| In the field of information technology,time as an essential dimension to describe the process of data change is an important part of many applications.The Web is the basic platform for information sharing and interaction today.Web data usually has high dynamics and timeliness because users can edit and publish data at any time.For a long time,the representation and storage management of temporal information has been the focus of various scientific researches.Among them,XML(Extensible Markup Language)is the main transmission and storage language for data sharing,and the related temporal extension has been widely studied.However,with the advent of artificial intelligence,users' requirements for the network are not limited to data sharing.People are increasingly demanding intelligent data analysis and processing.Note that,the network standard Web 2.0 used now lacks the description of data semantics.The meaning of data must be interpreted manually,and the provision of intelligent services is even harder.The emergence and development of the Semantic Web has brought about a solution.The resource description framework RDF(Resource Description Framework)and RDF Schema(collectively referred to as RDF(S))of Semantic Web can describe semantic between data powerfully,enhancing the machine's understanding of data and promoting the cooperation between people and machines.Moreover,the study of temporal data processing in the field of semantic Web has never been interrupted.At the beginning of the 20 th century,scholars proposed the temporal expansion of RDF(S),with specific entailment rules and semantic reasoning methods.In order to promote the semantic process of Web information,this thesis focuses on the automatic construction of temporal RDF(S)based on temporal XML,and studies the storage model for temporal RDF(S)based on distributed database HBase when observing the exponential growth of temporal RDF(S)data.Our main work is as follows:(1)The expression and calculation methods of time domain are proposed with analyzing time dimentions.Based on the selected time dimensions,temporal RDF(S),temporal XML and temporal XML Schema are defined formally.In addition,the applications of temporal XML and temporal XML Schema are introduced.(2)Based on the definition of temporal models,we propose the mapping ruls and algorithms for temporal RDF Schema extraction and temporal RDF instances transformation by temporal XML Schema and XML documents,respectively.A prototype system is designed and implemented to verify the validity and feasibility of the mapping method.(3)Propose the problems of HBase built-in time model,after exploring the data model and physical structure of HBase.According to the data characteristics of temporal RDF(S),a storage model for RDF(S)based on HBase is proposed.This model not only can store RDF data with tempora;features efficiently,but also can quickly respond to all Triple Patterns and queries for hierarchy information.Meanwhile,the corresponding query method of temporal RDF(S)is proposed for the storage model,and query experiments and evaluation of results are conducted via LUBM(Lehigh University Benchmark)data sets. |
