Neural Network Feature Reconstruction for Out-of-Distribution Detection

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Solution Overview

Problem

Existing methods for out-of-distribution (OOD) data detection in neural networks are complex and computationally expensive, requiring significant resources and hardware, making them unsuitable for real-world applications, especially in industrial and low-cost platforms.

Innovation Solution

A method that transforms features from a neural network layer from a high-dimensional space to a lower-dimensional space and back, calculating a feature reconstruction error to detect OOD data, which can be done using existing DNNs without training new models, reducing complexity and computational overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing methods for OOD detection are used, then detection accuracy is improved, but computational complexity and hardware requirements increase significantly

Engineering Contradiction:
ImproveOOD detection accuracyVSAvoidmodel complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential feature transformation and reconstruction operations needed for OOD detection, separating them from complex training processes. By taking out the core reconstruction error calculation from the overall detection system, the method achieves accurate OOD detection without requiring complex model architectures or extensive training procedures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses feature copying and reconstruction - creating a reconstructed version of the input feature map through transformation and inverse transformation. By comparing the original and reconstructed features, the system detects OOD data without needing complex classification models, achieving simplicity through this copying-comparison mechanism.

Inventive Principle:
Principle #26Copying

2Measurement precision

If existing methods for OOD detection are used, then detection accuracy is improved, but training time and computational resources increase

Engineering Contradiction:
ImproveOOD detection accuracyVSAvoidtraining time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs feature transformation and reconstruction operations as preliminary actions that can be executed without extensive training. By pre-defining the transformation pipeline (forward transformation to embedding space, then inverse transformation back), the system eliminates lengthy training phases while maintaining detection accuracy through the reconstruction error metric.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The detection system serves itself by using the neural network's own feature maps and internal transformations for OOD detection. The forward and inverse transformations operate on the network's existing features without requiring external training data or complex training procedures, making the system self-sufficient and training-free.

Inventive Principle:
Principle #25Self-service

3Reliability

If existing methods for OOD detection are used, then detection capability is improved, but hardware cost and computational power requirements increase

Engineering Contradiction:
Improvedetection capabilityVSAvoidcomputational energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameter space by transforming features into an embedding space and back, using dimensional transformation rather than complex model computations. This parameter change approach - moving between different feature representations through linear transformations - reduces computational energy requirements while maintaining reliable OOD detection capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex mechanical training processes and heavy computational models with a lighter transformation-based system. By substituting the traditional training-heavy approach with forward-inverse transformation operations, the system achieves the same detection capability with significantly reduced computational energy and simpler hardware requirements.

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

4Ease of manufacture

If simple detection methods are used, then computational requirements are reduced, but OOD detection accuracy decreases

Engineering Contradiction:
Improveimplementation simplicityVSAvoidOOD detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent moves the detection problem to another dimension by transforming features into an embedding space with different dimensional characteristics. This dimensional change allows simple linear transformations to achieve accurate detection - the forward transformation projects features to an embedding dimension, and the inverse transformation reconstructs them, with the reconstruction error providing accurate OOD detection without complex operations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20230298322A1Out-of-distribution detection using a neural network
Publication Date: 2023.09.21 INTEL CORP
  • US20230298322A1 patent drawing
  • US20230298322A1 patent drawing
  • US20230298322A1 patent drawing

AI summary

Features extracted from one or more layers of a trained deep neural network (DNN) are used to detect out-of-distribution (OOD) data, such as anomalies. An OOD detection process includes transforming a feature output from a layer of the DNN from a relatively high-dimensional feature space to a lower-dimensional space, and then performing a reverse transformation back to the higher-dimensional feature space, resulting in a reconstructed feature. A feature reconstruction error is calculated based on a difference between the reconstructed feature and the original feature output from the DNN. The OOD detection process may further include calculating a score based on the feature reconstruction error and generating a visual representation of the feature reconstruction error.