摘要
针对时空范围内,移动目标数据库中由于移动目标轨迹的不确定性导致的范围查询问题,在基于Bead/Necklace不确定性模型的基础上,将查询问题映射为2D平面的计算几何问题进行解决。针对时空中五种不同句法的不确定性范围查询类型确定了对应的定性查询算法,并通过查询多边形的偏置和轨迹点位置查询的方法实现新的修剪算法,其算法复杂度与查询区域边的数目呈线性关系。实验结果显示,提出的修剪策略更加有效地提高了系统的查询效率。
Focusing on the problem of efficient processing of spatiotemporal range queries for uncertain trajectories,where the uncertainty of the motion was modeled as a necklace-a sequence of beads,queries are solved by mapping to computational geometry problems in 2D plane.For different query predicate,the corresponding processing algorithms for the refinements stage are newly presented.The pruning algorithm is implemented by offset query polygon and object point location queries.Its complexity is linear with the edges of query polygon.As demonstrated by the experiments,it further more significantly speeds up the processing of system queries.
出处
《电子测量与仪器学报》
CSCD
2010年第8期722-729,共8页
Journal of Electronic Measurement and Instrumentation
基金
国家自然科学基金(编号:60903157)资助项目
