tailieunhanh - Báo cáo khoa học: "From Strings to Trees to Strings to Trees"

Sentences are not just strings of words (or are they ?), they have some (hierarchical) structure. This much is accepted by all grammar formalisms. But how much structure is needed? The more the sentences are like strings the less the need for structure. A certain amount of structure is necessary simply because a clause may embed another clause, or one clause may attach to another clause or parts of it. Leaving this need of structure aside, the question then is how much structure should a (minimal) clause have? Grammar formalisms can differ significantly on this issue. . | From Strings to Trees to Strings to Trees . Abstract Aravind K. Joshi Dept of Computer and Information Science University of Pennsylvania Philadelphia PA 19104 Sentences are not just strings of words or are they they have some hierarchical structure. This much is accepted by all grammar formalisms. But how much structure is needed The more the sentences are like strings the less the need for structure. A certain amount of structure is necessary simply because a clause may embed another clause or one clause may attach to another clause or parts of it. Leaving this need of structure aside the question then is how much structure should a minimal clause have Grammar formalisms can differ significantly on this issue. Minimal clauses can be just strings or words linked by dependencies dependency trees or with rich phrase structure trees or with fiat one level phrase structure trees almost strings and so on. How much hierarchical structure is needed for a minimal clause is still an open question that is being debated heatedly. How are clauses put together Are these operations more like string manipulations concatenation insertion or wrapping for example or are they more like tree transformations generalized transformations of the early transformational grammars for example Curiously the early transformational grammars although clearly using tree transformations actually formulated the transformations as pseudo string-like operations More recent non-transformational grammars differ significantly with respect to their use of string rewriting or tree rewriting operations. Grammar formalisms differ with respect to their stringiness or treeness. Also during their evolution they have gone back and forth between string-like and tree-like representations often combining them in different ways. These swings are a reflection of the complex interplay between aspects of language structure such as constituency dependency dominance locality of predicates and their arguments adjacency .

• Báo cáo khoa học
• From Strings to Trees
• Strings to Trees
• Aravind K
• Joshi
• 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