Johannes Hoffart


2018

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A Study of the Importance of External Knowledge in the Named Entity Recognition Task
Dominic Seyler | Tatiana Dembelova | Luciano Del Corro | Johannes Hoffart | Gerhard Weikum
Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

In this work, we discuss the importance of external knowledge for performing Named Entity Recognition (NER). We present a novel modular framework that divides the knowledge into four categories according to the depth of knowledge they convey. Each category consists of a set of features automatically generated from different information sources, such as a knowledge-base, a list of names, or document-specific semantic annotations. Further, we show the effects on performance when incrementally adding deeper knowledge and discuss effectiveness/efficiency trade-offs.

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diaNED: Time-Aware Named Entity Disambiguation for Diachronic Corpora
Prabal Agarwal | Jannik Strötgen | Luciano del Corro | Johannes Hoffart | Gerhard Weikum
Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

Named Entity Disambiguation (NED) systems perform well on news articles and other texts covering a specific time interval. However, NED quality drops when inputs span long time periods like in archives or historic corpora. This paper presents the first time-aware method for NED that resolves ambiguities even when mention contexts give only few cues. The method is based on computing temporal signatures for entities and comparing these to the temporal contexts of input mentions. Our experiments show superior quality on a newly created diachronic corpus.

2016

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DeepLife: An Entity-aware Search, Analytics and Exploration Platform for Health and Life Sciences
Patrick Ernst | Amy Siu | Dragan Milchevski | Johannes Hoffart | Gerhard Weikum
Proceedings of ACL-2016 System Demonstrations

2013

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HYENA-live: Fine-Grained Online Entity Type Classification from Natural-language Text
Mohamed Amir Yosef | Sandro Bauer | Johannes Hoffart | Marc Spaniol | Gerhard Weikum
Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics: System Demonstrations

2012

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HYENA: Hierarchical Type Classification for Entity Names
Mohamed Amir Yosef | Sandro Bauer | Johannes Hoffart | Marc Spaniol | Gerhard Weikum
Proceedings of COLING 2012: Posters

2011

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Robust Disambiguation of Named Entities in Text
Johannes Hoffart | Mohamed Amir Yosef | Ilaria Bordino | Hagen Fürstenau | Manfred Pinkal | Marc Spaniol | Bilyana Taneva | Stefan Thater | Gerhard Weikum
Proceedings of the 2011 Conference on Empirical Methods in Natural Language Processing