DHT

DHT, which transforms the edges of a graph into the nodes of a hypergraph.

ENGNN, use hypergraph after DHT to propagation

Background

Before methods only capture edge information implicitly, e.g. used as weight.

Contribute

  1. propose DHT, Dual Hypergraph Transformation
  2. propose a novel edge representation learning scheme ENGNN by using DHT.
  3. propose novel edge pooling methods.

Method

DHT: how to transfer graph to hypergraph

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Step1: Get origin graph representation

Firstly, we get the initial node feature and edge feature. \[ node \space feature: X\in R^{n\times d} \]

\[ edge\space feature: E\in R^{m\times d'} \]

Than we use an incidence matrix M rather than an adjacency matrix to represent graph structure. \[ incidence\space matrix: M\in \{0,1\}^{n\times m} \] So the origin graph is \[ G=(X,M,E) \]

Step 2: Use DHT to get hypergraph \(G^*\)

The hypergraph represent \[ G^*=(X^*,M^*,E^*) \]

\[ X^*=E \]

\[ M^*=M^T \]

\[ E^*=X \]

\[ DHT:G=(X,M,E)->G^*=(E,M^T,X) \]

While DHT is a bijective transformation: \[ DHT:G^*=(E,M^T,X)->G=(X,M,E) \]

EHGNN: an edge representation learning framework using DHT

\[ E^{(l+1)}=ENGNN(X^{(l)},M,E^{(l)})=GNN(DHT(X^{(l)},M,E^{(l)})) \]

So ENGNN consists of DHT and GNN, while GNN can be any GNN function.

After ENGNN, EHGNN, \(E^{(L)}\) is returned to the original graph by applying DHT to dual hypergraph \(G^∗\). Then, the remaining step is how to make use of these edge-wise representations to finish the task.

Pooling

To be continue...

Advantage

DHT

  1. low time complexity
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