Department of Mathematics and Statistics Talks for the week February 16-20, 2009 (previous week)

Analysis Seminar: "Part 2 - Transition to turbulence, small disturbances and sensitivity analysis"   Date Monday, February 16, 2009 Time 4:00 pm – 5:00 pm CST Where Room G-4, Rolla Building Event Type Lectures & Seminars Presenter Dr. John Singler Sponsored by Department of Mathematics and Statistics Contact David Grow Description Predicting transition to turbulence is one of the longstanding problems in fluid mechanics. Recently, new transition scenarios have been proposed that are based on the sensitivity of the linearized equations of motion with respect to small disturbances. These new "mostly linear" theories have increased our understanding of the transition process, but the role of nonlinearity has not been thoroughly explored. In this talk, sensitivity analysis is used to explore the effects of small disturbances on transition to turbulence. A model problem is used to demonstrate that sensitivity analysis can predict the behavior of the disturbed system. Three dimensional Navier-Stokes equations are considered and small disturbances are shown to have great potential to trigger transition. Time Scales Seminar: "Dynamic cobweb models"   Date Wednesday, February 18, 2009 Time 4:00 pm – 4:50 pm CST Where Room G-4, Rolla Building Event Type Lectures & Seminars Presenter Julius Heim Sponsored by Department of Mathematics and Statistics Contact Martin Bohner More http://web.mst.edu/~bohner/seminar/ts.html Demonstration: "How to Use a Slide Rule"   Date Thursday, February 19, 2009 Time 12:00 pm – 1:00 pm CST Where Meramec-Gasconade Room, Havener Center Event Type Special Events Sponsored by University Archives Contact Diana Ahmad Cost FREE Description Ever wondered what Joe Miner is carrying on his left shoulder? Professor Jerry Bayless will show us how to use a slide rule. Antique and industry specific slide rules will be on display. Topology/Algebra Seminar: "Intro to Contact Algebras (Continued)"   Date Thursday, February 19, 2009 Time 4:00 pm – 5:00 pm CST Where Room G-5, Rolla Building Event Type Lectures & Seminars Presenter Dr. Matt Insall Sponsored by Mathematics and Statistics Contact Robert Roe Description In [1], Dimiter Vakarelov describes the concept of a contact algebra, which was introduced by Dimov and Vakarelov in [2] to help formalize a notion, championed by Whitehead in [3], of "contact" between regions in space. Formally, a contact algebra is a pair A=(B, C), where B=(B,0,1,^,v,~) is a Boolean algebra, and C is a binary relation on the set B, such that the following hold: (C1) xCy implies x>0; (C2) xC(yvz) if either xCy or xCz; (C3) xCy implies yCx; (C4) x^y>0 implies xCy. Examples of contact algebras include the algebra of regular closed subsets of a topological space, and the algebra of regular open subsets of a topological space. This kind of "pointless" topology, or "pointless" geometry, has applications in artificial intelligence and knowledge representation, via qualitative spatial reasoning, and represents a fertile area of interaction between classical Boolean algebra, topology and logic. [1] D. Vakarelov, Region-Basel Theory of Space: Algebras of Regions, Represent at ion Theory, and Logics, In: Mathematical Problems from Applied Logic. Logics for the XX-Ist Century. II. Edited by Dov M. Gabbay et. al. Int'l Mathematical Series, 5, Springer, 2007. [2] G. Dimov and D. Vakarelov, Contact algebras and region-based theory of space. A proximity approach. I, Fundam. Inform. (2006) [3] A. N. Whitehead, Process and Reality. New York, MacMillan, 1929.