Asia
Parametric Mixture Models for Multi-Labeled Text
We propose probabilistic generative models, called parametric mixture models(PMMs), for multiclass, multi-labeled text categorization problem.Conventionally, the binary classification approach has been employed, in which whether or not text belongs to a category isjudged by the binary classifier for every category. In contrast, our approach can simultaneously detect multiple categories of text using PMMs. We derive efficient learning and prediction algorithms forPMMs. We also empirically show that our method could significantly outperform the conventional binary methods when applied tomulti-labeled text categorization using real World Wide Web pages.
Extracting Relevant Structures with Side Information
The problem of extracting the relevant aspects of data, in face of multiple conflicting structures, is inherent to modeling of complex data. Extracting structurein one random variable that is relevant for another variable has been principally addressed recently via the information bottleneck method [15]. However, such auxiliary variables often contain more information thanis actually required due to structures that are irrelevant for the task. In many other cases it is in fact easier to specify what is irrelevant than what is, for the task at hand. Identifying the relevant structures, however, can thus be considerably improved by also minimizing theinformation about another, irrelevant, variable. In this paper we give a general formulation of this problem and derive its formal, as well as algorithmic, solution. Its operation is demonstrated in a synthetic example and in two real world problems in the context of text categorization andface images. While the original information bottleneck problem is related to rate distortion theory, with the distortion measure replaced by the relevant information, extracting relevant features while removing irrelevant ones is related to rate distortion with side information.
The Effect of Singularities in a Learning Machine when the True Parameters Do Not Lie on such Singularities
Watanabe, Sumio, Amari, Shun-ichi
A lot of learning machines with hidden variables used in information sciencehave singularities in their parameter spaces. At singularities, the Fisher information matrix becomes degenerate, resulting that the learning theory of regular statistical models does not hold. Recently, it was proven that, if the true parameter is contained in singularities, then the coefficient of the Bayes generalization erroris equal to the pole of the zeta function of the Kullback information.
Efficient Learning Equilibrium
Brafman, Ronen I., Tennenholtz, Moshe
We introduce efficient learning equilibrium (ELE), a normative approach tolearning in non cooperative settings. In ELE, the learning algorithms themselves are required to be in equilibrium. In addition, the learning algorithms arrive at a desired value after polynomial time, and deviations from a prescribed ELE become irrational afterpolynomial time. We prove the existence of an ELE in the perfect monitoring setting, where the desired value is the expected payoff in a Nash equilibrium. We also show that an ELE does not always exist in the imperfect monitoring case.
Graph-Driven Feature Extraction From Microarray Data Using Diffusion Kernels and Kernel CCA
Vert, Jean-philippe, Kanehisa, Minoru
We present an algorithm to extract features from high-dimensional gene expression profiles, based on the knowledge of a graph which links together genesknown to participate to successive reactions in metabolic pathways. Motivated by the intuition that biologically relevant features are likely to exhibit smoothness with respect to the graph topology, the algorithm involves encoding the graph and the set of expression profiles intokernel functions, and performing a generalized form of canonical correlation analysis in the corresponding reproducible kernel Hilbert spaces. Functionprediction experiments for the genes of the yeast S. Cerevisiae validate this approach by showing a consistent increase in performance when a state-of-the-art classifier uses the vector of features instead of the original expression profile to predict the functional class of a gene.
Automatic Acquisition and Efficient Representation of Syntactic Structures
Solan, Zach, Ruppin, Eytan, Horn, David, Edelman, Shimon
The distributional principle according to which morphemes that occur in identical contexts belong, in some sense, to the same category [1] has been advanced as a means for extracting syntactic structures from corpus data. We extend this principle by applying it recursively, and by using mutualinformation for estimating category coherence. The resulting model learns, in an unsupervised fashion, highly structured, distributed representations of syntactic knowledge from corpora. It also exhibits promising behavior in tasks usually thought to require representations anchored in a grammar, such as systematicity.
Clustering with the Fisher Score
Tsuda, Koji, Kawanabe, Motoaki, Mรผller, Klaus-Robert
Recently the Fisher score (or the Fisher kernel) is increasingly used as a feature extractor for classification problems. The Fisher score is a vector of parameter derivatives of loglikelihood of a probabilistic model. This paper gives a theoretical analysis about how class information is preserved inthe space of the Fisher score, which turns out that the Fisher score consists of a few important dimensions with class information and many nuisance dimensions. When we perform clustering with the Fisher score, K-Means type methods are obviously inappropriate because they make use of all dimensions. So we will develop a novel but simple clustering algorithmspecialized for the Fisher score, which can exploit important dimensions.This algorithm is successfully tested in experiments with artificial data and real data (amino acid sequences).
Calendar of Events
Aided Design of User Interfaces. (ICKEDS 2004). "Halpern presents a masterful, complete and unified account of the many ways in which the connections between logic, probability theory and commonsensical linguistic terms can be formalized. 'believed,' 'known,' 'default,' 'relevant,' "Presents a novel thesis--that the mind is a'independent,' and'preferred' are given rigorous program whose components are semantically semantical and syntactical analyses, and their meaningful modules--and explores it with a rich interrelationships explicated and exemplified. An array of evidence drawn from a variety of fields.