In facsimile, a frequency modulationsystem where one frequency represents picture black and another frequency represents picture white[?]. Frequencies between these two limits may represent shades of gray
An intentional frequency change used for modulation purposes
... Hegelian tradition as a whole. In the great division of the Hegelian school, he, in company with Michelet and others, formed the "centre," midway between Erdmann and Gabler ...