University Park, Pa.,    Penn State head wrestling coach Troy Sunderland announced the signing of 125-pounder Adam Smith Friday, three days into the early signing period which began Nov. 8.     Smith, a two-time PIAA State Championship placer out of Newport, Pa., is expected to be Penn State's only addition during the early period.     "Adam is a very strong, explosive and aggressive wrestler," Sunderland said. "We had a chance to see what a dedicated, hard worker he was in our camps and really like the intensity he displays when wrestling."     Smith has posted a 95-10 career mark heading into his senior season at Newport High. An honor roll student, he finished third in the PIAA Championships as a sophomore and was fifth last year after posting a 33-3 mark at 112 pounds.    "Adam will improve our competitiveness at 125 pounds both in the room and on the competition mat," Sunderland said. "We're very happy to have him join our program."    He is a three-year dual meet starter and a team captain in his senior campaign. He also finished second and third in the 2000 and 1999 regionals, has twice been named Tri-Valley League MVP and finished third in the 2000 freestyle state championships.