The Journal of the Operational Research Society, Vol. 55, No. 12 (Dec., 2004), pp. 1275-1280 (6 pages) The fixed-charge problem is a non-linear programming problem of practical interest in business ...

Inspired by a theoretical model of particles moving around on a chessboard, new robot swarm research shows that, as magnetic interactions increase, dispersed 'dumb robots' can abruptly gather in large ...