A test of sphericity for high-dimensional data and its application for detection of divergently spiked noise

In this paper, we study two-stage and sequential sampling procedures for estimating the rth power of the exponential scale parameter, i.e., βr, where the fixed-width confidence interval is considered. The exact operating characteristics of sequential procedures for fixed-width, 2δ (δ>0), confidence interval estimation is given. We show that the results of Zacks (2009 Zacks, S. (2009). The Exact Distributions of the Stopping Times and Their Functionals in Two-Stage and Sequential Fixed-Width Confidence Intervals of the Exponential Parameter, Sequential Analysis 28: 69–81.[Taylor & Francis Online] , [Google Scholar]), for two-stage and sequential procedures, can be deduced from our general results