HACKER Q&A
📣 netfortius

Anyone here working on/with membrane computing?


Although probably late in this field, I have recently come across the topic, sourced/starting from an old paper by one of the main actors in this area, Gheorghe Paun ("An impossibility theorem for indicators aggregation"), who I then followed through to learning about Membrane Computing. I am planning to buy the introductory book on the topic, also authored by Paun, but not right away. I was wondering if there are individuals who could speak to the how and why, and maybe work on applications in this space.


  👤 guiraldelli Accepted Answer ✓
I have worked with it [1], in particular with a special class of it, MP (Metabolic P).

In a nutshell, it is a theoretical model inspired by biology, but which produces many interesting results, as super-Turing computational power.

I am not sure whether it is still, but the reference on web for the subject was http://ppage.psystems.eu/ .

Besides Păun, other big names in the topic are Perez-Jimenez, Gheorghe and Manca.

As far as I am concerned, there are little practical application of it, even though the theoretical potential is considerable.

I tried to focus on more day-to-day application of MP [2], and I managed to get some nice results, but further advance was limited by external forces.

Do I recommend to buy an introductory book on the subject? No, mostly because I think the material online from the people I mentioned above, plus their publication, is more than enough to acquire the knowledge. Besides, I bet the book is published by Elsevier, which usually mean it is a simple collection of papers, except the fact I am not fan of that publishing house.

If you have any more direct question, feel free to contact me—hopefully I can be of some help.

But, I have the impression that membrane computing is still a very academic topic disconnected from the engineering world.

If it is what you like, then it might satisfy you. :)

[1]: https://ricardo.guiraldelli.com/research.html#doctorate

[2]: https://ricardo.guiraldelli.com/research.html#available-mate...


👤 mindcrime

👤 pubby
In a somewhat-related area, Alan Kay viewed object-oriented programming as cells (objects) and their transport proteins (messages). Like biology, the system is a big ugly mess, but it's made up of tiny self-contained units that can handle themselves. The actor model continues this idea, but usually drops the connection to biology.

👤 al2o3cr
The claims of "solve NP problems in linear time" appear to come with a giant gotcha: they involve allowing the number of membranes to grow exponentially with the problem size! For instance, see:

https://www.cs.auckland.ac.nz/research/groups/CDMTCS/researc...

This seems like a huge problem for any electronic representation, since most any computational approach will deliver "super-Turing" results if you allow the machine to grow faster than the problem...


👤 mikewarot
This seems to be a special case of a computational fabric.[1] If you reduce computation to the barest minimum, you get down to a cartesian grid of 4 input 4 output Look Up Tables (LUTs). If you clock them in alternating phases, like colors on a checkerboard, you avoid all race conditions, and get deterministic general purpose computing which can run this type of algorithm.

I was reading George Gilder back in the 1980s when that idea hit me, and its been in the back of my brain ever since.

[1] https://en.wikipedia.org/wiki/Fabric_computing


👤 cvccvroomvroom
Similar to VM emulation, the problems with electronic or Turing simulation of chemical and biological processes are many. Simulating a sea of neurons or organelles doesn't tend to scale well without using actual organic processes.

I wouldn't bother without a specific need that can be accelerated with biochemistry directly. Turing completeness can't be improved on.


👤 nextos
Luca Cardelli, who is quite famous in formal methods, did a lot of work in the area during the early 2000s: http://lucacardelli.name