Winged via structures to increase overlay margin are generally described. A three-dimensional image generator is provided that generates data on the virtual space image seen from a viewpoint indicated by the viewpoint position information and outputting a three dimensional image to the display. The method identifies jammed channels by applying a boxcar filter, in order to identify narrow peaks in the spectrum that are substantially larger in magnitude than adjacent channels. The outer shaft as well as the inner shaft are rotatable by the adjuster and are rotatable relative to one another by the adjuster such that relative positions of given cams controlling given ones of the intake and exhaust valves are changeable. Other embodiments are described and claimed.