Nexstar extends contract of Gary Weitman, executive vice president-chief communications officer, for an unspecified multiyear term ... ECS, advanced technology, science and engineering solutions company, names Martin Klein, ex-DOD Joint Artificial Intelligence Center and a former ECS executive, vice president-analytics and AI ... Kofax, intelligent automation software provider, names Ceridian’s Jeff Hartnett senior vice president-sales, Americas ... Comcast promotes Tracy Pitcher to senior vice president-Comcast Business, at its Central Division headquarters in Atlanta ... Identiv, IoT security company, adds Software House founder John Moss as senior adviser ... Zayo, communications infrastructure provider, adds ex-interim PG&E CEO Bill Smith, also ex-BellSouth and AT&T, to its board ... Rivada Networks adds Michele Flournoy, undersecretary of defense under President Barack Obama, to its board.