Home > Seminars and Colloquia > 2006-2007

Hans Anderson

Graduate Student

UMD Department of Mathematics and Statistics

For musical recordings of a single instrument playing only one note at a time, there exists reliable software for detecting the pitches and transcribing them into musical notation. But for polyphonic recordings (those that contain sounds of several simultaneous pitches) very little has been accomplished. This is surprising because humans do it so well and because unlike other audio recognition tasks, such as speech recognition, it doesn't require deep conceptual understanding. In order to move a step closer to a software solution, we implement a computer model of one theory of human hearing and use it to encode audio recordings in a format similar to musical notation. This compact, efficient format has possible applications including voice over I.P. and live music synthesis.

Nicholas Volkmann

Graduate Student

UMD Department of Mathematics and Statistics

Lake Malawi, one of the most diverse lakes in the world, is located between southeast Africa and tropical east Africa, which has been shown to be a climatic boundary between wet and dry regions. In this project, we will study the behavior of the water level of Lake Malawi to determine if it behaves like the lakes in wet, tropical east Africa or not. We will investigate the highs and lows of these lakes. Time series analysis in the time domain as well as the frequency domain will be discussed. In particular, results in fitting ARIMA models, periodicity of each lake, and coherency will be presented.

Justin Eberhardt

Graduate Student

UMD Department of Mathematics and Statistics

The intrinsic dimension of a dataset is often much less than the dimension of the original dataset. It is valuable to know the intrinsic dimension of a dataset so that the high dimensional dataset can be replaced by a lower dimensional dataset that is easier to manipulate. Traditional intrinsic dimension estimators, such as principal component analysis can only be used on linear spaces. Non-linear manifolds require other methods, such as nearest-neighbor estimators. We will compare three nearest-neighbor estimators based on several criteria and show that two estimators perform well on a wide range of non-linear datasets.

Professor Vilmos Komornik

Institute of Mathematics

University of Louis Pasteur

We report on some joint works with C. Baiocchi and P. Loreti. In a paper of 1936, dedicated to Dirichlet series, Ingham established an elegant generalization of Parseval's equality. Later his theorem proved to be extremely useful in control theory. Motivated by various applications, we discuss several improvements and extensions of this result and we explain its connection to a classical variational problem.

Timothy Naegeli, candidate for deparmental honors, Regression and Variable Selection via Lasso

Soleh Dib, UMD Putnam Award Winner, Solving a Putnam Problem

Jon Wentz, Shawn Walwick, and Soleh Dib, Mathematical Computing Contest (MCM) honorable mention recipients, The Airplane Seating Problem

UMD Department of Mathematics and Statistics

Hear from these distinguished students.

Junyan Shen

Graduate Student

UMD Department of Mathematics and Statistics

Financial mathematics (or financial engineering) is a new discipline in mathematics that uses math and statistics to study financial markets. One main goal of financial mathematics is to establish math models and set prices for financial derivatives. I'll briefly introduce the concept of financial derivative including futures and options and then focus on the ideas of model construction for options. I'll also talk about my effort to learn this subject and my experience of applying to graduate programs in financial math.

Each day, every faculty member and graduate student in our department is using a computer to read e-mail, organize files, generate presentations and graphics, write papers, and play around on the internet. In this colloquium, you will learn some of the tricks that people in the department use to make their computing experience a little bit nicer.

A list of presenters and topics:

Andrew Larson: What's better than notepad? ...Notepad++

Ron Regal: Cross-platform text editing (Between Unix and Windows)

Xiaowei Zhan: SAS Tips: How to import data and make it look NICE.

Nicaise Mbunteu: How to write a paper in TeX if you don't know how to use TeX.

Joe Gallian: Try Gmail - it's better!

Angela Sharp: Keeping a grade book in Microsoft Excel

Hans Anderson: Two lines of code that produce a 3D animated graph in Mathematica

John Greene: A demonstration of Maple

Heather Kahler

UW-Superior Instructor

Fair Division is a multi-disciplinary topic that is of interest and is relevant to the fields of mathematics, economics, sociology, and political science. Though the fair division algorithms are intriguing in their own right, there are many practical applications including the allocation of property, rent, and chores. This colloquium will focus on envy-free division in both discrete and continuous contexts. No prior knowledge of fair division is needed.

