DNN Outlier Detection Using T-Way Feature Combinations

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Solution Overview

Problem

Deep Neural Networks (DNNs) struggle with outlier detection due to the need for large training data sets and unpredictability in handling unseen image types, leading to erroneous results, particularly in medical imaging.

Innovation Solution

A method using t-way feature combinations to analyze DNN feature vectors, flagging abnormal inputs by quantizing feature vectors to discrete values and comparing against thresholds, reducing the impact on normal inputs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If DNNs are used for outlier detection, then processing efficiency and data representation capability are improved, but reliability deteriorates due to heavy dependence on training data and unpredictability on unseen inputs

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidoutput reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary action by computing statistics of feature vector values during the training phase and storing them for later use. This pre-computed statistical information is then applied during outlier detection to reliably identify outliers without requiring the DNN to have seen similar inputs during training, thus improving reliability while maintaining processing efficiency.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If large training data sets are used to improve DNN performance, then detection accuracy is improved, but the need for extensive retraining and data collection increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidretraining time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The invention extracts the essential statistical characteristics of normal data by computing statistics of feature vector values during training. These extracted statistical parameters are then used for outlier detection without requiring the full training dataset, thereby maintaining detection accuracy while eliminating the need for extensive retraining and data collection.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If traditional outlier detection methods are used, then interpretability is improved, but processing capability for large amounts of data deteriorates

Engineering Contradiction:
ImproveinterpretabilityVSAvoiddata processing capability
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system segments the complex outlier detection problem into two parts: first, the DNN processes large amounts of data efficiently to extract feature vectors; second, simple statistical comparisons are performed on these feature vectors to detect outliers. This segmentation allows the system to maintain both high data processing capability and interpretability, as the statistical comparison step is easily understandable.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12493667B2Outlier detection in a deep neural network using t-way feature combinations
Publication Date: 2025.12.09 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US12493667B2 patent drawing
  • US12493667B2 patent drawing
  • US12493667B2 patent drawing

AI summary

Outlier detection using a Deep Neural Network (DNN) includes running a trained DNN model on an received input item. A first feature vector is extracted from the input item and quantized to discrete values. A first number of special t-way feature combinations are computed in the input item and compared against a computed threshold. Based on the comparison, the input item is flagged as an outlier and an alert is generated notifying of the flagged input item.