Level Crossing Analysis of Growing surfaces
  We investigate the average frequency of positive slope $\nu_{\alpha}^{+} $, crossing the height $\alpha = h- \bar h$ in the surface growing processes. The exact level crossing analysis of the random deposition model and the Kardar-Parisi-Zhang equation in the strong coupling limit before creation of singularities are given. 
F. Shahbazi, S. Sobhanian, M. Reza Rahimi Tabar, S. Khorram, G.R.   Frootan and H.Zahed