  Langevin dynamics simulations of the vortex matter in the highly-anisotropic
high-temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_8$ were performed. We
introduced point defects as a smoothened distribution of a random potential.
Both the electromagnetic and Josephson interactions among pancake vortices were
included. A special shaking and annealing process was introduced to let the
system approach the equilibrium configuration. We are able to see the inverse
melting transition from the Bragg-glass to the amorphous vortex glass state, in
agreement with recent experiments.
