Home > Seminars and Colloquia > 2005-2006

Moderator: Carmen Latterell

Panelists: Dr. Kay Wohlhuter, Department of Education, UMD;

Sheila Nyback, Morgan Park; Heather Kahler, UWS;

Brian Freyberg, Esko High School; David Brown, East.

The panelists are all people who hold teaching licenses in mathematics. Each will talk for approximately five minutes about the path each has taken. Audience members may ask any related question. For example, what can be expected in the first year of high school teaching? What does a Ph.D. in mathematics education involve? What is some advice for a resume or interviewing? How did you find your job? What do you wish you had done differently?

by: Dr. Mariza de Andrade

Interim-Chair, Division of Biostatistics

Mayo Clinic and Mayo Clinic College of Medicine

Rochester, Minnesota

In this seminar I describe different linkage methods used to identify genetic factors predisposing to complex diseases. I will focus on two studies, one involving identification of genetic factors for familial lung cancer and the other the identification of genetic factors predisposing to hypertension and its target organ complications in families. Different linkage approaches were applied, and I will describe their advantages and disadvantages.

Five Math/Stat majors are graduating this spring with departmental honors. Part of the requirement to receive departmental honors is to complete a research project. In this colloquium these five students will present brief descriptions of the research they completed.

by: John Burrows, Technical Director

Integration & Data Management Services

Accenture/Best Buy Technology Group

Graduate of UMD

A background in mathematics has many direct and indirect beneficial usages within Information Systems. During this informal discussion, a high-level overview of one person's usage of mathematics throughout a 20 year career within Information Systems will be provided. Topics touched on will range from common usage of statistics within systems performance analysis, to the benefits of general analytical thinking skills obtained from a background in mathematics. At the end of this discussion session, students will also have an opportunity to ask general questions regarding a career within Information Systems and hear one person's perspective.

by: Professor Bruce Peckham

Department of Mathematics and Statistics

UMD

Peatlands exist in a significant part of northern Minnesota. Some of these peatlands are dominated by moss, while others have moss coexisting with other shrubs. From a modeling point of view, moss is treated differently from other shrubs because moss receives most of its nutrients from rainwater, rather than in uptake from roots. This leads to a differential equations model which allows the possibility of either "moss monoculture" or "coexistence" equilibrium states. The talk will discuss both the development of the model and its behavior, including "bifurcations" as parameters are varied.

by: Professor Dalibor Froncek

Department of Mathematics and Statistics

UMD

Suppose you want to schedule a round robin tournament (every team plays every other team) of eight teams but do not have enough time to play all 28 games. You may decide that each team will play just five games rather than the usual seven. Now you need to choose which games to drop. It surely makes a difference if the team ranked No. 4 misses the games against the teams ranked No. 1 and 2 while team ranked No. 5 misses the games against the teams ranked No. 7 and 8. Overall, team No. 5 then has much stronger opponents than No. 4.

We will explore ways how to make such a tournament as fair as possible and also how to make it unfair. We will show that these two tasks are in fact complementary and that by achieving one, we also achieve the other. To do that, we introduce some notions of graph theory, including "vertex-magic vertex labeling," and show how graph theory can help us solve the scheduling problem.

by: Professor Daniel Pope

Department of Mechanical and Industrial Engineering

UMD

When a fuel droplet enters the combustion chamber, it interacts with the chamber gas causing circulation within the droplet and evaporation from the droplet surface. The moving droplet experiences a drag force that opposes its motion and the droplet velocity decreases. In suspended droplet combustion experiments under forced convection, the droplet is suspended from a filament and the relative velocity between the ambient oxidizer and the droplet is usually held constant. This talk addresses the difference in combustion behavior, given the same initial conditions, of an isolated liquid fuel droplet under two scenarios: moving droplet and suspended droplet combustion in a forced convection environment. The first problem simulates the injection of a droplet into a combustion chamber. In this case, the droplet is allowed to decelerate due to the drag force. The second scenario simulates the conditions that are typically present in experiments that employ the suspended droplet technique (constant velocity). A numerical model has been developed to simulate the two cases. The equations and methods employed in the model, the validation of the model and results for n-heptane droplet combustion will be presented.

by: *Melanie Wood

Princeton Math Graduate Student

Princeton, New Jersey

Insight. Originality. Inspiration. New perspectives. Opening your mind. Finding a different way. Playing around. That is mathematics.

