ColloquiaTalk by Dimitris Margaritis on Wednesday, April 10, 2002

[Margery Ishmael]

Wednesday, April 10, 2002
2:30 pm
Ryerson 251

Dimitris Margaritis, Carnegie Mellon University
"Probabilistic Model Structure from Data"

Abstract:
Probabilistic models are useful for modeling non-deterministic data
generation processes.  Examples of these can be found in genetic
domains representing gene expression interactions, socio-economic
domains representing stock market prices influences by current events,
and many others.  The greatest problem in modeling such processes is
determining the structure of the model.  In my talk I will present
work I have done at Carnegie Mellon towards inferring the structure of
a specific class of models called Bayesian networks (BNs).  I will
present the GS ("grow-shrink") algorithm which uses conditional
independence tests to determine the BN structure.  I will also present
a statistical independence test that shows progress towards a
conditional independence test for domains with continuous variables, a
problem currently unsolved in its generality.  I will also show
some results of an application that uses Bayesian network models to
answer count queries from very large databases.  My approach features
constant time in the size of the database, a small space overhead, and
linear preprocessing time.  Moreover it is easily parallelizable and
can be readily used for data-mining purposes, at no extra cost.

Bio: I am currently a Ph.D. student in the Computer Science Department at 
Carnegie Mellon University. My advisor is Sebastian Thrun.  My main 
interest currently lies within the field of Machine Learning in the 
discovery of the structure of Bayesian networks from data. In the past I 
worked on applying Machine Learning to Vision and Image Retrieval.
http://www-2.cs.cmu.edu/~dmarg/

Host: Svetlozar Nestorov

*The talk will be followed by refreshments in Ryerson 255*
Persons with disabilities who may need assistance should call 773.834.8977

If you would like to meet with the speaker, please send e-mail to 
marge at cs.uchicago.edu

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Margery Ishmael
Secretary to the Chairman, Department of Computer Science
The University of Chicago
1100 E. 58th Street, Chicago, IL. 60637-1581
tel. 773.834.8977  fax. 773.702.8487
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