Charles C. Lee

Also published as: Charles Lee


2020

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To Schedule or not to Schedule: Extracting Task Specific Temporal Entities and Associated Negation Constraints
Barun Patra | Chala Fufa | Pamela Bhattacharya | Charles Lee
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

State of the art research for date-time entity extraction from text is task agnostic. Consequently, while the methods proposed in literature perform well for generic date-time extraction from texts, they don’t fare as well on task specific date-time entity extraction where only a subset of the date-time entities present in the text are pertinent to solving the task. Furthermore, some tasks require identifying negation constraints associated with the date-time entities to correctly reason over time. We showcase a novel model for extracting task-specific date-time entities along with their negation constraints. We show the efficacy of our method on the task of date-time understanding in the context of scheduling meetings for an email-based digital AI scheduling assistant. Our method achieves an absolute gain of 19% f-score points compared to baseline methods in detecting the date-time entities relevant to scheduling meetings and a 4% improvement over baseline methods for detecting negation constraints over date-time entities.

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ScopeIt: Scoping Task Relevant Sentences in Documents
Barun Patra | Vishwas Suryanarayanan | Chala Fufa | Pamela Bhattacharya | Charles Lee
Proceedings of the 28th International Conference on Computational Linguistics: Industry Track

A prominent problem faced by conversational agents working with large documents (Eg: email-based assistants) is the frequent presence of information in the document that is irrelevant to the assistant. This in turn makes it harder for the agent to accurately detect intents, extract entities relevant to those intents and perform the desired action. To address this issue we present a neural model for scoping relevant information for the agent from a large document. We show that when used as the first step in a popularly used email-based assistant for helping users schedule meetings, our proposed model helps improve the performance of the intent detection and entity extraction tasks required by the agent for correctly scheduling meetings: across a suite of 6 downstream tasks, by using our proposed method, we observe an average gain of 35% in precision without any drop in recall. Additionally, we demonstrate that the same approach can be used for component level analysis in large documents, such as signature block identification.

2000

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When Endpoint Meets Endpoint: A Corpus-based Lexical Semantic Study of Mandarin Verbs of Throwing
Mei-Chun Liu | Chu-Ren Huang | Charles Lee | Ching-Yi Lee
International Journal of Computational Linguistics & Chinese Language Processing, Volume 5, Number 1, February 2000: Special Issue on Chinese Verbal Semantics

1998

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The Advantages of 3D-Trees in Modeling Human Sentence Processing
Charles C. Lee
Proceedings of the 12th Pacific Asia Conference on Language, Information and Computation