So WCCI 2012 has come and gone, so now it’s up to the proceedings to make an actual change in the world. Hopefully some of the attendees found some new perspective or idea to influence their future work, though the whole experience is pretty full-on, so I thought I’d use this post as an excuse to write down my two biggest “lessons learnt.” (Whether I apply or use these is the future is a different matter…)
EAs typically use one of a few common representations for the individuals they are evolving, such as integer or real-valued vectors. (There are others that aren’t relevant here.) In general, these vectors are of a fixed length and can change either (semi-)randomly or through exchanges with other individuals. Gene Expression is a concept where a vector has more elements than required, but a secondary Boolean vector indicates whether each “gene” (element) is “expressed” (active or ignored).
For example, the vector “12345” with expression vector “10110” implies the solution should be (based on) “134”. However, because the expression vector can change independently, the un-expressed values are retained. Dan Ashlock‘s presentations showed that even allowing a small amount of slack space (adding 4 elements to a 24 element vector) had a significant impact.
What’s potentially more interesting is the application of this concept on GPUs. Because of their architecture, variable-length vectors are particularly inefficient to use. Slack space up to the maximum possible length is a possibility, but then you need a way of indicating which elements should be ignored. My own intent was to include a length attribute, but an alternative would be to include an expression vector.
All the attendees at Zbigniew Michalewicz‘s lecture will know what I’m referring to here, since it had quite an impact. One of the main messages was that a lot of research is in “silos,” trying to find the fastest/best solution to a very narrow problem, and does not consider that (a) fast-enough is good-enough and (b) there are real-world applications that are completely ignored. Other presenters made similar points, perhaps better identifying the underlying reasons (lack of industry-academia interaction, time/effort/money required to create better than proof-of-concept software).
Probably the best outcome from this presentation was the defensive reactions it provoked: the number of people who said “hang on, look at what I’ve been working on” seemed to be higher than the number of written publications and certainly reached a wider audience. Normally I’m not a fan of purely “awareness raising” presentations, but in this case the awareness of actual work was raised, even if it was not work done by the presenter.
It will be interesting with my new job being in the “industry” that seems so mythical to academia. I’m quite happy about the move, mainly because I’d prefer my main output to be production-quality software rather than settling for prototypes and publications. Presumably I’ll get to go to tech conferences at some point, rather than academic ones, but for me WCCI 2012 was made great by having a pretty significant social group there. Even though I’m leaving academia, at least I’ve done it and it wasn’t all bad.