Hans Anderson

Graduate Student

UMD Department of Mathematics and Statistics

The ECPOHYS project is a mathematical model of the growth of a small forest of Populus trees. It aims to provide a better understanding of the processes that influence tree growth and to predict the forest ecosystem's response to pollution and climate change. The ECOPHYS computer program periodically outputs geometric data to describe the shape and location of each leaf in the forest. We will show some simple ways to convert this type of data into computer-generated graphics and animations and we will compare open source graphics software with the commercial packages used in video games and movies.

Fenghuan Wang

MS Candidate

UMD Department of Mathematics and Statistics

In this report, we derived two new beam models under different circumstances, namely, the point load beam model of the bending motion and the point load beam model of the torsional motion. The relationship of the mass and EI with the measured frequencies and the length of the bridge are derived. These two models might provide a way of identifying whether the measured frequencies are from the bending motion or not. When the loading ratio is small, the point load model and the uniformly distributed load model are similar in the sense of natural frequency.

John Pastor

Professor

UMD Department of Biology

There is currently a debate in ecology as to whether foods, webs and ecosystems are controlled "from the top" by the highest trophic level (herbivores or predators) or whether nutrient availability at the "bottom" exerts the strongest control. I will present and analyze a simple differential equation model of an open system consisting of a nutrient, a plant that takes up the nutrient, and a consumer that eats the plant. The model shows that both the consumer at the top and nutrient input at the bottom control the food web, but in different ways. There are critical levels of nutrient input that must be exceeded for each successively higher trophic level to be added and maintain stable coexistence with the lower trophic levels. The highest trophic level, in turn, completely controls the equilibrium of the next lower trophic level, with control weakening downward to successively lower trophic levels. Implications for experimental design and analysis will also be discussed.

Brent Laurila

Duluth Denfeld High School

Brent Laurila graduated from UMD with a degree in teaching mathematics.

He is now a mathematics teacher at Denfeld! During his talk, he will give a bit of advice for current teaching mathematics majors and field questions. Audience members may ask anything, from how to get a job to how to survive the first year of teaching.

Professors Dalibor Froncek, Marshall Hampton and Zhuangyi Liu

Department of Mathematics and statistics

University of Minnesota Duluth

It comes as a surprise to some people that mathematicians are still working to discover new mathematics! While some advances require years of background preparation in order to make any progress, others can be attacked with just an undergraduate background. In this colloquium, Professors Dalibor Froncek, Marshall Hampton and Zhuangyi Liu will describe a variety of potential research projects for undergraduates. The colloquium should be accessible to all Math/Stat students, and of interest whether or not you plan on doing a research project.

Professor Joe Gallian

Department of Mathematics and statistics

University of Minnesota Duluth

Many states use complicated algorithms or formulas to assign driver's license numbers but keep the method confidential. Just for the fun of it, Professor Gallian attempted to figure out how the states code their license numbers. In this talk he will discuss how he was able to break the codes for Minnesota and Missouri. The talk illustrates an important problem-solving technique by scientists but is not emphasized in mathematics classes. It also teaches the lesson that sometimes things done just for the sake of curiosity can have applications. The talk is intended for a general audience. No advanced mathematics is needed.

Professor Ronald Regal

Department of Mathematics and statistics

University of Minnesota Duluth

In this talk I will pull together various pieces of advice for mathematics and statistics majors from your undergraduate years to later career paths. My first piece of advice is to major in mathematics, something you are already doing. I will show short clips from two movies, one showing what, from my point of view, study of mathematics is not about and another showing what studying mathematics is about. From there I will give various pieces of advice, perspectives, and lessons from books, magazines, talks, and my personal favorite source, song lyrics. Sources include Ernest Hemingway, Emmitt Smith, Ronnie Van Zant, Technology Review, a plant geneticist, statistician John Tukey, author Po Bronson, and the Chair of Harvard's Department of Cancer Biology. Some of the questions include: What makes successful innovators? What good are proofs in the real world? What is first thing to do when analyzing data? How can you handle failure? How do you help prepare your resume even as a freshman?

