I am interested in fast, general, reasoning and search methods, with an emphasis on stochastic proceduresa promising recent development for solving computationally hard problems. I also investigate various sources of complexity in hard problems, using theoretical and experimental methods. This work explores interesting connections between computer science, AI, and statistical physics. In addition, I study issues in problem representation, including the robustness of encodings, abstraction, compilation, and approximation methods. These issues are critical to the successful application in realistic domains of reasoning and search methods. In terms of applications, I am particularly interested in challenge problems from planning, knowledge representation, machine learning, and data mining. Our planning system, BlackBox, developed jointly with Henry Kautz of AT&T Labs, is one of the current fastest general-purpose planning systems.
I also pursue applications in areas outside AI, such as operations research and software/protocol verification.
NSF Faculty Early Career Development Award
Referee/Reviewer: Science, Artificial Intelligence J., JACM; J. Automated Reasoning; NSF review panel
Scaling properties of constraint-based planners. Fourth Int. Conf. Artificial Intelligence Planning Systems, Pittsburgh, PA, June 1998.
Heavy-tailed phenomena in combinatorial search. Georgia Tech, Atlanta, GA, Oct. 1997.
Compute-intensive methods for artificial intelligence. Four-hour tutorial. Fourteenth Nat. Conf. Artificial Intelligence, New Providence, RI, Aug. 1997 (with Henry Kautz).
Compute-intensive methods for knowledge representation and reasoning. DARPA Young Investigators Meeting, New Providence, RI, Aug. 1997.
Evidence for invariants in local search. Fourteenth Nat. Conf. Artificial Intelligence, New Providence, RI, Aug. 1997.
Algorithm portfolio design. AT&T Labs, Florham Park, NJ, July 1997.
Randomization in backtrack search: Exploiting heavy-tailed profiles for solving hard scheduling problems. Proc. Fourth Int. Conf. Artificial Intelligence Planning Systems (AIPS-98), Pittsburgh, PA (June 1998), 208-213 (with C. Gomes, K. McAloon, and C. Tretkoff).
The role of domain-specific knowledge in the planning as satisfiability framework. Proc. Fourth Int. Conf. Artificial Intelligence Planning Systems (AIPS-98), Pittsburgh, PA (June 1998), 181-189 (with H. Kautz).
Greedy local search. In MIT Encyclopedia of the Cognitive Sciences, S. Russell and M. Jordan (Eds.), Cambridge: MIT Press, 1998.
Heavy-tailed probability distributions in combinatorial search. Proc. Constraint Programming (CP 97), Linz, Austria (Oct. 1997) (with C. Gomes and N. Crato).
Ten challenges in propositional reasoning and search. Proc. Fifteenth Int. Conf. Artificial Intelligence (IJCAI 97), Nagoya, Japan (Aug. 1997) (with H. Kautz and D. McAllester).
Problem structure in the presence of perturbations. Proc. Fourteenth Nat. Conf. Artificial Intelligence (AAAI 97), New Providence, RI, (Aug. 1997) (with C. Gomes).
Evidence for invariants in local search. Proc. Fourteenth Nat. Conf. Artificial Intelligence (AAAI 97), New Providence, RI (Aug. 1997) (with D. McAllester and H. Kautz).
Algorithm portfolio design: theory vs. practice. Proc. Thirteenth Conf. Uncertainty in AI, New Providence, RI (Aug. 1997) (with C. Gomes).
Referralnet: combining social networks and collaborative filtering. Comm. ACM 40, 3 (1997), 63-65 (with H. Kautz and M. Shah).
The hidden web. Artificial Intelligence Magazine 18, 2 (1997), 27-36 (with H. Kautz and M. Shah).
Message filtering techniques. US patent no. 5619648, 1997 (with L.M. Cabale, H.A. Kautz and A.E. Milewski).
Methods and apparatus for constraint satisfaction. US patent no. 5636328, 1997 (with H.A. Kautz).