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Colloquium 2000-2001

Date/Time Speaker Title/Abstract

Thursday
September 28, 2000
3:30 PM in ILB 370
Uwe Kaiser
University of Siegen, Germany
Quantum topology, Vassiliev invariants and Skein theory
Abstract:  TBA

Thursday
November 9, 2000
3:00 PM in ILB 345
Please Notice Unusual
Time and Location
Xin-Min Zhang
University of South Alabama
Sierpinski Pedal Triangles
Abstract:  In this talk, we will construct a 2-parameter family of Sierpinski-type triangles in terms of the pedal triangles of a given triangle. This family includes the ordinary Sierpinski Triangle as a special member when the initial triangle is equilateral. We shall investigate the fractal dimensions of Sierpinski Pedal Triangles and the related area ratio problems. Some computer generated graphs will also be provided. This talk is based on recent joint work by the speaker and Drs. R. Hitt (of USA) and J. Ding (of USM). The talk will be presented at a very elementary level. Everyone, especially, undergraduate and graduate students are encouraged to come and enjoy the discovery of a new fractal!

Thursday
November 16, 2000
4:00 PM in ILB 140
Physics Colloquium
Please Notice Unusual
Time and Location
Carl Brans
Loyola University, New Orleans
Scalar Fields and Gravity
Abstract:  TBA

Tuesday
November 21, 2000
11:00 AM in ILB 235
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Time and Location
Nabendu Pal
University of Louisiana at Lafayette
Careers in Mathematics and Statistics
Abstract:  This talk focuses on the recent trends in the job market for the graduate students in the areas of
  • Applied Mathematics;
  • Pure Mathematics, and
  • Statistics.
Among other things we will talk about job opportunities in -
  • different sectors (academics, government and industry)
  • various regions within the United States; and
  • international job market.
We will also discuss the excellent opportunities for the students offered by the Department of Mathematics, University of Louisiana at Lafayette, to pursue graduate degrees with concentration in pure as well as applied mathematics, and statistics.

Wednesday
November 29, 2000
2:30 PM in ILB 405
Sponsored by MathStat Club
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Time and Location
Janet P. Buckingham
Statistical Analysis Section Southwest Research Institute San Antonio, Texas
Statistics is NOT a four-letter word - Statistical Applications in an R&D Environment
Abstract:  A discussion of how statistics plays a part in successful projects in a research and development organization. Views from a consulting statistician on a variety of problems faced by engineers and scientists will be presented. This talk is non-technical and will give insight on applying statistics to research projects.

Thursday
November 30, 2000
3:30 PM in ILB 370
Cornelius Pillen
University of South Alabama
On Self-Extensions
Abstract:  Fix a positive integer n, a prime p, and look at square matrices of size n by n whose entries are integers modulo p. Then take the subset of those matrices whose determinants are not equal to zero and use the usual matrix multiplication as the operation. We just construted a finite group. This group is just one example of an infinite family of groups called Chevalley groups. Now take the n-dimensional vector space consisting of vectors whose components are also integers modulo p. Again the usual matrix operation defines an "action" of our group on the vector space. Vector spaces that are equipped with such an action are called modules. In this talk we will give an introduction to the study of group actions for finite Chevalley groups. In particular, we want to look at vector spaces that contain no subspaces that are left invariant under the action of the group. These are called simple modules. Finally, we will give a partial answer to the following question: Is it possible to build a new module out of two isomorphic simple ones?

Tuesday
January 16, 2001
3:30 PM in ILB 370
Please Notice Unusual
Day
Chris Bendel
University of Wisconsin, Stout
If you meet a module on the street, how can you tell if it's projective?
Abstract:  It is well known that a module over a finite group is projective if and only if it is injective. Indeed, this holds more generally for any finite-dimensional cocommutative Hopf algebra over a field. In general, however, these fundamental concepts are not the same. In this talk, we will present a survey of methods for determining the projectivity of a module over a class of algebras over a field of prime characteristic. We will first note the differences between the situation for finite groups and more general Hopf algebras. Then, we will focus on a specific method based on a result of Chouinard, which states that a module over a finite group is projective if and only if it is projective upon restriction to every elementary abelian subgroup. We present a generalization of this to a larger family of Hopf algebras (or finite group schemes) which encompasses finite groups as well as nipotent restricted Lie algebras (and more generally unipotent infinitesimal group schemes).

