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空间数据索引技术及其在GIS软件中的应用 被引量:2
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作者 谢跟踪 苏江文 《海南师范学院学报(自然科学版)》 2005年第4期372-376,共5页
空间数据库的索引是提高空间数据库存储效率、空间检索性能的关键技术.在综述现有空间数据库索引技术的基础上,对比分析R树、R+树和R*树索引,认为R*树索引可获得较高的结点存贮利用率,还可以避免结点的分裂.最后给出了R*树索引在V isual... 空间数据库的索引是提高空间数据库存储效率、空间检索性能的关键技术.在综述现有空间数据库索引技术的基础上,对比分析R树、R+树和R*树索引,认为R*树索引可获得较高的结点存贮利用率,还可以避免结点的分裂.最后给出了R*树索引在V isualTopo软件中的应用实例. 展开更多
关键词 空间数据索引 R^*树索引 VisualTopo
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A new approach for effectively determining fracture network connec- tions in fractured rocks using R tree indexing 被引量:2
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作者 LIU Hua-mei WANG Ming-yu SONG Xian-feng 《Journal of Coal Science & Engineering(China)》 2011年第4期401-407,共7页
Determinations of fracture network connections would help the investigators remove those "meaningless" no-flow-passing fractures, providing an updated and more effective fracture network that could considerably impr... Determinations of fracture network connections would help the investigators remove those "meaningless" no-flow-passing fractures, providing an updated and more effective fracture network that could considerably improve the computation efficiency in the pertinent numerical simulations of fluid flow and solute transport. The effective algorithms with higher computational efficiency are needed to accomplish this task in large-scale fractured rock masses. A new approach using R tree indexing was proposed for determining fracture connection in 3D stochastically distributed fracture network. By com- paring with the traditional exhaustion algorithm, it was observed that from the simulation results, this approach was much more effective; and the more the fractures were investigated, the more obvious the advantages of the approach were. Furthermore, it was indicated that the runtime used for creating the R tree indexing has a major part in the total of the runtime used for calculating Minimum Bounding Rectangles (MBRs), creating the R tree indexing, precisely finding out fracture intersections, and identifying flow paths, which are four important steps to determine fracture connections. This proposed approach for the determination of fracture connections in three-dimensional fractured rocks are expected to provide efficient preprocessing and critical database for practically accomplishing numerical computation of fluid flow and solute transport in large-scale fractured rock masses. 展开更多
关键词 fracture network connection fractured rooks R tree indexing
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