Somehow our society and even our education system has perpetuated the myth that mathematics is about memorization, technicalities, formulas and equations, only one correct answer. Yet this picture utterly fails to describe the creative process that is professional mathematics.

This talk is intended for the general audience. Students will earn colloquium attendance points for the this talk.

*Ms. Wood's visit is sponsored by a grant from the UMD Commission on Women.

(Panel discussion)

by:

Professor Carmen Latterell

Department of Mathematics and Statistics

Professor Janelle Wilson

Department of Sociology

UMD

and

*Melanie Wood

Princeton Mathematics Graduate Student

Princeton, New Jersey

Each member of the panel will discuss her view and experiences of society's perception of mathematicians. Movie clips and music will be played. Time for audience insights and questions will be allowed. Students will earn colloquium points for this event.

Following the panel discussion the UMD Math Club will host a pizza party offering free pizza and soft drinks in 130 SCC.

*Ms. Wood's visit is sponsored by a grant from the UMD Commission on Women.

by: Wesley Griffiths & Ross Anderson

St. Paul Travelers

Graduating Class of 2000

UMD

The talk will cover the following topics:

Where do actuaries work?

What type of work are actuaries involved in?

What skills to you need to be an actuary?

What UMD classes will best prepare you for a job as an actuary?

What are the actuarial exams all about?

How do I get a job as an actuary?

What is the going market rate for actuaries?

by: Professor Jay Austin

Large Lakes Observatory/Department of Physics

UMD

Numerical modeling has, over the last few decades, become a standard technique in oceanography for understanding the fundamental nature of fluid circulation in complex oceanographic, estuarine, and lacustrine systems. These models solve the Navier-Stokes equations and an equation of state on a grid of points, utilizing a set of simplifications and assumptions that allow a numerical approximation for the circulation and hydrography (distribution of dynamic and passive tracers) to be determined. I will discuss the basic physics behind the equations, some of the numerical techniques used in one particular model, and give examples of two systems I am currently working with: a shelfestuary interaction idealization, and a semi-realistic seasonal model of Lake Superior.

by: Dr. William Krossner

Statistical Consultant

Most of us remember from the U.S. 2004 presidential election, that those states which gave their electoral votes to the Republican candidate are called "red",those to the Democratic candidate, "blue." This rubric comes from a post-election map published in a weekly news magazine.

A statistical comparison based on a variety of objective, published social statistics shows a remarkably consistent difference between the two groups of states. The speaker will present the data and attempt to give a social psychological explanation as to why the statistical differences might be expected to have led to a difference in voting.

If you can define the terms median, percentile, and correlation coefficient you will be able to understand this talk.

The terms "white" in the title comes from the likelihood that there will be heated audience discussion by partisans of the two political parties.

Most of us remember from the U.S. 2004 presidential election, that those states which gave their electoral votes to the Republican candidate are called

by: INGE PETTERSEN

MS Candidate: Program in Applied and Computational Mathematics

Advisor: Steven Trogdon

UMD

For the Newtonian fluid flow there are by now a considerable collection of algorithms that solve hyperbolic differential euqations. One of the basic issues in the discrete version is to consistently average the fluxes across the cell interfaces. One approach, the Marquita flux method, uses characteristic information from the exact fluxes to define the flux averaging.

The aim of the current presentation is to extend this Newtonian algorithm to a special relativistic algorithm that handles the relativistic fluxes correctly.

by: Joseph Erickson

MS Candidate: Program in Applied and Computational Mathematics

Advisors: Harlan Stech and Steven Trogdon

U.M.D.

In order to ensure the safety of bridges, it is useful to create reliable models that predict strength. Important factors in constructing such models are the boundary conditions. It is of interest to examine what effects boundary conditions have on bridge motions through the use of mathematical models.

In this paper several models are derived. All models stem from the Bernoulli beam equation. The models associate vibrational characteristics to strength. Initially, simply supported and clamped boundary conditions are investigated. Upon introducing the previous mentioned boundary conditions, new boundary conditions are derived that have both simply supported and clamped characteristics. They are referred to as the rotational spring and hybrid boundary conditions.

