title: Threshold Digraphs.
abstract: A digraph whose degree sequence has a unique vertex labeled realization is called threshold. In this paper we present several characterizations of threshold digraphs and their degree sequences, and show these characterizations to be equivalent. Using this result, we obtain a new, short proof of the Fulkerson-Chen theorem on degree sequences of general digraphs.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.
authors.forename: Brian
authors.initials: B
authors.lastname: Cloteaux
authors.affiliation: The College of William and Mary, Williamsburg, VA 23185.
authors.forename: M Drew
authors.initials: MD
authors.lastname: LaMar
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Moseman
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.
authors.forename: James
authors.initials: J
authors.lastname: Shook
keywords: Fulkerson-Chen theorem; digraph realizations; threshold digraphs