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The Math of a Fly's Eye May Prove Useful

Posted by kdawson on from the saw-that-one-coming dept.

cunniff writes "Wired Magazine points us to recent research that demonstrates an algorithm derived from the actual biological implementation of fly vision (PLoS paper here). Quoting the paper: 'Here we present a model with multiple levels of non-linear dynamic adaptive components based directly on the known or suspected responses of neurons within the visual motion pathway of the fly brain. By testing the model under realistic high-dynamic range conditions we show that the addition of these elements makes the motion detection model robust across a large variety of images, velocities and accelerations.' The researchers claim that 'The implementation of this new algorithm could provide a very useful and robust velocity estimator for artificial navigation systems.' Additionally, the paper describes the algorithm as extremely simple, capable of being implemented on very small and power-efficient processors. Best of all, the entire paper is public and hosted via a service that allows authenticated users to give feedback."

25 of 90 comments (clear)

  1. Presentation by pete-classic · · Score: 5, Funny

    After presenting his paper, researcher David O'Carroll strode off the stage and into a sliding glass door.

    -Peter

  2. Anyone know about bees? by hatemonger · · Score: 5, Interesting

    The researchers drew their algorithm from neural circuits attuned to side-to-side yaw, but O’Carroll said the same types of equations are probably used in computing other optical flows, such as those produced by moving forward and backwards through three-dimensional space.

    I vaguely remember seeing a study that examined how bees travel without hitting anything but using very few neurons. Something about the relative size change of objects between eyes. They tested this by putting bees in a clear tunne with patterns on belts on the right and left walls. By changing the speed of the belts, the bees would ram into the walls, but as long as the belts were moving at the same speed, the bees were fine. Is this ringing a bell for anyone else?

    1. Re:Anyone know about bees? by Bazzargh · · Score: 5, Informative

      You mean this: http://www.ncbi.nlm.nih.gov/pubmed/2069903 "Range perception through apparent image speed in freely flying honeybees."

  3. Re:I don't get it... by Anonymous Coward · · Score: 4, Insightful

    Look, you've got to at least RTFS.

  4. We don't understand it but we can do it by erroneus · · Score: 2, Insightful

    Why does this sound like every PC user and quite a few programmers I have had to deal with?

    I find it unimaginable that people would attempt to implement a technology that is not fully understood. Doing so will eventually yield unexpected results or at the very least, results that cannot be explained.

    I am not saying that everything we presently or regularly do is something that everyone presently understands as I am sure there are ample examples of this happening everywhere. Usually, however, "someone" somewhere actually knows and understands because they created it. In this case, it seems, things are being created and implemented without a full working understanding of how it all works. At the very least, such inventions should be unworthy of patenting.

    1. Re:We don't understand it but we can do it by Anonymous Coward · · Score: 5, Insightful

      You'd be surprised. About medicine.

      Starting with simple Aspirin, the line of medicaments that have known positive results but nobody knows why, is loooooooong.

    2. Re:We don't understand it but we can do it by 4D6963 · · Score: 2, Insightful

      Why isn't it modded off-topic? So we don't know everything for sure about how a fly's brain works, but it doesn't matter, because we're looking at them for inspiration for the algorithms actually implemented, which we actually understand. No one's stupid enough to not understand their own algorithms, at least not at that level.

      --
      You just got troll'd!
    3. Re:We don't understand it but we can do it by hatemonger · · Score: 5, Insightful

      I find it unimaginable that people would attempt to implement a technology that is not fully understood. Doing so will eventually yield unexpected results or at the very least, results that cannot be explained.

      Except that occasionally building a working model is a useful step to understanding it. I'm happy that Edward Jenner in 1796 started infecting people with cow pox as a way to prevent small pox even though he didn't fully understand why it worked.

    4. Re:We don't understand it but we can do it by MBCook · · Score: 4, Insightful

      Well, it's not flying airplanes full of people. They've copied a system that seems to work well, and they are testing it for ultra-small UAVs. They'll get a better idea of how it works then.

      There are many things people have used throughout history without understanding how they work. Salt preservation is ancient, but we didn't discover the bacteria it kills until the last 200 years.

      Sometimes, "works" is good enough. And works often leads to understands.

      I think this is really cool. We've been trying to do this kind of thing for years. The fly does it with a tiny-micro-fraction of the resources we were using, and does a much MUCH better job. By testing this system, perhaps we'll find out WHY our systems are tricked by certain stimulus and this one isn't.

      It's not like they put a bunch of stuff together and said "this works, as far as we can tell", they took a proven system and copied it.

      --
      Comment forecast: Bits of genius surrounded by a sea of mediocrity.
    5. Re:We don't understand it but we can do it by Nobo · · Score: 3, Interesting

      A scientist says, "This works, but I don't know why, How do I complete the theory?"
      An engineer says, "This works, but I don't know why. How do I use it to build something that does what I want?"
      A good engineer says, "This works, but I don't know why. How do I use it to build something that does what I want.. And, in what domain does my model break down and how do I make sure I don't get my system into that domain?"

