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arXiv 2005.01058math.STstat.APstat.MEstat.TH
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依赖环境中的高斯线性模型选择

Gaussian linear model selection in a dependent context

Emmanuel Caron, Jérôme Dedecker, Bertrand Michel

摘要:

本文研究了非参数线性模型,当误差过程为相依高斯过程时。我们专注于通过模型选择方法的均值向量的估计。首先给出了罚函数的一般理论形式,保证了模型集合中的罚估计量满足一个预言不等式。然后,我们推导出一个惩罚形状涉及的协方差阵的误差,它可以选择成比例的尺寸时,误差过程是平稳的和短程相关的谱半径。然而,这种惩罚在某些情况下可能太粗糙,特别是当误差过程是长范围相关的时。在第二部分中,我们专注于固定设计的回归模型,假设误差过程是一个平稳的高斯过程。我们提出了一个模型选择过程,以估计平均函数通过分段多项式上的一个定期分区,当误差过程是短程依赖,长程依赖或反持续。我们提出了不同种类的处罚,这取决于内存的过程。对于每种情况下,建立一个自适应估计,并计算收敛速度。由于几组模拟,我们研究了所有类型的错误(短内存,长内存和反持久性错误)的这些不同的处罚的性能。最后,我们给出了我们的方法的应用程序,著名的尼罗河数据,这清楚地表明,必须考虑的误差过程的依赖类型。

英文摘要:

In this paper, we study the nonparametric linear model, when the error process is a dependent Gaussian process. We focus on the estimation of the mean vector via a model selection approach. We first give the general theoretical form of the penalty function, ensuring that the penalized estimator among a collection of models satisfies an oracle inequality. Then we derive a penalty shape involving the spectral radius of the covariance matrix of the errors, which can be chosen proportional to the dimension when the error process is stationary and short range dependent. However, this penalty can be too rough in some cases, in particular when the error process is long range dependent. In a second part, we focus on the fixed-design regression model assuming that the error process is a stationary Gaussian process. We propose a model selection procedure in order to estimate the mean function via piecewise polynomials on a regular partition, when the error process is either short range dependent, long range dependent or anti-persistent. We present different kinds of penalties, depending on the memory of the process. For each case, an adaptive estimator is built, and the rates of convergence are computed. Thanks to several sets of simulations, we study the performance of these different penalties for all types of errors (short memory, long memory and anti-persistent errors). Finally, we give an application of our method to the well-known Nile data, which clearly shows that the type of dependence of the error process must be taken into account.

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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