基于HSIC-GL的多元时间序列非线性Granger因果关系分析

Nonlinear Granger Causality Analysis for Multivariate Time Series Using HSIC-GL Model

  • 摘要: 因果分析是数据挖掘领域重要的研究课题之一.由于传统的Granger因果模型难以准确识别多变量系统的非线性因果关系,本文提出一种基于Hilbert-Schmidt独立性准则(Hilbert-Schmidt independence criterion,HSIC)的组Lasso模型的Granger因果分析方法.首先,利用HSIC将输入样本和输出样本映射到再生核Hilbert空间,克服了传统的Granger因果模型不能应用于非线性系统的缺陷.然后,建立具有组Lasso约束的回归模型,对多变量及其组派生变量进行因果分析,并采用贝叶斯信息准则进行模型选择,避免了人为设置滞后阶数和正则化参数.最后,根据HSIC-GL模型的回归系数和显著性检验结果,实现了多变量时间序列之间的非线性因果分析.通过对非线性和混沌系统的仿真实验,验证了该方法的有效性.最后将其应用于沈阳空气质量指数(AQI)和气象时间序列的因果关系分析.

     

    Abstract: Causality analysis is an important research topics in the field of data mining, but traditional Granger causality models have difficulty accurately identifying the nonlinear causality of multivariable systems. We propose a novel Granger causality analysis method based on the HSIC and group Lasso (HSIC-GL) model. Firstly, we use the Hilbert-Schmidt independence criterion (HSIC) to map the input and output samples into the Hilbert space of the reproducing kernel, which overcomes the inability to apply the traditional Granger causality model to nonlinear systems. Then, we establish a regression model with group Lasso constraints, which implements a causality analysis between multivariate and group-derived variables. The Bayesian information criterion is used for model selection, which prevents the artificial setting of the lag order and regularization parameters. Lastly, based on the regression coefficients and the results of significance tests of the HSIC-GL model, a nonlinear causality analysis is performed on the multivariable time series. The effectiveness of the proposed method is verified by the results of simulations of nonlinear and chaotic systems. We successfully applied this method to the air quality index and meteorological time series in Shenyang, China.

     

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