Yang Liu, Yuanming Yu and Chenglong Ma, three junior students from CS Special Pilot Class of Tsinghua University (Yao Class) went to the University of Pennsylvania, Philadelphia, USA, to conduct a month-long visiting study from November 1 to December 10, 2009. Although their trip was interrupted by the snow when they left Beijing, the beautiful night scenery at Tokyo Bay wiped away the trouble brought by the flight delay. And the fruitful visit across the Atlantic they experienced for the next month has made their trip a worthwhile one.    

At the Department of Computer and Information Science, the three students received kind supervision from Professor Sanjeev Khanna as they met once or twice every week. Yang Liu studied SCSI (Shortest Common Super-sequence) during the visit, while Chenglong Ma made some beneficial exploration in LCS&SCS, PCP and zero-knowledge proof. Be it Algorithms course given by Professor Khanna or seminars held every Friday with senior Ph.D students and Professors, the warm and heated academic atmosphere left the three students a great impression. “Each seminar goes on in a heated atmosphere as everyone puts forward his ideas or concerns. Although we also have this kind of practice here at Tsinghua University, I’ve never been encouraged like that, and this point deserves our learning,” Yang Liu wrote in his summary.

When they were in Philadelphia, the three students would never miss the great opportunity to understand the history of such a renowned historical city as they visited Independence Hall, the Liberty Bell and other places of interests. Besides, the fact that they had to cook for themselves has also made them experience the importance of independency abroad.