A system may include several nodes coupled by in inter-node network. A primary fluid layer is formed on an anchoring substrate. The replacement software system is prepared to take control of the active processing element when state information is communicated to it from the original software system. The magnetic pole center is a center of a magnetic pole in a circumferential direction with respect to a rotation axis. The filtering apparatus of filter regulator can be used with one or more spray guns or in a spraying system.