World Knowledge Representation

World knowledge representation aims to represent entities and relations in the knowledge graph in low-dimensional semantic space, which have been widely used in large knowledge-driven tasks. In this chapter, we first introduce the concept of the knowledge graph. Next, we introduce the motivations and give an overview of the existing approaches for knowledge graph representation. Further, we discuss several advanced approaches that aim to deal with the current challenges of knowledge graph representation. We also review the real-world applications of knowledge graph representation, such as language modeling, question answering, information retrieval, and recommender systems.