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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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基于观察者方位的方向关系及其查询处理
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作者 闫计云 刘永炎 +1 位作者 邓成玉 石伟铂 《微计算机应用》 2009年第11期55-59,共5页
通过分析观察者本身及其方位特点,在基于投影的模型基础上,首先提出了一种新的基于观察者方位的方向关系模型。然后结合新模型的特点,对方向关系查询空间建立了R*-树索引,利用拓扑学和矩形代数理论,提出了三步过滤法用以减少索引空间,... 通过分析观察者本身及其方位特点,在基于投影的模型基础上,首先提出了一种新的基于观察者方位的方向关系模型。然后结合新模型的特点,对方向关系查询空间建立了R*-树索引,利用拓扑学和矩形代数理论,提出了三步过滤法用以减少索引空间,降低了R*-树中矩形的重叠区域,减少了查询路径。最后给出了方向关系查询算法。实验表明,与传统的基于投影模型的查询方法相比,新模型的基于观察者方位的查询方法节省了I/O时间,提高了查询效率。 展开更多
关键词 方向关系 观察者方位 方向查询 r*-树索引
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