An array of sensor elements is formed by the incorporation of sensing materials into porous structures, creating sensing systems with extremely large surface areas with sensing molecules attached to mimic the large number of cilia of an olfactory system. The hub has an inner surface that surrounds an axis and defines a bore. The redundant frame determination module determines whether a target frame is a redundant frame based on the motion vectors corresponding to the target frame and the motion vectors corresponding to a frame preceding the target frame. An observation apparatus for collecting observation data and an optical correction system for effecting optical correction are provided on the second frame. The decoded channel, time and length information can be communicated directly to a VCR and used by the VCR directly to automatically activate the VCR to record a given television information broadcast corresponding to the communicated channel, time and length. The zero current detector includes a temperature compensation unit to control a responsivity of the zero current detector which not influenced by temperature change.