UCNC day 2

UCNC day 2, a full day of talks.

First up was Masami Hagiya with an invited tutorial on “Gellular Automata”. These are a form of cellular automata implemented using gels and chemical reactions. The walls between cells can be “decomposed” or “composed” using chemical reactions – or instead can “swell” or “unswell” forming a valve. This allows chemicals to move between cells. There are theoretical results demonstrating these systems can in principle implement certain kinds of CAs. The tutorial moved on to talking about implementations. Most of the manipulations involve a form of DNA chemical computing: using complementary strands to form networks of polymers, or to control diffusion by attaching anchors. These processes can be controlled by the DNA technique of “strand displacement” that breaks the bonds between the complementary strands. There are some initial prototype implementations. These are still rather complicated, needing multiple chemical species to implement relatively simple state transitions. However, it is early days yet, and more efficient approaches may well be discovered.

Next was the workshop on Membrane systems (mostly P-Systems). Rudolf Freund started off with a tutorial, helping to introduce the concepts to people not that familiar with the area. Then on to the technical talks, covering a wide set of membrane computing topics.

Finally was the afternoon technical session. We started with a talk on Affine Automata: these use an underlying logic that is partway between classical probabilistic automata and quantum automata. Next was a talk about languages (sets of strings) arising from finite walks on Sierpinsky gaskets. And finally we had a talk on Matrix Ins-del (insertion deletion) systems (although I think a better name would be List Ins-del systems). These three combined nicely as a range of different ways of looking at language (in the CS sense) recognisers.

Then off to The Great Wall Chinese restaurant, for a very nice duck in ginger.