TY - GEN
T1 - A synchronous context free grammar for time normalization
AU - Bethard, Steven
N1 - Publisher Copyright:
© 2013 Association for Computational Linguistics.
PY - 2013
Y1 - 2013
N2 - We present an approach to time normalization (e.g. the day before yesterday→2013-04-12) based on a synchronous context free grammar. Synchronous rules map the source language to formally defined operators for manipulating times (FINDENCLOSED, STARTATENDOF, etc.). Time expressions are then parsed using an extended CYK+ algorithm, and converted to a normalized form by applying the operators recursively. For evaluation, a small set of synchronous rules for English time expressions were developed. Our model outperforms HeidelTime, the best time normalization system in TempEval 2013, on four different time normalization corpora.
AB - We present an approach to time normalization (e.g. the day before yesterday→2013-04-12) based on a synchronous context free grammar. Synchronous rules map the source language to formally defined operators for manipulating times (FINDENCLOSED, STARTATENDOF, etc.). Time expressions are then parsed using an extended CYK+ algorithm, and converted to a normalized form by applying the operators recursively. For evaluation, a small set of synchronous rules for English time expressions were developed. Our model outperforms HeidelTime, the best time normalization system in TempEval 2013, on four different time normalization corpora.
UR - http://www.scopus.com/inward/record.url?scp=84924426972&partnerID=8YFLogxK
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M3 - Conference contribution
AN - SCOPUS:84924426972
T3 - EMNLP 2013 - 2013 Conference on Empirical Methods in Natural Language Processing, Proceedings of the Conference
SP - 821
EP - 826
BT - EMNLP 2013 - 2013 Conference on Empirical Methods in Natural Language Processing, Proceedings of the Conference
PB - Association for Computational Linguistics (ACL)
T2 - 2013 Conference on Empirical Methods in Natural Language Processing, EMNLP 2013
Y2 - 18 October 2013 through 21 October 2013
ER -