时空数据模型建模方法研究

【作者】 林广发； 冯学智； 江辉仙；

【机构】 福建师范大学地球信息科学系； 南京大学城资系；

【摘要】 时态GIS研究很重要,但也是一个尚未解决的难点问题,其中的核心是时空数据模型的研究。目前提出的时空数据模型很多,但通用的模型仍然没有出现。其中一个很重要的原因是缺乏一个构建时空数据模型的方法论。本文从分析时空数据管理系统中的数据冗余与数据对象的粒度之间的关系入手,研究现实世界变化的变化对象/对象组分之间的内聚性与同步变化/异步变化的关系规律、驱动变化的事件等问题,从而提出了一个构建时空数据模型的方法。认为,研究时空数据模型有两条途径,一条是研究对象之间的相互联系及对象内部普遍存在的等级层次结构,合理设计模型中相应的对象结构;另一条是研究驱动变化的事件自身的特点及事件之间的逻辑关系,据此设计数据更新的方法并在模型中表达对象变化的原因。这两条路径必须结合起来。更多还原

【Abstract】 The temporal problem in Geographical Information System (GIS) is a very important stumper to be solved. The Main difficulty in the problem is to construct a Spatio-Temporal Data Model (STDM). Till now, there have appeared many kinds of STDM, but none of them is universally accepted. All are specially designed for ad hoc purpose. One of the main reason caused the state is the absence of methodology. A methodology for modeling STDM was given in the paper by analyzing the rule of entities’ change. It took the contradiction between data redundancy and data granularity as a start of analysis. Then the object granularity was found to be a key factor to balance the contradiction. The mechanism of the balance lies in the synchronous change and asynchronous change among different entities or components of an entity during the spatial processing. Furthermore, the factors determining synchronous or asynchronous change include the cohesion difference among different objects, the events causing entity change and the spatio-temporal observation scale. According to these conclusions, two approaches were put forward for STDM study. One is to investigate the inter-relationship among entities and the ubiquitous hierarchy within an entity and design corresponding object structure,another is to study the character of events as the driver for space process and the logic relationship between events,so as to design data update method and to express the reason of change. These two approaches must to be integrated.更多还原