Friday
February 9, 2001
3:30 PM in ILB 370
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Day
Bimal K Sinha
University of Maryland Baltimore County
A statistical comparison of CMW and DPW for monitoring groundwater pollutants
Abstract:  Monitoring of groundwater pollutants is performed by boring wells at predetermined locations in the ground and assessing trace amounts of certain chemicals. In this talk a statistical comparison between the traditional conventionally monitored wells (CMW) and the more recent direct push wells (DPW) based on actual data will be presented. The problem is nontrivial because of the highly sparse nature of the data arising out of many `flagged' cases. A Bayesian solution will be indicated.

Monday
February 12, 2001
3:30 PM in ILB 370
Please Notice Unusual
Day
Daniel Shapiro
Ohio State University
Products of Sums of Squares
Abstract:  No Title

An [r,s,n]-formula is defined to be an expression of the type:

displaymath8

where the tex2html_wrap_inline10 's and tex2html_wrap_inline12 's are indeterminates and each tex2html_wrap_inline14 is a bilinear form in X and Y. For example, norms of complex numbers provide a [2,2,2]-formula while quaternions and octonions provide [4,4,4] and [8,8,8]-formulas. In 1898 Hurwitz proved that there is an [n,n,n]-formula iff n = 1, 2, 4 or 8, and he posed the general question of determining when such formulas exist. In the 1920s Hurwitz and Radon settled the case s = n. The general question seems very difficult, but many interesting aspects and applications have been studied in the past few decades, touching on algebra, combinatorics, topology, and geometry.


Monday
February 12, 2001
Mobile Mathematics Circle Lecture
Sponsored by the Alabama Space Consortium
7 pm in ILB 430
Please Notice Unusual
Day and Time
Daniel Shapiro
Ohio State University
Scissors Congruence
Abstract:  Consider polygonal figures in the plane. If a figure is cut into a finite number of pieces, those pieces can be rearranged without overlapping (as in a jigsaw puzzle) to make another figure. Certainly the new figure has the same area as the original. However suppose we start with two figures of equal area. Must there be a way to cut the first figure into pieces which can then be rearranged to make the second figure? This question will be discussed, along with various possibilities for generalization.

Monday
February 19, 2001
3:30 pm in ILB 370
Please Notice Unusual
Day
Titu Andreescu
University of Nebraska
Mathematical Induction: An Elegant and Powerful Method
Abstract:  My talk will feature essay-type, open-ended problems in undergraduate mathematics in an attempt to move away from routine exercises and memorized algorithms toward creative solutions to unconventional problems. I will present examples and Olympiad problems from Algebra, Geometry, Number Theory, and Combinatorics, because they are interesting, fun to solve, and they best reflect mathematical ingenuity and elegant arguments.

Monday
February 19, 2001
Mobile Mathematics Circle Lecture
Sponsored by the Alabama Space Consortium
7 pm in ILB 430
Please Notice Unusual
Day and Time
Titu Andreescu
University of Nebraska
Some of my favorite problems
Abstract:  A variety of examples and Olympiad problems from Algebra, Geometry, Number Theory, and Combinatorics will be presented. They have been selected because they are interesting, fun to solve and unconventional.

Thursday
March 22, 2001
3:30 PM in ILB 370
Ed Sandifer
Western Connecticut State University
Euler's Fourteen Problems
Abstract:  In 1755, Leonhard Euler sent a list of 14 "Quaestiones Mathematicae" to the St Petersburg Academy, with the intent that those problems serve as a guide for mathematical research for the next several years. Using these problems as a model, we discuss the ways problems have been set before the mathematical community and the role of problem lists, like Euler's and Hilbert's. We also look at the particular problems Euler posed, in the context of his times and the great mathematical, scientific and philosophical issues of the day.

