Evolving Graph Convolutional Networks for Dynamic Graph Adaptation

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Solution Overview

Problem

Existing methods using constant Graph Convolutional Networks (GCNs) fail to adapt to dynamic graphs, requiring knowledge of all nodes over time and struggling with new nodes that emerge after training, leading to ineffective classification and prediction.

Innovation Solution

The development of EvolveGCN, which evolves GCN parameters over time using a recurrent mechanism, allowing it to handle new nodes and adapt to changing graph structures by updating parameter matrices at each time step, incorporating mechanisms like Gated Recurrent Units (GRU) or Long Short-Term Memory (LSTM) for weight evolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a constant Graph Convolutional Network is used, then the model structure is simple and easy to implement, but it fails to adapt to dynamic graphs and cannot handle new nodes that emerge after training

Engineering Contradiction:
Improveadaptability to dynamic graphsVSAvoidmodel complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transforming the static GCN model into a dynamic one through the EvolveGCN architecture. The model evolves its parameters over time using recurrent mechanisms (GRU or LSTM) that update parameter matrices at each time step based on previous parameters and current graph structures. This allows the network to adapt to dynamic graphs and handle new nodes that emerge after training, while maintaining a relatively simple base GCN structure that is updated incrementally rather than completely restructured.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a constant GCN requires knowledge of all nodes over time, then the model can process complete graph information, but it cannot effectively classify new nodes that appear after training

Engineering Contradiction:
Improveclassification performanceVSAvoidhandling new nodes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by pre-training the GCN model on initial graph data to learn fundamental graph convolution operations and parameter patterns. The recurrent evolution mechanism then builds upon this preliminary learning to adapt to new nodes and structures over time. This allows the model to have reliable classification performance on seen data while maintaining the flexibility to handle new nodes that emerge after training, rather than requiring all nodes to be known in advance.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If the GCN parameters are updated at each time step, then the model can capture graph dynamism, but it increases computational complexity and training difficulty

Engineering Contradiction:
Improveprediction accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by evolving the GCN parameter matrices (weight matrices and bias terms) over time through recurrent updates. Instead of changing the entire network architecture or adding complex components, the model updates its parameters incrementally at each time step using GRU or LSTM mechanisms. This approach captures graph dynamism and improves prediction accuracy while avoiding the computational complexity that would result from more substantial architectural modifications.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11537852B2Evolving graph convolutional networks for dynamic graphs
Publication Date: 2022.12.27 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11537852B2 patent drawing
  • US11537852B2 patent drawing
  • US11537852B2 patent drawing

AI summary

A system includes a plurality of graph convolutional networks corresponding to a plurality of time steps, each network modelling a graph including nodes and edges, and in turn including a plurality of graph convolution units; an evolving mechanism; and an output layer. Each of the units, for a given one of the time steps, takes as input a graph adjacency matrix, a node feature matrix, and a parameter matrix for a current layer, and outputs a new node feature matrix for a next highest layer. The mechanism takes as input a parameter matrix for a prior time step updates the input parameter matrix, and outputs the parameter matrix for the given time step. The output layer obtains, as input, output of each of the units for a final time step, and based on the output of each of the units for the final time step, outputs a graph solution.