“…An air crash was caused by bearing failure resulting from damage to the cage supporting the bearing balls (Smalley, Baldwin, Mauney, & Millwater, 1996). The reports (Kalkat, Yildirim, & Uzmay, 2005;Sun, Chen, & Li, 2007) have clearly described the fault diagnosis of rotational mechanical system which focused on faulty shaft. Vibration-based monitoring techniques, both in the time and frequency domains, have been widely used for detection and diagnosis of bearing defects for several decades.…”