Computing has been evolving from a standalone device to a massive network of devices. This results in a distributed system running over, sometimes, millions of individual computing devices; e.g., sensor network in battle field, P2P, etc. How would you define, mathmatically, the computing power of such systems? (Traditional Turing theory adopts a hierachy of computing power such as: finite automata, pda, Turing Machine; in parallel, we have regular, context-free, recursive, r.e., for the problems hierachy.)