  Using the method proposed in a previous paper, we calculate pulsar braking
indices in the models with torque contributions from both inner and outer
accelerating regions, assuming that the interaction between them is negligible.
We suggest that it is likely that the inverse Compton scattering induced polar
vacuum gap and the outer gap coexist in the pulsar magnetosphere. We include
the new near threshold vacuum gap models with curvature-radiation and inverse
Compton scattering induced cascades, respectively; and find that these models
can well reproduce the measured values of the braking indices.
