利用约束满足问题进行多洞面实体相似性度量

Similarity Measurement of Multi-holed Regions Using Constraint Satisfaction Problem

多洞面实体作为现实世界的抽象,主要用来表示拥有多个内部边界的地理实体,如包含多个湖泊的区域,或带有岛屿的湖泊。为了度量这些空间实体,提出了一种顾及多约束的多洞面实体相似性度量模型,该模型将多洞区域看做微场景,将洞视为空间对象,洞之间的方向表示为空间分布关系。顾及复杂多洞面实体中洞与洞之间的方向、几何形状等约束条件,利用傅里叶描述子来描述洞的形状,使用方向特征矩阵来表示洞之间的分布,将相似性度量过程转换变成满足约束条件问题。利用由结点和边组成的关联图对约束条件的匹配过程进行描述。采用伊朗西北部的乌鲁米耶湖作为实验数据,对其不同年份的形态进行相似性度量,实验结果表明该方法简单可行且不失精度。

Multi-holed plane object,as one of the abstracts of the real world,mainly represent geographic objects having more than one interior boundary,such as areas that contain a few lakes,or lakes with islands.To realize the matching between these spatial objects,the paper proposed a model of similarity measurement on multi-holed regions,with several restrictions being taken into account.In this model,the multi-holed plane object was viewed as a micro-spatial-scene,where holes and direction between holes playing roles of spatial objects and spatial distribution relations respectively.Taking into the direction between holes and the shape of holes account,Fourier descriptor was utilized to describe the shape of holes and Feature Matrix of direction was applied to represent the distribution relationship between holes,then the process of measuring similarity would be transformed into a constraint satisfaction problem（CSP）.Association graph containing nodes and edges could be adopted to represent the matching solutions of CSP.In the paper,A case study of Urmia,a lake in Iran,is given to illustrate the whole process of similarity measurement among the shapes of the lake in different years,and the result of experiment is presented to be simple and applicable.