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Rolando Brondolin rolando.brondolin@mail.polimi.itLucaCerina luca.cerina@mail.polimi.itAlessandra Fusco alessandra1.fusco@mail.polimi.it

SynCH Design

2Images from https://backyardbrains.com/ and http://techmog.com

Focus on NMF (1)

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Non-negativeMatrixFactorization(NMF)

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Focus on NMF (2)

GivenanonnegativematrixA� Rm×n andapositiveintegerk<min{m,n}findnonnegativematricesW� Rm×k andH� Rk×n tominimizethefunctional:

Img:Cheung,VincentCK,etal. "Musclesynergypatternsasphysiologicalmarkersofmotorcorticaldamage."ProceedingsoftheNationalAcademyofSciences 109.36(2012):14652-14656.

A->EMGsampledsignal,W->MuscleSynergy,H->Time-varyingactivation

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NMFheuristicsiterativelyupdatesWandHandconvergestoalocaloptimalsolution,checkingateachstepthevalueofthecostfunction.Polynomial time[1],butstillexpensive!

[1]Vavasis,StephenA."Onthecomplexityofnonnegativematrix factorization."SIAMJournalonOptimization 20.3(2009):1364-1377.

FPGAs• Highpower• Low energy consumption• Difficult todevelop• Real-timeNMFfeasible with

acceptable energy costs

Microprocessors• Highpower• HighEnergyconsumption• Real-timeNMFfeasible but at

highenergy cost

Microcontrollers• Low power• Low Energy• Real-timeNMFnot feasible on

site,external CPUis needed

Chosen architecture

Rolando Brondolin rolando.brondolin@mail.polimi.it

LucaCerina luca.cerina@mail.polimi.it

Alessandra Fusco alessandra1.fusco@mail.polimi.it

Synch- Synergicallycontrolledhand(www.facebook.com/synchnecst)

@SynCHNecst(www.twitter.com/SynCHNecst)