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Summary Of Several Autoencoder models Presentor: Ji Gao Department of Computer Science, University of Virginia https://qdata.github.io/deep2Read/

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Page 1: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

SummaryOfSeveralAutoencodermodels

Presentor:JiGao

DepartmentofComputerScience,UniversityofVirginiahttps://qdata.github.io/deep2Read/

Page 2: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

List

• AdversarialAutoencoders• PixelGAN Autoencoders• GeneratinganddesigningDNAwithdeepgenerativemodels• FeedbackGAN(FBGAN)forDNA:aNovelFeedback-LoopArchitectureforOptimizingProteinFunctions• AutoregressiveGenerativeAdversarialNetworks

Page 3: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

AdversarialautoencodersAlireza Makhzani, JonathonShlens,Navdeep Jaitly, IanGoodfellow,BrendanFrey

• Useadversariallearningintrainingautoencoders

Page 4: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Autoencoders

• Autoencoder

• Decoder=Generator:Startfromaprior(oftennormaldistribution),producesample

Page 5: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Autoencoders

WhyDecoderwork?• Anydistributionin𝑑 dimensioncanbegeneratedbyasufficientlycomplicatedfunctionon𝑑 normallydistributionalvariables.

Page 6: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Whynotdirectlyoptimizedecoder?

• Ifdirectlyoptimizedecoderviasampling,itwilltakeexponentiallynumberofsamples(Andalsoexponentiallyparameters)• Alotofthesamplingareuseless,foraX,weonlyneedthepartofzthatarelikelytoproduceX• FindmostlikelyztoproduceXcansavehugeamountoftimeandmaketheprocesstractable

Page 7: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

VariationalAutoencoder

𝐷#$(𝑄(𝑧)||𝑃(𝑧|𝑥)) = 𝐸.~0[log𝑄 𝑧 − log𝑃(𝑧|𝑥)]

= 𝐸.~0[log𝑄 𝑧 − log𝑃 𝑥 𝑧 − log𝑃 𝑧 + log𝑃(𝑥)]

Latentvariable𝑧~𝑃(𝑧) Ifwesample𝑄(𝑧) toapproximate𝑃(𝑥),wehave

log𝑃(𝑥) − 𝐷#$(𝑄(𝑧)||𝑃(𝑧|𝑥)) = 𝐸.~0[log𝑃 𝑧|𝑥 ] − 𝐷#$(𝑄(𝑧)||𝑃(𝑧))

Bayesian

Reasonabletolet𝑄(𝑧) conditionedonx.

Wehave:log𝑃(𝑥) ≥ 𝐸.~0[log𝑃 𝑧|𝑥 ] − 𝐷#$(𝑄(𝑧|𝑥)||𝑃(𝑧))

Variationalbound

Page 8: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

VariationalAutoencoderlog𝑃(𝑥) ≥ 𝐸.~0[log𝑃 𝑧|𝑥 ] − 𝐷#$(𝑄(𝑧|𝑥)||𝑃(𝑧))InVAE,welet𝑄 𝑧 𝑥 = 𝑁(𝑧|𝜇 𝑥;𝜃 , Σ(𝑥; 𝜃))

Inthiscase:

Samplexandz,wehave

Page 9: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Posterier

• GaussianPosterier

Page 10: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

VariationalAutoencoder

FromTutorialonVariationalAutoencoders https://arxiv.org/abs/1606.05908

Page 11: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Adversarialautoencoder

• VAEworkson

• 𝐷#$(𝑄 𝑧 𝑥 ||𝑃 𝑧 ) termcanbeoptimizedinadversarialtraining• Trainrepeatedlyintwosteps:1.Maximize𝐸.~0[log𝑃 𝑥|𝑧 ]2.Minimizethedistancebetween𝑄(𝑧|𝑥) and𝑃(𝑧)

log𝑃(𝑥) ≥ 𝐸.~0[log𝑃 𝑥|𝑧 ] − 𝐷#$(𝑄(𝑧|𝑥)||𝑃(𝑧))

Page 12: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Freedomofchoosingq()

