Data Collection for the Sloan Digital Sky Survey—A Network-Flow Heuristic
Robert H. Lupton, F. Miller Maley, Neal E. Young · Journal of Algorithms · 1998
This paper describes an NP-hard combinatorial optimization problem arising in the Sloan Digital Sky Survey and a practical approximation algorithm that has been implemented and will be used in the survey. The algorithm is based on network flow theory and Lagrangian relaxation.