Sequential Machine Learning Model Consistency via LwF-Logit Feedback

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Solution Overview

Problem

In a restricted multi-center learning environment, where data from all data centers cannot be utilized simultaneously, catastrophic forgetting occurs as the model learned at a previous data center is forgotten when the current data center performs machine learning with its own data set, especially in neural networks using gradient descent, existing methods like fine-tuning, Elastic Weight Consolidation (EWC), and Learning without Forgetting (LwF) face challenges in preventing drastic changes in feature spaces.

Innovation Solution

The method involves generating feature spaces and predictive label information based on data sets, using neural network parameters to minimize differences between label and feature spaces through back propagation, and updating parameters to maintain consistency across sequential machine learning stages, ensuring that the first machine learning model's parameters remain unchanged when applied to subsequent data sets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fine-tuning method is used to adapt model parameters to current data set, then learning efficiency is improved, but catastrophic forgetting occurs as parameters change drastically

Engineering Contradiction:
Improvelearning efficiencyVSAvoidcatastrophic forgetting
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The method pre-calculates LwF-logit values for all current stage data sets before initiating learning, using model parameters from the previous stage. This preliminary action preserves information about previous stage relationships while enabling efficient current stage learning, preventing catastrophic forgetting by establishing a reference point before parameter updates begin

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If EWC method is used to regularize important parameters, then catastrophic forgetting is reduced, but determination of parameter importance is imperfect

Engineering Contradiction:
Improvecatastrophic forgettingVSAvoidparameter importance determination
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The method introduces LwF-logit as an intermediary representation that captures the relationship between previous stage data and model parameters. This intermediary serves as a mediator that preserves information about parameter importance without requiring direct calculation of Fisher information matrix, achieving better precision in determining which parameters should be preserved

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of information

If LwF method is used to preserve previous models, then catastrophic forgetting is addressed, but feature space changes drastically due to unlimited flexibility

Engineering Contradiction:
Improvecatastrophic forgettingVSAvoidfeature space stability
Core Design Contradiction:
Loss of informationVSStability of the object's composition

Solution Approach 1:

The method uses LwF-logit as feedback from the previous stage model to guide current stage learning. By comparing current predictions against the pre-calculated LwF-logit values, the system receives feedback that penalizes drastic feature space changes while still allowing necessary adaptations to current data, thus maintaining feature space stability

Inventive Principle:
Principle #23Feedback

4Reliability

If sequential machine learning is performed across multiple data centers, then data privacy is maintained, but model performance degrades due to catastrophic forgetting

Engineering Contradiction:
Improvedata privacyVSAvoidmodel performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Before each sequential learning stage at a new data center, the method pre-calculates LwF-logit values based on the previous stage model and current data. This preliminary action establishes a reference framework that enables the model to adapt to new data while preserving knowledge from previous data centers, maintaining both data privacy and model performance across sequential stages

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11620529B2Method of continual-learning of data sets and apparatus thereof
Publication Date: 2023.04.04 LUNIT
  • US11620529B2 patent drawing
  • US11620529B2 patent drawing
  • US11620529B2 patent drawing

AI summary

This disclosure relates to a method of sequential machine learning of data sets and an apparatus thereof. The method may include generating a first machine learning model by generating a first feature space based on a first data set, generating first predictive label information based on the first feature space, performing machine learning on a relationship between the first data set and first label information related to a first data set, and performing machine learning on a relationship between the first predictive label information and the first feature space. The method may also include generating a second machine learning model based on the first machine learning model by generating a second feature space based on a second data set, generating second predictive label information based on the second feature space, and performing machine learning on a relationship between the second data set and a second label information.