# Weekly Colloquium

The Department hosts a weekly colloquium on Fridays at 2pm, usually in Southern Hall, room 303. If you would like to present, please contact Dr. Huiqing Zhu with a title and abstract. Please see our tips on abstracts below. You can also find links to previous years' titles and abstracts below.

 Date Presenter, Affiliation Title, Abstract 7 Oct 2016 Dr. Michael Starbird, University of Texas at Austin Geometric GemsPlain, plane geometry contains some of the most beautiful proofs ever—-some dating from ancient times and some created by living mathematicians. This talk will include some of my favorites including an incredibly clever way to see that a plane intersects a cone in an ellipse, a non-calculus method--developed by a living mathematician--for computing areas under challenging curves, and many more. Geometry provides many treats! 16 Sep 2016 Dr. Iliyan Iliev, USM Social Science Applications of Bayesian Structural VAR Models and Natural Language ProcessingComputerized text analysis and structural time series models have been underutilized in Social Science research despite their many applications. This project studies the dynamic interactions of energy sector campaign contributions to members of the U.S. Senate and their reactions. Congressional rhetoric is segregated from the database of Committee hearings using a Java script, and then analyzed using a Bayesian natural language processing algorithm. The categorized rhetoric over time is then linked to the campaign contributions data, and analyzed using a Bayesian time-series model. Conditioning on party and Senate class, I find strong evidence for a fully dynamic model, where rhetoric and contributions engage in a complex system of leads, lags, and contemporaneous interactions. 15 Sep 2016 Dr. John Travis, Mississippi College WebworkWeBWorK is an open-source online homework system delivering individualized assessment problems. Immediate feedback encourages students to persist until they succeed. Instructors receive real-time statistics that indicate how to better serve students. An Open Problem Library of over 35,000 refereed and catalogued problems covers nearly the entire mathematics curriculum. Most problems utilize a robust checking engine which allows almost any type of formula-like answer. More than 1000 institutions utilize WeBWorK, most in the USA, but also in Canada and Mexico, as well as Europe, Asia, and Africa. This talk gives an overview of WeBWorK's features, including recent improvements and a summary of how to utilize WeBWorK in the classroom. Participants are encouraged to bring an internet-capable device and participate in real-time. 29 Apr 2016 Dr. Sung Lee, USM TBA 22 Apr 2016 Dr. Raymond Atta-Fynn, University of Texas at Arlington Materials Modeling via DynamicsSampling rare events and reconstructing the free energy along a path from an initial to a final state of physical and chemical processes is one of the principal goals of materials modeling. This can be achieved with a computational technique known as metadynamics, which allows efficient sampling and permits an accurate reconstruction of the free energy landscape with the aid of a small set of collective variables. This talk will provide a brief overview of the metadynamics method and how it is applied to molecular and solid state systems. Specific applications in the context of metal ion structure and hydrolysis in aqueous environments, and the generation of atomistic structures of amorphous semiconductors will be presented. 15 Apr 2016 Dr. Paula Smithka, USM (Philosophy and Religion) Dr. Who and Philosophy 101Philosophy begins in wonder! (Aristotle said that). And Doctor Who certainly creates a sense of wonder in its companions. In this talk, I will provide a brief introduction to what philosophy is, the various areas of philosophical inquiry, and why Doctor Who is so very philosophical. 1 Apr 2016 Dr. Carmen Wright, Jackson State University The Generalized and Symmetric Spaces in $$\textrm{SL}_2(\mathbb F_q)$$ and $$\textrm{GL}_2(\mathbb F_q)$$We will discuss the generalized symmetric spaces for $$\textrm{SL}_2(\mathbb F_q)$$ and $$\textrm{GL}_2(\mathbb F_q)$$. Specifically, we will characterize the structure of these spaces, and prove that when the characteristic of $$\mathbb F_q$$ is not equal to two, the extended generalized symmetric space is equal to the generalized symmetric space for $$\textrm{SL}_2(\mathbb F_q)$$ and nearly equal for $$\textrm{GL}_2(\mathbb F_q)$$. 11 Mar 2016 Dr. Maarten Buijsman, USM (Marine Science) The Propagation and Dissipation of Tidal Internal Gravity Waves in Numerical SimulationsAs the surface tide propagates over underwater topography, energy is transferred to internal gravity waves that can propagate thousands of kilometers through an eddying ocean. Underway, these low-mode internal waves may scatter into high modes at steep topography, be affected by wave-wave interaction, and they may nonlinearly interact with the mesoscale eddy field. Their dissipation causes the mixing of water masses, sustaining the overturning circulation and affecting climate. It is not yet clear what their ultimate fate is. Do they dissipate their energy along the way or when they break on the continental shelves? In this talk I will address these questions with idealized numerical simulations and with the realistically forced Hybrid Coordinate Ocean Model, the operational forecast model of the US Navy. 4 Mar 2016 Dr. Ras Pandey, USM (Physics and Astronomy) Random walk, polymer chain, and protein by computer simulation experimentsRandom walks are a classical mechanism for analyzing phenomena as diverse as stock market trends and information in cell phone chips. They give a starting point for exploring the structure and dynamics of systems with string-like constituents, such as polymer chains and proteins. While polymer chains' structure and dynamics are relatively well understood, the structure and dynamics of a protein remain an open problem. Issues include atomic scale structures, first principle force-fields, structure-based constraints, etc. We discuss protein folding, self-assembly, and network formation with specific examples (e.g. histone H3.1, lysozyme, alpha-synuclein), using a coarse-grained approach involving large-scale computer simulations. 12 Feb 2016 Dr. Jiu Ding, USM A Piecewise Quadratic Interpolation Method for the Computation of Stationary DensitiesWe propose a piecewise quadratic interpolation method that can be efficiently used to approximate a stationary density of Frobenius-Perron operators associated with interval mappings. The convergence of the method for the Lasota-Yorke class of piecewise stretching mappings is proved, and numerical results are also presented. 5 Feb 2016 Dr. Bernd Schröder, USM Every order-preserving self map of the $$L^p$$ unit ball has a fixed pointThis talk will give a brief introduction why fixed points are important, why $$L^p$$ spaces are important and then proceed to prove that every order-preserving self map of the $$L^p$$ unit ball has a fixed point. We will then talk about how this result is applied and how it could be extended.

## Tips on abstracts

Dear speaker: We like to maintain a list of titles, topics, and abstracts, so that we (and you) have a record of who has visited and talked about which topic.

• The topic should be short, similar to the headlines in the AMS subject classifications.
• Please aim for no more than 100 words in your abstract. We're not fanatically rigorous about this, but an abstract should summarize the essence of a presentation, not give every detail. It’s a sales pitch, not a business plan. Keeping the abstract at 100 words also is a good preparatory step for a concise and informative talk that communicates the salient points of your work.
• You may notice that we are MathJax-enabled, so feel free to use $$\mathrm{\LaTeX}$$ markup in your abstract when appropriate.