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.. _entity_linking: |
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Entity Linking |
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==================================== |
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Entity linking is the process of matching concepts mentioned in natural language to their unique IDs and canonical forms stored |
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in a knowledge base. For example, an entity linking model might match the phrase ``blood thinners`` mentioned in conversation |
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to the knowledge base concept UID45623 anticoagulant. Entity linking applications range from helping automate ingestion of |
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large amounts of data to assisting in real time concept normalization. |
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Within NeMo we use the entity linking approach described in Liu et. al's NAACL 2021 "`Self-alignment Pre-training for Biomedical Entity Representations <https://arxiv.org/abs/2010.11784v2>`_" :cite:`nlp-entity_linking-liu2021selfalignment`. |
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The main idea behind this approach is to reshape an initial concept embedding space such that synonyms of the same concept are |
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pulled closer together and unrelated concepts are pushed further apart. The concept embeddings from this reshaped space can then |
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be used to build a knowledge base embedding index. |
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.. image:: entity_linking_overview.jpg |
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:alt: Entity-Linking-Overview |
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:width: 800px |
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Our BERT-base + Self Alignment Pretraining implementation allows you to train an entity linking encoder. We also provide example code |
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on building an index with `Medical UMLS <https://www.nlm.nih.gov/research/umls/index.html>`_ concepts `NeMo/examples/nlp/entity_linking/build_index.py <https://github.com/NVIDIA/NeMo/tree/stable/examples/nlp/entity_linking/build_index.py>`__. |
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Please try the example Entity Linking model in a Jupyter notebook (can run on `Google's Colab <https://colab.research.google.com/github/NVIDIA/NeMo/blob/v1.0.2/tutorials/nlp/Entity_Linking_Medical.ipynb>`__). |
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Connect to an instance with a GPU (**Runtime** -> **Change runtime type** -> select **GPU** for the hardware accelerator). |
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An example script on how to train the model can be found here: `NeMo/examples/nlp/entity_linking <https://github.com/NVIDIA/NeMo/tree/stable/examples/nlp/entity_linking>`__. |
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References |
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.. bibliography:: nlp_all.bib |
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:style: plain |
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:labelprefix: nlp-entity_linking |
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:keyprefix: nlp-entity_linking- |
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