The Reverse $k$-Nearest Neighbor (R$k$NN) query over moving objects on road networks seeks to find all moving objects that consider the specified query point as one of their $k$ nearest neighbors. In location based services, many users probably submit R$k$NN queries simultaneously. However, existing methods largely overlook how to efficiently process multiple such queries together, missing opportunities to share redundant computations and thus reduce overall processing costs. To address this, this work is the first to explore batch processing of multiple R$k$NN queries, aiming to minimize total computation by sharing duplicate calculations across queries. To tackle this issue, we propose the BR$k$NN-Light algorithm, which uses rapid verification and pruning strategies based on geometric constraints, along with an optimized range search technique, to speed up the process of identifying the R$k$NNs for each query. Furthermore, it proposes a dynamic distance caching mechanism to enable computation reuse when handling multiple queries, thereby significantly reducing unnecessary computations. Experiments on multiple real-world road networks demonstrate the superiority of the BR$k$NN-Light algorithm on the processing of batch queries.
翻译:路网移动对象的反向$k$近邻查询旨在找出所有将指定查询点视作其$k$个最近邻之一的移动对象。在基于位置的服务中,许多用户可能同时提交反向$k$近邻查询。然而,现有方法大多忽略了如何高效地批量处理多个此类查询,错失了通过共享冗余计算以降低整体处理成本的机会。为此,本研究首次探索了多个反向$k$近邻查询的批量处理,旨在通过跨查询共享重复计算来最小化总计算量。为解决此问题,我们提出了BR$k$NN-Light算法,该算法采用基于几何约束的快速验证与剪枝策略,并结合优化的范围搜索技术,以加速识别每个查询的反向$k$近邻。此外,算法提出了一种动态距离缓存机制,使得在处理多个查询时能够复用已有计算结果,从而显著减少不必要的计算。在多个真实路网上的实验验证了BR$k$NN-Light算法在批量查询处理上的优越性。