  In this paper, we address a class of distributed optimization problems in the
presence of inter-agent communication delays based on passivity. We first focus
on unconstrained distributed optimization and provide a passivity-based
perspective for distributed optimization algorithms. This perspective allows us
to handle communication delays while using scattering transformation. Moreover,
we extend the results to constrained distributed optimization, where it is
shown that the problem is solved by just adding one more feedback loop of a
passive system to the solution of the unconstrained ones. We also show that
delays can be incorporated in the same way as the unconstrained problems.
Finally, the algorithm is applied to a visual human localization problem using
a pedestrian detection algorithm.
