Two U.S. wrestlers have moved on to wrestle in the quarterfinals of their weight divisions at the 2001 Greco-Roman World Championships Dec. 7 in Patras, Greece.      1996 Olympic silver medalist Brandon Paulson (Golden Valley, Minn./Minnesota Storm) had a bye this morning at 54 kg and will face Rakym Assembekov of Kazakstan in the quarterfinals tonight.     2000 Olympian Kevin Bracken (Colorado Springs, Colo./NYAC) defeated Akaki Chachua of Georgia at 63 kg by a 13-2 technical fall to move to the quarterfinals. There he will face Michael Beilin of Israel.      Keith Sieracki (Colorado Springs, Colo./U.S. Army) lost his match this morning to Tamas Berzicza of Hungary, 3-0. Berzicza moves on to the quarterfinals while Sieracki is done and will have to wait to see what place he will finish.    2001 Greco-Roman World Championships    Patras, Greece, Dimitrios Tofalos Arena    54 kg    Brandon Paulson, Golden Valley, Minn. (Minnesota Storm); dec. Vitalie Ceban (Moldova), 6-1; dec.  Dariusz Jablonski (Poland), 11-2    63 kg    Kevin Bracken, Colorado Springs, Colo. (NYAC); won by tech. fall over Chieh Yen Shih (Chinese Taipai), 11-0, 1:56; dec. Christos Gikas (Greece), 6-0; won by tech. fall over Akaki Chachua (Georgia), 13-2, 4:06    76 kg    Keith Sieracki, Colorado Springs, Colo. (U.S. Army); Keith Sieracki, won by tech. fall over Mal Suraj (India), 13-0, 1:19;  dec. Andrea Minguzzi (Italy), 4-0; lost dec. to Tamas Berzicza (Hungary), 3-0;     97 kg    Jason Loukides, Colorado Springs, Colo. (U.S. Army), dnp; lost dec. to Petru Sudureak (Romania), 6-0; lost by tech. Fall to Urs Burgler (Switzerland), 10-0, 1:39