Roshan Koirala

Department of Mathematics and statistics

University of Minnesota Duluth

Optimal foraging theory has been a topic of interest among ecologists and statisticians. Allan OatenÕs stochastic model and GreenÕs optimal rules have been influential in providing valuable information about how predators search for their prey, and how different strategies can lead to different outcomes. This paper will look at various optimal solutions for different conditions presented by Oaten, Iwasa et al and Green, as well as focus on Bayesian methods. The use of prior information is central in Bayesian statistics, and this paper will analyze how using a certain prior leads us to a particular posterior distribution.

Professor Scot Adams

Director of Graduate Studies

Department of Mathematics

University of Minnesota at Twin Cities

Are you interested in mathematics with an eye toward starting a career in quantitative finance? Are you pursuing a career in finance and the capital markets, with an interest in learning more of the underlying mathematics? The Mathematics Department at the University of Minnesota (Twin Cities campus) has a new professional Master's program, and it may be for you! I will briefly describe how mathematics is used in finance and also talk about our program, leaving lots of time for Q & A.

http://www.math.umn.edu/finmath/

mfmath@umn.edu

David Rusin

Department of Mathematics and Statistics

Northern Illinois University

Where do good calculus problems come from? IIt's not easy to construct questions for which all the computations work out nicely. Sometimes the creation of a good calculus problem requires tools from more advanced mathematics. In this talk I will show how to construct one type of good calculus problem; along the way we'll encounter some tools from number theory and even algebraic geometry. There will be something for everyone in the talk, even those whose background is just first-semester calculus.

Professor Jan Verschelde, University of Illinois at Chicago

Because of its local quadratic convergence, Newton's method is often the preferred approach to numerically solve nonlinear problems. While Newton's method needs an initial guess, sufficiently close to a solution, globally convergent solvers use homotopies and do not require the user to provide an initial guess for a solution. When the nonlinear system is polynomial, homotopy methods can find approximations for all isolated solutions. Examples will be given of mechanical design problems which lead to polynomial systems. Every real solution of such a polynomial system corresponds to one particular assembly of the mechanism. Parallel computers are used to solve large polynomial systems.

Dalibor Froncek, Department of Mathematics and Statistics, UMD

Graph theory is a very useful tool for scheduling round robin tournaments. We will explore many different ways how to schedule tournaments with perfect or near perfect properties, like home-away pattern of carry-over effect.

However, when it comes to real life, we often need to give up perfection and beauty for everyday constraints, like team budgets. We will discuss how to schedule tournaments with several divisions, incomplete tournaments, or how to fight corruption in (Czech) soccer.

Professor Dick Green Department of Mathematics and Statistics, UMD

Optimal foraging theory consists of a collection of models that represent how animals choose and look for food. Bayesian foraging models are used to study how animals use information about the environment to decide when to leave one food patch and move on to another. Optimal patch-leaving rules are found using Bayes' theorem and dynamic programming. After a recent talk, a member of the audience asked me whether there is a "Bayesian foraging for dummies." The answer is no, but I would like to remedy the deficiency. In this talk I will try to explain as simply as I can how to find an optimal patch-leaving rule for a Bayesian forager. I will also mention how an understanding of such a rule may be useful in the study of animal behavior and ecology.

Marshall Hampton, Department of Mathematics and Statistics, UMD

Biology is rapidly becoming more quantitative as new high-throughput methods deliver massive amounts of information. Circadian (daily) rhythms provide an exciting example of this shift in action. Virtually every creature on earth has some sort of 24-hour cycle in metabolism and behavior that persists in the absence of environmental cues. Recent advances in genomics and bioinformatics have uncovered many of the molecular mechanisms underlying these circadian rhythms, which in turn have allowed the development of detailed mathematical models of these processes. This talk will survey some these discoveries as well as some background on the biology and bioinformatic algorithms involved.

John Greene Math Department, UMD

Download abstract

Dr. Joan Kwako, Education Department, UMD

We all know that it is significantly easier to assess students' knowledge than their complex problem solving abilities. Because of this it is not uncommon for our assessments to focus more on reproducing what students have practiced as opposed to engaging them in more complex thought processes that demonstrate true understanding. In this talk I will use the PISA pyramid model of item design to describe how one can design tasks that will provide insight not only into what students are able to do, but whether they truly understand what they are doing. By focusing on a common test question, finding the derivative, I will demonstrate how this question can be changed to not only inform one of a student's ability-knowledge of how to find a derivative-but to also inform one of whether that student really understands what a derivative is.

