Masayuki Ishii


2025

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JaCorpTrack: Corporate History Event Extraction for Tracking Organizational Changes
Yuya Sawada | Hiroki Ouchi | Yuichiro Yasui | Hiroki Teranishi | Yuji Matsumoto | Taro Watanabe | Masayuki Ishii
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: Industry Track

Corporate history in corporate annual reports includes events related to organizational changes, which can provide useful cues for a comprehensive understanding of corporate actions.However, extracting organizational changes requires identifying differences in companies before and after an event, raising concerns about whether existing information extraction systems can accurately capture the relations.This work introduces JaCorpTrack, a novel event extraction task designed to identify events related to organizational changes.JaCorpTrack defines five event types related to organizational changes and is designed to identify the company names before and after each event, as well as the corresponding date.Experimental results indicate that large language models (LLMs) exhibit notable disparities in performance across event types.Our analysis reveals that these systems face challenges in identifying company names before and after events, and in interpreting event types expressed under ambiguous terminology.We will publicly release our dataset and experimental code at https://github.com/naist-nlp/JaCorpTrack

1994

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An Efficient Parser Generator for Natural Language
Masayuki Ishii | Kazuhisa Ohta | Hiroaki Saito
COLING 1994 Volume 1: The 15th International Conference on Computational Linguistics