tree adjoining grammar parsing

... auxiliary tree is called the spine of the auxiliary tree. An elementary tree is either an initial tree or an auxiliary tree. We use a to refer to initial trees and/3 for auxiliary trees. A ... existing tag parsing algorithms, 1 Introduction We study parsing of tree adjoining grammars (tag) with particular emphasis on the use of shared forests to represent all the parse trees deriving ... existing tag parsing algorithms. 2 Tree Adjoining Grammars Ta~ is a tree generating formalism introduced in [Joshi et al., 1975]. A tag is defined by a finite set of elementary trees that...

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... capability of synchronous tree adjoin- ing grammars. Computational Intelligence, 10(4). K. Vijay-Shanker and D.J. Weir. 1993. The use of shared forests in tree adjoining grammar parsing. In Proceedings ... necessary for characterizing structural de- scriptions: Tree adjoining grammars. In L. Kart- tunen D. Dowty and A. Zwicky, editors, Natural language parsing: Psychological, computational and theoretical ... References Anne Abeill6, Yves Schabes, and Aravind K. Joshi. 1990. Using lexicalized tree adjoining grammars for machine translation. In Proceedings of the 13th International Conference...

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... approach to other lexicalized grammars. In Section 8 we conclude with some directions for future work. 2 Lexicalized Tree- Adjoining Grammar Lexicalized Tree- Adjoining Grammar (LTAG) (Sch- abes ... some novel ap- plications of Explanation-Based Learning (EBL) technique to parsing Lexicalized Tree- Adjoining grammars. The novel as- pects are (a) immediate generalization of parses in ... specialize a grammar for the ATIS domain by storing chunks of the parse trees present in a treebank of parsed examples. The idea is to reparse the training examples by letting the parse tree drive...

Ngày tải lên: 20/02/2014, 22:20

... of trees, called initial trees and auxiliary trees respectively. The trees in the set IuA are called elementary trees. We assume that the reader is familiar with the definitions of adjoining ... to the Production of O(n 6) Earley Parsers for Tree Adjoining Grammars. In Proceedings of the 1st International Workshop on Tree Adjoining Grammars. Dagstuhl Castle, F.R.G Satta, Giorgio, ... Lexicalization to Parsing. In Proceedings of the 1st International Workshop on Parsing Technologies. Pittsburgh, PA. To also appear under the title: Parsing with Lexicalized Tree Adjoining Grammar. ...

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... grammar rules and type signatures for typed feature structure grammars (TFSGs). The static analysis tries to predict at compile-time which feature paths will cause unification failure during parsing ... that of TFSGs. While simpler formalisms such as context-free grammars (CFGs) also face slow all-paths parsing times when the size of the grammar increases significantly, TF- SGs (which generally have ... by grammar developers to simplify TFSGs themselves at the source-code level, here we only exploit it for internally identifying index keys for more efficient chart parsing with the existing grammar. ...

Ngày tải lên: 20/02/2014, 15:21

... trees and .A is a set of auxiliary trees. Trees in :TU.A are also called elementary trees. We refer to the root of an elementary tree t as Rt. Each auxiliary tree has exactly one distin- guished ... context-free grammars. Computational Linguis- tics, 17(3):315-323. A. K. Joshi and Y. Schabes. 1992. Tree- adjoining gram- mars and lexicalized grammars. In M. Nivat and A. Podelski, editors, Tree ... methods for TAG parsing. An item is a tuple [N, i, j, fl, f2] rep- resenting the set of all trees t such that (i) t is a subtree rooted at N of some derived elementary tree; and (ii) t's...

Ngày tải lên: 20/02/2014, 18:20

... str!ng, the derived tree structure of the string. The formalism of tree- adjoining grammars (TAG), on the other hand, decouples these two notions of derivation tree and derived tree. Intuitively, ... Figure 1: A sample tree- adjoining grammar NP NP I I N N Adj N Adj N roasted Adj N red Adj N i I I I red pepper roasted pepper (a) (b) Figure 2: Two trees derived by the grammar of Figure ... the derived tree spec- ified when several trees are adjoined at the same node. Assume that in a given tree T at a particular address t, the predicative tree P and the k mod- ifier trees M1,...

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... decision -tree questions, see (Magerman, 1994). 3 SPATTER Parsing The SPATTER parsing algorithm is based on inter- preting parsing as a statistical pattern recognition process. A parse tree for ... for the decision- tree growing process for the appropriate feature's tree (e.g. each tagging event is used for growing the tagging tree, etc.). After the decision trees are grown, they ... the label in the tree- bank. Table 1 shows the results of SPATTER evaluated against the Penn Treebank on the Wall Street Jour- nal section 00. Comparisons Avg. Sent. Length Treebank Constituents...

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... easily and transparently. Tree adjoining grammars (TAGs) (Joshi, Levy and Takahashi, 1975, Vijay-Shanker and Joshi, 1988) possess trees as basic grammar structures, and grammar rules are used ... category as the root of the tree. These two types of trees comprise the class of elementary trees. There is a trec adjoining operation which is used to form derived trees. AppLication of this ... tree with that of the tree into which it is adjoined. In this way, a more complete description of the final tree is gradually constructed. However, in FTAG tree descriptions the internal tree...

Ngày tải lên: 21/02/2014, 20:20

... elements of the set of subtrees of the tree : such a relation is called a string- tree correspondence. An example of a string -tree correspondence is given in fig. I. TREE: NP I [ 4 NP 2 :AP ... of grammar rules applied (as in derivation trees). The inclusion of the substring-subtree correspondence is also another characteristic of the grammar formalism. One also sees that the grammar ... STRING -TREE CORRESPONDENCE GRAMMAR: A DECLARATIVE GRAMMAR FORMALISM FOR DEFINING THE CORRESPONDENCE BETWEEN STRINGS OF TERMS AND TREE STRUCTURES YUSOFF ZAHARIN Groupe...

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... Abeill~, Anne; and Joshi, Aravind: K., August 1988. Parsing Strategies with 'Lexiealized' Grammars: Application to Tree Ad- joining Grammars. In Proceedings of the 12 th Interna- tional ... Contezt-Sensitive Grammar Formalisms. PhD thesis, Department of Computer and Information Science, Uni- versity of Pennsylvania. - 26 - Long-Distance Scrambling and Tree Adjoining Grammars* Tilman ... elementary trees of TAG, allows us to "lexicalize" a TAG gram- mar: we can associate each tree in a grammar with a lexical item [Schabes et al 1988, Schabes 1990] 4. The tree will...

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