Query relaxation of fuzzy spatiotemporal RDF data

RDF is a framework used to describe web resources, which is a recommended standard by W3C and has been applied to many fields. Moreover, with the rapid development of spatiotemporal data and its applications, its query has received extensive attention. At the same time, fuzzy information cannot be ignored in many practical spatiotemporal applications. The research on fuzzy spatiotemporal data query has become one of the most important topics. In fact, when the number of query results is small or even empty, especially in the process of querying fuzzy spatiotemporal data, query relaxation is necessary. In addition, there are still few researches on query relaxation of fuzzy spatiotemporal data. In order to solve this problem, the paper proposes a fuzzy spatiotemporal RDF attributes relaxation method and a simple triple relaxation method to obtain a broader query relaxation results. Then it returns the top- k results with the highest similarity to the initial query. Finally, two groups of experiments are carried out to show the performance advantages of our approach. The experimental results show that the proposed two relaxation methods could meet the requirements of general and high result expectations.