## Seminars and Colloquia by Series

### Joint DOS/ACO Seminar - The reflex algorithm - Convex optimization by random reflection

Series
Other Talks
Time
Wednesday, March 17, 2010 - 13:30 for 1 hour (actually 50 minutes)
Location
ISyE Executive Classroom
Speaker
Merrick FurstCollege of Computing, Georgia Tech
Santosh Vempala and I have been exploring an intriguing new approach to convex optimization. Intuition about first-order interior point methods tells us that a main impediment to quickly finding an inside track to optimal is that a convex body's boundary can get in one's way in so many directions from so many places. If the surface of a convex body is made to be perfectly reflecting then from every interior vantage point it essentially disappears. Wondering about what this might mean for designing a new type of first-order interior point method, a preliminary analysis offers a surprising and suggestive result. Scale a convex body a sufficient amount in the direction of optimization. Mirror its surface and look directly upwards from anywhere. Then, in the distance, you will see a point that is as close as desired to optimal. We wouldn't recommend a direct implementation, since it doesn't work in practice. However, by trial and error we have developed a new algorithm for convex optimization, which we are calling Reflex. Reflex alternates greedy random reflecting steps, that can get stuck in narrow reflecting corridors, with simply-biased random reflecting steps that escape. We have early experimental experience using a first implementation of Reflex, implemented in Matlab, solving LP's (can be faster than Matlab's linprog), SDP's (dense with several thousand variables), quadratic cone problems, and some standard NETLIB problems.

### PI DAY!!

Series
Other Talks
Time
Sunday, March 14, 2010 - 13:59 for 3 hours
Location
Skiles Courtyard
Speaker
N/AGT
Come celebrate pi day with math club! Pot-luck, so bring food! Math club will be providing the pies, so we ask that everyone else try to bring more substantial food. ;)Bring any games and such you want as well.

### Mathmagics with Dr. Baker

Series
Other Talks
Time
Wednesday, March 10, 2010 - 16:30 for 1 hour (actually 50 minutes)
Location
Skiles 269
Speaker
Matt BakerGeorgia Tech
Join math club for Dr. Baker's mathematical magic show.

### Preparing Teachers for the New Generation of K-16 Students - Letting Go of the Reliance upon the Traditional Statistics Introductory Course

Series
Other Talks
Time
Monday, March 8, 2010 - 11:00 for 1 hour (actually 50 minutes)
Location
Room 129, Global Learning Center (behind the GA Tech Hotel)
Speaker
Christine FranklinUniversity of Georgia

Statistics is now a part of the K-12 curriculum (including elementary school) and there is much activity in the area of statistics education. This colloquium is intended for any and all faculty, staff, and students, who are interested in, have taught, or have children in k-12 schools.

### Mathemagics - the art of mental calculation

Series
Other Talks
Time
Saturday, March 6, 2010 - 19:00 for 1 hour (actually 50 minutes)
Location
Instructional Center Room 103
Speaker
Art BenjaminHarvey Mudd College
The speaker has combined his two loves to create a dynamic presentation called "Mathemagics," suitable for all audiences, where he demonstrates and explains his secrets for performing rapid mental calculations faster than a calculator. Reader's Digest calls him "America's Best Math Whiz". He has presented his high energy talk for thousands of groups throughout the world. This event is free but reservations are required. The signup form will be available before 5pm on February 25. See details about the speaker.

### Southeast SIAM Student Conference

Series
Other Talks
Time
Saturday, March 6, 2010 - 09:00 for 8 hours (full day)
Location
Skiles 269
Speaker
SIAM Student ConferenceSchool of Mathematics, Georgia Tech
The SIAM Student Chapter at Georgia Tech will be hosting this conference. It is an extension of the ACES Workshop which has been held yearly by the universities of Auburn, Clemson, Emory, and South Carolina since 2006. As with the ACES Workshop, this conference is an opportunity for graduate students to present their research in applied mathematics and related fields as well as to meet with other graduate students from different universities and departments. See the conference site for more details.

### Karlovitz Lecture - Life in the Treetops - Forest Canopy Research in Rainforest Ecosystems

Series
Other Talks
Time
Wednesday, March 3, 2010 - 19:30 for 1 hour (actually 50 minutes)
Location
LeCraw Auditorium, College of Management, Room 100
Speaker
Nalini NadkarniEvergreen State College

Please Note: Hosted by Academic Affairs Honors Program in collaboration with the College of Sciences.

To watch a 15-minute presentation by Dr. Nadkarni see the YouTube link.

### How to Partition a Mixed Phase Space - with Applications to Atomic Physics

Series
Other Talks
Time
Monday, March 1, 2010 - 15:00 for 1 hour (actually 50 minutes)
Location
Howey N110
Speaker
Kevin MitchellUniversity of California, Merced
Hamiltonian systems typically exhibit a mixture of chaos and regularity, complicating any scheme to partition phase space and extract a symbolic description of the dynamics. In particular, the dynamics in the vicinity of stable islands can exhibit extremely complicated topology. We present an approach to extracting symbolic dynamics in such systems using networks of nested heteroclinic tangles-- fundamental geometric objects that organize phase space transport. These tangles can be used to progressively approximate the behavior in the vicinity of stable island chains. The net result is a symbolic approximation to the dynamics, and an associated phase-space partition, that includes the influence of stable islands. The utility of this approach is illustrated by examining two applications in atomic physics -- the chaotic escape of ultracold atoms from an atomic trap and the chaotic ionization of atoms in external fields.

### Club Math - Mathematics of the Lottery

Series
Other Talks
Time
Wednesday, February 24, 2010 - 16:30 for 1 hour (actually 50 minutes)
Location
Skiles 269
Speaker
Skip GaribaldiDepartment of Mathematics and Computer Science
Dr. Skip Garibaldi, Emory University's Winship Distinguished Professor, will make a presentation on Mathematics of the Lottery. He will discuss his expository article: "Finding good bets in the lottery, and why you shouldn't take them" recently published in the American Mathematical Monthly, Volume 117 (2010) 3-26.

### Georgia Scientific Computing Symposium

Series
Other Talks
Time
Saturday, February 20, 2010 - 09:00 for 8 hours (full day)
Location
Skiles 249
Speaker
Georgia Scientific Computing SymposiumSchool of Mathematics, Georgia Tech
The purpose of the Georgia Scientific Computing Symposium (GSC 2010) is to provide an opportunity for professors, postdocs and graduate students in the Atlanta area to meet in an informal setting, to exchange ideas, and to highlight local scientific computing research. The one-day symposium is open to the whole research community. The event is free but registration is required.