居民地数据是一类重要的地形数据,其变化非常频繁.当居民地数据更新以后,数据生产者如何提取增量信息并及时发布给用户是迫切需要解决的问题.增量信息是由于居民地的变化引起的,不同的变化产生的增量信息存在很大差异。因此分析居民地的变化是实现增量信息发布的一个重要前提.本文着重于分析居民地变化的分类及其描述.基于变化的4个相关因子。提出了居民地变化分类模型。并利用规则表达式(IF-THEN)描述了各种变化类型及其产生的增量信息.最后,以我国1:25万地形数据库的居民地数据的增量信息生成验证了上述思想.图3.表1,参6.
Residential data is a kind of important topographic data and continually change. In order to keep the data up-to-date, data producers need update the data frequently. When the residential data are updated, the incremental information must be dispensed to the end-users to keep their client-databases current. Incremental information refers to the changed information of residential entity. In the real world, residential entity changes in many forms. Identifying the change type of residential entity (i.e. captures the semantics of change) and representing them in the data world can help end-users understand the change commonly and be convenient for end-users to integrate these change information into their databases. A classification and qualitative representation of change was focused on. A classification of change was offered based on muhi-faetors and these change type was represent and related incremental information with IF-THEN expressions. 3refs., 1tab., 6refs.