It comes as a surprise to some people that mathematicians are still working to discover new mathematics! While some advances require years of background preparation in order to make any progress, others can be attacked with just an undergraduate background. In this colloquium, Professors Dalibor Froncek, John Greene, Carmen Latterell, Kathryn Lenz, and Bruce Peckham will describe a variety of potential research projects for undergraduates. The colloquium should be accessible to all Math/Stat students, and of interest whether or not you plan on doing a research project.

A pizza party hosted by the Math Club will follow from 4-5pm. New Math/Stat majors are especially invited to attend. Friends are welcome.

# Seminar and Colloquia: 2006 - 2007

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.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 | 6/12/07 | An Audio Coder Based on a Model of Human Hearing | Hans Anderson, Math Department UMD |

G | 5/31/07 | Statistical Analysis of Climatic Effects on Lake Malawi | Nicholas Volkmann, Math Department UMD |

G | 5/30/07 | Estimating Intrinsic Dimension | Justin Eberhardt, Math Department UMD |

G | 5/3/07 | Ingham Type Theorems | Professor Vilmos Komornik, Institute of Mathematics University of Louis Pasteur |

U | 4/26/07 | Undergraduate Honors and Contests Colloquium | Timothy Naegeli, Soleh Dib, Jon Wentz, Shawn Walwick |

U | 4/12/07 | Introduction to Financial Mathematics (Option Pricing) | Junyan Shen, Math Department UMD |

G | 4/5/07 | Helpful Computing Advice | Andrew Larson, Ron Regal, Xiaowei Zhan, Nicaise Mbunteu, Joe Gallian, Angela Sharp, Hans Anderson, John Greene |

U | 3/29/07 | An Introduction to Fair Division | Heather Kahler, UW-Superior Instructor |

U | 3/8/07 | 3d Animation and Ray Tracing: Producing Great-looking Visualizations of Mathematical Results | Hans Anderson, Math Department UMD |

G | 3/2/07 | New Beam Models for Nondestructive Inspection of Timber Bridges | Fenghuan Wang, Math Department UMD |

G | 3/1/07 | Are Ecosystems and Food Webs Controlled from the Top-Down or from the Bottom-Up? Some Answers from a Simple Model of a Consumer, a Plant and a Nutrient | John Pastor, Biology Department UMD |

U | 2/22/07 | Advice from a new mathematics teacher | Brent Laurila, Duluth Denfeld High School |

U | 2/15/07 | OPPORTUNITIES FOR UNDERGRADUATE RESEARCH IN MATH | Dalibor Froncek, Marshall Hampton and Zhuangyi Liu, Math Department UMD |

U | 2/8/07 | Breaking Driver's License Codes | Joe Gallian, Math Department UMD |

U | 1/25/07 | Some Advice and Lessons for Mathematical, Statistical, and Life Pursuits | Ronald Regal, Math Department UMD |

G | 1/19/07 | Optimal Foraging Theory: A Bayesian Approach | Roshan Koirala |

G | 11/30/06 | Financial Mathematics at UMNTC | Professor Scot Adams Director of Graduate Studies Department of Mathematics University of Minnesota at Twin Cities |

U | 11/16/06 | The search for the perfect calculus problem | David Rusin, Northern Illinois University |

G | 11/09/06 | Solving Polynomial Systems using Numerical Homotopies | Professor Jan Verschelde, University of Illinois at Chicago |

U | 11/02/06 | TOURNAMENT SCHEDULING: (Graph) Theory and (Real Life) Practice | Dalibor Froncek, Math Department, UMD |

G | 10/26/06 | Bayesian foraging for dummies | Professor Dick Green Department of Mathematics and Statistics, UMD |

U | 10/19/06 | Charting the map of sleep: the mathematics and bioinformatics of circadian rhythms | Marshall Hampton, Math Department UMD |

U | 10/12/06 | The Burgstahler Coincidence | John Greene, Math Department UMD |

U | 10/05/06 | Creating effective assessments: Designing tests, quizzes, and homework sets that assess student understanding, not just knowledge | Dr. Joan Kwako, Education Department, UMD |

