High Compression-Rate Automatic Summarization of Newspaper Articles Based on Combined Use of Significant Sentence Extraction and Sentence Compression

1.本文使用的语料库中包含了成对的报刊文章和相应的手工摘要。这个语料库提供了关于人类如何做简短摘要的信息。为了有效地获取这些信息，短语对齐是必要的之间的原始句子和它的摘要。我们开发了一个利用概念距离和短语间依赖性的短语对齐器。2.在研究期开始之前，我们使用根据原始句子集中的依赖距离分布估计的短语间依赖强度。然而，这种方法忽略了原句与其摘要之间的关系。在这项工作中，我们估计短语间的依赖强度从相对频率的短语对存在于原始句子中具有一定的依赖路径长度，并保持在相应的摘要中的修饰语-修饰关系。主观评价实验结果表明， ...更多信息 3.在本研究所采用的短语抽取式句子压缩中，原句子中不存在偏正关系的短语在压缩后的句子中有时会出现偏正关系。这种现象可能会降低压缩句子的可读性。为了提高压缩句子的可读性，我们提出了一种修改偏正短语结尾的方法。主观评价实验的结果表明了该方法的有效性。4.在概率框架下对句子压缩方法进行了改进。在计算从原始句子生成压缩句子的概率时，出现类似于短语重要性和短语间依赖性的量，其可以从训练语料库估计。结果表明，这种概率的方法达到我们以前的，启发式的方法相当的性能。少

1.In this work, we use a corpus in which pairs of newspaper articles and corresponding hand-made short summaries are contained. This corpus provides information about how humans make short summaries. To obtain such information effectively, phrase alignment is necessary between the original sentence and its summary. We developed a phrase aligner that makes use of conceptual distance and inter-phrase dependency.2.Before the research period started, we were using the inter-phrase dependency strength estimated from the distribution of dependency distance in the set of original sentences. This method misses, however, the relationship between the original sentence and its summary. In this work, we estimated the inter-phrase dependency strength from the relative frequency of phrase pairs that exist in the original sentence with a certain dependency path length and remain having modifier-modified relation in the corresponding summary. The result of a subjective evaluation experiment showed sig … More nificant improvement in the quality of compressed sentences.3.In the phrase extraction type sentence compression, which is employed in this research, phrases that are not in modifier-modified relation in the original sentence sometimes appear to have modifier-modified relation in the compressed sentence. Such a phenomenon may degrade the readability of compressed sentences. We worked out a method to modify the phrase ending of the modifier-phrase for improving the readability of compressed sentences. The result of subjective evaluation experiment showed the effectiveness of the method.4.We reformulated our sentence compression method in a probabilistic framework. In calculating the probability that a compressed sentence is generated from an original sentence, quantities similar to phrase significance and inter-phrase dependency appear, which can be estimated from a training corpus. It was shown that this probabilistic approach attains comparable performance as our former, heuristic approach. Less