Moving Object XML Database And Applications In The Simulation Resource Management

Moving objects are stored in moving object database by certain data models. To meet the needs of a variety of applications, moving object database typically contains a variety of data models, while this approach brings the issue of heterogeneous data access. XML is suitable for moving object data management. Moving object XML document is the basic object in the Moving Object XML Database (MOXMLDB), and space and time are two important properties of moving objects. Current research on MOXMLDB is deficient, so spatio-temporal data integration in XML, moving objects XML storage model and indexing on spatio-temporal XML data are getting more and more attention. Most of data on the simulation resource management system contains time and space properties, but the HLA framework does not provide capabilities of data acquisition and playback. Here, MOXMLDB solves the related problems.This paper mainly focuses on XML storage model and XML indexing of moving objects, besides it does applied research on moving objects data capture and playback in the simulation resource management system. First, after analyzing simple storage model that has the shortcomings on spatio-temporal queries, this paper presents a moving object XML data storage model called Spatio-temporal Storage Model that gathers XML data records by certain spatio-temporal conditions. Considering the characteristics of the document being transfer to memory when doing spatio-temporal queries, the model gathers the records that are closer linked in spatio-temporal relationship. When doing the queries related to spatio-temporal conditions, the scope of document transferred into memory is reduced, so the efficiency of query is improved. Second, this paper proposes three moving object XML index structure. The first one proposes an idea of spatio-temporal separation that structures the temporal and spatial index trees respectively. We can index from the two sub-trees simultaneously when doing spatio-temporal queries, so the time of the spatio-temporal queries is reduced. Focusing on the importance of temporal conditions in the moving object indexing, the second one proposes an improved 3DR tree that removes spatial conditions in non-leaf node, to improve the efficiency of the queries relating to temporal conditions. The third one is used for current and future indexes that consist of a HASH table and an R-tree. The leaf node of a certain moving object can be positioned by HASH table, and R-tree is a spatial structure determined by future trajectory. Based on this structure, we propose a bottom-up update algorithm and a K nearest neighbor query algorithm containing iterative idea. At last, based on the storage and indexing of MOXMLDB, we apply MOXMLDB to simulation resource management system, resolve the key technical issues met in the data acquisition, and propose and implement several kinds of simulation relating queries, such as sequence playback, rollback, the current information querying, the future information predicting and the information of adjacent members querying.