A fence rail clip for attaching a fence rail to a vertical fence post is disclosed. The preferred embodiment utilizes a sweep mode function to provide frequency compensation over a range of frequency drift broader than the frequency drift accommodated by a phase lock loop, without increasing the noise characteristics of the phase lock loop. The closure further comprises an anti-crush rib for seating on a container top wall and preventing crushing of the container neck. DNS may be applied in a DAC, by adaptively selecting one or more of a plurality DAC elements in the DAC and switching off the selected one or more of the plurality DAC elements such that the selected one or more of the plurality DAC elements do not contribute to generating an output of the DAC. The performance of these behavior experts is compared with various objective functions.