Neural Network Pruning via Stability Metrics

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Solution Overview

Problem

Existing methods for pruning neural networks often fail to determine the optimal time for removing nodes, leading to decreased efficiency and increased training time due to incorrect node removal.

Innovation Solution

A system that analyzes neural networks during training to calculate a stability metric, ranking neurons and determining a stable sub-network for optimal pruning, allowing for the removal of unstable nodes to maintain network performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If nodes are removed from neural networks to increase efficiency, then network complexity is reduced, but network performance may decrease if nodes are removed incorrectly

Engineering Contradiction:
Improveneural network complexityVSAvoidnetwork performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the parameter being optimized from arbitrary or random node selection to stability-based node selection. By calculating stability metrics (such as gradient norm, weight magnitude, or activation stability) for each node and removing only the least stable nodes, the system maintains network performance while achieving complexity reduction. This parameter change transforms the pruning criterion from heuristic to metric-driven.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback mechanisms by continuously monitoring network performance during the pruning process and using this information to guide subsequent pruning decisions. The stability metric calculation provides feedback about which nodes are critical versus removable, and performance monitoring provides feedback about whether pruning is too aggressive. This closed-loop approach ensures that complexity reduction does not compromise performance.

Inventive Principle:
Principle #23Feedback

2Productivity

If traditional pruning methods are used, then some nodes are removed, but training time increases due to incorrect node removal requiring additional training

Engineering Contradiction:
Improvetraining efficiencyVSAvoidtraining time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by calculating stability metrics for all nodes before performing pruning. This preliminary stability assessment identifies which nodes are safe to remove in advance, preventing the need for additional training iterations. By determining node stability beforehand based on metrics like gradient history or weight importance, the system ensures that removed nodes are truly redundant, eliminating the time loss associated with retraining.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamics by making the pruning process adaptive rather than static. The stability metrics are calculated dynamically during training based on actual network behavior and gradient information, allowing the pruning strategy to adapt to the specific characteristics of the network and dataset. This dynamic approach prevents premature or incorrect pruning that would require additional training time.

Inventive Principle:
Principle #15Dynamics

3Speed

If nodes are removed to simplify the network, then computational efficiency improves, but accuracy may be compromised

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidnetwork accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent changes the pruning parameter from uniform or random selection to stability-based selection. By using metrics such as gradient norm, weight magnitude, or activation stability as the selection criterion, the system identifies nodes that can be removed without impacting accuracy. This parameter change ensures that computational efficiency gains are achieved while maintaining the accuracy-critical nodes in the network.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by treating different nodes differently based on their individual stability characteristics. Rather than applying a uniform pruning strategy across all nodes, the system calculates and uses local stability metrics for each node to determine its removability. This allows the network to maintain high-quality (accuracy-critical) nodes while removing lower-quality (less important) nodes, preserving overall accuracy while improving efficiency.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20220292360A1Pruning neural networks
Publication Date: 2022.09.15 NVIDIA CORP
  • US20220292360A1 patent drawing
  • US20220292360A1 patent drawing
  • US20220292360A1 patent drawing

AI summary

Apparatuses, systems, and techniques to remove one or more nodes of a neural network. In at least one embodiment, one or more nodes of a neural network are removed, based on, for example, whether the one or more nodes are likely to affect performance of the neural network.