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arXiv physics/0111103physics.data-ancond-mat
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非平稳性对去趋势波动分析的影响

Effect of nonstationarities on detrended fluctuation analysis

Zhi Chen, Plamen Ch. Ivanov, Kun Hu, H. Eugene Stanley

摘要:

去趋势波动分析(DFA)是一种尺度分析方法,用于量化信号中的长程幂律相关性。许多物理和生物信号是“噪声”,异质性和表现出不同类型的非平稳性,这可能会影响这些信号的相关性。我们系统地研究了在实际数据中经常遇到的三种类型的非平稳性的影响。具体地说,我们考虑以三种方式形成的非平稳序列:(i)将从不连续的实验记录中获得的数据段拼接在一起,或者从连续记录中去除一些噪声和不可靠的部分,并将剩余的部分拼接在一起--这是一种通常用于在信号分析之前准备数据的“切割”过程;(ii)向具有已知相关性的信号添加具有不同幅度的随机异常值或尖峰的可调浓度,以及(iii)生成包括具有不同属性(例如,不同标准偏差或不同相关指数)的段的信号。我们比较了平稳相关信号和这三种非平稳相关信号的标度结果之间的差异。

英文摘要:

Detrended fluctuation analysis (DFA) is a scaling analysis method used to quantify long-range power-law correlations in signals. Many physical and biological signals are ``noisy'', heterogeneous and exhibit different types of nonstationarities, which can affect the correlation properties of these signals. We systematically study the effects of three types of nonstationarities often encountered in real data. Specifically, we consider nonstationary sequences formed in three ways: (i) stitching together segments of data obtained from discontinuous experimental recordings, or removing some noisy and unreliable parts from continuous recordings and stitching together the remaining parts -- a ``cutting'' procedure commonly used in preparing data prior to signal analysis; (ii) adding to a signal with known correlations a tunable concentration of random outliers or spikes with different amplitude, and (iii) generating a signal comprised of segments with different properties -- e.g. different standard deviations or different correlation exponents. We compare the difference between the scaling results obtained for stationary correlated signals and correlated signals with these three types of nonstationarities.

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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