Numerical implentations are also presented. Special attention is given to the hybrid boundary condition model. The numerical results provide insight into the applicability of such models.

by: Professor Marshall Hampton

Department of Mathematics and Statistics UMD

The point vortex model in fluid mechanics has been used to help understand a wide range of phenomena, including superfluid helium, hurricanes, ocean circulation, wakes, and turbulence. In this talk we will look at the history of the point vortex model within the context of dynamical systems and fluid mechanics, see some beautiful and, pictures those to the Democratic candidate, discuss some solved and unsolved related problems This rubric comes from a post-election map published in a weekly news magazine. A statistical comparison based on a variety of objective, published social statistics shows a remarkably consistent difference between the two groups of states. The speaker will present the data and attempt to give a social psychological explanation as to why the statistical differences might be expected to have led to a difference in voting. If you can define the terms median, percentile, and correlation coefficient you will be able to understand this talk. The terms to vortices and fluids. One of these problems has a $1,000,000 prize for the solution!

by: Dr. Emmanuel Ugo Enemuoh

Department of Mechanical & Industrial Engineering

UMD

Ultrasonic nondestructive evaluation (NDE) of materials remains one of the most widely used techniques of inspection and characterization of both metals and advanced composite materials. There is still need to develop methods of processing ultrasonic waves to increase signal to noise ratio.

This presentation will illustrate ultrasonic signal processing based on the Discrete Wavelet Transform, to characterize the time-frequency content of the propagating waves. Features extracted after Discrete Wavelet processing of the wave signals result in damage index that is robust with respect to noise and is related to the extent of damage. The method allows for fast inspection with the potential for quantifying the size of flaw.

This wavelet technique of signal processing will further be implemented in the NDE and structural health monitoring research topics being conducted by the author including: Acousto-Ultrasonic characterization of adhesively bonded joints of advanced composite materials.

by: Joshua Jacobs

UMD Department of Matematics and Statistics

The formal concept of a factor group is relatively young. Though historically recent in its formal form, applications of the intuitive notion of a factor groups have influenced culture and art for thousands of years. In the art of M.C. Escher we have some of the most pronounced expressions of factor groups in the repeating patterns of various plane tessellations. In this talk we examine the concept of the factor group in its most basic forms. We will then explore its expression in art, both ancient and recent. Some visually surprising results occur.

This talk may be thoroughly enjoyed without previous knowledge of group theory.

by: Professor Sarah Greenwald

Department of Mathematical Sciences

Appalachian State University

Boone, North Carolina

The quest to understand the precise geometry and shape of our universe began thousands of years ago, mathematicians when in the title comes from the likelihood that there will be heated audience discussion by partisans of the two political parties. and astronomers used mathematical models to try and explain their observations. We'll explore historical and current theories related to the geometry of the earth and universe during an interactive talk. A globe or child's ball will be useful. For more information, see mathaware.org.

by: Dr. Sergei Bezrukov

Department of Mathematics-Computer Science

University of Wisconsin-Superior

It is easily shown that any tree T is a subgraph of the hypercube Q_n of dimension n for n sufficiently large. We consider the problem of finding, for a given tree T, a minimum n such that T is a subgraph of Q_n. We formulate three obvious conditions a tree T has to satisfy for being a subgraph of Q_n. A conjecture of Havel, which is open for more than 30 years, is that those three conditions are also sufficient.

We consider the Havel's conjecture for caterpillars, a special kind of trees. Inspite of several attempts to prove it, the conjecture is open even for this class of trees. The conjecture is proved for certain types of caterpillars, though.

In this talk, we present a new approach to the Havel's conjecture. Although the original conjecture still remains open, our approach allows to confirm it for a wide class of caterpillars, which includes all known results as special cases. The talk is self-contained and includes all necessary notions. We also present (short) proofs for some theorems.

by: Dougla Sarah, Amber and Richard will discuss specific LU maths modules, how they fit into UMD math major options and basic differences between UMD and LU bachelors programs. They will also discuss financial concerns related to living abroad, whas Dunham

UMD Computer Science Department

In the late 1950's, the Dutch graphic artist M. C. Escher became the first person to create artistic patterns in the hyperbolic plane with his four "Circle Limit" prints. About twenty years later Dr. Dunham, David Witte a UMD REU student, and John Lindgren a UMD math major undertook the challenge of reproducing these patterns via computer graphics. This involved a combination of mathematics and computer science. The main challenge is replication: transforming copies of the basic subpattern or "motif" around the hyperbolic plane to create a final pattern without gaps or overlaps. The first program made use of a queue and the traversal of a Hamiltonian path in a directed graph of the symmetry group of the pattern. Later versions of the program used recursion and allowed for the creation of more general patterns. These replication algorithms make use of combinatorial relations among the polygons in the regular tessellations of the hyperbolic plane by regular p-gons meeting q at a vertex. A number of new patterns will be shown, in addition to our renditions of Escher's "Circle Limit" patterns.

