An Accelerated-Time Model for Response Curves
提出一种非参数方法分析曲线样本数据,假设观测曲线是基础随机过程的加速时间版本,加速因子是协变量的光滑函数,并通过交叉验证估计模型成分,以果蝇死亡率时间过程为例。
Abstract We propose a nonparametric method of data analysis for situations where the data consist of a sample of curves and a covariate is present. We assume the observed curves to be time-accelerated versions of a basic underlying stochastic process and assume the time acceleration factor for each observed process, determining the “eigenzeit,” to be a smooth function of the covariate. We discuss an iterative procedure to estimate the components of the model nonparametrically, using cross-validation to determine smoothing parameters using a leave-one-curve-out technique. Our example concerns time courses of mortality for a sample of cohorts of fruit flies.