Multiresolution analysis of point processes and statistical thresholding for Haar wavelet-based intensity estimation

Autor: Youssef Taleb, Edward A. K. Cohen
Rok vydání: 2020
Předmět:
Zdroj: Annals of the Institute of Statistical Mathematics. 73:395-423
ISSN: 1572-9052
0020-3157
Popis: We take a wavelet based approach to the analysis of point processes and the estimation of the first order intensity under a continuous time setting. A Haar wavelet multiresolution analysis of a point process is formulated which motivates the definition of homogeneity at different scales of resolution, termed $J$-th level homogeneity. Further to this, the activity in a point process' first order behavior at different scales of resolution is also defined and termed $L$-th level innovation. Likelihood ratio tests for both these properties are proposed with asymptotic distributions provided, even when only a single realization of the point process is observed. The test for $L$-th level innovation forms the basis for a collection of statistical strategies for thresholding coefficients in a wavelet based estimator of the intensity function. These thresholding strategies outperform the existing local hard thresholding strategy on a range of simulation scenarios. The presented methodology is applied to NetFlow data to demonstrate its effectiveness at characterizing multiscale behavior on computer networks.
Databáze: OpenAIRE