The present invention relates to the usage pattern, commonly found in many software applications, of defining sets of objects based on object attributes. Due to the predetermined amounts of the additional components, the ferrite material has an extremely good temperature characteristic, a high quality coefficient Q and high strength. The acquired image is corrected using the optimal correction function h. The computer-based imaging system can be further replaced by a compact and low-cost imaging circuit that functions reliably in a buoy with relatively low power consumption. The present invention uses the initial steps of a sol-gel process to assist in preparation of MR fluids that have significantly enhanced stability and redispersibility, without the use of ceramic particles such as silica or bridging polymers such as PVP.