Table 1.

Summary of notations used in this study.

Notation	Definition
$G$	Graph
$V$	Vertices set of one graph
$E$	Adjacency matrix of one graph
$E\left(i\right)$	Set of edges linked to node $i$
$E_k\left(i\right)$	Set of edges from the top-$k$ nearest nodes to node $i$
$e_{ij}$	Edge between node $i$ and node $j$
${\alpha }_i^f$	Node $i$ features at f convolutional layer after aggregation
$h_i^f$	Node $i$ features at f convolutional layer after update
$W_j^f$	Weights filter in aggregation operator
$N\left(i\right)$	Set of all adjacent nodes to node $i$
$H^f$	All node features at layer $f$
$z^f$	Representative features after readout operator at layer $f$
$\parallel$	Concatenation operator