TAILIEUCHUNG - Báo cáo khoa học: "Mildly Non-Projective Dependency Structures"

Syntactic parsing requires a fine balance between expressivity and complexity, so that naturally occurring structures can be accurately parsed without compromising efficiency. In dependency-based parsing, several constraints have been proposed that restrict the class of permissible structures, such as projectivity, planarity, multi-planarity, well-nestedness, gap degree, and edge degree. While projectivity is generally taken to be too restrictive for natural language syntax, it is not clear which of the other proposals strikes the best balance between expressivity and complexity. . | Mildly Non-Projective Dependency Structures Marco Kuhlmann Programming Systems Lab Saarland University Germany kuhlmann@ Joakim Nivre Vaxjo University and Uppsala University Sweden nivre@ Abstract Syntactic parsing requires a fine balance between expressivity and complexity so that naturally occurring structures can be accurately parsed without compromising efficiency. In dependency-based parsing several constraints have been proposed that restrict the class of permissible structures such as projectivity planarity multi-planarity well-nestedness gap degree and edge degree. While projectivity is generally taken to be too restrictive for natural language syntax it is not clear which of the other proposals strikes the best balance between expressivity and complexity. In this paper we review and compare the different constraints theoretically and provide an experimental evaluation using data from two treebanks investigating how large a proportion of the structures found in the treebanks are permitted under different constraints. The results indicate that a combination of the well-nestedness constraint and a parametric constraint on discontinuity gives a very good fit with the linguistic data. 1 Introduction Dependency-based representations have become increasingly popular in syntactic parsing especially for languages that exhibit free or flexible word order such as Czech Collins et al. 1999 Bulgarian Marinov and Nivre 2005 and Turkish Eryigit and Oflazer 2006 . Many practical implementations of dependency parsing are restricted to projective structures where the projection of a head word has to form a continuous substring of the sentence. While this constraint guarantees good parsing complexity it is well-known that certain syntactic constructions can only be adequately represented by non-projective dependency structures where the projection of a head can be discontinuous. This is especially relevant for languages with free or flexible word order.

• Báo cáo khoa học
• Mildly Non Projective
• Dependency Structures
• Marco Kuhlmann
• báo cáo khoa học
• mô hình ngôn ngữ
• xử lý ngôn ngữ tự nhiên
• Bài giảng Xử lý ngôn ngữ tự nhiên
• Ngôn ngữ tự nhiên
• Kỹ thuật lập trình
• Xử lý nhập nhằng ngữ nghĩa
• Xử lý ngữ nghĩa
• Xử lý ngôn ngữ
• Natural Language Processing
• Ngôn ngữ lập trình
• Nhập nhằng cấu trúc
• Tri thức về ngôn ngữ
• Mô hình n gram
• Dịch máy
• Phương pháp dịch máy
• Hiểu ngôn ngữ
• Phân tích ngữ nghĩa
• Phân loại tin tự động
• Biểu diễn vị từ
• Thuộc tính về sự kiện
• Thuộc tính về sự kiện
• Mô hình ngôn ngữ Google Book N grams
• Mô hình ngôn ngữ KenLM
• Phương pháp làm mịn
• Tách từ tiếng Việt
• Gán nhãn từ loại
• Phân tích cú pháp
• Nghĩa từ vựng
• Phân giải nhập nhằng từ
• Phân loại văn bản
• Lexical chain
• Phản hồi thông tin
• Bài toán PTCP
• Cấu trúc ngữ pháp
• Phân tích cú pháp xác suất
• CKY kết hợp xác suất
• Văn phạm phi ngữ cảnh xác suất
• Hình thái học