  We propose a neural network model for joint extraction of named entities and
relations between them, without any hand-crafted features. The key contribution
of our model is to extend a BiLSTM-CRF-based entity recognition model with a
deep biaffine attention layer to model second-order interactions between latent
features for relation classification, specifically attending to the role of an
entity in a directional relationship. On the benchmark "relation and entity
recognition" dataset CoNLL04, experimental results show that our model
outperforms previous models, producing new state-of-the-art performances.