by: Guihua Fei

UMD Department of Mathematics and Statistics

Biologist have long speculated on the reasons why there are no large meat eaters animals in Australia. There is an abundance of kangaroos, reptiles, but no large mammals like lions, tigers, etc. In this talk, we will build a mathematical model to describe the situation and try to give an answer to that question from a math point of view. Calculus and some basic linear algebra provide sufficient background for the talk. Some other mathematical models and applications will also be mentioned.

by: Professor Zhuangyi Liu

Department of Mathematics and Statistics UMD

Rigidizable/Inflatable materials offer the possibility of deployable large space structures, thus are of interest in applications where large optical or RF apertures are needed. We model and study the dynamics of a basic truss component consisting of two rigidizable/inflatable beams connected through two legs to a joint.

by: Sarah Wicker, Amber Palmer, and Richard Mathers

Department of Mathematics and Statistics UMD

Students Sarah Wicker, Amber Palmer and Richard Mathers will present their experiences as participants in the LU-UMD mathematics student exchange progam. UMD mathematics majors, Sarah Wicker, Amber Palmer and Gretchen Hanke, studied mathematics last spring semester at Loughborough University in England. Richard Mathers, as an LU student, studied mathematics at UMD last fall. Richard graduated from LU last spring and is now enrolled in UMD's master's degree program in applied and computational mathematics.

Sarah, Amber and Richard will discuss specific LU maths modules, how they fit into UMD math major options and basic differences between UMD and LU bachelors programs. They will also discuss financial concerns related to living abroad, what to do during spring break and their European travel adventures. They will describe British social life and culture, as well as Richard's experiences as a UK citizen living in the USA.

There will also be opportunities to ask the speakers questions concerning the LU-UMD exchange. Kathryn Lenz, Department of Mathematics and Statistics foreign studies advisor, and Marie Vuldjeva, UMD's foreign studies office, will also be on hand to answer questions and hand out relevant information.

Followed by Math Club Welcome and free pizza and pop

# Seminar and Colloquia: 2005 - 2006

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

**Panel discussion: What can be done with a Mathematics Teaching License?**

Moderator: Carmen Latterell

Panelists: Dr. Kay Wohlhuter, Department of Education, UMD;

Sheila Nyback, Morgan Park; Heather Kahler, UWS;

Brian Freyberg, Esko High School; David Brown, East.

**Abstract:**The panelists are all people who hold teaching licenses in mathematics. Each will talk for approximately five minutes about the path each has taken. Audience members may ask any related question. For example, what can be expected in the first year of high school teaching? What does a Ph.D. in mathematics education involve? What is some advice for a resume or interviewing? How did you find your job? What do you wish you had done differently?

**Time:**May 4, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**STATISTICAL ISSUES IN LINKAGE ANALYSIS WITH APPLICATION IN TWO STUDIES**

by: Dr. Mariza de Andrade

Interim-Chair, Division of Biostatistics

Mayo Clinic and Mayo Clinic College of Medicine

Rochester, Minnesota

**Abstract:**In this seminar I describe different linkage methods used to identify genetic factors predisposing to complex diseases. I will focus on two studies, one involving identification of genetic factors for familial lung cancer and the other the identification of genetic factors predisposing to hypertension and its target organ complications in families. Different linkage approaches were applied, and I will describe their advantages and disadvantages.

**Time:**April 28, 2006 4:00 p.m. - 5:00 p.m.**Location:**130 Solon Campus Center**Honors Colloquium**

"Modeling Ozone-Induced Leaf Damage" by Lindsey Deitz "Actuarial Reserving" by Alex Kranz "Numbers that are smooth with respect to a set of primes" by Laurence Lin "Scheduling the WCHA with graph theory" by Riitta Schaublin "Compartmental Models of Traffic Flow" by Shane Ellis

**Abstract:**Five Math/Stat majors are graduating this spring with departmental honors. Part of the requirement to receive departmental honors is to complete a research project. In this colloquium these five students will present brief descriptions of the research they completed.

