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arXiv 2104.07932cs.LGcs.CEstat.ML
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区间删失Hawkes过程

Interval-censored Hawkes processes

University of Technology Sydney(悉尼科技大学);The Australian National University(澳大利亚国立大学);Concordia University(康考迪亚大学);Google Research(谷歌研究院)

Marian-Andrei Rizoiu, Alexander Soen, Shidi Li, Pio Calderon, Leanne Dong, Aditya Krishna Menon, Lexing Xie

摘要:

区间删失数据仅记录特定时间间隔内事件的汇总计数-例如入院的患者数量或通过交通环路检测器的车辆数量-而不是事件的确切发生时间。目前还不清楚如何将Hawkes点过程拟合到这种数据。其典型的损失函数(点过程对数似然)不能计算没有确切的事件时间。此外,它不具有独立增量性质来使用泊松似然。这项工作建立了一个新的点过程,一套工具,并在区间删失数据的情况下拟合霍克斯过程的近似。首先,我们定义了平均行为泊松过程(MBPP),一个新的泊松过程与流行的自激霍克斯过程的直接参数对应。我们适合MBPP在区间删失设置使用区间删失泊松对数似然(IC-LL)。我们使用参数等价来揭示相关的Hawkes过程的参数。其次,我们引入了两个新的外生函数来区分外生事件和内生事件。我们提出了多脉冲外源函数-当外源事件被观察到的事件时间-和潜在的齐次泊松过程外源函数-当外源事件被呈现为区间删失量。第三,当没有解析解时,我们给出了几种近似方法来估计MBPP的强度和补偿函数。第四,也是最后,我们将MBPP的区间删失与一类更广泛的基于Bregman发散的函数联系起来。使用的连接,我们表明,流行度估计算法霍克斯强度过程(HIP)是MBPP的一个特殊情况。我们通过对合成数据和真实数据的实证检验来验证我们的模型。

英文摘要:

Interval-censored data solely records the aggregated counts of events during specific time intervals - such as the number of patients admitted to the hospital or the volume of vehicles passing traffic loop detectors - and not the exact occurrence time of the events. It is currently not understood how to fit the Hawkes point processes to this kind of data. Its typical loss function (the point process log-likelihood) cannot be computed without exact event times. Furthermore, it does not have the independent increments property to use the Poisson likelihood. This work builds a novel point process, a set of tools, and approximations for fitting Hawkes processes within interval-censored data scenarios. First, we define the Mean Behavior Poisson process (MBPP), a novel Poisson process with a direct parameter correspondence to the popular self-exciting Hawkes process. We fit MBPP in the interval-censored setting using an interval-censored Poisson log-likelihood (IC-LL). We use the parameter equivalence to uncover the parameters of the associated Hawkes process. Second, we introduce two novel exogenous functions to distinguish the exogenous from the endogenous events. We propose the multi-impulse exogenous function - for when the exogenous events are observed as event time - and the latent homogeneous Poisson process exogenous function - for when the exogenous events are presented as interval-censored volumes. Third, we provide several approximation methods to estimate the intensity and compensator function of MBPP when no analytical solution exists. Fourth and finally, we connect the interval-censored loss of MBPP to a broader class of Bregman divergence-based functions. Using the connection, we show that the popularity estimation algorithm Hawkes Intensity Process (HIP) is a particular case of the MBPP. We verify our models through empirical testing on synthetic data and real-world data.

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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