Goto

Collaborating Authors

 Government


Cognitive Architectures and General Intelligent Systems

AI Magazine

In this article, I claim that research on cognitive architectures is an important path to the development of general intelligent systems. I contrast this paradigm with other approaches to constructing such systems, and I review the theoretical commitments associated with a cognitive architecture. I illustrate these ideas using a particular architecture -- ICARUS -- by examining its claims about memories, about the representation and organization of knowledge, and about the performance and learning mechanisms that affect memory structures. I also consider the high-level programming language that embodies these commitments, drawing examples from the domain of in-city driving. In closing, I consider ICARUS's relation to other cognitive architectures and discuss some open issues that deserve increased attention.


Celebrating AI's Fiftieth Anniversary and Continuing Innovation at the AAAI/IAAI-06 Conferences

AI Magazine

The seeds of AI were sewn at the Dartmouth Conference in the summer of 1956. John McCarthy, then an assistant mathematics professor at Dartmouth, organized the conference and coined the name "artificial intelligence" in his conference proposal. This summer AAAI celebrates the first 50 years of AI; and continues to foster the fertile fields of AI at the National AI conference (AAAI-06) and Innovative Applications of AI conference (IAAI-06) in Boston.


Planning Graph Heuristics for Belief Space Search

Journal of Artificial Intelligence Research

Some recent works in conditional planning have proposed reachability heuristics to improve planner scalability, but many lack a formal description of the properties of their distance estimates. To place previous work in context and extend work on heuristics for conditional planning, we provide a formal basis for distance estimates between belief states. We give a definition for the distance between belief states that relies on aggregating underlying state distance measures. We give several techniques to aggregate state distances and their associated properties. Many existing heuristics exhibit a subset of the properties, but in order to provide a standardized comparison we present several generalizations of planning graph heuristics that are used in a single planner. We compliment our belief state distance estimate framework by also investigating efficient planning graph data structures that incorporate BDDs to compute the most effective heuristics. We developed two planners to serve as test-beds for our investigation. The first, CAltAlt, is a conformant regression planner that uses A* search. The second, POND, is a conditional progression planner that uses AO* search. We show the relative effectiveness of our heuristic techniques within these planners. We also compare the performance of these planners with several state of the art approaches in conditional planning.


Asynchronous Partial Overlay: A New Algorithm for Solving Distributed Constraint Satisfaction Problems

Journal of Artificial Intelligence Research

Distributed Constraint Satisfaction (DCSP) has long been considered an important problem in multi-agent systems research. This is because many real-world problems can be represented as constraint satisfaction and these problems often present themselves in a distributed form. In this article, we present a new complete, distributed algorithm called asynchronous partial overlay (APO) for solving DCSPs that is based on a cooperative mediation process. The primary ideas behind this algorithm are that agents, when acting as a mediator, centralize small, relevant portions of the DCSP, that these centralized subproblems overlap, and that agents increase the size of their subproblems along critical paths within the DCSP as the problem solving unfolds. We present empirical evidence that shows that APO outperforms other known, complete DCSP techniques.


A Continuation Method for Nash Equilibria in Structured Games

Journal of Artificial Intelligence Research

Structured game representations have recently attracted interest as models for multi-agent artificial intelligence scenarios, with rational behavior most commonly characterized by Nash equilibria. This paper presents efficient, exact algorithms for computing Nash equilibria in structured game representations, including both graphical games and multi-agent influence diagrams (MAIDs). The algorithms are derived from a continuation method for normal-form and extensive-form games due to Govindan and Wilson; they follow a trajectory through a space of perturbed games and their equilibria, exploiting game structure through fast computation of the Jacobian of the payoff function. They are theoretically guaranteed to find at least one equilibrium of the game, and may find more. Our approach provides the first efficient algorithm for computing exact equilibria in graphical games with arbitrary topology, and the first algorithm to exploit fine-grained structural properties of MAIDs. Experimental results are presented demonstrating the effectiveness of the algorithms and comparing them to predecessors. The running time of the graphical game algorithm is similar to, and often better than, the running time of previous approximate algorithms. The algorithm for MAIDs can effectively solve games that are much larger than those solvable by previous methods.


The 2005 International Florida Artificial Intelligence Research Society Conference (FLAIRS-05): A Report

AI Magazine

Several special tracks included a significant number of presentations. Zdravko Markov and Larry Holder, was the most extensive, with 18 papers presented of the 35 submitted. The conference continues by Vasile Rus, was the second largest. The last few years have seen a significant reception. This year's conference received version for publication consideration A best paper award was presented to Jeffrey A. Coble, Diane J. Cook, and The program included a general session Lawrence B. Holder of the University with many excellent papers spanning of Texas at Arlington for their paper titled a broad range of AI research areas "Structure Discovery in Sequentially and covering traditional topics such as Connected Data."


Unifying Undergraduate Artificial Intelligence Robotics: Layers of Abstraction over Two Channels

AI Magazine

From a computer science and artificial intelligence perspective, robotics often appears as a collection of disjoint, sometimes antagonistic subfields. The lack of a coherent and unified presentation of the field negatively affects teaching, especially to undergraduates. This article presents an alternative synthesis of the various subfields of AI robotics and shows how these traditional subfields fit into the whole. Finally, it presents a curriculum based on these ideas.


The Sixth International Conference on Case-Based Reasoning (ICCBR-05)

AI Magazine

The program committee selected the paper "Learning to Win: Case-Based Plan Selection in a Real-Time Strategy Game" by David W. Aha (Naval Research Laboratory), The second day featured reasoning research. This report describes the conference in detail. David Aha noted the need Derek Bridge, the University College to enhance the theoretical foundations Case-Based Reasoning (ICCBR) Cork, and Craig Knoblock, the of CBR. College Dublin) stressed the fact that meeting on case-based reasoning ICCBR-05 received 74 paper submissions in recent years we have focused on (CBR). Of these, the program committee needed with respect to experience highlighting the most significant selected 26 for poster presentations modeling and reuse.



Economic Properties of Social Networks

Neural Information Processing Systems

We examine the marriage of recent probabilistic generative models for social networks with classical frameworks from mathematical economics. We are particularly interested in how the statistical structure of such networks influences global economic quantities such as price variation. Our findings are a mixture of formal analysis, simulation, and experiments on an international trade data set from the United Nations.