Who is Judge Fang from The Diamond Age, or, Young Lady's Illustrated Primer and what is their importance?

Judge Fang is a judge in his early thirties, originally from New York. He is a magistrate in the Confucian clave of the Coastal Republic, located in Shanghai. Working closely with his two assistants, he sentences Bud to death after he attacked a member of the Ashanti tribe. He later serves as judge in the trial of one of the members of the street gang that committed the unreported attack and robbery on Hackworth.