Computer Shopper – September 2019

(C. Jardin) #1

118 SEPTEMBER 2019 |COMPUTERSHOPPER|ISSUE 379


Here we take alook at someof
thesenewinitiatives with aviewto
understandinghowANNswork,
what’sbeen achieved, and howthey
mightaffect the real world, at atime
whenmanyindustryexpertsbelieve
that conventional digital computers
areapproachingafundamental
performancelimit.

Theneuraladvantage
Beforelookinganyfurtherat this
potentially newapproach to
computation,it makes senseto
considerwhywemightwantto
mimicbiologyinthis way. Afterall,
acomparisonbetween the power
of the humanbrain and that of a
digital computer mightnot appear
to presentour brains in a
particularlyfavourable light.
Shakuntala Devi wasnicknamed
the Human Computer.She held the
world record formultiplyingtwo
randomlyselected 13-digitnumbers
–specifically,7,686,369,774,870and
2,465,099,745,779,to givethe
correct answerof18,947,668,177,995,
426,462,773,730duringher record
attempt–injust 28 seconds.Most
peoplewould take significantly longer,
even usingapen and paper–several
minutes would probablybe more
typical forthe vast majorityof people.
By wayofcontrast, an ordinary
desktopPCwould be able to perform
severalbillion such operationsin a
second, and if youweretoshell out on
an 18-corevariantofIntel’smonster
Core i9 X-serieschips,the figure
would be closerto atrillion.
Paradoxically,this comparison
doesn’t alwayshold true. Asurprising
assertion,perhaps?Well, just think
back to the last time youfelt like
tearingyour hair out, whiletryingfor
the umpteenth time to tell an
automated telephoneanswering
systemwhat youcould have
communicated to ahumanoperator
in seconds.Nowbear in mindthat the
currentstate-of-play in speech
recognition,flawed as it may be, is the
result of over60years of research.
Speech recognitionis just one
exampleof awhole range of
problems,generally referred to as
pattern recognition,in whichdigital
computers struggle,yethumans
excel. What’smore, in taskssuch as
face recognition,readinghandwritten
text, and manyaspectsof the
much-hypedfield of artificial
intelligence, programmershave
difficultyin comingup with alogical

sequenceofinstructionsthat a
computer canfollow, whilehumans
do this intuitively,havinglearnedfrom
experience. This is all the more
impressivewhen we bear in mindthat
the inputdatafor all thesetasksisso
variable.Rarely do twopeople
pronouncethe sameword exactly the
same,the samesentencewritten by
twoindividualscanlook remarkably
different, and aparticularhuman
face canappeardifferentdepending
on whether that personis smilingor
frowning, whether their face is
partiallyobscured by ahat, by the
presenceofmakeup, and even on
external conditionssuch as lighting.

Brainpower
The ANN approach to computingis
electronic rather than biological. Even
so, because the basicarchitectureis
inspired by animalbrains, we’ll start
by delvinginto the brain’s workings.
The processingpowerofthe brain
comes from neurons that are
connected to other neurons. This may
suggestasimilaritywith today’s
processors,whichcontains multiple
coresthat areable to exchangedata
with each other,but in reality things
couldn’t be moredifferent. First, those
neurons aremuch simplerthan even
the mostbasicdigital processorcore
has ever been.Whileaprocessor core

ABOVE:Under-
standingthe
workingsofthe
brainis atthe
forefrontof
researchinto
up-and-coming
computer
architectures

RIGHT:The
biologicalneuron
maybeasimple
computingelement,
butit makesupfor
thatwithitsvast
numbersand
interconnections

Photo:Gerry Shaw
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