A method of assigning a resource of a united system in which a plurality of single systems are complexly operated includes: determining a multi-user diversity order based on the quantity of users existing within the system; determining a cost function using the determined multi-user diversity order; and assigning a resource based on the determined cost function. A magnetic ring is provided near one end of the journal bearing forming an air bearing. A fluid passageway extends between the upper chamber and the lower chamber. A trimap is produced from the color image to define the color image into three distinct regions. In other implementations, the moving surfaces are operably associated with one or more resistance elements that effect the amount of force required to pivot or actuate the moving surfaces.