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arXiv 2109.09692cs.LGstat.ML
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多时间序列中的状态转换模型

Modeling Regime Shifts in Multiple Time Series

University of Sherbrooke(舍布鲁克大学);University of Quebec at Montreal(魁北克大学蒙特利尔分校)

Etienne Gael Tajeuna, Mohamed Bouguessa, Shengrui Wang

摘要:

我们调查的问题,发现和建模政权转移的生态系统包括多个时间序列称为共同发展的时间序列。区系转换是指序列在不同时间间隔内表现出的变化行为。学习这些变化的行为是时间序列预测的关键一步。虽然已经取得了进展,但现有方法存在以下缺点中的一个或多个:(1)未能考虑时间序列之间的关系以发现多个时间序列中的状态;(2)缺乏对序列所表现出的时间依赖行为进行建模的有效方法;(3)难以处理可能是信息性的数据不连续性。现有的大多数方法无法在一个统一的框架内处理这三个问题。因此,这促使我们努力设计一个原则性的方法来建模相互作用和时间依赖性的共同发展的时间序列。具体来说,我们通过将大量的时间序列集合总结成一个更轻、更有意义的结构(称为\textit{mapping grid})来对多个时间序列的生态系统进行建模。通过使用映射网格,我们的模型首先通过动态网络表示来学习时间序列行为依赖关系,然后通过完全时间依赖的Cox回归模型来学习状态转换机制。我们的方法的独创性在于在政权识别的时间序列之间的相互作用建模和建模时间依赖的政权转移概率,通常假设是静态的现有工作。

英文摘要:

We investigate the problem of discovering and modeling regime shifts in an ecosystem comprising multiple time series known as co-evolving time series. Regime shifts refer to the changing behaviors exhibited by series at different time intervals. Learning these changing behaviors is a key step toward time series forecasting. While advances have been made, existing methods suffer from one or more of the following shortcomings: (1) failure to take relationships between time series into consideration for discovering regimes in multiple time series; (2) lack of an effective approach that models time-dependent behaviors exhibited by series; (3) difficulties in handling data discontinuities which may be informative. Most of the existing methods are unable to handle all of these three issues in a unified framework. This, therefore, motivates our effort to devise a principled approach for modeling interactions and time-dependency in co-evolving time series. Specifically, we model an ecosystem of multiple time series by summarizing the heavy ensemble of time series into a lighter and more meaningful structure called a \textit{mapping grid}. By using the mapping grid, our model first learns time series behavioral dependencies through a dynamic network representation, then learns the regime transition mechanism via a full time-dependent Cox regression model. The originality of our approach lies in modeling interactions between time series in regime identification and in modeling time-dependent regime transition probabilities, usually assumed to be static in existing work.

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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