Tetsuro Sasada


2016

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Language Resource Addition Strategies for Raw Text Parsing
Atsushi Ushiku | Tetsuro Sasada | Shinsuke Mori
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We focus on the improvement of accuracy of raw text parsing, from the viewpoint of language resource addition. In Japanese, the raw text parsing is divided into three steps: word segmentation, part-of-speech tagging, and dependency parsing. We investigate the contribution of language resource addition in each of three steps to the improvement in accuracy for two domain corpora. The experimental results show that this improvement depends on the target domain. For example, when we handle well-written texts of limited vocabulary, white paper, an effective language resource is a word-POS pair sequence corpus for the parsing accuracy. So we conclude that it is important to check out the characteristics of the target domain and to choose a suitable language resource addition strategy for the parsing accuracy improvement.

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A Japanese Chess Commentary Corpus
Shinsuke Mori | John Richardson | Atsushi Ushiku | Tetsuro Sasada | Hirotaka Kameko | Yoshimasa Tsuruoka
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

In recent years there has been a surge of interest in the natural language prosessing related to the real world, such as symbol grounding, language generation, and nonlinguistic data search by natural language queries. In order to concentrate on language ambiguities, we propose to use a well-defined “real world,” that is game states. We built a corpus consisting of pairs of sentences and a game state. The game we focus on is shogi (Japanese chess). We collected 742,286 commentary sentences in Japanese. They are spontaneously generated contrary to natural language annotations in many image datasets provided by human workers on Amazon Mechanical Turk. We defined domain specific named entities and we segmented 2,508 sentences into words manually and annotated each word with a named entity tag. We describe a detailed definition of named entities and show some statistics of our game commentary corpus. We also show the results of the experiments of word segmentation and named entity recognition. The accuracies are as high as those on general domain texts indicating that we are ready to tackle various new problems related to the real world.

2015

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A Framework for Procedural Text Understanding
Hirokuni Maeta | Tetsuro Sasada | Shinsuke Mori
Proceedings of the 14th International Conference on Parsing Technologies

2014

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A Japanese Word Dependency Corpus
Shinsuke Mori | Hideki Ogura | Tetsuro Sasada
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

In this paper, we present a corpus annotated with dependency relationships in Japanese. It contains about 30 thousand sentences in various domains. Six domains in Balanced Corpus of Contemporary Written Japanese have part-of-speech and pronunciation annotation as well. Dictionary example sentences have pronunciation annotation and cover basic vocabulary in Japanese with English sentence equivalent. Economic newspaper articles also have pronunciation annotation and the topics are similar to those of Penn Treebank. Invention disclosures do not have other annotation, but it has a clear application, machine translation. The unit of our corpus is word like other languages contrary to existing Japanese corpora whose unit is phrase called bunsetsu. Each sentence is manually segmented into words. We first present the specification of our corpus. Then we give a detailed explanation about our standard of word dependency. We also report some preliminary results of an MST-based dependency parser on our corpus.

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Flow Graph Corpus from Recipe Texts
Shinsuke Mori | Hirokuni Maeta | Yoko Yamakata | Tetsuro Sasada
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

In this paper, we present our attempt at annotating procedural texts with a flow graph as a representation of understanding. The domain we focus on is cooking recipe. The flow graphs are directed acyclic graphs with a special root node corresponding to the final dish. The vertex labels are recipe named entities, such as foods, tools, cooking actions, etc. The arc labels denote relationships among them. We converted 266 Japanese recipe texts into flow graphs manually. 200 recipes are randomly selected from a web site and 66 are of the same dish. We detail the annotation framework and report some statistics on our corpus. The most typical usage of our corpus may be automatic conversion from texts to flow graphs which can be seen as an entire understanding of procedural texts. With our corpus, one can also try word segmentation, named entity recognition, predicate-argument structure analysis, and coreference resolution.

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FlowGraph2Text: Automatic Sentence Skeleton Compilation for Procedural Text Generation
Shinsuke Mori | Hirokuni Maeta | Tetsuro Sasada | Koichiro Yoshino | Atsushi Hashimoto | Takuya Funatomi | Yoko Yamakata
Proceedings of the 8th International Natural Language Generation Conference (INLG)