Reasoning Model for Temporal Knowledge Graph Based on Entity Multiple Unit Coding

[Objective] This paper tries to address the issues of incomplete entity information extraction and importance measurement of different timestamps for the events to be reasoned in temporal knowledge graph. [Methods] We proposed a new model based on entity multiple unit coding(EMUC). The EMUC introduces the entity slice feature encodings for the current timestamps, the entity dynamic feature encodings fusing timestamp embedding and entity static features, as well as entity segment feature encodings over historical steps. We also utilized a temporal attention mechanism to learn the importance weights of local structural information at different timestamps to the inference target. [Results] The experimental results of the proposed model on the ICEWS14 test set were MRR: 0.470 4, Hits@1: 40.31%, Hits@3: 50.02%, Hits@10: 59.98%, while on the ICEWS18 test set were MRR: 0.438 5, Hits@1: 37.55%, Hits@3: 46.92%, Hits@10: 56.85%, and on the YAGO test set are MRR: 0.656 4, Hits@1: 63.07%, Hits@3: 65.87%, Hits@10: 68.37%. Our model outperforms the existing methods on these evaluating metrics. [Limitations] EMUC has slow inference speed for large-scale datasets. [Conclusions] The newly temporal attention mechanism measures the importance of historical local structure information for reasoning, which effectively improves the reasoning performance of the temporal knowledge graph.