移动对象数据库模型、查询语言及实时交通流分析

提出一种移动对象数据库模型——Dynamic Transportation Network Based Moving Objects Database(简称DTNMOD),并给出了DTNMOD中基于移动对象时空轨迹的网络实时动态交通流分析方法.在DTNMOD中,交通网络被表示成动态的时空网络,可以描述交通状态、拓扑结构以及交通参数随时间的变化过程;网络受限的移动对象则用网络移动点表示.DTNMOD 模型包含了完整的数据类型和查询操作的定义,因此可以在任何可扩充数据库(如PostgreSQL 或SECONDO)中实现,从而得到完整的数据库模型和查询语言.为了对相关模型的性能进行比较与分析,基于PostgreSQL 实现了一个原型系统并进行了一系列的实验.实验结果表明,DTNMOD 提供了良好的区域查询及连接查询性能.

Data Model, Query Language, and Real-Time Traffic Flow Analysis in Dynamic Transportation Network Based Moving Objects Databases

This paper proposes a moving objects database model, dynamic transportation network based moving objects database (DTNMOD). Besides, a real-time traffic flow statistical analysis method based on moving object trajectories is provided. In DTNMOD, the underlying transportation network is modeled as a dynamic graph so that the state, topology, and traffic parameters of the transportation graph at any time instant can be tracked and queried.Moving objects are modeled as moving graph points which move only within predefined transportation networks.The data model is given as a collection of data types and operations which can be plugged as attribute types into a DBMS to obtain a complete data model and query language. To evaluate the performance of the proposed model,this paper has implemented a prototype system based on PostgreSQL and conducted a series of experiments. The experimental results show that DTNMOD provides good performances in processing region and join queries.