**Time:**April 27, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**Appled Usage of Mathematics within Information Systems - One Person's Experience**

by: John Burrows, Technical Director

Integration & Data Management Services

Accenture/Best Buy Technology Group

Graduate of UMD

**Abstract:**A background in mathematics has many direct and indirect beneficial usages within Information Systems. During this informal discussion, a high-level overview of one person's usage of mathematics throughout a 20 year career within Information Systems will be provided. Topics touched on will range from common usage of statistics within systems performance analysis, to the benefits of general analytical thinking skills obtained from a background in mathematics. At the end of this discussion session, students will also have an opportunity to ask general questions regarding a career within Information Systems and hear one person's perspective.

**Time:**April 20, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**A DIFFERENTIAL EQUATIONS MODEL FOR PEATLAND ECOLOGY**

by: Professor Bruce Peckham

Department of Mathematics and Statistics

UMD

**Abstract:**Peatlands exist in a significant part of northern Minnesota. Some of these peatlands are dominated by moss, while others have moss coexisting with other shrubs. From a modeling point of view, moss is treated differently from other shrubs because moss receives most of its nutrients from rainwater, rather than in uptake from roots. This leads to a differential equations model which allows the possibility of either "moss monoculture" or "coexistence" equilibrium states. The talk will discuss both the development of the model and its behavior, including "bifurcations" as parameters are varied.

**Time:**March 30, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**WANT TO SCHEDULE AN (UN)FAIR TOURNAMENT?**

by: Professor Dalibor Froncek

Department of Mathematics and Statistics

UMD

**Abstract:**Suppose you want to schedule a round robin tournament (every team plays every other team) of eight teams but do not have enough time to play all 28 games. You may decide that each team will play just five games rather than the usual seven. Now you need to choose which games to drop. It surely makes a difference if the team ranked No. 4 misses the games against the teams ranked No. 1 and 2 while team ranked No. 5 misses the games against the teams ranked No. 7 and 8. Overall, team No. 5 then has much stronger opponents than No. 4.

We will explore ways how to make such a tournament as fair as possible and also how to make it unfair. We will show that these two tasks are in fact complementary and that by achieving one, we also achieve the other. To do that, we introduce some notions of graph theory, including "vertex-magic vertex labeling," and show how graph theory can help us solve the scheduling problem.

**Time:**March 23, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**COMBUSTION OF MOVING DROPLETS AND SUSPENDED DROPLETS: TRANSIENT NUMERICAL RESULTS**

by: Professor Daniel Pope

Department of Mechanical and Industrial Engineering

UMD

**Abstract:**When a fuel droplet enters the combustion chamber, it interacts with the chamber gas causing circulation within the droplet and evaporation from the droplet surface. The moving droplet experiences a drag force that opposes its motion and the droplet velocity decreases. In suspended droplet combustion experiments under forced convection, the droplet is suspended from a filament and the relative velocity between the ambient oxidizer and the droplet is usually held constant. This talk addresses the difference in combustion behavior, given the same initial conditions, of an isolated liquid fuel droplet under two scenarios: moving droplet and suspended droplet combustion in a forced convection environment. The first problem simulates the injection of a droplet into a combustion chamber. In this case, the droplet is allowed to decelerate due to the drag force. The second scenario simulates the conditions that are typically present in experiments that employ the suspended droplet technique (constant velocity). A numerical model has been developed to simulate the two cases. The equations and methods employed in the model, the validation of the model and results for n-heptane droplet combustion will be presented.

**Time:**March 9, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**THE CREATIVE PROCESS OF MATHEMATICS**

by: *Melanie Wood

Princeton Math Graduate Student

Princeton, New Jersey

**Abstract:**Insight. Originality. Inspiration. New perspectives. Opening your mind. Finding a different way. Playing around. That is mathematics.

Somehow our society and even our education system has perpetuated the myth that mathematics is about memorization, technicalities, formulas and equations, only one correct answer. Yet this picture utterly fails to describe the creative process that is professional mathematics.

This talk is intended for the general audience. Students will earn colloquium attendance points for the this talk.

*Ms. Wood's visit is sponsored by a grant from the UMD Commission on Women.

