Please see my new homepage for updated information

Albert Xin Jiang email: jiang at cs dot ubc dot ca, albertjiang at gmail

I completed my Ph.D. under Professor Kevin Leyton-Brown, at the Laboratory of Computational Intelligence (LCI), Department of Computer Science, University of British Columbia. After working as a post-doc in Professor Milind Tambe's TEAMCORE group at USC, I have joined Trinity University as an assistant professor in computer science. Please check my new homepage for updated information.

Some recent news:

• I have successfully defended my PhD thesis on December 2, 2011.
• Starting 2012, I have joined Professor Milind Tambe's TEAMCORE group at USC as a post-doc.
• I am the runner up of the IFAAMAS-11 Victor Lesser Distinguished Dissertation Award.
• I received the 2012 Canadian Artificial Intelligence Association (CAIAC) Doctoral Dissertation Award for the best doctoral thesis in AI completed at a Canadian University in 2011.
• Chris Kiekintveld, Bo An and I gave a tutorial on Stackelberg Games with Applications to Security at the ACM-EC conference in Valencia, Spain, June 2012. Slides (pptx, pdf) for the tutorial are available.

Research

1. Development of compact representations of game-theoretic models.

This is motivated by the observation that while the standard representation of games as multi-dimensional tables is impractical due to the curse of dimensionality, most real-world games of interest have structured utility functions. I am involved in the development and analysis of Action-Graph Games (AGGs), a fully-expressive modeling language for representing simultaneous-move games. When utility functions exhibit commonly-encountered structure such as context-specific independence, anonymity and additivity, AGGs can represent such games compactly, i.e. using small numbers of bits. For a detailed introduction of AGGs, please see our paper in Games and Economic Behavior (joint work with Kevin Leyton-Brown and Navin Bhat). Recently, we have extended the AGG framework to represent games of incomplete information (joint with Kevin Leyton-Brown) and dynamic games (joint with Kevin Leyton-Brown and Avi Pfeffer). For more information on AGGs and extensions, see the AGG Project website.

2. Design and analysis of efficient algorithms for computing Nash and correlated equilibria given a compactly represented game.

A common subproblem is the computation of expected utility given an arbitrary mixed-strategy profile. For AGGs and their extensions, we provide efficient algorithms for this, and leverage these algorithms to achieve exponential speedups of existing algorithms for finding sample Nash equilibria. Software implementations are available at the AGG Project website. I am also interested in the problem of computing pure-strategy Nash equilibria for graphical game representations including AGGs and graphical games. When the associated graphs have bounded treewidth, techniques based on tree decomposition and dynamic programming are often applicable, while for classes of graphs with unbounded treewidth it is possible to prove hardness results. I am also interested in the computation of correlated equilibria and Stackelberg equilibira. For more details please see my list of publications.

Publications (Please see my new homepage for updated information)

• A.X. Jiang, Representing and Reasoning with Large Games, PhD Thesis, University of British Columbia, December 2011.
  Winner of the CAIAC Doctoral Dissertation Award for the best doctoral thesis in AI completed at a Canadian university in 2011, and the runner-up IFAAMAS-11 Victor Lesser Distinguished Dissertation Award.
  pdf | official link
• A.X. Jiang, Computational Problems in Multiagent Systems, MSc Thesis, University of British Columbia, 2006.
  pdf

• F. Fang, A.X. Jiang, M. Tambe. Optimal Patrol Strategy for Protecting Moving Targets with Multiple Mobile Resources. Accepted with minor revisions to JAIR, 2013.
• A.X. Jiang, K. Leyton-Brown, Polynomial-time Computation of Exact Correlated Equilibrium in Compact Games. Games and Economic Behavior, 2013.
  Preprint
  Official journal paper: DOI: 10.1016/j.geb.2013.02.002
• A.X. Jiang, K. Leyton-Brown and N. Bhat, Action-Graph Games, Games and Economic Behavior, Volume 71, Issue 1, January 2011, Pages 141-173.
  An earlier draft is available as University of British Columbia Technical Report TR-2008-13.
  Preprint: pdf
  Official journal paper: DOI 10.1016/j.geb.2010.10.012
  Website for Action-Graph Games software
• A.X. Jiang and K. Leyton-Brown, Bidding Agents for Online Auction Environments with Hidden Bids. Special Issue on Learning & Computational Game Theory, Machine Learning, Volume 67, Numbers 1-2, May, 2007.
  An eariler version was presented at Workshop on Game-Theoretic and Decision-Theoretic Agents (GTDT) at IJCAI 2005, Edinburgh, Scotland.
  Preprint: pdf
  Official journal paper