Mark Yim joined GAMCO Investors as analyst and portfolio manager for the $20 million Gabelli Japanese Value Fund and as a member of the firms global growth team. Its a new position. He reports to Caesar Bryan, portfolio manager, and Howard Ward, director of growth products, said Douglas Jamieson, president and COO. Mr. Yim had been principal at Cedar Tree Capital Management, an Asia/Japan long-short hedge fund, according to a GAMCO press release. Officials at Cedar Tree could not be reached for comment about Mr. Yims replacement.