1,721,065 research outputs found
Probabilistic Context-Free Grammars Estimated from Infinite Distributions
Full text linkIn this paper, we consider probabilistic context-free grammars, a class of generative devices that has been successfully exploited in several applications of syntactic pattern matching, especially in statistical natural language parsing. We investigate the problem of training probabilistic context-free grammars on the basis of distributions defined over an infinite set of trees or an infinite set of sentences by minimizing the cross-entropy. This problem has applications in cases of context-free approximation of distributions generated by more expressive statistical models. We show several interesting theoretical properties of probabilistic context-free grammars that are estimated in this way, including the previously unknown equivalence between the grammar cross-entropy with the input distribution and the so-called derivational entropy of the grammar itself. We discuss important consequences of these results involving the standard application of the maximum-likelihood estimator on finite tree and sentence samples, as well as other finite-state models such as Hidden Markov Models and probabilistic finite automata
A polynomial-time parsing algorithm for TT-MCTAG
No full textThis paper investigates the class of Tree-Tuple MCTAG with Shared Nodes, TT-MCTAG for short, an extension of Tree Adjoining Grammars that has been proposed for natural language processing, in particular for dealing with discontinuities and word order variation in languages such as German. It has been shown that the universal recognition problem for this formalism is NP-hard, but so far it was not known whether the class of languages generated by TT-MCTAG is included in PTIME. We provide a positive answer to this question, using a new characterization of TT-MCTAG
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
PARSEME-It Corpus - An annotated Corpus of Verbal Multiword Expressions in Italian
No full textIl contributo descrive una nuova risorsa linguistica annotata con polirematiche verbali per la lingua italiana. Viene presentato lo stato dell’arte relativamente all’identificazione ed all’annotazione di polirematiche per la lingua italiana, la metodologia adottata, le diverse categorie di polirematiche verbali annotate nel corpus, il corpus stesso e il processo di annotazione. Infine vengono illustrati i risultati ottenuti, le conclusioni e le prospettive future.This paper describes a new language resource annotated with verbal multiword expressions (VMWEs) in Italian.
The paper discusses the state of the art in VMWE identification and annotation in Italian, the methodology adopted, the various VMWE categories annotated, the corpus and the annotation process. Finally, the paper ends with results, conclusion and future work
A quantitative method for the attribution of medieval liturgical monody
No full textL’articolo mostra come tecniche di analisi stilometriche comunemente usate in ambito letterario (basate sulla distanza tra vettori delle frequenze di ngrammi di lettere) possano essere adattate con successo allo studio di repertori musicali “unidimensionali” (ovvero melodie prive di ritmo e di accompagnamento). I buonirisultatiottenutisuuncorpusdimonodie liturgie di origine medievale (Canto GregorianoeCantoRomanoAntico)sono un primo passo verso l’adozione e la creazione di tecniche automatiche a supporto di studi stilometrici a carattere e interesse strettamente musicologicoWe adapt a technique commonly used in the stylometric attribution of literary texts (based on a pseudo-distance between frequency-vectors of n-grams of letters) to the analysis of “unidimensional” musical repertoires (rhythm-free melody without accompaniment). We successfully apply the method to a corpus of liturgical monodies of medieval origin (the so-called Gregorian Chant, in comparison with the Old Roman Chant). Our results giveafirstindicationthatautomaticstylometrictechniquescanbefruitfullyadopted to support the study of refined problems in musicology
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Linguistic Features and Newsworthiness: an Analysis of News style
No full textIn this paper, we present a preliminary study on the style of headlines in order to evaluate the correlation between linguistic features and newsworthiness. Our hypothesis is that each particular linguistic form or stylistic variation can be motivated by the purpose of encoding a certain newsworthiness value. To discover the correlations between newsworthiness and linguistic features, we perform an analysis on the basis of characteristics considered indicative of a shared communicative function and of discriminating factors for headlines
PARAD-it: Eliciting Italian Paradigmatic Relations with Crowdsourcing
Full text linkIn this paper, we present a new
dataset of semantically related Italian
word pairs. The dataset consists of nouns,
adjectives and verbs together with their
synonyms, antonyms and hypernyms.
The data have been collected with
crowdsourcing from a pool of Italian native
speakers. The dataset, the first of its
kind, is useful not only to evaluate computational
models of Italian semantic relations,
but also for linguistic and psycholinguistic
investigations of the mental
lexicon
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