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arXiv 1404.0900cs.SIcs.DB
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影响力最大化:接近最优的时间复杂度满足实际效率

Influence Maximization: Near-Optimal Time Complexity Meets Practical Efficiency

Youze Tang, Xiaokui Xiao, Yanchen Shi

摘要:

给定一个社交网络G和一个常数k,影响力最大化问题要求G中的k个节点在预定义的扩散模型下(直接和间接)影响最大数量的节点。这个问题在病毒式营销中有着重要的应用,并在文献中得到了广泛的研究。现有的算法影响力最大化,然而,要么贸易近似保证实际效率,反之亦然。特别是,在突出的独立级联(IC)模型或线性阈值(LT)模型下实现常数因子近似的算法中,没有一个可以处理百万节点的图而不产生高昂的开销。本文提出了TIM算法,旨在弥合理论和实践中的影响力最大化。在理论方面,我们证明了TIM在O((k+ \ell)(n+m)\log n / ε^2)期望时间内运行,并以至少1 - n^{- \ell }的概率返回(1-1/e-ε)-近似解。在IC模型下,TIM的时间复杂度接近最优,因为它只比先前工作中建立的Ω(m + n)下限大\log n倍(对于固定的k、\ell和ε)。此外,TIM支持触发模型,这是一个通用的扩散模型,其中包括IC和LT作为特殊情况。在实践方面,TIM采用了新的经验主义,显着提高其经验效率,而不影响其渐近性能。我们用文献中测试过的最大数据集对TIM进行了实验评估,结果表明,它在运行时间上比最先进的解决方案(具有近似保证)高出四个数量级。特别是,当k = 50,ε= 0.2,\ell = 1时,TIM在商品机器上需要不到一个小时来处理具有4160万个节点和14亿条边的网络。

英文摘要:

Given a social network G and a constant k, the influence maximization problem asks for k nodes in G that (directly and indirectly) influence the largest number of nodes under a pre-defined diffusion model. This problem finds important applications in viral marketing, and has been extensively studied in the literature. Existing algorithms for influence maximization, however, either trade approximation guarantees for practical efficiency, or vice versa. In particular, among the algorithms that achieve constant factor approximations under the prominent independent cascade (IC) model or linear threshold (LT) model, none can handle a million-node graph without incurring prohibitive overheads. This paper presents TIM, an algorithm that aims to bridge the theory and practice in influence maximization. On the theory side, we show that TIM runs in O((k+\ell) (n+m) \log n / ε^2) expected time and returns a (1-1/e-ε)-approximate solution with at least 1 - n^{-\ell} probability. The time complexity of TIM is near-optimal under the IC model, as it is only a \log n factor larger than the Ω(m + n) lower-bound established in previous work (for fixed k, \ell, and ε). Moreover, TIM supports the triggering model, which is a general diffusion model that includes both IC and LT as special cases. On the practice side, TIM incorporates novel heuristics that significantly improve its empirical efficiency without compromising its asymptotic performance. We experimentally evaluate TIM with the largest datasets ever tested in the literature, and show that it outperforms the state-of-the-art solutions (with approximation guarantees) by up to four orders of magnitude in terms of running time. In particular, when k = 50, ε= 0.2, and \ell = 1, TIM requires less than one hour on a commodity machine to process a network with 41.6 million nodes and 1.4 billion edges.

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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