Julian Shun, who received his Ph.D. from the Computer Science Department, is the winner of the Association for Computing Machinery's (ACM) 2015 Doctoral Dissertation Award for his work describing new approaches for designing and implementing scalable parallel programs.

His dissertation, "Shared-Memory Parallelism Can Be Simple, Fast and Scalable," was also awarded the SCS Doctoral Dissertation Award last year. Shun is now a post-doctoral researcher at the University of California at Berkeley, where he was awarded a Miller Research Fellowship.

While parallelism is essential to achieving high performance in computing, writing efficient and scalable programs can be very difficult. Shun's thesis outlines a three-pronged approach to writing parallel programs:

• New tools and techniques for deterministic parallel programming;
• Introduction of Ligra, the first high-level shared-memory framework for parallel graph traversal algorithms; and
• New algorithms for a variety of important problems on graphs and strings that are both efficient in theory and practice.

Shun earned a bachelor's degree in computer science from the University of California, Berkeley. During the 2013-2014 academic year at CMU, he received a Facebook Graduate Fellowship.

He will receive the Doctoral Dissertation Award and its $20,000 prize at the annual ACM Awards Banquet on June 11, in San Francisco.  Honorable mentions will go to Aaron Sidford of MIT and Siavash Mirarab of the University of Texas at Austin. Financial sponsorship of the award is provided by Google Inc.

Previous SCS winners of the ACM dissertation award include Roderick Cattell (1978), Charles Leiserson (1982), Ketan Mulmuley (1986), Vijay Saraswat (1989), Kenneth McMillan (1992), Ion Stoica (2001), and Bryan Parno (2010).