Excellent! Thank you for your help gentlemen. - Jeff
On Mon, Oct 21, 2013 at 2:15 AM, Garikoitz Lerma-Usabiaga < [email protected]> wrote: > Hi, > I think this video explains it quite nicely too: > http://www.youtube.com/watch?v=z6r3ekreRzY > > Gari > > > On Mon, Oct 21, 2013 at 10:35 AM, Michael Ferrier < > [email protected]> wrote: > >> Hi Jeff, >> >> That is what the spatial pooler does. See pages 21-22 of the white paper >> for more details. Each column in an HTM region receives input from a unique >> subset of input bits, so when the region receives a pattern of input bits, >> regardless of what percentage of the input bits are on, some columns will >> receive more excitation than others. Only the 2% of columns that receive >> the highest amount of excitation will be activated. So regardless of what >> proportion of input bits are active, the region will end up with a sparse >> distributed representation of the input, with 2% of columns active. >> >> -Mike >> >> _____________ >> Michael Ferrier >> Department of Cognitive, Linguistic and Psychological Sciences, Brown >> University >> [email protected] >> >> >> On Sun, Oct 20, 2013 at 9:40 PM, Jeff Fohl <[email protected]> wrote: >> >>> Hello - >>> >>> I hope this is not being posted to the wrong list. This is my first post >>> here. Please let me know if there is a more appropriate place for this >>> question. >>> >>> In preparation for learning NuPIC, I have read "On Intelligence", and I >>> am now reading the HTM white paper put out by Numenta. >>> >>> Making my way through the white paper, I got stuck on one passage, which >>> I can't really make sense of. Wondering if anyone can help me through this >>> part. The passage in question is on pages 11-12 of the white paper PDF - >>> specifically the second paragraph included below. >>> >>> *HTM regions also use sparse distributed representations. In fact, the >>> memory mechanisms within an HTM region are dependent on using sparse >>> distributed representations, and wouldn’t work otherwise. The input to an >>> HTM region is always a distributed representation, but it may not be >>> sparse, so the first thing an HTM region does is to convert its input into >>> a sparse distributed representation.* >>> >>> *For example, a region might receive 20,000 input bits. The percentage >>> of input bits that are “1” and “0” might vary significantly over time. One >>> time there might be 5,000 “1” bits and another time there might be 9,000 >>> “1” bits. The HTM region could convert this input into an internal >>> representation of 10,000 bits of which 2%, or 200, are active at once, >>> regardless of how many of the input bits are “1”. As the input to the HTM >>> region varies over time, the internal representation also will change, but >>> there always will be about 200 bits out of 10,000 active. * >>> >>> So, what exactly is going on here? How does a fluctuating input flow of >>> 20,000 bits get converted into 200 bits? Obviously there is something >>> important going on here, but I don't understand what it is. Any help >>> illuminating this would be greatly appreciated! >>> >>> Many thanks, >>> >>> Jeff >>> >>> _______________________________________________ >>> nupic mailing list >>> [email protected] >>> http://lists.numenta.org/mailman/listinfo/nupic_lists.numenta.org >>> >>> >> >> _______________________________________________ >> nupic mailing list >> [email protected] >> http://lists.numenta.org/mailman/listinfo/nupic_lists.numenta.org >> >> > > _______________________________________________ > nupic mailing list > [email protected] > http://lists.numenta.org/mailman/listinfo/nupic_lists.numenta.org > >
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