**Time:**March 2, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**THE PUBLIC PERCEPTION OF MATHEMATICIANS**

(Panel discussion)

by:

Professor Carmen Latterell

Department of Mathematics and Statistics

Professor Janelle Wilson

Department of Sociology

UMD

and

*Melanie Wood

Princeton Mathematics Graduate Student

Princeton, New Jersey

**Abstract:**Each member of the panel will discuss her view and experiences of society's perception of mathematicians. Movie clips and music will be played. Time for audience insights and questions will be allowed. Students will earn colloquium points for this event.

Following the panel discussion the UMD Math Club will host a pizza party offering free pizza and soft drinks in 130 SCC.

*Ms. Wood's visit is sponsored by a grant from the UMD Commission on Women.

**Time:**March 2, 2006 3:30 p.m. - 4:30 p.m. --Panel**Location:**120 Solon Campus Center**CAREERS IN ACTUARIAL SCIENCE**

by: Wesley Griffiths & Ross Anderson

St. Paul Travelers

Graduating Class of 2000

UMD

**Abstract:**The talk will cover the following topics:

Where do actuaries work?

What type of work are actuaries involved in?

What skills to you need to be an actuary?

What UMD classes will best prepare you for a job as an actuary?

What are the actuarial exams all about?

How do I get a job as an actuary?

What is the going market rate for actuaries?

**Time:**February 16, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**NUMERICAL MODELING OF THE CIRCULATION, HYDROGRAPHY, AND CHEMISTRY OF AQUATIC AND MARINE SYSTEMS**

by: Professor Jay Austin

Large Lakes Observatory/Department of Physics

UMD

**Abstract:**Numerical modeling has, over the last few decades, become a standard technique in oceanography for understanding the fundamental nature of fluid circulation in complex oceanographic, estuarine, and lacustrine systems. These models solve the Navier-Stokes equations and an equation of state on a grid of points, utilizing a set of simplifications and assumptions that allow a numerical approximation for the circulation and hydrography (distribution of dynamic and passive tracers) to be determined. I will discuss the basic physics behind the equations, some of the numerical techniques used in one particular model, and give examples of two systems I am currently working with: a shelfestuary interaction idealization, and a semi-realistic seasonal model of Lake Superior.

**Time:**February 9, 2006 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**RED, BLUE AND WHITE: A STATISTICAL VIEW**

by: Dr. William Krossner

Statistical Consultant

**Abstract:**Most of us remember from the U.S. 2004 presidential election, that those states which gave their electoral votes to the Republican candidate are called "red",those to the Democratic candidate, "blue." This rubric comes from a post-election map published in a weekly news magazine.

A statistical comparison based on a variety of objective, published social statistics shows a remarkably consistent difference between the two groups of states. The speaker will present the data and attempt to give a social psychological explanation as to why the statistical differences might be expected to have led to a difference in voting.

If you can define the terms median, percentile, and correlation coefficient you will be able to understand this talk.

The terms "white" in the title comes from the likelihood that there will be heated audience discussion by partisans of the two political parties.

Most of us remember from the U.S. 2004 presidential election, that those states which gave their electoral votes to the Republican candidate are called

**Time:**February 2, 2006 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**A SEMI-DISCRETE ALGORITHM FOR SOLVING RELATIVISTIC INVISCID FLOW**

by: INGE PETTERSEN

MS Candidate: Program in Applied and Computational Mathematics

Advisor: Steven Trogdon

UMD

**Abstract:**For the Newtonian fluid flow there are by now a considerable collection of algorithms that solve hyperbolic differential euqations. One of the basic issues in the discrete version is to consistently average the fluxes across the cell interfaces. One approach, the Marquita flux method, uses characteristic information from the exact fluxes to define the flux averaging.

The aim of the current presentation is to extend this Newtonian algorithm to a special relativistic algorithm that handles the relativistic fluxes correctly.

**Time:**January 27, 2006 10:00 a.m.**Location:**130 Solon Campus Center**THE IMPACT OF BOUNDARY CONDITIONS ON THE FREE VIBRATIONS OF BEAMS**

by: Joseph Erickson

MS Candidate: Program in Applied and Computational Mathematics

Advisors: Harlan Stech and Steven Trogdon

U.M.D.

**Abstract:**In order to ensure the safety of bridges, it is useful to create reliable models that predict strength. Important factors in constructing such models are the boundary conditions. It is of interest to examine what effects boundary conditions have on bridge motions through the use of mathematical models.

