Renewal Theory and Some Applications (2006)

by Norman Matloff.

Supposre a certain lamp is used continuously, and that whenever its bulb burns out, it is immediately replaced by a new one. Let N(t) denote the number of replacements, called renewals here, that have occurred up through time t. Assume the lifetimes of the bulbs, L1, L2, L3, ... are independent and identically distributed. The collection of random variables N(t),t ≥ 0 is called a renewal process. The quantities Ri = L1 +...+Li are called the renewal points. [via]

http://heather.cs.ucdavis.edu/~matloff/256/Pe...