TITLE: Power Grid Blackouts - Models and Algorithms

SPEAKER: Professor Daniel Bienstock, IEOR Department at Columbia, NY

DATE / TIME: Friday, November 30,2007 / 2:30-3:45 p.m.

LOCATION: Room 453 Mohler Lab, 200 W. Packer Avenue

ABSTRACT: We consider a number of multi-stage combinatorial optimization problems
related to the dynamics of a power grid under stress. The development of a large blackout, in simplified form, is a multi-step process. In each step some set of edges of the network (which happen to cany "too much flow") are turned off, resulting in a smaller network. This smaller network is (typically) used to cany the same amount of demand, which results in some new set of edges to be overloaded. This type of model, a form of which was initially developed by Dobson et al, leads to a "cascade" behavior. The initial event that starts the process is caused by natural, though unlikely, factors. The problems we consider are: (1) given a network, does it have a small-cardinality weakness that would set off a catastrophic cascade, and (2) given a network
with a cascade under development, what is a good online strategy for stopping the cascade. We will discuss these problems and related background.

BIOGRAPHY: Daniel Bienstock is a professor of Operations Research at the IEOR
department at Columbia University, where he has been since 1989. His research encompasses theoretical and computational aspects of discrete and continuous optimization, and applications to logistics, finance, network design and routing. He received the Presidential Young Investigator award in 1990. He gave a plenary talk at the 2005 SIAM Conference on Optimization (Stockholm) and a semi-plenary talk at the 2006 Mathematical Programming Symposium (Rio). He is the author of over fifty papers in refereed journals, and a book,"Potential Function Methods for Approximately Solving Linear Programs".

ALL FULL-TIME ISE DEFT. GRADUATE STUDENTS ARE REQUIRED TO ATTEND
REFRESHMENTS WILL BE SERVED FOLLOWING THE SEMINAR