arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2003.07429stat.MLcs.LGstat.APstat.ME
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上下文相关的自激点过程:模型、方法和高维风险界

Context-dependent self-exciting point processes: models, methods, and risk bounds in high dimensions

University of Wisconsin-Madison(威斯康星大学麦迪逊分校);University of Chicago(芝加哥大学)

Lili Zheng, Garvesh Raskutti, Rebecca Willett, Benjamin Mark

摘要:

高维自回归点过程模拟当前事件如何触发或抑制未来事件,例如社交网络中的一个成员的活动可以影响他或她的邻居的未来活动。虽然过去的工作主要集中在估计的基础网络结构的基础上,在网络的每个节点上发生的事件的时间,本文探讨了更微妙的问题,估计上下文相关的网络,反映如何与事件(如社交媒体的内容后)相关的功能调节节点之间的影响力的强度。具体来说,我们利用组合时间序列和正则化方法在机器学习的思想进行网络估计的高维标记点过程。两个模型和相应的估计被认为是详细的:自回归多项式模型适合于分类标记和逻辑正态模型适合于在不同类别的混合成员标记。重要的是,逻辑正态模型导致凸负对数似然目标,并捕获跨类别的依赖性。我们为这两个估计,我们验证模拟和合成数据生成模型提供理论保证。我们进一步验证我们的方法,通过两个真实的数据的例子,并展示了这两种方法的优点和缺点。

英文摘要:

High-dimensional autoregressive point processes model how current events trigger or inhibit future events, such as activity by one member of a social network can affect the future activity of his or her neighbors. While past work has focused on estimating the underlying network structure based solely on the times at which events occur on each node of the network, this paper examines the more nuanced problem of estimating context-dependent networks that reflect how features associated with an event (such as the content of a social media post) modulate the strength of influences among nodes. Specifically, we leverage ideas from compositional time series and regularization methods in machine learning to conduct network estimation for high-dimensional marked point processes. Two models and corresponding estimators are considered in detail: an autoregressive multinomial model suited to categorical marks and a logistic-normal model suited to marks with mixed membership in different categories. Importantly, the logistic-normal model leads to a convex negative log-likelihood objective and captures dependence across categories. We provide theoretical guarantees for both estimators, which we validate by simulations and a synthetic data-generating model. We further validate our methods through two real data examples and demonstrate the advantages and disadvantages of both approaches.

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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