This paper studies few-shot relation extraction, which aims at predicting the relation for a pair of entities in a sentence by training with a few labeled examples in each relation. To more effectively generalize to new relations, in this paper we study the relationships between different relations and propose to leverage a global relation graph. We propose a novel Bayesian meta-learning approach to effectively learn the posterior distribution of the prototype vectors of relations, where the initial prior of the prototype vectors is parameterized with a graph neural network on the global relation graph. Moreover, to effectively optimize the posterior distribution of the prototype vectors, we propose to use the stochastic gradient Langevin dynamics, which is related to the MAML algorithm but is able to handle the uncertainty of the prototype vectors. The whole framework can be effectively and efficiently optimized in an end-to-end fashion. Experiments on two benchmark datasets prove the effectiveness of our proposed approach against competitive baselines in both the few-shot and zero-shot settings.

本文研究了利用少量标记数据进行关系抽取的方法，为了更好地概括新关系，我们提出了利用全局关系图的方法，使用贝叶斯元学习的方法来有效地学习关系的原型向量的后验分布，并使用随机梯度Langevin动力学来优化原型向量的后验分布，整个框架能够有效且高效地进行端对端优化。实验表明，我们的方法在少样例和零样例场景下的效果均优于竞争基线。

基于关系图的贝叶斯元学习进行少样本关系抽取