On the Time and the Excess of Linear Boundary Crossings of Sample Sums
Kao, Chung-Siung
Ann. Statist., Tome 6 (1978) no. 1, p. 191-199 / Harvested from Project Euclid
For an infinite sequence of independent and identically distributed random variables $X, X_1, X_2,\cdots; X_n,\cdots$ for which $EX = 0$ and $\operatorname{Var} X = 1$, the behavior of crossings that $S_n = \sum_{1\leqq k\leqq n} X_k \geqq n\varepsilon (\varepsilon > 0)$ for some $n \geqq 1$ has recently been under intensive investigation, of which the subject matters are the largest excess $Z = \sup_{n\geqq 1} (S_n - n\varepsilon)^+$, the last time $M = \sup \{n; S_n \geqq n\varepsilon, 1 \leqq n < \infty\}$, or $= 0$ if no such $\sup$ exists, and the number of crossings $N = \sum_{1\leqq n<\infty} I\{S_n \geqq n\varepsilon\}$ ($I$ means the indicator function). This paper describes a striking distributional similarity between $\varepsilon^2N$ and $\varepsilon^2(M - N)$ in the limiting sense as $\varepsilon \rightarrow 0$. Moreover, a new and systematic treatment for the moments problem unifies the previously published results as well as giving some new results. Existence of the limiting moments as $\varepsilon \rightarrow 0$ and of the moment generating function is also considered in detail. Most of the results for the one-sided crossings (i.e., $S_n \geqq n\varepsilon$) are then extended to cover their analogues in two-sided crossings (i.e., $|S_n| \geqq n\varepsilon)$.
Publié le : 1978-01-14
Classification:  Sample sums,  linear boundary crossings,  largest excess,  last time,  total number,  limiting distribution,  limiting moments,  moment generating functions,  60F10,  60F15,  60G50
@article{1176344078,
     author = {Kao, Chung-Siung},
     title = {On the Time and the Excess of Linear Boundary Crossings of Sample Sums},
     journal = {Ann. Statist.},
     volume = {6},
     number = {1},
     year = {1978},
     pages = { 191-199},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1176344078}
}
Kao, Chung-Siung. On the Time and the Excess of Linear Boundary Crossings of Sample Sums. Ann. Statist., Tome 6 (1978) no. 1, pp.  191-199. http://gdmltest.u-ga.fr/item/1176344078/