Alumni's Words

David K. Y. Yau
BSc 1989 (New Asia)

Associate Professor of Computer Science, Purdue University
Distinguished Scientist, Advanced Digital Sciences Center, Singapore


When I started college, computers were a novelty, and I knew little about them. I only knew that if you entered the tricky "right" commands, they would give you the "right" results. Armed with that faith, I set out to assert human superiority and intellect over these willful machines. The journey was at times excruciating. In Year 2, I must have spent the longest sleepless bout in my life for work when we worked on a DBMS that would manage investment portfolios. I scarcely knew about investments or portfolios, but that didn't stop us from producing something with layers of flashy pull down menus and cool soft buttons. That was my idea of computing.


Fast forward to Year 4. My classmate ``Mr. Chan'' and I picked an expert system project that would classify the surface geographical features of planet Earth. It was my most extended attempt yet to produce something by independent study. We pored through a book by Zadeh and a few other cryptic papers on ``expert systems'' and ``fuzzy logic.'' All of a sudden our daily vocabulary included these terms and others like ``backward chaining.'' We were also fortunate to have two expert advisors (most students had only one!) in Professors KS Leung and Yee Leung . After months of programming, we were overjoyed when, on feeding satellite GIS data for Hong Kong into our system, a map resembling Hong Kong would actually appear, complete with all the plausible surface features -- foliage, soil, water, whatnot!


As I became nostalgic with ``deep intellectual inquisition'' while working as Management Associate, I remembered how we had produced the GIS expert system and decided that I wanted to become a bona fide ``computer scientist.'' In graduate school, I would learn more about computational complexity, computability, and Godel's Incompleteness Theorem. I would understand that our expert system, despite what we thought it could do, could be incredibly inefficient and might not even produce any meaningful results at all. Much more important than our novice expert system, computing in general has significant inherent limitations. But then, from the Internet to Google and Facebook, to the IBM machine that mastered Jeopardy!, computing did change the world, didn't it? I think I have learned that, although things in theory are always so predictably gloomy, there is always enough to be found and done in practice that could make a big, big difference.


It's interesting that this realization all started for me at CUHK. It occurred during one of the most carefree periods of my life. It was when my classmates and I would study in the library together, cook instant noodles for late night snack together, stay up all night to watch France beat Brazil in a classic World Cup quarterfinal together, go backpacking in Europe for two months together, and shared serious thoughts, juicy stories, and stupid jokes alike together.