• ComparetoVAE,inthisformitcanbeoptimizedusingseveraldifferentways:• 1.Deterministic:𝑞 𝑧 𝑥 isadeterministicfunctiononx• 2.Gaussianposterior:𝑄 𝑧 𝑥 = 𝑁 𝑧 𝜇 𝑥; 𝜃 , Σ 𝑥; 𝜃 similartoVAE.Canusethesamereparameterization• 3.Universalapproximator posterior,𝑞 𝑧 𝑥, 𝜂 = 𝛿(𝑧 − 𝑓(𝑥, 𝜂))

Page 13: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Adversarialautoencoderperformance

Page 14: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Loglikelihood

Page 15: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Supervisedlearning

• Fullysupervisedlearningtogeneratesamplesinaparticularway

Page 16: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Semi-supervisedlearning

• 2adversarialnets:Onewithcategoricaldata• Traininthreephases:• 1.Reconstructionphase• 2.Regularizationphase• 3.Semi-supervisedphase

Page 17: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

PixelGAN AutoencodersAlirezaMakhzani,BrendanFrey

Page 18: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

PixelGAN Autoencoders

• UsePixelCNN asthegenerativepath• PixelCNN conditionedonq(z|x)

Page 19: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Categoricalprior

Page 20: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Experiment

Page 21: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

GeneratinganddesigningDNAwithdeepgenerativemodelsNathanKilloran,LeoJ.Lee,AndrewDelong,DavidDuvenaud,BrendanJ.Frey

• 2017• ThreeapproachestogenerateDNAsequence:• 1.GAN• 2.Activationmaximization(DeepDream)• 3.Ajointof1and2

Page 22: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

GANondiscreteoutput

• DNAsequenceisdiscrete,similartoNLPtask• WGAN-GPcangeneratethesequenceinthedirectway:

LetGANdirectlyoutputone-hotcharacterembeddings fromalatentvectorwithoutanydiscretesamplingstep.Softmax directlypassedtocritic.

Page 23: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

GANonDNA

• UsesuchmethodonDNA:

Page 24: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

ActivationMaximization

• ThemethodisactuallyDeepDream:• Startfromsamplex,makeittargetatacertainpropertyt(output)• 𝑥 → 𝑥 + 𝜖∇E𝑡• Worksoncontinuouscase,soneedtorelaxdiscretesymbolsintocontinuouscase

Page 25: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Jointmethod

• UseGANtogeneratesample• Useactivationmaximizationtooptimizeasampletocertainproperties

Page 26: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Experiment:Motif

• Samplesequencestunedtohaveahighpredictorscore

Page 27: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Experiment

Page 28: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

FeedbackGAN(FBGAN)forDNA:aNovelFeedback-LoopArchitectureforOptimizingProteinFunctionsAnvita Gupta,JamesZou

• 2018• Target:DesignDNAautomaticallyfollowingsomeproperties

Page 29: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

FeedbackGAN

• (a)WGAN-GPasgenerator• (b)Analyzer:supposetobeanyfunction• Ratethegeneratedsamples• Markthetopsortedsamplesasrealsamples

• (c)Feedbackscheme• Sendthetopsortedsamplebacktothediscriminator

Page 30: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Evaluation

• Beforetraining,3.125%ofsequencesinitially followedthecorrectgenestructure• Aftertraining,77.08%ofsampledsequencescontainedthecorrectgenestructure

Page 31: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

AutoregressiveGenerativeAdversarialNetworksYasin Yazici,Kim-HuiYap,StefanWinkler

• ICLR18Workshop

Page 32: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

ARGAN

• ReplacediscriminatorintoaCNN+Autoregressivemodel• Motivation:anautoregressivemodelwouldmodelthefeaturedistributionbetterthanfullyconnectedlayers

Page 33: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

S-ARGANandC-ARGAN

Page 34: Summary Of Several Autoencoder models - GitHub Pages€¦ · Adversarial autoencoders Alireza Makhzani, Jonathon Shlens, NavdeepJaitly, Ian Goodfellow, Brendan Frey • Use adversarial

Result