arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.04214stat.ME
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基于小波的时间序列模型鲁棒两步推理

Robust Two-Step Wavelet-Based Inference for Time Series Models

Stéphane Guerrier, Roberto Molinari, Maria-Pia Victoria-Feser, Haotian Xu

摘要:

复杂的时间序列模型,例如具有附加噪声、随机游动、舍入误差和/或漂移的ARMA $(p,q)$模型(之和),越来越多地用于在诸如生物学、生态学、工程学和经济学等领域中的数据分析,其中所观察到的信号的长度可能非常大。对这些模型进行推断和/或从这些模型进行预测可能是非常具有挑战性的,原因有几个:(i)数据可能包含可能对估计过程产生不利影响的离群值;(ii)当模型包括不止几个参数和/或时间序列很大时,计算复杂度可能变得过高;(iii)模型构建和/或选择为先前的任务增加了另一层(计算)复杂性;以及(iv)同时解决(i)、(ii)和(iii)的解决方案在实践中不存在。出于这个原因,本文的目的是共同应对这些挑战,提出了一个总体框架,稳健的两步估计的基础上有界影响M估计的小波方差。在这个角度来看,我们首先开发的联合渐近正态性的条件,后者估计,从而提供必要的工具来执行(直接)推理基于尺度的信号分析。利用模型独立的第一步估计的权重,只计算一次,然后我们开发的渐近性质的两步鲁棒估计使用的框架的广义小波矩方法(GMWM),因此定义的鲁棒GMWM(RGMWM),我们然后使用鲁棒模型估计和推理的计算效率的方式,即使是大的时间序列。仿真研究表明,良好的有限样本性能的RGMWM估计和应用的例子突出了所提出的方法的实际意义。

英文摘要:

Complex time series models such as (the sum of) ARMA$(p,q)$ models with additional noise, random walks, rounding errors and/or drifts are increasingly used for data analysis in fields such as biology, ecology, engineering and economics where the length of the observed signals can be extremely large. Performing inference on and/or prediction from these models can be highly challenging for several reasons: (i) the data may contain outliers that can adversely affect the estimation procedure; (ii) the computational complexity can become prohibitive when models include more than just a few parameters and/or the time series are large; (iii) model building and/or selection adds another layer of (computational) complexity to the previous task; and (iv) solutions that address (i), (ii) and (iii) simultaneously do not exist in practice. For this reason, this paper aims at jointly addressing these challenges by proposing a general framework for robust two-step estimation based on a bounded influence M-estimator of the wavelet variance. In this perspective, we first develop the conditions for the joint asymptotic normality of the latter estimator thereby providing the necessary tools to perform (direct) inference for scale-based analysis of signals. Taking advantage of the model-independent weights of this first-step estimator that are computed only once, we then develop the asymptotic properties of two-step robust estimators using the framework of the Generalized Method of Wavelet Moments (GMWM), hence defining the Robust GMWM (RGMWM) that we then use for robust model estimation and inference in a computationally efficient manner even for large time series. Simulation studies illustrate the good finite sample performance of the RGMWM estimator and applied examples highlight the practical relevance of the proposed approach.

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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