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arXiv 1805.03320cs.DB
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数据库图中Top-k序列模式的挖掘:一个新的挖掘问题和一种基于抽样的方法

Mining Top-k Sequential Patterns in Database Graphs:A New Challenging Problem and a Sampling-based Approach

Mingtao Lei, Lingyang Chu, Zhefeng Wang

摘要:

在许多现实世界的网络中,顶点通常与全面描述顶点行为的事务数据库相关联。一个典型的例子是社交网络,其中每个用户的行为都由一个交易数据库来描述,该数据库存储他每天发布的内容。事务数据库是一组事务,其中事务是一组项。网络中的每条路径都是一个顶点序列,这些顶点序列会导致多个交易序列。由网络中所有路径引起的事务序列形成了一个非常大的序列数据库。从序列数据库中寻找频繁的序列模式,可以发现网络中许多路径上频繁出现的有趣的连续性。然而,这是一个具有挑战性的任务,因为由数据库图诱导的序列数据库太大,无法显式地诱导和存储。在本文中,我们提出了新的概念,数据库图,自然模型广泛的现实世界的网络,通过关联每个顶点与一个交易数据库。我们的目标是从数据库图中找出序列数据库中的前k个频繁序列模式。我们证明了这个问题是#P-hard问题。为了解决这个问题,我们提出了一个有效的两步抽样算法,近似的top-k频繁序列模式,可证明的质量保证。在合成数据集和真实数据集上的大量实验结果证明了该方法的有效性和效率。

英文摘要:

In many real world networks, a vertex is usually associated with a transaction database that comprehensively describes the behaviour of the vertex. A typical example is the social network, where the behaviour of every user is depicted by a transaction database that stores his daily posted contents. A transaction database is a set of transactions, where a transaction is a set of items. Every path of the network is a sequence of vertices that induces multiple sequences of transactions. The sequences of transactions induced by all of the paths in the network forms an extremely large sequence database. Finding frequent sequential patterns from such sequence database discovers interesting subsequences that frequently appear in many paths of the network. However, it is a challenging task, since the sequence database induced by a database graph is too large to be explicitly induced and stored. In this paper, we propose the novel notion of database graph, which naturally models a wide spectrum of real world networks by associating each vertex with a transaction database. Our goal is to find the top-k frequent sequential patterns in the sequence database induced from a database graph. We prove that this problem is #P-hard. To tackle this problem, we propose an efficient two-step sampling algorithm that approximates the top-k frequent sequential patterns with provable quality guarantee. Extensive experimental results on synthetic and real-world data sets demonstrate the effectiveness and efficiency of our method.

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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