  We analyze a sample of bright long bursts and find that the pulses duration
have a lognormal distribution while the intervals between pulses have an excess
of long intervals (relative to lognormal distribution). This excess can be
explained by the existence of quiescent times, long periods with no signal
above the background. The lognormal distribution of the intervals (excluding
the quiescent times) is similar to the distribution of the pulses width. This
result suggests that the quiescent times are made by a different mechanism than
the rest of the intervals. It also suggests that the intervals (excluding the
quiescent times) and the pulse width are connected to the same parameters of
the source. We find that there is a correlation between a pulse width and the
duration of the interval preceding it. There is a weaker, but still a
significant, correlation between a pulse width and the interval following it.
The significance of the correlation drops substantially when the intervals
considered are not adjacent to the pulse.