Friday
April 6, 2001
3:30 pm in ILB 370
Please Notice Unusual
Day
Noel Brady
University of Oklahoma
Finding Surfaces in Free-by-Cyclic Groups
Abstract:  Groups arise whenever we see symmetry in mathematics. For example, you see lots of symmetries in a wallpaper pattern in your home. The group in this instance consists of rigid motions of the plane which move the wallpaper pattern in such a way that it superimposes perfectly on itself. Such rigid motions are called symmetries of the pattern. We may translate or shift the pattern one unit to the right and see that it superimposes on itself. If we shift it a further 2 units to the right, then we have shifted it a total of 3 units. There is a basic algebra at work here similar to the algebra of numbers under addition: $1+2=3$. This algebraic object, the collection of all symmetries of the pattern together with the operation of composition, is called a group. Groups have a formal definition in mathematics, and have been studied independently of geometry for a long time. Geometric group theory is a new branch of mathematics which advocates a return to geometry when dealing with groups. An abstract group can be viewed as a group of symmetries of some geometric object. We can study and try to classify groups by studying these geometric objects. Gromov achieved remarkable success with this approach when he defined the notion of a hyperbolic group, and showed that hyperbolic groups have some very beautiful properties. In this talk, we'll give a brief survey of hyperbolic groups, and then talk about some ideas for finding closed hyperbolic surface groups inside other hyperbolic groups.

Friday
April 13, 2001
3:30 pm in ILB 370
Please Notice Unusual
Day
Subhash C. Bagui
University of West Florida
Breast Cancer Detection Using Rank Nearest Neighbor Classification Rules
Abstract:  In this article we propose a new generalization of the rank nearest neighbor (RNN) classification rule for multivariate data for diagnosis of breast cancer. We study the performance of this rule using two well known databases and compare the results with the conventional k-NN rule. We observe that this rule performed remarkably well, and the computational complexity of the proposed k-RNN rule is much less than the conventional k-NN rule.

Tuesday
April 17, 2001
2:00 pm in ILB 370
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Day and Time
Pedro Lopez
Kansas State University and IST in Lisbon, Portugal
Quandle Cohomology and Invariants for Embeddings of Codimension 2
Abstract:  In [1] quandle cocycles are used to concoct invariants for embeddings of codimension two; 2-cocycles give rise to invariants for (classical) knots and 3-cocycles give rise to invariants for knotted surfaces. Refining the ideas in [1] we are able to derive new invariants. References: [1] J. S. Carter et al, Quandle Cohomology and State-Sum Invariants of Knotted Curves and Surfaces, math>GT/9903135, 1999

Wednesday
April 18, 2001
Keynote Address at the USA Research Forum
1:10 pm in the Student Center Ballroom
David S. Moore
Purdue University
Statistical Thinking: How to Tell the Facts from the Artifacts
Abstract:  Statistics in its technical dress has miraculous properties: it makes invisible effects visible, appeases hostile editors, and sets shared standards for many fields of science. Yet a few elements of statistical thinking can help any educated person assess most ``statistical'' controversies. Are we dealing with data or anecdotes? How were the data obtained? How large is the advertised effect relative to variation among individuals? What lurking variables were considered (or ignored)? This nontechnical talk illustrates the principles of statistical thinking through examples.

Wednesday
April 18, 2001
3:30 pm in ILB 140
David S. Moore
Purdue University
Statistical Literacy and Statistical Competence for the New Century
Abstract:  In an environment in which much that once required thought is automated, what should all educated people know about data, variation, and chance? That's statistical literacy. What should someone who works with data now and then in her job remember from the statistics course she took 5 years ago? That's statistical competence. Both statistical literacy and statistical competence are important to knowledge workers, more important in most settings than the detailed mastery that constitutes statistical professionalism. This informal talk offers one opinion on the nature of statistical literacy and statistical competence, and indirectly on the teaching of statistics to beginners.

Wednesday
May 30, 2001
3:30 pm in ILB 370
Please Notice Unusual
Day
Ilia Kapovich
University of Illinois at Urbana-Champaign
On the Poenaru condition and almost convexity.
Abstract:  Poenaru condition P(n) generalizes Cannon's almost convexity condition for a finitely generated group and says that balls in the Cayley graph of the group have some mild convexity properties. We generalize the Poenaru condition and prove, in particular, that Poenaru P(2)-groups are finitely presentable, have word problem solvable in exponential time and that they satisfy linear isodiametric and double exponential isoperimetric inequalities.

 

 


Last modified on Wednesday, 08-Jan-03 15:09:32

Department of Mathematics and Statistics
ILB 325
University of South Alabama
Mobile, AL 36688
phone: (251) 460-6264 (voice), (251) 460-7969 (fax)
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