Alexander Kobrin, a 25-year-old Russian, won the gold medal Sunday at the conclusion of the 12th Van Cliburn International Piano Competition before a capacity crowd at Bass Performance Hall in Fort Worth. For the first time, the 17-day competition offered streaming audio and video in real time on its Web site. During the finals, Internet users could vote for their favorite, resulting also in an Internet audience prize for Mr. Kobrin. Second place in the main contest and two other prizes went to Joyce Yang, 19, of South Korea, the competition's youngest participant and a student at the Juilliard School who lives in Manhattan. Besides her silver medal, she won the Steven De Groote Memorial Award for best performance of chamber music and the Beverley Taylor Smith Award for the best performance of a new work. Third prize went to Sa Chen, 25, of China. Each of the top three winners receives $20,000, United States concert tours and career management for the next three concert seasons. Three other finalists, Davide Cabassi, 28, of Italy; Chu-Fang Huang, 22, of China; and Robert Plano, 26, of Italy each received $10,000, the concert tours and career management.