In this paper several models are derived. All models stem from the Bernoulli beam equation. The models associate vibrational characteristics to strength. Initially, simply supported and clamped boundary conditions are investigated. Upon introducing the previous mentioned boundary conditions, new boundary conditions are derived that have both simply supported and clamped characteristics. They are referred to as the rotational spring and hybrid boundary conditions.

Numerical implentations are also presented. Special attention is given to the hybrid boundary condition model. The numerical results provide insight into the applicability of such models.

**Time:**December 12, 2005 2:15 p.m.**Location:**130 Solon Campus Center**MYSTERIES OF POINT VORTICES**

by: Professor Marshall Hampton

Department of Mathematics and Statistics UMD

**Abstract:**The point vortex model in fluid mechanics has been used to help understand a wide range of phenomena, including superfluid helium, hurricanes, ocean circulation, wakes, and turbulence. In this talk we will look at the history of the point vortex model within the context of dynamical systems and fluid mechanics, see some beautiful and, pictures those to the Democratic candidate, discuss some solved and unsolved related problems This rubric comes from a post-election map published in a weekly news magazine. A statistical comparison based on a variety of objective, published social statistics shows a remarkably consistent difference between the two groups of states. The speaker will present the data and attempt to give a social psychological explanation as to why the statistical differences might be expected to have led to a difference in voting. If you can define the terms median, percentile, and correlation coefficient you will be able to understand this talk. The terms to vortices and fluids. One of these problems has a $1,000,000 prize for the solution!

**Time:**December 1, 2005 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**DAMAGE DETECTION AND EVALUATION USING WAVELET ANALYSIS APPROACH**

by: Dr. Emmanuel Ugo Enemuoh

Department of Mechanical & Industrial Engineering

UMD

**Abstract:**Ultrasonic nondestructive evaluation (NDE) of materials remains one of the most widely used techniques of inspection and characterization of both metals and advanced composite materials. There is still need to develop methods of processing ultrasonic waves to increase signal to noise ratio.

This presentation will illustrate ultrasonic signal processing based on the Discrete Wavelet Transform, to characterize the time-frequency content of the propagating waves. Features extracted after Discrete Wavelet processing of the wave signals result in damage index that is robust with respect to noise and is related to the extent of damage. The method allows for fast inspection with the potential for quantifying the size of flaw.

This wavelet technique of signal processing will further be implemented in the NDE and structural health monitoring research topics being conducted by the author including: Acousto-Ultrasonic characterization of adhesively bonded joints of advanced composite materials.

**Keywords:**nondestructive evaluation (NDE), wavelet analysis, acousto-ultrasonic and ultrasonic signal**Time:**November 17, 2005 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Escher and the Art of Factor Groups**

by: Joshua Jacobs

UMD Department of Matematics and Statistics

**Abstract:**The formal concept of a factor group is relatively young. Though historically recent in its formal form, applications of the intuitive notion of a factor groups have influenced culture and art for thousands of years. In the art of M.C. Escher we have some of the most pronounced expressions of factor groups in the repeating patterns of various plane tessellations. In this talk we examine the concept of the factor group in its most basic forms. We will then explore its expression in art, both ancient and recent. Some visually surprising results occur.

This talk may be thoroughly enjoyed without previous knowledge of group theory.

**Time:**November 3, 2005 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**GEOMETRY OF THE EARTH AND UNIVERSE**

by: Professor Sarah Greenwald

Department of Mathematical Sciences

Appalachian State University

Boone, North Carolina

**Abstract:**The quest to understand the precise geometry and shape of our universe began thousands of years ago, mathematicians when in the title comes from the likelihood that there will be heated audience discussion by partisans of the two political parties. and astronomers used mathematical models to try and explain their observations. We'll explore historical and current theories related to the geometry of the earth and universe during an interactive talk. A globe or child's ball will be useful. For more information, see mathaware.org.

**Time:**October 11, 2005 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**ON EMBEDDING TREES INTO THE HYPERCUBE**

by: Dr. Sergei Bezrukov

Department of Mathematics-Computer Science

University of Wisconsin-Superior

**Abstract:**It is easily shown that any tree T is a subgraph of the hypercube Q_n of dimension n for n sufficiently large. We consider the problem of finding, for a given tree T, a minimum n such that T is a subgraph of Q_n. We formulate three obvious conditions a tree T has to satisfy for being a subgraph of Q_n. A conjecture of Havel, which is open for more than 30 years, is that those three conditions are also sufficient.

