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arXiv 2104.01632cs.LGcs.AI
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Isconna:基于频率和模式的流异常检测

Isconna: Streaming Anomaly Detection with Frequency and Patterns

National University of Singapore(新加坡国立大学)

Rui Liu, Siddharth Bhatia, Bryan Hooi

摘要:

边流是动态网络的一种常见表示形式。它可以随着时间的推移而演变,不断添加新类型的节点或边。用于异常检测的现有方法依赖于边缘出现计数或比较在历史记录中发现的模式片段。在这项工作中,我们提出了Isconna,它侧重于边缘记录的频率和模式。突发检测组件以各个时间戳之间的异常为目标,而模式检测组件突出显示跨时间戳段的异常。这两个分量一起产生三个中间分数,其被聚合成最终异常分数。Isconna并不主动探索或维护模式片段;而是测量边缘记录的连续存在和不存在。Isconna算法是一种在线算法,它不保留原始的边记录信息,只在少量的count-min sketches(CMS)中保留统计值。Isconna的空间复杂度$O(rc)$由两个用户特定的参数确定,即CMS的大小。在最坏的情况下,Isconna的时间复杂度可以达到$O(rc)$,但它可以在实践中摊销。实验表明,Isconna在六个真实世界的数据集上的性能优于五个最先进的基于频率和/或模式的基线,这些数据集具有多达2000万条边缘记录。

英文摘要:

An edge stream is a common form of presentation of dynamic networks. It can evolve with time, with new types of nodes or edges being continuously added. Existing methods for anomaly detection rely on edge occurrence counts or compare pattern snippets found in historical records. In this work, we propose Isconna, which focuses on both the frequency and the pattern of edge records. The burst detection component targets anomalies between individual timestamps, while the pattern detection component highlights anomalies across segments of timestamps. These two components together produce three intermediate scores, which are aggregated into the final anomaly score. Isconna does not actively explore or maintain pattern snippets; it instead measures the consecutive presence and absence of edge records. Isconna is an online algorithm, it does not keep the original information of edge records; only statistical values are maintained in a few count-min sketches (CMS). Isconna's space complexity $O(rc)$ is determined by two user-specific parameters, the size of CMSs. In worst case, Isconna's time complexity can be up to $O(rc)$, but it can be amortized in practice. Experiments show that Isconna outperforms five state-of-the-art frequency- and/or pattern-based baselines on six real-world datasets with up to 20 million edge records.

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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