Mathematics and Computer Science
COLLOQUIUM

SPRING 2010 Tuesday April 6, 2010 at 1:40 in Room C620 Sebastian Hanlon Gameplay Programmer, BioWare, a division of EA BSc 2004 and MSc 2006 Computer Science University of Lethbridge There Is No Done, Only Convergence: Agile Development In Practice Video game development is challenging under any methodology: the marketplace moves fast, and responding to changes is critical. Is there a risk of being "too agile" and getting caught in an endless cycle of changes? Sebastian Hanlon shares lessons learned at a AAA game studio. Sebastian has been a gameplay engineer at BioWare Edmonton (part of Electronic Arts) since 2006. He has worked on a number of AAA game development projects including the critically acclaimed and award-winning "Dragon Age: Origins" and "Mass Effect 2". His interests include bringing visceral action gameplay to engaging story-driven games, and tools that unlock rapid iteration and multidisciplinary collaboration. Friday March 19 11:00-11:50 Room B775 Micah B. Milinovich Assistant Professor Department of Mathematics University of Mississipi Ph.D., University of Rochester, 2008 Research interests: Analytic Number Theory The vertical distribution of the zeros of the Riemann zeta-function Understanding the distribution of the zeros of the Riemann zeta-function has been important goal of mathematics over the last century. It believed that all the nonreal zeros of the zeta-function lie on a vertical line, called the critical line. The conjecture is known as the Riemann Hypothesis (RH). Assuming the RH, it is not hard to compute the average spacing between consecutive zeros of the Riemann zeta-function on the critical line. In this talk I will describe various methods that show these zeros are not regularly spaced. In particular, I will describe some methods that show there are in finitely many pairs of consecutive zeros that are significantly farther apart than average and that there are infinitely many pairs of zeros that are closer together than average. Friday Jan 08 12:00-12:50 Room C640 Daya Gaur University of Lethbridge Research interests: approximation algorithms Member of the MITACS-NCE project on Facility Location Optimization. A primal-dual algorithm for the unconstrained fractional matching problem We consider a variant of the maximum cardinality matching problem. In which negative edge values and arbitrary positive capacities on the vertices are allowed. We use the primal-dual approach. We characterize the optimal solution to the dual of the restricted primal (DRP) and give a combinatorial algorithm for solving the DRP. This is joint work with Bobby Chan and Ramesh Krishnamurti. FALL 2009 Mondays, 12:00-12:50, room W565 Wednesday Oct. 21 Room A580 Michael P. Lamoureux Professor, Mathematics and Statistics Adjunct Professor, Geoscience University of Calgary Research interests: Functional analysis, C*-algebras, noncommutative geometry Nonselfadjoint operator algebras, C*-dynamical systems Mathematics of wave propagation and seismic imaging Numerical methods and applications to geophysics. Properties of Gabor multipliers for physical modeling We present techniques developed for numerical modeling of wave propagation, and source-signature removal in seismic imaging, based on a class of linear operators known as Gabor multipliers. These operators are localized Fourier multipliers, whose actions is selectively localized by an element of a partition of unity. We discuss boundedness and stability properties for these operators, approximations to PDEs and pseudodifferential operators, and an approximate functional calculus. Nov. 02 Habiba Kadiri University of Lethbridge Research interests: Analytic Number Theory, L-functions, distribution of primes. Celebrating 150 years of the Riemann Hypothesis. The Riemann Hypothesis is a conjecture that was formulated in 1859 by the German mathematician Bernhard Riemann. It is widely considered to be the most important open problem in pure mathematics today. A correct solution to this problem would result in a US $1,000,000 prize awarded by the Clay Mathematics Institute. This conjecture establishes the location of the zeros of a specific complex variable function. We will discuss the history of this problem and how it is intimately related to the distribution of prime numbers. Nov. 16 Amir Akbary University of Lethbridge Research interests: Number Theory, L-functions, Reduction mod p of elliptic curves, Polynomials over finite fields. Highly Composite Numbers A number is called highly composite if it has more divisors than any smaller number. The first 10 highly composite numbers are 2, 4, 6, 12, 24, 36, 48, 60, 120, 180. These numbers were introduced and studies by Ramanujan in 1915. In this talk we describe some elementary properties of these numbers as given in Ramanujan's paper. We also discuss the relation of these numbers to some deep results and conjectures in the analytic theory of numbers. I will try my best to make the talk accessible. Nov. 23 Masami Tatsuno Department of Neuroscience Canadian Centre for Behavioural Neuroscience University of Lethbridge Research Interests: Information processing in brain like systems, modeling brain functions with neural networks, brain signal analysis. Introduction to computational neuroscience Computational neuroscience is a field of neuroscience that aims to understand how information is represented and processed in the brain by modeling the nervous systems. In this talk, I will give an overview of computational neuroscience and discuss how it provides useful concepts for understanding brain information processing, which is based on different computational principles than silicone-based computers. Nov. 30 Shahadat Hossain University of Lethbridge Research interests: numerical optimization and its applications, design of efficient algorithms for sparse matrix problems. Computing with Pascal's Triangle Many interesting combinatorial identities can be derived from the ''Pascal's arithmetic triangle", the triangle of binomial coefficients named after Blaise Pascal. In this introductory talk I will emphasize the computational aspects of this famous triangle of numbers. I will first discuss the LU factorization of the Pascal's matrix and review some related calculations. I will then introduce a sparse matrix determination problem in numerical optimization whereby the nxr real matrix with r<< n defining a compression- reconstruction procedure must satisfy the Haar condition. Properties of this Pascal-like compression-reconstruction matrix will be presented. Dec. 07 Dennis Connolly University of Lethbridge Research interests: probability and applied statistics. The life and works of Alexander Craig Aitken He was one of New Zealand's greatest mathematicians, considered as ``the greatest algebraist of the century'' (Sir Edmund Whittaker) and ``the greatest mental calculator officially recorded'' (Martin Gardiner). He was elected to the prestigious Royal Society of London in 1936 for his work in mathematics. Some of his notable publications are: Statistical Mathematics, Determinants and Matrices, Theory of Canonical Matrices, From Gallipoli to the Somme, along with approximately 70 research papers in: Algebra, Statistics, Economics, Actuarial Science, Numerical Analysis. Everybody is welcome ! Previous years: 2008-2009 - 2007-2008 - 2005 - 2004 - 2003 - 2002 - 2001 Student Seminar (Please email me to the above address if you wish to come visit us and give a talk). Contact: Habiba Kadiri (kadiri@cs.uleth.ca)