Using a simple model with link removals as well as link additions, we show
that an evolving network is scale free with a degree exponent in the range of
(2, 4]. We then establish a relation between the network evolution and a set of
non-homogeneous birth-and-death processes, and, with which, we capture the
process by which the network connectivity evolves. We develop an effective
algorithm to compute the network degree distribution accurately. Comparing
analytical and numerical results with simulation, we identify some interesting
network properties and verify the effectiveness of our method.