CORNING - Public television personality Jean Shepherd comes to Corning Community College for a 1 p.m. lecture performance Thursday in the college's gymnasium. Shepherd's nightly radio show on New York's WOR and his contributions for "Playboy" combined to make him a legend on the eastern seaboard. His program, Jean Shepherd's America, for the public television system was returned to the air by public demand, and recently completed its fourth showing. Shepherd was born in the mid-west, where he worked summers as a sports announcer before going into the Signal Corps from 1944-46. After attending Northwestern University, the University of Chicago, and finally Indiana University without graduating, he became a radio commentator in Cincinnati and later in Philadelphia.