      Sizable chunks of control theory, frequency analysis, and some other core theoretical components of what we now consider to be solid engineering work were being applied long before the theoretical basis behind them was solidly proven to be correct from a pure mathematical standpoint.

    6. Re:We don't understand it but we can do it by Rockoon · · Score: 2, Interesting

      I believe the poster was talking about understanding the algorithm itself, not the fly brain.

      The key idea here is that emergent algorithms (which is what these sort of things are) are unpredictable. It is one thing to understand the methodology, another to grok the full picture.

      In any sort of complex input space, you cannot test all possible input permutations and so cannot guarantee that these algorithms wont go ahead and output the worst possible thing from time to time.

      In some cases we can get away with emergent algorithms because the worst possible output isnt going to kill anybody (for example, using an ANTS algorithm for network routing is OK because the worst case is the already frequent phenomenon of a lost packet, and we are using the ANTS algorithm specifically because it does better routined and thus, in general loses fewer packets)

      --
      "His name was James Damore."
    7. Re:We don't understand it but we can do it by Hatta · · Score: 5, Informative

      Aspirin's mechanism of action was unknown for a long time, but now we know it's due to suppression of prostaglandin synthesis by irreversible inhibition of cyclooxygenase enzymes.

      --
      Give me Classic Slashdot or give me death!
    8. Re:We don't understand it but we can do it by PitaBred · · Score: 2, Interesting

      Stupid? They're multiple non-linear equations interacting with each other. The people who came up with the algorithms themselves state that they don't understand the full effects of the algorithms. They know that they work, they know if they remove parts of the algorithm they stop working nearly as well, but they can't predict the output from the input.

      --
      My blog. Good stuff (when I remember to update it). Read it.
    9. Re:We don't understand it but we can do it by daveime · · Score: 2, Funny

      Someone from Mumbai underbid you on ELance again ?

    10. Re:We don't understand it but we can do it by Anomalyst · · Score: 2, Interesting

      A scientist says, "This works, but I don't know why

      Here is my falsifiable hypothesis, I'll test it experimentally and see if successful results can be reproduced independently.
      Theory comes a LONG ways down the road.

      --
      There is no right to feel safe thru security vaudeville at the expense of everyone's freedom, privacy and tax money.
  5. Thousand scientists in a room with a typewriter... by chogori · · Score: 2, Interesting
    Okay, so the article is titled "Secret Math", and...

    Though they built the system, the researchers don’t quite understand how it works.

    and...

    Intriguingly, the algorithm doesn’t work nearly as well if any one operation is omitted. The sum is greater than the whole, and O’Carroll and Brinkworth don’t know why.

    Wow, some interesting "science" that's going on here.
    Great result, but, really, way to go guys! You can't understand a non-linear system's behavior; join the club. I still can't understand why z_n+1 = z_n^2 + c looks so pretty either.

  6. A good read... by CockMonster · · Score: 3, Insightful

    But where's the source code???

    1. Re:A good read... by SomeoneGotMyNick · · Score: 4, Funny

      But where's the source code???

      You don't want to read it. It's written in Fly and the comments contain too many buzz-words.

    2. Re:A good read... by Njoyda+Sauce · · Score: 4, Funny

      It's also buggy.

      --

      You can only be young once, but you can be immature forever.
    3. Re:A good read... by daveime · · Score: 2, Funny

      Fly tends to get caught in the Web, but you can usually Spider the results. Also Gecko eats Fly.

    4. Re:A good read... by somersault · · Score: 2, Funny

      It got stuck after they wrote their fly paper.

      --
      which is totally what she said
  7. Re:I don't get it... by cmiller173 · · Score: 3, Funny

    And if God had intended for Man to drink beer we would have been born with stomachs.

  8. Don't understand how it works by PPH · · Score: 5, Funny

    We've implemented this algorithm in several autonomous flying surveillance vehicles. While it appears to work adequately, we're still trying to determine why the only thing they manage to locate is cow shit.

    --
    Have gnu, will travel.
  9. "Fly" programming language by tlambert · · Score: 2, Funny

    "Fly" programming language ...and just like the original thing, it has garbage collection!

    -- Terry

  10. Refreshing Story by BJ_Covert_Action · · Score: 4, Insightful

    This might be offtopic but seeing a legitimate R&D story on slashdot with a link to the actual (open) technical write up of the research made my day. I haven't read the whole paper yet (I will when I get home) but going through it and reading the first few sections I can see that the researchers included their (simulink?) processing models as well as some good data in the results section. This story finally gave me something worth breaking out my old signal processing and DAC notes from college out over and studying the raw math and theory behind the algorithm.

    I have to say, I really wish we would see more papers like this posted and published openly. It's very inspiring when other folk in similar fields can access a paper's full contents and start playing with similar models themselves...

    --
    Motorcycles, Robots, Space Gossip and More!