[Jairsubscribers] 8 new articles published by JAIR (Sept-Oct 2008)
jair-ed at ISI.EDU
Sun Nov 30 15:45:52 PST 2008
Dear JAIR subscriber:
This message lists papers that have been recently published in JAIR and describes how to access them. (If you wish to remove yourself from this mailing list, see instructions at the end of this message.)
I. New JAIR Articles
S. Esmeir and S. Markovitch (2008)
"Anytime Induction of Low-cost, Low-error Classifiers: a Sampling-based Approach",
Volume 33, pages 1-31
For quick access go to <http://www.jair.org/papers/paper2602.html>
Machine learning techniques are gaining prevalence in the production of a wide range of classifiers for complex real-world applications with nonuniform testing and misclassification costs. The increasing complexity of these applications poses a real challenge to resource management during learning and classification. In this work we introduce ACT (anytime cost-sensitive tree learner), a novel framework for operating in such complex environments. ACT is an anytime algorithm that allows learning time to be increased in return for lower classification costs. It builds a tree top-down and exploits additional time resources to obtain better estimations for the utility of the different candidate splits. Using sampling techniques, ACT approximates the cost of the subtree under each candidate split and favors the one with a minimal cost. As a stochastic algorithm, ACT is expected to be able to escape local minima, into which greedy methods may be trapped. Experiments with a variety of datasets were conducted to compare ACT to the state-of-the-art cost-sensitive tree learners. The results show that for the majority of domains ACT produces significantly less costly trees. ACT also exhibits good anytime behavior with diminishing returns.
B. Lubin, A. I. Juda, R. Cavallo, S. Lahaie, J. Shneidman and D. C. Parkes (2008)
"ICE: An Expressive Iterative Combinatorial Exchange",
Volume 33, pages 33-77
For quick access go to <http://www.jair.org/papers/paper2440.html>
We present the design and analysis of the first fully expressive, iterative combinatorial exchange (ICE). The exchange incorporates a tree-based bidding language (TBBL) that is concise and expressive for CEs. Bidders specify lower and upper bounds in TBBL on their value for different trades and refine these bounds across rounds. These bounds allow price discovery and useful preference elicitation in early rounds, and allow termination with an efficient trade despite partial information on bidder valuations. All computation in the exchange is carefully optimized to exploit the structure of the bid-trees and to avoid enumerating trades. A proxied interpretation of a revealed-preference activity rule, coupled with simple linear prices, ensures progress across rounds. The exchange is fully implemented, and we give results demonstrating several aspects of its scalability and economic properties with simulated bidding strategies.
D. Martinez, O. Lopez de Lacalle and E. Agirre (2008)
"On the Use of Automatically Acquired Examples for All-Nouns Word Sense Disambiguation ",
Volume 33, pages 79-107
For quick access go to <http://www.jair.org/papers/paper2395.html>
This article focuses on Word Sense Disambiguation (WSD), which is a Natural Language Processing task that is thought to be important for many Language Technology applications, such as Information Retrieval, Information Extraction, or Machine Translation. One of the main issues preventing the deployment of WSD technology is the lack of training examples for Machine Learning systems, also known as the Knowledge Acquisition Bottleneck. A method which has been shown to work for small samples of words is the automatic acquisition of examples. We have previously shown that one of the most promising example acquisition methods scales up and produces a freely available database of 150 million examples from Web snippets for all polysemous nouns in WordNet. This paper focuses on the issues that arise when using those examples, all alone or in addition to manually tagged examples, to train a supervised WSD system for all nouns. The extensive evaluation on both lexical-sample and all-words Senseval benchmarks shows that we are able to improve over commonly used baselines and to achieve top-rank performance. The good use of the prior distributions from the senses proved to be a crucial factor.
Y. Gal and A. Pfeffer (2008)
"Networks of Influence Diagrams: A Formalism for Representing Agents' Beliefs and Decision-Making Processes",
Volume 33, pages 109-147
For quick access go to <http://www.jair.org/papers/paper2503.html>
This paper presents Networks of Influence Diagrams (NID), a compact, natural and highly expressive language for reasoning about agents' beliefs and decision-making processes. NIDs are graphical structures in which agents' mental models are represented as nodes in a network; a mental model for an agent may itself use descriptions of the mental models of other agents. NIDs are demonstrated by examples, showing how they can be used to describe conflicting and cyclic belief structures, and certain forms of bounded rationality. In an opponent modeling domain, NIDs were able to outperform other computational agents whose strategies were not known in advance. NIDs are equivalent in representation to Bayesian games but they are more compact and structured than this formalism. In particular, the equilibrium definition for NIDs makes an explicit distinction between agents' optimal strategies, and how they actually behave in reality.
R. Meir, A. D. Procaccia, J. S. Rosenschein and Aviv Zohar (2008)
"Complexity of Strategic Behavior in Multi-Winner Elections",
Volume 33, pages 149-178
For quick access go to <http://www.jair.org/papers/paper2566.html>
Although recent years have seen a surge of interest in the computational aspects of social choice, no specific attention has previously been devoted to elections with multiple winners, e.g., elections of an assembly or committee. In this paper, we characterize the worst-case complexity of manipulation and control in the context of four prominent multi-winner voting systems, under different formulations of the strategic agentâs goal.
