Author/Authors :
Di Giacomo، نويسنده , , Emilio and Liotta، نويسنده , , Giuseppe and Meijer، نويسنده , , Henk and Wismath، نويسنده , , Stephen K.، نويسنده ,
Abstract :
This paper studies the problem of drawing directed acyclic graphs in three dimensions in the straight-line grid model so that all directed edges are oriented in a common (upward) direction. We show that there exists a family of outerplanar directed acyclic graphs whose volume requirement is super-linear. We also prove that for the case of directed trees a linear-volume upper bound is achievable.