U | 09/21/06 | Opportunities for Undergraduate Research in Math |

**An Audio Coder Based on a Model of Human Hearing**

Hans Anderson

Graduate Student

UMD Department of Mathematics and Statistics

**Abstract:**For musical recordings of a single instrument playing only one note at a time, there exists reliable software for detecting the pitches and transcribing them into musical notation. But for polyphonic recordings (those that contain sounds of several simultaneous pitches) very little has been accomplished. This is surprising because humans do it so well and because unlike other audio recognition tasks, such as speech recognition, it doesn't require deep conceptual understanding. In order to move a step closer to a software solution, we implement a computer model of one theory of human hearing and use it to encode audio recordings in a format similar to musical notation. This compact, efficient format has possible applications including voice over I.P. and live music synthesis.

**Time:**Tuesday, June 12, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Statistical Analysis of Climatic Effects on Lake Malawi**

Nicholas Volkmann

Graduate Student

UMD Department of Mathematics and Statistics

**Abstract:**Lake Malawi, one of the most diverse lakes in the world, is located between southeast Africa and tropical east Africa, which has been shown to be a climatic boundary between wet and dry regions. In this project, we will study the behavior of the water level of Lake Malawi to determine if it behaves like the lakes in wet, tropical east Africa or not. We will investigate the highs and lows of these lakes. Time series analysis in the time domain as well as the frequency domain will be discussed. In particular, results in fitting ARIMA models, periodicity of each lake, and coherency will be presented.

**Time:**Thursday, May 31, 2007 1:00 p.m. - 2:00 p.m.**Location:**130 Solon Campus Center**Estimating Intrinsic Dimension**

Justin Eberhardt

Graduate Student

UMD Department of Mathematics and Statistics

**Abstract:**The intrinsic dimension of a dataset is often much less than the dimension of the original dataset. It is valuable to know the intrinsic dimension of a dataset so that the high dimensional dataset can be replaced by a lower dimensional dataset that is easier to manipulate. Traditional intrinsic dimension estimators, such as principal component analysis can only be used on linear spaces. Non-linear manifolds require other methods, such as nearest-neighbor estimators. We will compare three nearest-neighbor estimators based on several criteria and show that two estimators perform well on a wide range of non-linear datasets.

**Time:**Wednesday, May 30, 2007 2:00 p.m. - 3:00 p.m.**Location:**130 Solon Campus Center**Ingham Type Theorems**

Professor Vilmos Komornik

Institute of Mathematics

University of Louis Pasteur

**Abstract:**We report on some joint works with C. Baiocchi and P. Loreti. In a paper of 1936, dedicated to Dirichlet series, Ingham established an elegant generalization of Parseval's equality. Later his theorem proved to be extremely useful in control theory. Motivated by various applications, we discuss several improvements and extensions of this result and we explain its connection to a classical variational problem.

**Time:**Thursday, May 3, 2007 4:00 p.m. - 5:00 p.m.**Location:**130 Solon Campus Center**Undergraduate Honors and Contests Colloquim**

Timothy Naegeli, candidate for deparmental honors, Regression and Variable Selection via Lasso

Soleh Dib, UMD Putnam Award Winner, Solving a Putnam Problem

Jon Wentz, Shawn Walwick, and Soleh Dib, Mathematical Computing Contest (MCM) honorable mention recipients, The Airplane Seating Problem

UMD Department of Mathematics and Statistics

**Abstract:**Hear from these distinguished students.

**Time:**Thursday April 26, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Introduction to Financial Mathematics (Option Pricing)**

Junyan Shen

Graduate Student

UMD Department of Mathematics and Statistics

**Abstract:**Financial mathematics (or financial engineering) is a new discipline in mathematics that uses math and statistics to study financial markets. One main goal of financial mathematics is to establish math models and set prices for financial derivatives. I'll briefly introduce the concept of financial derivative including futures and options and then focus on the ideas of model construction for options. I'll also talk about my effort to learn this subject and my experience of applying to graduate programs in financial math.

**Time:**Thursday April 12, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Helpful Computing Advice**

**Abstract:**Each day, every faculty member and graduate student in our department is using a computer to read e-mail, organize files, generate presentations and graphics, write papers, and play around on the internet. In this colloquium, you will learn some of the tricks that people in the department use to make their computing experience a little bit nicer.

