Extracting Gromov-Witten invariants of a conifold from semi-stable   reduction and relative GW invariants of pairs
  The study of open/closed string duality and large $N$ duality suggests a Gromov-Witten theory for conifolds that sits on the border of both a closed Gromov-Witten theory and an open Gromov-Witten theory. In this work we employ the result of Jun Li on Gromov-Witten theory for a projective singular variety of the gluing form $Y_1\cup_D Y_2$ to extract Gromov-Witten invariants of a conifold. 
Chien-Hao Liu and Shing-Tung Yau