  Recently, one has seen a surge of interest in developing such methods
including ones for learning such representations for (undirected) graphs (while
preserving important properties). However, most of the work to date on
embedding graphs has targeted undirected networks and very little has focused
on the thorny issue of embedding directed networks. In this paper, we instead
propose to solve the directed graph embedding problem via a two-stage approach:
in the first stage, the graph is symmetrized in one of several possible ways,
and in the second stage, the so-obtained symmetrized graph is embedded using
any state-of-the-art (undirected) graph embedding algorithm. Note that it is
not the objective of this paper to propose a new (undirected) graph embedding
algorithm or discuss the strengths and weaknesses of existing ones; all we are
saying is that whichever be the suitable graph embedding algorithm, it will fit
in the above proposed symmetrization framework.
