  We study the Kozai-Lidov mechanism in a hierarchical triple system in detail
by the direct integration of the first-order post Newtonian equations of
motion. We analyse a variety of models with a pulsar to evaluate the cumulative
shift of the periastron time of a binary pulsar caused by the gravitational
wave emission in a hierarchical triple system with Kozai-Lidov mechanism. We
compare our results with those by the double-averaging method. The deviation in
the eccentricity, even if small, is important in the evaluation of the emission
of the gravitational waves. We also calculate the cumulative shift of the
periastron time by using obtained osculating orbital elements. If Kozai-Lidov
oscillations occur, the cumulative shift curve will bend differently from that
of the isolated binary. If such a bending is detected through the radio
observation, it will be the first indirect observation of gravitational waves
from a triple system.
