In an issue of Interfaces from a few years back was the Edelman-award winning work by Eva Lee and Marco Zaider on using O.R. in cancer treatments. The basic IP model chooses voxels for radiation targeting. The goal is to radiate as much of the cancerous portion while avoiding the healthy areas. The radiation spreading has a 1/r^2 intensity profile, i.e. the intensity of radiation falls off with the square of the distance from the target. Many other wave propagating phenomena follow the same behavior. So I realized that the formulation of a light optimization capstone we ran a couple of years ago (written up here), was similar in this way. In our problem, locations for lights are chosen to meet room illumination threshold standards while minimizing bulb cost, power usage, or a combination of the two. The targets in our model are the classroom desks. I am guessing this problem has come up in many ways in many areas. Maybe it even has a name? Do you know?