改进规则的可放缩矢量图形地图的查询模型

Query Model of Improved Rules Scalable Vector Graphics Map

摘要:

分析了基于SVG(可放缩矢量图形)格式时态GIS（地理信息系统）领域，尤其是地理元素查询方面的研究现状，针对现有的XML（可扩展标记语言）查询方法进行了分析和对比.在基于SVG语法规则改进研究的基础上，并结合LISA Ⅱ(layered intersection scan algorithm Ⅱ,分层交叉扫描算法Ⅱ)查询技术，提出了一种适合改进规则的SVG格式的GIS数据地理元素查询模型及其算法，通过定义关键字查询语法规则表达式，定义关键字查询的“&”和“or”操作规则，实现了组合查询；通过定义实体元素节点，减少了节点数，提高了查询效率.该模型实现了SVG格式地图的地理元素查询，包括对整幅地图的各种组合查询和分图层的各种组合查询，解决了基于SVG格式地图元素查询的技术瓶颈.大量的数据验证表明，该查询模型是有效的.

Abstract:

Based on the scalable vector graphics(SVG) format, an analysis was made of the temporal geographic information system(GIS) field, especially current research status of geographic element query, and then a comparative study was made with the existing extensible markup language(XML) query methods. A SVG grammar rules based research was proposed. In combination with the LISA Ⅱ query technology, a query model and the corresponding algorithm applicable for the GIS data geographic element of the improved rules SVG format were proposed. A combination query was achieved by defining keyword query syntax regular expressions and the keyword query “&” and “or” operation rules. In addition, the number of nodes was reduced, and the query efficiency improved by defining the entity element node. Study results show that the model achieves geographic elements queries of SVG format map, including various combinations queries on the entire map and various combinations queries of layers. As a result, the technical bottleneck of query is solved based on SVG format map elements. Lots of data validate this query model is effective.