The NBI matrix model of IIB Superstrings
  We investigate the NBI matrix model with the potential $X\Lambda+X^{-1}+(2\eta+1)\log X$ recently proposed to describe IIB superstrings. With the proper normalization, using Virasoro constraints, we prove the equivalence of this model and the Kontsevich matrix model for $\eta\ne0$ and find the explicit transformation between the two models. 
J. Ambj{\o}rn and L. Chekhov