Learning Discrete Structures for Graph Neural Networks Luca - - PowerPoint PPT Presentation

learning discrete structures for graph neural networks
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Learning Discrete Structures for Graph Neural Networks Luca - - PowerPoint PPT Presentation

Learning Discrete Structures for Graph Neural Networks Luca Franceschi , Mathias Niepert, Massimilano Potil, Xiao He Poster later: Pacific Ballroom # 177 Introduction & Motivations Aim: apply Graph Neural Networks (GNN) to settings in which


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Learning Discrete Structures for Graph Neural Networks

Luca Franceschi, Mathias Niepert, Massimilano Potil, Xiao He

Poster later: Pacific Ballroom # 177

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Introduction & Motivations

Aim: apply Graph Neural Networks (GNN) to settings in which an input graph is not available (or it is incomplete/nosiy)

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LDS: Jointly Learning Structure and Parameters

Formulation: bilevel programming problem (gradient-based HPO) with discrete random variables ⇒ discrete and sparse graph

Aτ~Pθ

θ

...

wt+1= Φ(wt,A1) = wt - γ∇Lt(wt,A1) wt+τ= wt+τ-1 - γ∇Lt+τ-1(wt+τ-1,Aτ)

...

w

Data points Initialize parameters Sample graphs Compute hypergradients and update θ of graph generator GCN: Graph generator:

A1~Pθ

Compute gradients of and update GCN parameters

wt+τ wt+τ-1 wt ...

Validation

θ

∇θ 𝔽[F(wθ,τ , θ)]

nodes See Franceschi et al. Forward and Reverse Gradient-based Hyperparameter Optimization, ICML 2017

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Experiments: Semi-supervised Learning

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Many Thanks!

Poster # 177

Github page: https://github.com/lucfra/LDS

Some learned representations by a GCN on Citeseer Dense Graph kNN Graph LDS graph

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