
Accession Number : AD0425901
Title : ESTIMATING THE CURRENT MEAN OF A NORMAL DISTRIBUTION WHICH IS SUBJECTED TO CHANGES IN TIME,
Corporate Author : STANFORD UNIV CALIF
Personal Author(s) : Chernoff,H. ; Zacks,S.
Report Date : 31 OCT 1963
Pagination or Media Count : 42
Abstract : A tracking problem is considered. Observations are taken on the successive positions of an object traveling on a path, and it is desired to estimate its current position. The objective is to arrive at a simple formula which implicitly accounts for possible changes in direction and discounts observations taken before the latest change. To develop a reasonable procedure, a simpler problem is studied. Successive observations are taken on n independently and normally distributed random variables X sub 1, X sub 2, ..., X sub n with means mu sub 1, mu sub 2, ..., mu sub n and variance 1. Each mean mu sub i is equal to the preceding mean mu sub (i1) except when an occasional change takes place. The object is to estimate the current mean mu sub n. This problem is studied from a Bayesian point of view. An 'ad hoc' estimator is described, which applies a combination of the A.M.O.C. Bayes estimator and a sequence of tests designed to locate the last time point of change. The various estimators are then compared by a Monte Carlo study of samples of size 9. This Bayesian approach seems to be more appropriate for the related problem of testing whether a change in mean has occurred. This test procedure is simpler than that used by Page. The power functions of the two procedures are compared. (Author)
Descriptors : (*TRAJECTORIES, MATHEMATICAL PREDICTION), (*TRACKING, STATISTICAL DISTRIBUTIONS), TIME, PROBABILITY, STATISTICAL ANALYSIS, MONTE CARLO METHOD, DISTRIBUTION THEORY, DETERMINANTS(MATHEMATICS), ANALYSIS OF VARIANCE, STATISTICAL TESTS
Distribution Statement : APPROVED FOR PUBLIC RELEASE