51 research outputs found

    Blind Detection of Independent Dynamic Components

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    In certain applications of independent component analysis (ICA) it any of interest to test hypotheses concerning the number of components or simply to test whether a given number of components is significant relative to a "white noise" null hypothesis. We estimate probabilities of such competing hypotheses for ICA based on dynamic decorrelation. The probabilities are evaluated in the so-called Bayesian information criterion approximation, however, they are able to detect the content of dynamic components as efficient as an unbiased test set estimator. Keywords: Blind Source Separation (BSS), Dynamic Components, Independent Component Analysis (ICA), BIC detection 1

    Signal Detection using ICA: Application to Chat Room Topic Spotting

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    Signal detection and pattern recognition for online grouping huge amounts of data and retrospective analysis is becoming increasingly important as knowledge based standards, such as XML and advanced MPEG, gain popularity. Independent component analysis (ICA) can be used to both cluster and detect signals with weak a priori assumptions in multimedia contexts. ICA of real world data is typically performed without knowledge of the number of non-trivial independent components, hence, it is of interest to test hypotheses concerning the number of components or simply to test whether a given set of components is significant relative to a "white noise" null hypothesis. It was recently proposed to use the so-called Bayesian information criterion (BIC) approximation, for estimation of such probabilities of competing hypotheses. Here, we apply this approach to the understanding of chat. We show that ICA can detect meaningful context structures in a chat room log file

    Independent component analysis for understanding multimedia content

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    Abstract. This paper focuses on using independent component analysis of combined text and image data from web pages. This has potential for search and retrieval applications in order to retrieve more meaningful and context dependent content. It is demon-strated that using ICA on combined text and image features pro-vides a synergistic eect, i.e., the retrieval classication rates in-crease if based on multimedia components relative to single media analysis. For this purpose a simple probabilistic supervised clas-si er which works from unsupervised ICA features is invoked. In addition, we demonstrate the use of the suggested framework for automatic annotation of descriptive key words to images

    Modeling text with generalizable Gaussian mixtures

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    We apply and discuss generalizable Gaussian mixture (GGM) models for textmining. The model automatically adapts model complexity for a given text representation. We show that the generalizability of these models depends on the dimensionality of the representation and the sample size. We discuss the relation between supervised and unsupervised learning in text data. Finally, we implement a novelty detector based on the density model. 1. INTRODUCTION Information retrieval is a very active research field which is starting to adapt advanced machine learning techniques for solving hard real world problems [17, 18]. Textmining or pattern recognition in text data is used to categorize text according to topic, to spot new topics, and in a broader sense to create more intelligent searches, e.g., by WWW search engines [12, ?, 14]. Textmining proceeds by pattern recognition based on text features, typically document summary statistics. While there are numerous highlevel language models for extr..

    Social change and the family: Comparative perspectives from the west, China, and South Asia

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    This paper examines the influence of social and economic change on family structure and relationships: How do such economic and social transformations as industrialization, urbanization, demographic change, the expansion of education, and the long-term growth of income influence the family? We take a comparative and historical approach, reviewing the experiences of three major sociocultural regions: the West, China, and South Asia. Many of the changes that have occurred in family life have been remarkably similar in the three settings—the separation of the workplace from the home, increased training of children in nonfamilial institutions, the development of living arrangements outside the family household, increased access of children to financial and other productive resources, and increased participation by children in the selection of a mate. While the similarities of family change in diverse cultural settings are striking, specific aspects of change have varied across settings because of significant pre-existing differences in family structure, residential patterns of marriage, autonomy of children, and the role of marriage within kinship systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45661/1/11206_2005_Article_BF01124383.pd
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