The signed John Shurna, a sweet-shooting forward from Northwestern, to a one-year contract, said his agent, Mark Bartelstein. The deal is partly guaranteed. Shurna, who stands 6 feet 10 inches, converted 44 percent of his 3-pointers last season at Northwestern while averaging 20 points a game. He is frequently compared to the Knicks’ Steve Novak because of his height and shooting ability. With Shurna, the Knicks have 16 players under contract, counting training camp invitees.