A list of presenters and topics:

Andrew Larson: What's better than notepad? ...Notepad++

Ron Regal: Cross-platform text editing (Between Unix and Windows)

Xiaowei Zhan: SAS Tips: How to import data and make it look NICE.

Nicaise Mbunteu: How to write a paper in TeX if you don't know how to use TeX.

Joe Gallian: Try Gmail - it's better!

Angela Sharp: Keeping a grade book in Microsoft Excel

Hans Anderson: Two lines of code that produce a 3D animated graph in Mathematica

John Greene: A demonstration of Maple

**Time:**Thursday April 5, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**An Introduction to Fair Division**

Heather Kahler

UW-Superior Instructor

**Abstract:**Fair Division is a multi-disciplinary topic that is of interest and is relevant to the fields of mathematics, economics, sociology, and political science. Though the fair division algorithms are intriguing in their own right, there are many practical applications including the allocation of property, rent, and chores. This colloquium will focus on envy-free division in both discrete and continuous contexts. No prior knowledge of fair division is needed.

**Time:**Thursday March 29, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**3d Animation and Ray Tracing: Producing Great-looking Visualizations of Mathematical Results**

Hans Anderson

Graduate Student

UMD Department of Mathematics and Statistics

**Abstract:**The ECPOHYS project is a mathematical model of the growth of a small forest of Populus trees. It aims to provide a better understanding of the processes that influence tree growth and to predict the forest ecosystem's response to pollution and climate change. The ECOPHYS computer program periodically outputs geometric data to describe the shape and location of each leaf in the forest. We will show some simple ways to convert this type of data into computer-generated graphics and animations and we will compare open source graphics software with the commercial packages used in video games and movies.

**Time:**Thursday March 8, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**New Beam Models for Nondestructive Inspection of Timber Bridges**

Fenghuan Wang

MS Candidate

UMD Department of Mathematics and Statistics

**Abstract:**In this report, we derived two new beam models under different circumstances, namely, the point load beam model of the bending motion and the point load beam model of the torsional motion. The relationship of the mass and EI with the measured frequencies and the length of the bridge are derived. These two models might provide a way of identifying whether the measured frequencies are from the bending motion or not. When the loading ratio is small, the point load model and the uniformly distributed load model are similar in the sense of natural frequency.

**Time:**Friday March 2, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Are Ecosystems and Food Webs Controlled from the Top-Down or from the Bottom-Up? Some Answers from a Simple Model of a Consumer, a Plant and a Nutrient**

John Pastor

Professor

UMD Department of Biology

**Abstract:**There is currently a debate in ecology as to whether foods, webs and ecosystems are controlled "from the top" by the highest trophic level (herbivores or predators) or whether nutrient availability at the "bottom" exerts the strongest control. I will present and analyze a simple differential equation model of an open system consisting of a nutrient, a plant that takes up the nutrient, and a consumer that eats the plant. The model shows that both the consumer at the top and nutrient input at the bottom control the food web, but in different ways. There are critical levels of nutrient input that must be exceeded for each successively higher trophic level to be added and maintain stable coexistence with the lower trophic levels. The highest trophic level, in turn, completely controls the equilibrium of the next lower trophic level, with control weakening downward to successively lower trophic levels. Implications for experimental design and analysis will also be discussed.

**Time:**Thursday March 1, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Advice from a new mathematics teacher**

Brent Laurila

Duluth Denfeld High School

**Abstract:**Brent Laurila graduated from UMD with a degree in teaching mathematics.

He is now a mathematics teacher at Denfeld! During his talk, he will give a bit of advice for current teaching mathematics majors and field questions. Audience members may ask anything, from how to get a job to how to survive the first year of teaching.

**Time:**Thursday February 22, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**OPPORTUNITIES FOR UNDERGRADUATE RESEARCH IN MATH**

Professors Dalibor Froncek, Marshall Hampton and Zhuangyi Liu

Department of Mathematics and statistics

University of Minnesota Duluth

**Abstract:**It comes as a surprise to some people that mathematicians are still working to discover new mathematics! While some advances require years of background preparation in order to make any progress, others can be attacked with just an undergraduate background. In this colloquium, Professors Dalibor Froncek, Marshall Hampton and Zhuangyi Liu will describe a variety of potential research projects for undergraduates. The colloquium should be accessible to all Math/Stat students, and of interest whether or not you plan on doing a research project.

