that public colleges and universities should be tuitionfree.
Time: Thursday, November 7, 2013, 3:004:00PM
Location: 150 Chemistry
Independent Variable Rescale to Solve Parabolic PDEs with Periodic Boundary Conditions Containing State Dependent Coefficients
by
Brian Hinderliter, Department of Mechanical and Industrial Engineering, UMD
Abstract:
Developing a test procedure that can predict the corrosion protection of a coating designed to last for 20 years is challenging, particularly accurately predicting behavior over decades with tests that last months. Fick’s second law of diffusion (parabolic PDE) is applied to coating surfaces exposed to varying surface water concentrations and temperatures (boundary conditions) at cyclical intervals. The diffusion coefficient is temperature dependent, in this example, of an Arrhenius form. The governing equations are solved using Laplace transforms after time rescaling to account for the variation in temperature, which impacts the diffusion coefficient between the wet and dry portions of several accelerated weathering protocols. This serves to predict the asymptotic water concentration in the coating as well as at the coatingmetal interface based on physical constants of the coating and parameters of the accelerated weathering protocol of interest. The analytic solution to Fick’s second law also allows the water concentration at the substratecoating interface to be predicted based on Arrhenius parameters of the diffusion process. This resultant average time of wetness and water concentration variance at the coatingsubstrate interface can be used to more directly compare corrosion and adhesion loss between various accelerated weathering protocols and natural weathering conditions.
Time: Thursday, October 31, 2013, 3:004:00PM
Location: 130 Solon Campus Center
Attitudes and prestige systems among Varieties of Kriol Language in Belize
by
Ron Regal, Department of Mathematics, UMD
William Salmon, Department of Linguistics, UMD
Abstract:
Belize, formerly British Honduras, gained full independence from Great Britain in 1981. While there is a strong influence of English as a result of its colonial history, Belize is linguistically diverse. In an ongoing project, Jennifer Gomez Menjivar, Foreign Languages UMD, and William Salmon, Linguistics, UMD, are examining the attitude and prestige system in place among varieties of Kriol, an Englishbased creole. As part of their study, Drs. Menjivar and Salmon had respondents rate speakers from Belize City and Punta Gorda, two different cities in Belize, on 16 personality attributes. Will Salmon will describe their study, and Ron Regal will tell some about considerations statistical data analysis and an analysis in this study in particular.
The talk will give an introduction to one aspect of linguistics and will be particularly of interest to students potentially interested in double majors in mathematics/statistics and linguistics. Study reports on language attitudes toward varieties of Belizean Kriol in coastal Belize. We used a verbalguise test with 82 participants, collecting both quantitative and qualitative data in Punta Gorda and Belize City, and we found that the variety of Kriol spoken in Belize City is perceived along several dimensions as being of greater prestige than the variety spoken in Punta Gorda. Derivative of these findings is the potentially more interesting fact that there is more than one variety of Kriol spoken in Belize in the first place—a fact which has not been previously reported in the literature. This research is part of an ongoing project investigating the overt and covert linguistic prestige system in place with respect to Belizean Kriol. The larger project will break down attitude factors among the individual ethnic groups in Belize in a series of articles.
Time: Thursday, October 24, 2013, 3:004:00PM
Location: 150 Chemistry
David Clark, Department of Mathematics, UMTC
Abstract: The seven siblings at the Clark farm have a massive list of chores to do. How can they divide them up fairly? Can they divide them fairly? Luckily, designs can help! Designs are a combinatorial object, which encode fairness, balance, and geometric structure. They are useful in a remarkable variety of situations, from dividing chores fairly through designing statistical experiments. One of the key modern uses of designs is to provide flexible and efficient errorcorrecting codes, which protect data transmissions from errors. We will define designs, give many examples, and study how their representation as (0,1)matrices provides a surprising link to cutting edge communications.
Time: Thursday, October 17, 2013, 3:004:00PM
Location: 130 Solon Campus Center
Math Majors and Information Security in a Digital Age: Any Connection?
by
Dr. William Krossner
Abstract: We consider the usual model of a sender of information, a channel of communication, and the intended receiver of this information. In the digital age, what role does mathematics play in rendering the transmitted information secure from the eyes of unintended or malicious receiving entities (such as spies, governments, corporations, cybercriminals, and the like)? Of course, for centuries various cryptographic methods (codes and ciphers) have been invented and used to try to keep information secret.
In the 20th century, the design of cryptographic methods was taken over by mathematics, so much so that today there are many job openings for math majors and graduates in both governmental and commercial entities around the world to deal with information security issues. The speaker will briefly outline one of the earliest allmathematical cipher methods (from 1929), but spend most of the time demonstrating the verylittleknown fact that within each computer operating system (Windows, Mac or Linux) there is a cryptographic laboratory available for use, powerful enough to produce cipher methods difficult for even supercomputers to solve. Any math major is smart enough to use this laboratory, and everything connected with it is free.
Audience members who bring their own USB drives may copy all of the speaker's apps for their own use at the end of the talk.
Time: Thursday, October 10, 2013, 3:004:00PM
Location: 150 Chemistry
Families of Infinite Series With Interesting Limiting Structure
by
John Greene, Department of Mathematics, UMD
Time: Thursday, October 3, 2013, 3:004:00PM
Location: 130 Solon Campus Center
Mathematics: The Science of Patterns
by
Joseph Gallian
Professor of Mathematics, UMD
Abstract: I will discuss three research projects involving patterns I have worked on that are accessible to a broad interdisciplinary audience. One was to figure out the algorithms used by computers to check the validity of product identification numbers on bar codes, credit cards, and books. Another entails deciphering the secret algorithm used by Minnesota and other states to code driver's license numbers. The third was to devise algorithms to create intricate symmetry patterns.
Although intellectual curiosity is the motivation for all my research, the results sometime yield unanticipated applications and unexpected media attention.
These will be described in the presentation.
Time: Friday, September 20, 2013, 3:004:00PM
Location: 70 Montague Hall
Steiner problems, soap films, minimal surfaces, and complex analysis
by
Michael Dorff
Professor of Mathematics, Brigham Young University
Abstract: We will start with a Steiner problem that ask the question what is the shortest path between several points. Then we will transform Steiner problems up one dimension to minimal surfaces that can be modeled by soap films demonstrating a few handson examples. As we do this we will discuss some differential geometry as background for minimal surfaces, diverge into complexvalued harmonic mappings, and discuss the connection between minimal surfaces and complexvalued harmonic mappings. Finally we will discuss some new research using complexvalued harmonic mappings to construct harmonic mappings.
Time: Thursday, September 19, 2013, 4:30PM
Location: 130 Solon Campus Center
How Math is Changing the World
by
Michael Dorff
Professor of Mathematics, Brigham Young University
Abstract: In Oct 2010, an article called "How much math do we really need?" was published in the Washington Post. The author, a mathematician, wrote, "Unlike literature, history, politics and music, math has little relevance to everyday life" and "All the mathematics one needs in real life can be learned in early years without much fuss." Is this true? Have you ever been asked, "What can you do with a degree in math?" Except for teaching, many people are clueless on what you can do with strong math skills. In this talk, we will discuss some of the exciting things mathematicians in business, industry, and government are doing in their careers and how these things are changing the world. And we will reveal the three things that recruiters say every math student should do to get a job.
Time: Thursday, September 19, 2013, 3:004:00PM
Location: 150 Chemistry