Difference between revisions of "CATS-Apr-19-2013"

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== Title ==
 
== Title ==
The Combinatorics of Hidden Diversity
+
Risk in network routing games
  
 
== Speaker ==
 
== Speaker ==
David Johnson is Head of the Algorithms and Optimization Department
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Evdokia Nikolova is an Assistant Professor at the Computer Science &
at AT&T Labs-Research in Florham Park, NJ, and has been a researcher
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Engineering Department at Texas A&M University. Previously she was a
at the Labs (in its many incarnations) since 1973, when he received his
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postdoctoral associate in the Computer Science and Artificial
PhD from MIT. He is perhaps best known as the co-author of COMPUTERS
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Intelligence Laboratory at MIT. She graduated with a BA in Applied
AND INTRACTABILITY: A GUIDE TO THE THEORY OF NP-COMPLETENESS, for which
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Mathematics with Economics from Harvard University, MS in Mathematics
he and his co-author M. R. Garey won the INFORMS Lanchester Prize.
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from Cambridge University (U.K.) and Ph.D. in Computer Science from
His research interests include approximation algorithms for combinatorial
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MIT. She is interested in risk analysis from an algorithmic
problems, a subject on which he had several of the first key papers,
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perspective arising in stochastic optimization, networks, economics
starting with his PhD thesis on the infamous "bin packing" problem.
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and complex systemsShe has worked on applications to transportation
In recent years he has become a leader in the experimental analysis of
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and is also interested in energy and other domains where her work may
algorithms, and has been the creator and lead organizer for the series
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apply.
of DIMACS Implementation Challenges, covering topics from Network Flows
 
to the Traveling Salesman ProblemHe also founded the ACM-SIAM
 
Symposium on Discrete Algorithms (SODA), and served as its Steering
 
Committee Chair for its first 23 years.  He is an ACM Fellow, a SIAM
 
Fellow, an AT&T Fellow, and the winner of the 2010 Knuth Prize for
 
outstanding contributions to the foundations of computer science.
 
  
 
== Abstract ==
 
== Abstract ==
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One relevant paper is here:
 
One relevant paper is here:
 
http://faculty.cse.tamu.edu/nikolova/papers/Stochastic-selfish-routing-full.pdf
 
http://faculty.cse.tamu.edu/nikolova/papers/Stochastic-selfish-routing-full.pdf
 +
 
A short summary of the paper is here:
 
A short summary of the paper is here:
 
http://www.sigecom.org/exchanges/volume_11/1/NIKOLOVA.pdf
 
http://www.sigecom.org/exchanges/volume_11/1/NIKOLOVA.pdf

Latest revision as of 19:05, 15 April 2013

Title[edit]

Risk in network routing games

Speaker[edit]

Evdokia Nikolova is an Assistant Professor at the Computer Science & Engineering Department at Texas A&M University. Previously she was a postdoctoral associate in the Computer Science and Artificial Intelligence Laboratory at MIT. She graduated with a BA in Applied Mathematics with Economics from Harvard University, MS in Mathematics from Cambridge University (U.K.) and Ph.D. in Computer Science from MIT. She is interested in risk analysis from an algorithmic perspective arising in stochastic optimization, networks, economics and complex systems. She has worked on applications to transportation and is also interested in energy and other domains where her work may apply.

Abstract[edit]

Network routing games are instrumental in understanding traffic patterns and improving congestion in networks. They have a direct application in transportation and telecommunication networks and extend to many other applications such as task planning, etc. Theoretically, network games were one of the central examples in the development of algorithmic game theory.

In these games, multiple users need to route between di fferent source-destination pairs and links are congestible, namely, each link delay is a non-decreasing function of the flow on the link. Many of the fundamental game theoretic questions are now well understood for these games, for example, does equilibrium exist, is it unique, can it be computed e fficiently, does it have a compact representation; the same questions can be asked of the socially optimal solution that minimizes the total user delay.

So far, most research has focused on the classical models in which the link delays are deterministic. In contrast, real world applications contain a lot of uncertainty, which may stem from exogenous factors such as weather, time of day, weekday versus weekend, etc. or endogenous factors such as the network tra ffic. Furthermore, many users are risk-averse in the presence of uncertainty, so that they do not simply want to minimize expected delays and instead may need to add a bu ffer to ensure a guaranteed arrival time to a destination.

I present my recent work on a new stochastic network game model with risk-averse users. Risk-aversion poses a computational challenge and it often fundamentally alters the mathematical structure of the game compared to its deterministic counterpart, requiring new tools for analysis. The talk will discuss best response and equilibrium analysis, as well as equilibrium efficiency (price of anarchy) and a new concept, the price of risk.

One relevant paper is here: http://faculty.cse.tamu.edu/nikolova/papers/Stochastic-selfish-routing-full.pdf

A short summary of the paper is here: http://www.sigecom.org/exchanges/volume_11/1/NIKOLOVA.pdf