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arXiv 1706.04764cs.DScs.LGcs.SI
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基于滑动窗口的有效代表子集选择

Efficient Representative Subset Selection over Sliding Windows

National University of Singapore(新加坡国立大学);Singapore Management University(新加坡管理大学)

Yanhao Wang, Yuchen Li, Kian-Lee Tan

摘要:

代表性子集选择(RSS)是用户从海量数据集中获取见解的重要工具。现有文献将RSS建模为子模最大化问题以捕获所选子集的代表性的“收益递减”属性,但通常仅具有单个约束(例如,基数),这限制了它在许多现实问题中的应用。为了捕获数据的近因问题,并支持不同类型的约束,我们制定动态RSS数据流最大化子模块功能受一般$d$ -背包约束(SMDK)在滑动窗口。我们提出了一个\textsc{KnapWindow}框架(KW)的SMDK。KW将用于SMDK的\textsc{KnapStream}算法(KS)作为仅附加流的子例程。它在滑动窗口上维护一系列检查点和KS实例。理论上,KW是SMDK的$\frac{1-\varepsilon}{1+d}$近似。此外,我们提出了一个\textsc{KnapWindowPlus}框架(KW $^{+}$),以改善KW。KW $^{+}$构建索引\textsc{SubKnapChk}来管理检查点和KS实例。\textsc{SubKnapChk}删除检查点,只要它的后续检查点可以接近它。通过保持更少的检查点,KW $^{+}$实现了比KW更高的效率,同时仍然保证SMDK的$\frac{1-\varepsilon'}{2+2d}$近似解。最后,我们评估的效率和解决方案的质量KW和KW $^{+}$在现实世界的数据集。实验结果表明,KW实现了超过两个数量级的加速比批处理基线,并保持高质量的解决方案SMDK滑动窗口。KW $^{+}$的运行速度比KW快5-10倍,同时提供具有同等甚至更好实用程序的解决方案。

英文摘要:

Representative subset selection (RSS) is an important tool for users to draw insights from massive datasets. Existing literature models RSS as the submodular maximization problem to capture the "diminishing returns" property of the representativeness of selected subsets, but often only has a single constraint (e.g., cardinality), which limits its applications in many real-world problems. To capture the data recency issue and support different types of constraints, we formulate dynamic RSS in data streams as maximizing submodular functions subject to general $d$-knapsack constraints (SMDK) over sliding windows. We propose a \textsc{KnapWindow} framework (KW) for SMDK. KW utilizes the \textsc{KnapStream} algorithm (KS) for SMDK in append-only streams as a subroutine. It maintains a sequence of checkpoints and KS instances over the sliding window. Theoretically, KW is $\frac{1-\varepsilon}{1+d}$-approximate for SMDK. Furthermore, we propose a \textsc{KnapWindowPlus} framework (KW$^{+}$) to improve upon KW. KW$^{+}$ builds an index \textsc{SubKnapChk} to manage the checkpoints and KS instances. \textsc{SubKnapChk} deletes a checkpoint whenever it can be approximated by its successors. By keeping much fewer checkpoints, KW$^{+}$ achieves higher efficiency than KW while still guaranteeing a $\frac{1-\varepsilon'}{2+2d}$-approximate solution for SMDK. Finally, we evaluate the efficiency and solution quality of KW and KW$^{+}$ in real-world datasets. The experimental results demonstrate that KW achieves more than two orders of magnitude speedups over the batch baseline and preserves high-quality solutions for SMDK over sliding windows. KW$^{+}$ further runs 5-10 times faster than KW while providing solutions with equivalent or even better utilities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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