The professor of computer science, 45, is only the fourth recipient of the prize from the Association for Computing Machinery.
Competition to identify innovations with greatest potential for positive impact in communities around the world.
Follow-up to previous reports shows improvement, but that still more can be done.
$30,000 prizes awarded to inventive students nationwide; four leading universities celebrate 2011 winners
New institute will expand frontiers of cancer research
Undergraduate financial aid up 5 percent; tuition, 3.9 percent