We consider the Havel's conjecture for caterpillars, a special kind of trees. Inspite of several attempts to prove it, the conjecture is open even for this class of trees. The conjecture is proved for certain types of caterpillars, though.

In this talk, we present a new approach to the Havel's conjecture. Although the original conjecture still remains open, our approach allows to confirm it for a wide class of caterpillars, which includes all known results as special cases. The talk is self-contained and includes all necessary notions. We also present (short) proofs for some theorems.

**Time:**October 27, 2005 3:00 p.m. - 4:00 p.m.**Location:**130 Solon Campus Center**Computer Generation of Hyperbolic Escher Patterns**

by: Dougla Sarah, Amber and Richard will discuss specific LU maths modules, how they fit into UMD math major options and basic differences between UMD and LU bachelors programs. They will also discuss financial concerns related to living abroad, whas Dunham

UMD Computer Science Department

**Abstract:**In the late 1950's, the Dutch graphic artist M. C. Escher became the first person to create artistic patterns in the hyperbolic plane with his four "Circle Limit" prints. About twenty years later Dr. Dunham, David Witte a UMD REU student, and John Lindgren a UMD math major undertook the challenge of reproducing these patterns via computer graphics. This involved a combination of mathematics and computer science. The main challenge is replication: transforming copies of the basic subpattern or "motif" around the hyperbolic plane to create a final pattern without gaps or overlaps. The first program made use of a queue and the traversal of a Hamiltonian path in a directed graph of the symmetry group of the pattern. Later versions of the program used recursion and allowed for the creation of more general patterns. These replication algorithms make use of combinatorial relations among the polygons in the regular tessellations of the hyperbolic plane by regular p-gons meeting q at a vertex. A number of new patterns will be shown, in addition to our renditions of Escher's "Circle Limit" patterns.

**Time:**October 20, 2005 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**Why are there no large meat-eating mammals in Australia?**

by: Guihua Fei

UMD Department of Mathematics and Statistics

**Abstract:**Biologist have long speculated on the reasons why there are no large meat eaters animals in Australia. There is an abundance of kangaroos, reptiles, but no large mammals like lions, tigers, etc. In this talk, we will build a mathematical model to describe the situation and try to give an answer to that question from a math point of view. Calculus and some basic linear algebra provide sufficient background for the talk. Some other mathematical models and applications will also be mentioned.

**Time:**October 6, 2005 3:30 p.m. - 4:30 p.m.**Location:**130 Solon Campus Center**MODELING AND ANALYSIS OF A JOINT-LEG-BEAM SYSTEM**

by: Professor Zhuangyi Liu

Department of Mathematics and Statistics UMD

**Abstract:**Rigidizable/Inflatable materials offer the possibility of deployable large space structures, thus are of interest in applications where large optical or RF apertures are needed. We model and study the dynamics of a basic truss component consisting of two rigidizable/inflatable beams connected through two legs to a joint.

**Time:**September 29, 2005 3:00 p.m.**Location:**130 Solon Campus Center**STUDY MATHEMATICS AT LOUGHBOROUGH UNIVERSITY, ENGLAND**

by: Sarah Wicker, Amber Palmer, and Richard Mathers

Department of Mathematics and Statistics UMD

**Abstract:**Students Sarah Wicker, Amber Palmer and Richard Mathers will present their experiences as participants in the LU-UMD mathematics student exchange progam. UMD mathematics majors, Sarah Wicker, Amber Palmer and Gretchen Hanke, studied mathematics last spring semester at Loughborough University in England. Richard Mathers, as an LU student, studied mathematics at UMD last fall. Richard graduated from LU last spring and is now enrolled in UMD's master's degree program in applied and computational mathematics.

Sarah, Amber and Richard will discuss specific LU maths modules, how they fit into UMD math major options and basic differences between UMD and LU bachelors programs. They will also discuss financial concerns related to living abroad, what to do during spring break and their European travel adventures. They will describe British social life and culture, as well as Richard's experiences as a UK citizen living in the USA.

There will also be opportunities to ask the speakers questions concerning the LU-UMD exchange. Kathryn Lenz, Department of Mathematics and Statistics foreign studies advisor, and Marie Vuldjeva, UMD's foreign studies office, will also be on hand to answer questions and hand out relevant information.

**Time:**September 22, 2005 4:00 p.m.Followed by Math Club Welcome and free pizza and pop

**Location:**130 Solon Campus Center