arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1609.00286math.STstat.TH
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基于PCA的函数线性回归估计

PCA-based estimation for functional linear regression with functional responses

Masaaki Imaizumi, Kengo Kato

摘要:

本文研究了预测变量和响应变量均为随机函数的回归模型。我们考虑一个泛函线性模型,其中响应变量在每个时间点的条件均值由预测变量的线性泛函给出。在本文中,我们感兴趣的条件期望算子的积分核$b(s,t)$的估计,其中$s$是一个输出变量,而$t$是一个变量,与预测变量相互作用。这个问题是一个不适定的反问题,我们考虑两个估计的基础上的功能主成分分析(PCA)。我们证明了在适当的正则性条件下,基于单截断的估计量对于积分平方误差的收敛速度是由$t$中的函数$b (s,t)$的光滑性以及协方差算子特征值的衰减率所表征的,但该收敛速度不依赖于$s$中的$b(s,t)$的光滑性.该速率被证明是极小极大最优的,因此$s$中$b(s,t)$的平滑度不会影响估计$b$的难度。我们还考虑了另一种估计的基础上的双重截断,并提供了条件下的替代估计达到最佳率。我们进行模拟,以验证性能PCA为基础的估计在有限样本。最后,我们应用我们的估计调查的工作时间和总收入的生命周期模式之间的关系,以及电力现货价格和风力发电馈电之间的关系。

英文摘要:

This paper studies a regression model where both predictor and response variables are random functions. We consider a functional linear model where the conditional mean of the response variable at each time point is given by a linear functional of the predictor variable. In this paper, we are interested in estimation of the integral kernel $b(s,t)$ of the conditional expectation operator, where $s$ is an output variable while $t$ is a variable that interacts with the predictor variable. This problem is an ill-posed inverse problem, and we consider two estimators based on the functional principal component analysis (PCA). We show that under suitable regularity conditions, an estimator based on the single truncation attains the convergence rate for the integrated squared error that is characterized by smoothness of the function $b (s,t)$ in $t$ together with the decay rate of the eigenvalues of the covariance operator, but the rate does not depend on smoothness of $b(s,t)$ in $s$. This rate is shown to be minimax optimal, and consequently smoothness of $b(s,t)$ in $s$ does not affect difficulty of estimating $b$. We also consider an alternative estimator based on the double truncation, and provide conditions under which the alternative estimator attains the optimal rate. We conduct simulations to verify the performance of PCA-based estimators in the finite sample. Finally, we apply our estimators to investigate the relation between the lifetime pattern of working hours and total income, and the relation between the electricity spot price and the wind power infeed.

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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