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Dario Izzo

Probabilistic Logic Allows Computer Chip to Run Faster - 3 views

www.azonano.com/news.asp

INF MAD probabilistic computing AI

shared by Dario Izzo on 07 Dec 09 - Cached
  • Dario Izzo on 07 Dec 09
     
    Francesco pointed out this research one year ago, we dropped it as noone was really considering it ... but in space a low CPU power consumption is crucial!! Maybe we should look back into this?
  • ...6 more comments...
  • Ma Ru on 07 Dec 09
     
    Q1: For the time being, for what purposes computers are mainly used on-board?
  • Dario Izzo on 07 Dec 09
     
    for navigation, control, data handling and so on .... why?
  • Ma Ru on 07 Dec 09
     
    Well, because the point is to identify an application in which such computers would do the job... That could be either an existing application which can be done sufficiently well by such computers or a completely new application which is not already there for instance because of some power consumption constraints... Q2 would be then: for which of these purposes strict determinism of the results is not crucial? As the answer to this may not be obvious, a potential study could address this very issue. For instance one can consider on-board navigation systems with limited accuracy... I may be talking bullshit now, but perhaps in some applications it doesn't matter whether a satellite flies on the exact route but +/-10km to the left/right? ...and so on for the other systems. Another thing is understanding what exactly this probabilistic computing is, and what can be achieved using it (like the result is probabilistic but falls within a defined range of precision), etc. Did they build a complete chip or at least a sub-circiut, or still only logic gates...
  • Dario Izzo on 07 Dec 09
     
    Satellites use old CPUs also because with the trend of going for higher power modern CPUs are not very convenient from a system design point of view (TBC)... as a consequence the constraints put on on-board algorithms can be demanding. I agree with you that double precision might just not be necessary for a number of applications (navigation also), but I guess we are not talking about 10km as an absolute value, rather to a relative error that can be tolerated at level of (say) 10^-6. All in all you are right a first study should assess what application this would be useful at all.. and at what precision / power levels
  • Joris _ on 07 Dec 09
     
    The interest of this can be a high fault tolerance for some math operations, ... which would have for effect to simplify the job of coders! I don't think this is a good idea regarding power consumption for CPU (strictly speaking). The reason we use old chip is just a matter of qualification for space, not power. For instance a LEON Sparc (e.g. use on some platform for ESA) consumes something like 5mW/MHz so it is definitely not were an engineer will look for some power saving considering a usual 10-15kW spacecraft
  • Dario Izzo on 07 Dec 09
     
    What about speed then? Seven time faster could allow some real time navigation at higher speed (e.g. velocity of a terminal guidance for an asteroid impactor is limited to 10 km/s ... would a higher velocity be possible with faster processors?) Another issue is the radiation tolerance of the technology ... if the PCMOS are more tolerant to radiation they could get more easily space qualified.....
  • Joris _ on 08 Dec 09
     
    I don't remember what is the speed factor, but I guess this might do it! Although, I remember when using an IMU that you cannot have the data above a given rate (e.g. 20Hz even though the ADC samples the sensor at a little faster rate), so somehow it is not just the CPU that must be re-thought. When I say qualification I also imply the "hardened" phase.
  • Francesco Biscani on 08 Dec 09
     
    I don't know if the (promised) one-order-of-magnitude improvements in power efficiency and performance are enough to justify looking into this. For once, it is not clear to me what embracing this technology would mean from an engineering point of view: does this technology need an entirely new software/hardware stack? If that were the case, in my opinion any potential benefit would be nullified. Also, is it realistic to build an entire self-sufficient chip on this technology? While the precision of floating point computations may be degraded and still be useful, how does all this play with integer arithmetic? Keep in mind that, e.g., in the Linux kernel code floating-point calculations are not even allowed/available... It is probably possible to integrate an "accelerated" low-accuracy floating-point unit together with a traditional CPU, but then again you have more implementation overhead creeping in. Finally, recent processors by Intel (e.g., the Atom) and especially ARM boast really low power-consumption levels, at the same time offering performance-boosting features such as multi-core and vectorization capabilities. Don't such efforts have more potential, if anything because of economical/industrial inertia?
Luís F. Simões

