改述片語是使用不同的描述方式來表達相同的意思。自動產生改述片語可以應用於許多自然語言處理的課題中。我們提出一個產生改述片語的方法，使得產生的片語保留原始片語的語意及語法。此方法將產生改述片語的問題轉換為圖形理論方法，圖形中包含直接及間接的改述片語關係。方法中使用多個語言學的特徵來辨識候選改述片語之間的相似度，並使用權重式PageRank演算法評估候選改述片語與原始片語的相關性。本論文使用一組常用於學術文章的片語作為評估，人工評估結果顯示我們提出的方法優於現今最佳的其他方法。文法與語意的精確度均有顯著的提升。

Paraphrases are alternative ways to express the same meaning. Automatically generating paraphrases can be applied in many of National Language Processing tasks. We propose a method for generating paraphrases which preserve the meaning and the syntax of a given phrase. In our approach, the paraphrasing problem is transformed into a graph representing direct and indirect paraphrase relations. The method involves incorporating various linguistically motivated features to reflect the similarities of paraphrase candidates, and using Weighted PageRank Algorithm to evaluate the relevance of paraphrase candidates. Evaluation on a set of phrases commonly used in research articles shows that our method significantly outperforms the state-of-the-art methods under both semantic and syntactic considerations.

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