Is there any repository of unsolved problems?

I'm seeking for a good topic for my Ph.D. research in the Semantic Web
field. Would you mind to help me to find the place where I can see the
list of unsolved problems? I don't necessarily mean the list of Ph.D.
topics :) , but that could probably be the list of current directions
where the help is needed and where many questions are opened.

Sincerely yours,

Yury V. Katkov
Laboratory of intelligent systems
of the Saint-Petersburg National University of Information
Technologies, Mechanics and Optics, Russia

Received on Monday, 7 March 2011 21:54:59 UTC