Knowledge graphs (KGs) have been widely used for question answering (QA) applications, especially the entity based QA. However, searching an-swers from an entire large-scale knowledge graph is very time-consuming and it is hard to meet the speed need of real online QA systems. In this pa-per, we design a sub-graph searching mechanism to solve this problem by creating sub-graph index, and each answer generation step is restricted in the sub-graph level. We use this mechanism into a real online QA chat system, and it can bring obvious improvement on question coverage by well answer-ing entity based questions, and it can be with a very high speed, which en-sures the user experience of online QA.

中文翻译：

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基于子图搜索的在线问答系统

知识图 (KG) 已广泛用于问答 (QA) 应用程序，尤其是基于实体的 QA。然而，从整个大规模知识图中搜索答案非常耗时，难以满足真实在线 QA 系统的速度需求。在这篇论文中，我们设计了一种子图搜索机制，通过创建子图索引来解决这个问题，并且每个答案生成步骤都限制在子图级别。我们将这种机制应用到一个真正的在线QA聊天系统中，通过很好的基于实体的问题的回答，可以明显提高问题覆盖率，而且速度非常快，保证了在线QA的用户体验.