Representation of Functional Data in Neural Networks

Functional Data Analysis (FDA) is an extension of traditional data analysis to functional data, for example spectra, temporal series, spatio-temporal images, gesture recognition data, etc. Functional data are rarely known in practice; usually a regular or irregular sampling is known. For this reason, some processing is needed in order to benefit from the smooth character of functional data in the analysis methods. This paper shows how to extend the Radial-Basis Function Networks (RBFN) and Multi-Layer Perceptron (MLP) models to functional data inputs, in particular when the latter are known through lists of input-output pairs. Various possibilities for functional processing are discussed, including the projection on smooth bases, Functional Principal Component Analysis, functional centering and reduction, and the use of differential operators. It is shown how to incorporate these functional processing into the RBFN and MLP models. The functional approach is illustrated on a benchmark of spectrometric data analysis.Comment: Also available online from: http://www.sciencedirect.com/science/journal/0925231

Centering in-the-large: Computing referential discourse segments

We specify an algorithm that builds up a hierarchy of referential discourse segments from local centering data. The spatial extension and nesting of these discourse segments constrain the reachability of potential antecedents of an anaphoric expression beyond the local level of adjacent center pairs. Thus, the centering model is scaled up to the level of the global referential structure of discourse. An empirical evaluation of the algorithm is supplied.Comment: LaTeX, 8 page

Message-Passing Protocols for Real-World Parsing -- An Object-Oriented Model and its Preliminary Evaluation

We argue for a performance-based design of natural language grammars and their associated parsers in order to meet the constraints imposed by real-world NLP. Our approach incorporates declarative and procedural knowledge about language and language use within an object-oriented specification framework. We discuss several message-passing protocols for parsing and provide reasons for sacrificing completeness of the parse in favor of efficiency based on a preliminary empirical evaluation.Comment: 12 pages, uses epsfig.st

Evaluating Centering for Information Ordering Using Corpora

In this article we discuss several metrics of coherence defined using centering theory and investigate the usefulness of such metrics for information ordering in automatic text generation. We estimate empirically which is the most promising metric and how useful this metric is using a general methodology applied on several corpora. Our main result is that the simplest metric (which relies exclusively on NOCB transitions) sets a robust baseline that cannot be outperformed by other metrics which make use of additional centering-based features. This baseline can be used for the development of both text-to-text and concept-to-text generation systems. </jats:p

A Comparison of the Referential Properties of Third Person Pronouns in Finnish and Estonian

Abstract: This paper investigates the referential properties of third person anaphors in two closely related languages, Finnish and Estonian. Previous crosslinguistic research has shown that the most salient referents are referred to with the most reduced referring expressions. Moreover, factors such as (i) grammatical role, (ii) word order and (iii) the main/subordinate clause distinction have been claimed to be correlated with referent salience. In this paper, we focus on how these factors influence the referential properties of the different members of the third person anaphoric paradigms in Finnish and Estonian. We use corpus evidence and native speaker survey data to investigate the referential properties of the Estonian forms and to compare them to the patterns observed for the Finnish pronoun hän ‘s/he’ and demonstrative tämä ‘this’ (see Kaiser, this volume; Kaiser 2000). Our preliminary results suggest that (i) the Estonian short pronoun ta ‘s/he’ patterns like the Finnish pronoun hän ‘s/he’, in that they both prefer to refer to subjects, and (ii) the Estonian demonstratives see/too ‘this/that’ resemble the Finnish demonstrative tämä ‘this,’ generally referring to non-subjects, postverbal NPs or subjects in subordinate clauses. Moreover, we find that the Estonian long pronominal form tema ‘s/he’ differs from the Finnish demonstrative tämä, despite their historical connection: As suggested by Pajusalu (1997), in Estonian, tema is used to refer to entities that contrast with something, whereas in Finnish tämä is used for entities low in salience (Kaiser, this volume). The implications of our findings for ‘accessibility hierarchy’-based approaches to reference resolution are also discussed

Incremental Centering and Center Ambiguity

In this paper, we present a model of anaphor resolution within the framework of the centering model. The consideration of an incremental processing mode introduces the need to manage structural ambiguity at the center level. Hence, the centering framework is further refined to account for local and global parsing ambiguities which propagate up to the level of center representations, yielding moderately adapted data structures for the centering algorithm.Comment: 6 pages, uuencoded gzipped PS file (see also Technical Report at: http://www.coling.uni-freiburg.de/public/papers/cogsci96-center.ps.gz