T. De Laet, J. De Schutter and H. Bruyninckx (2008)
"A Rigorously Bayesian Beam Model and an Adaptive Full Scan Model for Range Finders in Dynamic Environments",
Volume 33, pages 179-222
For quick access go to <http://www.jair.org/papers/paper2540.html>
This paper proposes and experimentally validates a Bayesian network model of a range finder adapted to dynamic environments. All modeling assumptions are rigorously explained, and all model parameters have a physical interpretation. This approach results in a transparent and intuitive model. With respect to the state of the art beam model this paper: (i) proposes a different functional form for the probability of range measurements caused by unmodeled objects, (ii) intuitively explains the discontinuity encountered in te state of the art beam model, and (iii) reduces the number of model parameters, while maintaining the same representational power for experimental data. The proposed beam model is called RBBM, short for Rigorously Bayesian Beam Model. A maximum likelihood and a variational Bayesian estimator (both based on expectation-maximization) are proposed to learn the model parameters.
Furthermore, the RBBM is extended to a full scan model in two steps: first, to a full scan model for static environments and next, to a full scan model for general, dynamic environments. The full scan model accounts for the dependency between beams and adapts to the local sample density when using a particle filter. In contrast to Gaussian-based state of the art models, the proposed full scan model uses a sample-based approximation. This sample-based approximation enables handling dynamic environments and capturing multi-modality, which occurs even in simple static environments.
T. Grinshpoun and A. Meisels (2008)
"Completeness and Performance Of The APO Algorithm",
Volume 33, pages 223-258
For quick access go to <http://www.jair.org/papers/paper2611.html>
Asynchronous Partial Overlay (APO) is a search algorithm that uses cooperative mediation to solve Distributed Constraint Satisfaction Problems (DisCSPs). The algorithm partitions the search into different subproblems of the DisCSP. The original proof of completeness of the APO algorithm is based on the growth of the size of the subproblems. The present paper demonstrates that this expected growth of subproblems does not occur in some situations, leading to a termination problem of the algorithm. The problematic parts in the APO algorithm that interfere with its completeness are identified and necessary modifications to the algorithm that fix these problematic parts are given. The resulting version of the algorithm, Complete Asynchronous Partial Overlay (CompAPO), ensures its completeness. Formal proofs for the soundness and completeness of CompAPO are given. A detailed performance evaluation of CompAPO comparing it to other DisCSP algorithms is presented, along with an extensive experimental evaluation of the algorithms unique behavior. Additionally, an optimization version of the algorithm, CompOptAPO, is presented, discussed, and evaluated.
I. Rezek, D. S. Leslie, S. Reece, S. J. Roberts, A. Rogers, R. K. Dash and N. R. Jennings (2008)
"On Similarities between Inference in Game Theory and Machine Learning",
Volume 33, pages 259-283
For quick access go to <http://www.jair.org/papers/paper2523.html>
In this paper, we elucidate the equivalence between inference in game theory and machine learning. Our aim in so doing is to establish an equivalent vocabulary between the two domains so as to facilitate developments at the intersection of both ﬁelds, and as proof of the usefulness of this approach, we use recent developments in each ﬁeld to make useful improvements to the other. More speciﬁcally, we consider the analogies between smooth best responses in ﬁctitious play and Bayesian inference methods. Initially, we use these insights to develop and demonstrate an improved algorithm for learning in games based on probabilistic moderation. That is, by integrating over the distribution of opponent strategies (a Bayesian approach within machine learning) rather than taking a simple empirical average (the approach used in standard ﬁctitious play) we derive a novel moderated ﬁctitious play algorithm and show that it is more likely than standard ﬁctitious play to converge to a payoff-dominant but risk-dominated Nash equilibrium in a simple coordination game. Furthermore we consider the converse case, and show how insights from game theory can be used to derive two improved mean ﬁeld variational learning algorithms. We ﬁrst show that the standard update rule of mean ﬁeld variational learning is analogous to a Cournot adjustment within game theory. By analogy with ﬁctitious play, we then suggest an improved update rule, and show that this results in ﬁctitious variational play, an improved mean ﬁeld variational learning algorithm that exhibits better convergence in highly or strongly connected graphical models. Second, we use a recent advance in ﬁctitious play, namely dynamic ﬁctitious play, to derive a derivative action variational learning algorithm, that exhibits superior convergence properties on a canonical machine learning problem (clustering a mixture distribution).
II. Unsubscribing from our Mailing List
To remove yourself from the JAIR subscribers mailing list, visit our
Web site (http://www.jair.org/), follow the link "notify me of new
articles", enter your email address in the form at the bottom of the
page, and follow the directions. In the event that you've already
deleted yourself from the list and we keep sending you messages like
this one, send mail to jair-ed at isi.edu.
More information about the Jairsubscribers