**Time:**Thursday February 15, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Breaking Driver's License Codes**

Professor Joe Gallian

Department of Mathematics and statistics

University of Minnesota Duluth

**Abstract:**Many states use complicated algorithms or formulas to assign driver's license numbers but keep the method confidential. Just for the fun of it, Professor Gallian attempted to figure out how the states code their license numbers. In this talk he will discuss how he was able to break the codes for Minnesota and Missouri. The talk illustrates an important problem-solving technique by scientists but is not emphasized in mathematics classes. It also teaches the lesson that sometimes things done just for the sake of curiosity can have applications. The talk is intended for a general audience. No advanced mathematics is needed.

**Time:**Thursday February 8, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Some Advice and Lessons for Mathematical, Statistical, and Life Pursuits**

Professor Ronald Regal

Department of Mathematics and statistics

University of Minnesota Duluth

**Abstract:**In this talk I will pull together various pieces of advice for mathematics and statistics majors from your undergraduate years to later career paths. My first piece of advice is to major in mathematics, something you are already doing. I will show short clips from two movies, one showing what, from my point of view, study of mathematics is not about and another showing what studying mathematics is about. From there I will give various pieces of advice, perspectives, and lessons from books, magazines, talks, and my personal favorite source, song lyrics. Sources include Ernest Hemingway, Emmitt Smith, Ronnie Van Zant, Technology Review, a plant geneticist, statistician John Tukey, author Po Bronson, and the Chair of Harvard's Department of Cancer Biology. Some of the questions include: What makes successful innovators? What good are proofs in the real world? What is first thing to do when analyzing data? How can you handle failure? How do you help prepare your resume even as a freshman?

**Time:**Thursday January 25, 2007 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Optimal Foraging Theory: A Bayesian Approach**

Roshan Koirala

Department of Mathematics and statistics

University of Minnesota Duluth

**Abstract:**Optimal foraging theory has been a topic of interest among ecologists and statisticians. Allan OatenÕs stochastic model and GreenÕs optimal rules have been influential in providing valuable information about how predators search for their prey, and how different strategies can lead to different outcomes. This paper will look at various optimal solutions for different conditions presented by Oaten, Iwasa et al and Green, as well as focus on Bayesian methods. The use of prior information is central in Bayesian statistics, and this paper will analyze how using a certain prior leads us to a particular posterior distribution.

**Time:**Friday January 19, 2007 3:15 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Financial Mathematics at UMNTC**

Professor Scot Adams

Director of Graduate Studies

Department of Mathematics

University of Minnesota at Twin Cities

**Abstract:**Are you interested in mathematics with an eye toward starting a career in quantitative finance? Are you pursuing a career in finance and the capital markets, with an interest in learning more of the underlying mathematics? The Mathematics Department at the University of Minnesota (Twin Cities campus) has a new professional Master's program, and it may be for you! I will briefly describe how mathematics is used in finance and also talk about our program, leaving lots of time for Q & A.

http://www.math.umn.edu/finmath/

mfmath@umn.edu

**Time:**Thursday Nov. 30, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**The search for the perfect calculus problem**

David Rusin

Department of Mathematics and Statistics

Northern Illinois University

**Abstract:**Where do good calculus problems come from? IIt's not easy to construct questions for which all the computations work out nicely. Sometimes the creation of a good calculus problem requires tools from more advanced mathematics. In this talk I will show how to construct one type of good calculus problem; along the way we'll encounter some tools from number theory and even algebraic geometry. There will be something for everyone in the talk, even those whose background is just first-semester calculus.

**Time:**Thursday Nov. 16, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Solving Polynomial Systems using Numerical Homotopies**

Professor Jan Verschelde, University of Illinois at Chicago

**Abstract:**Because of its local quadratic convergence, Newton's method is often the preferred approach to numerically solve nonlinear problems. While Newton's method needs an initial guess, sufficiently close to a solution, globally convergent solvers use homotopies and do not require the user to provide an initial guess for a solution. When the nonlinear system is polynomial, homotopy methods can find approximations for all isolated solutions. Examples will be given of mechanical design problems which lead to polynomial systems. Every real solution of such a polynomial system corresponds to one particular assembly of the mechanism. Parallel computers are used to solve large polynomial systems.

