Binary Neural Network Architecture Search via Gradient Descent

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Solution Overview

Problem

Current neural architecture search (NAS) methods for binary neural networks are inefficient due to reliance on reinforcement learning, computational resource intensity, and lack of optimization for binary networks, leading to approximation errors and vanishing gradient problems.

Innovation Solution

The method employs an optimized search space, zeroise layers, diversity parameters, and inter-cell skip connections to perform NAS, allowing for efficient generation of binary neural networks with reduced flaws and improved accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If reinforcement learning is used for neural architecture search, then the neural network can be automatically designed, but the search process takes too long and requires excessive computing resources

Engineering Contradiction:
Improveautomated neural network designVSAvoidsearch time
Core Design Contradiction:
Extent of automationVSLoss of time

Solution Approach 1:

The patent replaces the reinforcement learning-based search mechanism with a differentiable architecture search method using gradient descent. Instead of using complex RL agents to explore the search space, the invention formulates architecture search as an optimization problem where architecture parameters are continuously relaxed and optimized through gradient-based methods, dramatically reducing search time and computational requirements

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the parameter representation by relaxing discrete architecture parameters into continuous domains. This allows the use of gradient descent for optimization instead of reinforcement learning, enabling efficient and automated neural network architecture design without the excessive computational burden of RL-based methods

Inventive Principle:
Principle #35Parameter changes

2Extent of automation

If reinforcement learning is used for neural architecture search, then the neural network can be automatically designed, but excessive computing resources are required

Engineering Contradiction:
Improveautomated neural network designVSAvoidcomputing resources
Core Design Contradiction:
Extent of automationVSUse of energy by moving object

Solution Approach 1:

The patent substitutes the computationally intensive reinforcement learning system with a gradient-based optimization approach. By formulating architecture search as a differentiable optimization problem, the method reduces computing resource requirements while maintaining automated design capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses a supernet that copies and shares weights across multiple possible architecture configurations. This allows gradient information to be efficiently propagated through all potential architectures simultaneously, reducing the computational resources needed compared to evaluating each architecture separately through reinforcement learning

Inventive Principle:
Principle #26Copying

3Ease of manufacture

If direct approximation of floating point neural networks is used for binary neural networks, then the design process is simplified, but approximation errors and quantization errors increase

Engineering Contradiction:
Improvedesign process simplicityVSAvoidapproximation accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent performs preliminary action by training the supernet in floating-point precision first, then applying quantization to obtain binary neural networks. This preliminary training in higher precision ensures that the network learns optimal architecture and parameters before binary conversion, minimizing approximation and quantization errors while keeping the design process manageable

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention cushions against quantization errors by training with floating-point precision beforehand and using knowledge distillation from the floating-point supernet to guide the binary network training. This preliminary high-precision training creates a robust foundation that tolerates the subsequent binary quantization better

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Device complexity

If conventional NAS procedures optimized for floating point neural networks are applied to binary neural networks, then the search process can be simplified, but the suitability and performance for binary networks deteriorates

Engineering Contradiction:
Improvesearch procedure complexityVSAvoidbinary network suitability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by designing a search space and training procedure specifically tailored for binary neural networks. The supernet architecture, loss functions, and training strategies are locally optimized for binary constraints, ensuring both simplicity and high suitability for binary network generation

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the parameter optimization approach to accommodate binary constraints. By using differentiable architecture search with gradient descent and implementing proper quantization strategies, the method maintains simple search procedures while ensuring high reliability and suitability for binary neural networks

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11132600B2Method and device for neural architecture search optimized for binary neural network
Publication Date: 2021.09.28 GWANGJU INST OF SCI & TECH
  • US11132600B2 patent drawing
  • US11132600B2 patent drawing
  • US11132600B2 patent drawing

AI summary

A method for generating a target network by performing neural architecture search using optimized search space is provided. The method includes steps of: a computing device (a) if a target data is inputted into the target network, allowing the target network to apply neural network operation to the target data, to generate an estimated search vector; and (b) allowing a loss layer to calculate architecture parameter losses by referring to the estimated search vector and a ground truth search vector, and to perform backpropagation by referring to the architecture parameter losses to update architecture parameter vectors for determining final layer operations among candidate layer operations included in an optimized layer type set corresponding to the optimized search space and wherein the final layer operations are to be performed by neural blocks, within cells of the target network, arranged according to an optimized cell template corresponding to the optimized search space.