A note on optimal detection of a change in distribution

成果类型:
Article
署名作者:
Yakir, B
署名单位:
Hebrew University of Jerusalem
刊物名称:
ANNALS OF STATISTICS
ISSN/ISSBN:
0090-5364
DOI:
10.1214/aos/1069362390
发表日期:
1997
页码:
2117-2126
关键词:
摘要:
Suppose X-1, X-2,..., Xv-1 are lid random variables with distribution F-0, and X-v, Xv+1,... are are lid with distributed F-1. The change point v is unknown. The problem is to raise an alarm as soon as possible after the distribution changes from F-0 to F-1 (detect the change), but to avoid false alarms. Pollak found a version of the Shiryayev-Roberts procedure to be asymptotically optimal for the problem of minimizing the average run length to detection over all stopping times which satisfy a given constraint on the rate of false alarms. Here we find that this procedure is strictly optimal for a slight reformulation of the problem he considered. Explicit formulas are developed for the calculation of the average run length (both before and after the change) for the optimal stopping time.