This paper investigates the second order properties of a stationary process after random sampling. While a short memory process gives always rise to a short memory one, we prove that long-memory can disappear when the sampling law has heavy enough tails. We prove that under rather general conditions the existence of the spectral density is preserved by random sampling. We also investigate the effects of deterministic sampling on seasonal long-memory.
Robust Forecasting of Sequences with Periodically Stationary Long Memory Multiplicative Seasonal Increments Observed with Noise and Cointegrated Sequences
A generalized portmanteau test of independence between two stationary time series
我们提出了在频域中的广义波特曼托型检验统计量来检验两个平稳时间序列之间的独立性。检验统计量的形成类似于Chen和Deo(2004,Econometric Theory 20,382-416)中的一个,他们将组合拟合优度检验的适用性扩展到长记忆情况。在独立性的原假设下,在相当温和的条件下,得到了该统计量的渐近标准正态分布。特别地,允许每个时间序列具有短记忆、长记忆或反持续性。仿真研究表明,测试具有合理的规模和功率特性。
Adaptive estimator of the memory parameter and goodness-of-fit test using a multidimensional increment ratio statistic
在Surgailis { \it et al.}中首次定义并研究了增量比(IR)统计量。(2007)用于估计平稳或增量平稳高斯过程的记忆参数。在这里,提出了三个扩展的情况下,平稳过程。首先对由多个IR统计量组成的向量建立了多维中心极限定理。其次,可以从该定理推导出拟合优度$χ^2$型检验。最后,这一定理允许构建自适应版本的估计和测试,研究在一般的半参数框架。证明了长记忆参数的自适应估计具有预言性质。模拟证明了有趣的准确性和鲁棒性的估计和测试,即使在非高斯的情况下。
Sampling from the Mean-Field Stationary Distribution
Institute for Advanced Study(高等研究院);University of Toronto(多伦多大学);Vector Institute(矢量研究所);Princeton University(普林斯顿大学);Georgia Institute of Technology(佐治亚理工学院)