Decay time is the number of milliseconds between decay events.
Touch value is the value that each URL will receive if it is hit in the log. (The value a URL will receive in count when someone browses to the URL.)
Decay equation is the equation that controls how the
count field is updated every time there is a decay event. The
variable decay will take on the value 1, 2, 3, 4, ..., n
for every time a decay event has occurred for this URL. If a URL is
touched (visited) again decay will reset to 1, and of
course the count field is updated with Touch value. If
the count field reaches 0 or below, the URL is removed from the table.