空间目标的聚合模型

本文定义了集合元素的聚合算子，简述其特性，以此聚合算子为基础，提出了空间目标的聚合模型。根据ＧＩＳ空间目标的属性，分析了聚合算子的表现形式。由此模型的特点可以得出：聚合模型适合于ＧＩＳ层次数据的组织，它能减少数据的冗余和维护数据的一致性。经概念及含义的比较，指出了面向对象的模型方法很适合此聚合模型的实施。

AGGREGATE MODELING FOR SPATIAL OBJECTS

An aggregate operator is formally defined in this paper and some properties of this operator are outlined. Based on the aggregate operator, this paper put forward an aggregate model for spatial objects in GIS. The forms of the aggregate operations are discussed according to the attributes of the spatial objects. An simple application is used as an example to describe the usage of the model which is well suited to model hierachically structured spatial objects. It can reduces the data redundance and preserves the data consistance. The object oriented programming method is found as the most effective tool to implement this model by comparison of some concepts in OO data model with those in the aggregate model.