UTokyo Repository 東京大学
 

UTokyo Repository >
124 情報理工学系研究科 >
40 電子情報学専攻 >
1244025 修士論文(電子情報学専攻) >

このページ(論文)をリンクする場合は次のURLを使用してください: http://hdl.handle.net/2261/51736

タイトル: イベント共参照関係を利用した因果関係知識の獲得
その他のタイトル: Extracting Causal Relation using Event Coreference
著者: 田中, 翔平
著者(別言語): Tanaka, Shohei
発行日: 2012年3月22日
抄録: Causal relations are essential knowledge for interpreting discourse structure of text. This paper presents a method that extracts causal relations of lexical patterns in the form of quasi Horn clauses: for example, "A acquires B" AND "B is located in X"→"the acquisition gives A operations in X". The input of the method is a relation tuple consisting of two entities and a verb, e.g., (A, acquire, B). The method finds coreferencial expressions of the given relation that mention the same event. We use nominal forms of verbs included in FrameNet for finding the coreference expression. If a nominal form of a relation occurs as the subject in the dependency tree of a sentence, the sentence is likely to describe what is caused by the event. Then the method uses several NLP techniques (part-of-speech tagging, coreference resolution, dependency parsing and named entity recognition) in order to build a lexical pattern containing the entities (A and B). However, such rules are so specific that computers cannot reuse the knowledge of causality relation: for example, "the acquisition gives A operations in Nevada". Therefore, the proposed method generalize the rules by introducing a variable X and estimating the relation between X and A or between X and B. For evaluation, we asked human annotators to judge the correctness of the causal-relation rules. The result shows that the proposed method precisely extracts the causal-relation rules.
内容記述: 報告番号: ; 学位授与年月日: 2012-03-22 ; 学位の種別: 修士 ; 学位の種類: 修士(情報理工学) ; 学位記番号: ; 研究科・専攻: 情報理工学系研究科電子情報学専攻
URI: http://hdl.handle.net/2261/51736
出現カテゴリ:025 修士論文
1244025 修士論文(電子情報学専攻)

この論文のファイル:

ファイル 記述 サイズフォーマット
48106422.pdf745.57 kBAdobe PDF見る/開く

本リポジトリに保管されているアイテムはすべて著作権により保護されています。

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - ご意見をお寄せください