Stochastic Pattern Recognition Dramatically Outperforms Conventional Techniques - Techn... - 2 views

www.technologyreview.com/...27598

stochastic probabilistic computing pattern_recognition robotics navigation

shared by Luís F. Simões on 23 Feb 12 - No Cached
  • A stochastic computer, designed to help an autonomous vehicle navigate, outperforms a conventional computer by three orders of magnitude, say computer scientists
  • These guys have applied stochastic computing to the process of pattern recognition. The problem here is to compare an input signal with a reference signal to determine whether they match.   In the real world, of course, input signals are always noisy so a system that can cope with noise has an obvious advantage.  Canals and co use their technique to help an autonomous vehicle navigate its way through a simple environment for which it has an internal map. For this task, it has to measure the distance to the walls around it and work out where it is on the map. It then computes a trajectory taking it to its destination.
  • Although the idea of stochastic computing has been around for half a century, attempts to exploit have only just begun. Clearly there's much work to be done. And since one line of thought is that the brain might be a stochastic computer, at least in part, there could be exciting times ahead.
  • ...1 more annotation...
  • Ref: arxiv.org/abs/1202.4495: Stochastic-Based Pattern Recognition Analysis
  • Luís F. Simões on 23 Feb 12
     
    hey! This is essentially the Probabilistic Computing Ariadna
  • LeopoldS on 25 Feb 12
     
    The link is there but my understanding of our purpose is different than what I understood from the abstract. In any case,the authors are from Palma de Mallorca, Balears, Spain "somebody" should somehow make them aware of the Ariadna study ... E.g somebody no longer in the team :-)
Luís F. Simões

How to Grow a Mind: Statistics, Structure, and Abstraction - 4 views

www.sciencemag.org/...1279

AI cognition learning Bayesian probabilistic probabilistic computing

shared by Luís F. Simões on 21 Mar 11 - No Cached
  • Luís F. Simões on 21 Mar 11
     
    a nice review on the wonders of Hierarchical Bayesian models. It cites a paper on probabilistic programming languages that might be relevant given our recent discussions. At Hippo's farewell lunch there was a discussion on how kids are able to learn something as complex as language from a limited amount of observations, while Machine Learning algorithms no matter how many millions of instances you throw at them, don't learn beyond some point. If that subject interested you, you might like this paper.
  • Ma Ru on 21 Mar 11
     
    Had an opportunity to listen to JBT and TLG during one summer school.. if they're half as good in writing as they are in speaking, should be a decent read...
Marcus Maertens

Who needs qubits? Factoring algorithm run on a probabilistic computer | Ars Technica - 2 views

arstechnica.com/...un-on-a-probabilistic-computer

PHY INF technology

shared by Marcus Maertens on 19 Sep 19 - No Cached
  • Marcus Maertens on 19 Sep 19
     
    advantages: p-bits run on room temperature and are easier to connect than q-bit.
Dario Izzo

Computers in space - 3 views

www.dansdata.com/spacecomp.htm

INF probabilistic computing

shared by Dario Izzo on 07 Dec 09 - Cached
  • Dario Izzo on 07 Dec 09
     
    A link to help the discussion a few posts below....
  • LeopoldS on 08 Dec 09
     
    one post above you mean ...?
  • Ma Ru on 08 Dec 09
     
    Now that you commented, it's below :) [Edit] Fun reading btw.
ESA ACT

Probabilistic computing: Sacrificing Accuracy For Speed and Efficiency In Processors - 0 views

tech.slashdot.org/article.pl

INF MAD

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Via slashdot. Is that new? Must be of interest for global optimisation.
Nicholas Lan

rapid 3D model acquisition with a webcam from Cambridge uni - 0 views

www.engadget.com/...ing-with-any-stationary-webcam

3D modelling feature based computer vision probabilistic webcam

shared by Nicholas Lan on 24 Nov 09 - Cached
Ma Ru liked it
  • Nicholas Lan on 24 Nov 09
     
    impressive, particularly if it works like it does in the video the whole time. paper here http://mi.eng.cam.ac.uk/~qp202/
  • Ma Ru on 24 Nov 09
     
    Well, impressive indeed... have to try it out...
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