**Time:**Thursday Nov. 9, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**TOURNAMENT SCHEDULING: (Graph) Theory and (Real Life) Practice**

Dalibor Froncek, Department of Mathematics and Statistics, UMD

**Abstract:**Graph theory is a very useful tool for scheduling round robin tournaments. We will explore many different ways how to schedule tournaments with perfect or near perfect properties, like home-away pattern of carry-over effect.

However, when it comes to real life, we often need to give up perfection and beauty for everyday constraints, like team budgets. We will discuss how to schedule tournaments with several divisions, incomplete tournaments, or how to fight corruption in (Czech) soccer.

**Time:**Thursday Nov. 2, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Bayesian foraging for dummies**

Professor Dick Green Department of Mathematics and Statistics, UMD

**Abstract:**Optimal foraging theory consists of a collection of models that represent how animals choose and look for food. Bayesian foraging models are used to study how animals use information about the environment to decide when to leave one food patch and move on to another. Optimal patch-leaving rules are found using Bayes' theorem and dynamic programming. After a recent talk, a member of the audience asked me whether there is a "Bayesian foraging for dummies." The answer is no, but I would like to remedy the deficiency. In this talk I will try to explain as simply as I can how to find an optimal patch-leaving rule for a Bayesian forager. I will also mention how an understanding of such a rule may be useful in the study of animal behavior and ecology.

**Time:**Thursday Oct. 26, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Charting the map of sleep: the mathematics and bioinformatics of circadian rhythms**

Marshall Hampton, Department of Mathematics and Statistics, UMD

**Abstract:**Biology is rapidly becoming more quantitative as new high-throughput methods deliver massive amounts of information. Circadian (daily) rhythms provide an exciting example of this shift in action. Virtually every creature on earth has some sort of 24-hour cycle in metabolism and behavior that persists in the absence of environmental cues. Recent advances in genomics and bioinformatics have uncovered many of the molecular mechanisms underlying these circadian rhythms, which in turn have allowed the development of detailed mathematical models of these processes. This talk will survey some these discoveries as well as some background on the biology and bioinformatic algorithms involved.

**Time:**Thursday Oct. 19, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**The Burgstahler Coincidence**

John Greene Math Department, UMD

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**Time:**Thursday Oct. 12, 2006 Refreshements at 2:45 Talk 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Creating effective assessments: Designing tests, quizzes, and homework sets that assess student understanding, not just knowledge**

Dr. Joan Kwako, Education Department, UMD

**Abstract:**We all know that it is significantly easier to assess students' knowledge than their complex problem solving abilities. Because of this it is not uncommon for our assessments to focus more on reproducing what students have practiced as opposed to engaging them in more complex thought processes that demonstrate true understanding. In this talk I will use the PISA pyramid model of item design to describe how one can design tasks that will provide insight not only into what students are able to do, but whether they truly understand what they are doing. By focusing on a common test question, finding the derivative, I will demonstrate how this question can be changed to not only inform one of a student's ability-knowledge of how to find a derivative-but to also inform one of whether that student really understands what a derivative is.

**Time:**Thursday Oct. 5, 2006 Refreshements at 2:45 Talk 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Opportunities for Undergraduate Research in Math**

**Abstract:**It comes as a surprise to some people that mathematicians are still working to discover new mathematics! While some advances require years of background preparation in order to make any progress, others can be attacked with just an undergraduate background. In this colloquium, Professors Dalibor Froncek, John Greene, Carmen Latterell, Kathryn Lenz, and Bruce Peckham will describe a variety of potential research projects for undergraduates. The colloquium should be accessible to all Math/Stat students, and of interest whether or not you plan on doing a research project.

A pizza party hosted by the Math Club will follow from 4-5pm. New Math/Stat majors are especially invited to attend. Friends are welcome.

**Time:**Thursday, September 21, 2005 3:00--4:00 colloquium, 4:00-5:00 free pizza**Location:**130 Solon Campus Center