arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.07160stat.ME
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聚集Hawkes过程参数估计的蒙特卡罗期望最大化算法

A Monte Carlo EM Algorithm for the Parameter Estimation of Aggregated Hawkes Processes

Leigh Shlomovich, Edward Cohen, Niall Adams, Lekha Patel

摘要:

从真实事件数据中产生的一个关键困难是事件时间戳记录的不精确性。在许多情况下,由于活动量太大,以高精度保留事件时间是昂贵的。加上测量准确性的实际限制,汇总数据是常见的。为了使用点过程来模拟这样的事件数据,用于处理参数估计的工具是必不可少的。在这里,我们考虑霍克斯过程的参数估计,霍克斯过程是一种自激点过程,已在金融股票市场,地震和社交媒体级联的建模中得到应用。提出了一种新的基于蒙特卡罗期望最大化(MC-EM)算法的聚合Hawkes过程参数估计优化方法。通过详细的模拟研究,我们证明了现有的方法是能够产生严重偏差和高度可变的参数估计,我们的新MC-EM方法显着优于他们在所有研究的情况下。这些结果突出了正确处理汇总数据的重要性。

英文摘要:

A key difficulty that arises from real event data is imprecision in the recording of event time-stamps. In many cases, retaining event times with a high precision is expensive due to the sheer volume of activity. Combined with practical limits on the accuracy of measurements, aggregated data is common. In order to use point processes to model such event data, tools for handling parameter estimation are essential. Here we consider parameter estimation of the Hawkes process, a type of self-exciting point process that has found application in the modeling of financial stock markets, earthquakes and social media cascades. We develop a novel optimization approach to parameter estimation of aggregated Hawkes processes using a Monte Carlo Expectation-Maximization (MC-EM) algorithm. Through a detailed simulation study, we demonstrate that existing methods are capable of producing severely biased and highly variable parameter estimates and that our novel MC-EM method significantly outperforms them in all studied circumstances. These results highlight the importance of correct handling of aggregated 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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