Báo cáo khoa học: "Statistical Models for Unsupervised Prepositional Phrase Attachment" pdf

... Statistical Models for Unsupervised Prepositional Phrase Attachment Adwait Ratnaparkhi Dept. of Computer and Information Science University of Pennsylvania ... Abstract We present several unsupervised statistical models for the prepositional phrase attachment task that approach the accuracy of the best su- pervised methods for this task. Our unsuper- ... base for...

Ngày tải lên: 17/03/2014, 07:20

... AFNLP Minimized Models for Unsupervised Part-of-Speech Tagging Sujith Ravi and Kevin Knight University of Southern California Information Sciences Institute Marina del Rey, California 90292 {sravi,knight}@isi.edu Abstract We ... dictionary varies for different models from Figure 5. In the case of the observed grammar (Figure 6), precision increases 5 For all experiments, EM traini...

Ngày tải lên: 17/03/2014, 01:20

... syntactic information does not suffice to make an assignment decision. Prepositional phrase (PP) attachment is, perhaps, the canonical case of structural ambiguity. What kind of information ... sense. As a result, before deciding attachment, it is first nec- essary to determine the correct sense for each word. 3 None of the preceding methods used classes for verbs. 4 For reas...

Ngày tải lên: 31/03/2014, 04:20

... correctly, and was added to the phrase dic- tionary. However, if the phrase Almmlkp AlmtHdp is not in the phrase dictionary, it will not be translated correctly by a monotone phrase decoder even if the ... to a phrase- based model. (Och et al., 2004; Tillman, 2004) propose orientation-based distortion models lexicalized on the phrase level. There are two important distinctions be...

Ngày tải lên: 08/03/2014, 02:21

... in- crease in performance of about 2-3% for most mod- els. For General-LM, results increased by 8-10%. The Poisson and general fertility models show a 2- 5% gain in performance over the basic ... into phrases. Each clump is then generated from a sin- gle formal language word using a translation model. The notion of what constitutes a natural clumping depends on the formal langu...

Ngày tải lên: 08/03/2014, 21:20

... how DA can be used for parameter estimation for models of language structure that use dynamic programming to compute posteriors over hidden structure, such as hidden Markov models (HMMs) and stochastic ... algorithm (like the forward-backward algorithm). The M step for these models normalizes the posterior expected counts from the E step to get probabilities. 4 3 With an M step mo...

Ngày tải lên: 23/03/2014, 19:20

... ap- propriate for a formalism like CCG with a large set of lexical categories than one generic token for all unknown words. The performance of the baseline model is shown in the top row of table 3. For ... for passive, bare infinitives and ing-forms. There is a separate level for nouns and noun phrases, but, like the nonterminal NP in the Penn Treebank, noun phrases do not carry any...

Ngày tải lên: 31/03/2014, 06:20

... Meeting of the Association for Computational Linguistics, pages 115–119, Jeju, Republic of Korea, 8-14 July 2012. c 2012 Association for Computational Linguistics Topic Models for Dynamic Translation ... the most useful notion of domain for better translations. We take a finer-grained, flexible, unsupervised ap- proach for lexical weighting by domain. We induce unsupervised dom...

Ngày tải lên: 19/02/2014, 19:20

... Association for Computational Linguistics Ensemble Methods for Unsupervised WSD Samuel Brody School of Informatics University of Edinburgh s.brody@sms.ed.ac.uk Roberto Navigli Dipartimento di Informatica Universit ` a ... about 27 person-years of human annotation effort. This paper focuses on unsupervised methods which we argue are useful for broad coverage sense disambiguation. Un...

Ngày tải lên: 08/03/2014, 02:21

... which helped improve performance. 2.2 Beyond Two-Level Models To this point, we have focused solely on a model for two-level fine-to-coarse sentiment analysis not only for simplicity, but because ... different applications have different needs. For example, a summarization system for product reviews might require polarity classification at the sentence or phrase level; a question an...

Ngày tải lên: 08/03/2014, 02:21