Teacher-Student Learning Model for Label-Free Domain Adaptation

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Solution Overview

Problem

Existing methods to prevent catastrophic forgetting in learned models require manual labeling, which is labor-intensive and suboptimal.

Innovation Solution

A learning device that acquires clean and mixture signals, extracts feature values, estimates teacher and student vector representations, and calculates a value to learn a student model without labels, aligning its estimations with a source domain teacher model.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If partial update method is used to prevent catastrophic forgetting, then estimation accuracy is maintained, but manual labeling work increases person's load

Engineering Contradiction:
Improveestimation accuracyVSAvoidperson's load
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-supervised learning where the model automatically generates its own training signals through consistency regularization across different augmentations, eliminating the need for manual labeling. The model learns to maintain consistent representations despite input variations, achieving continual learning without human annotation effort.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

A teacher-student framework is introduced where a teacher model provides guidance to a student model during continual learning. The teacher model, trained on source domain data, acts as an intermediary that helps the student model adapt to new domains while preserving knowledge from previous domains, reducing reliance on manual labels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If learned model is relearned in application domain, then adaptation to new environment is achieved, but catastrophic forgetting occurs

Engineering Contradiction:
Improveadaptation to new environmentVSAvoidestimation accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system implements continual learning by continuously updating the model with new domain data while maintaining continuous connection to source domain knowledge through the teacher-student framework. This continuous learning process prevents catastrophic forgetting by continuously reinforcing previous knowledge while adapting to new environments.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The teacher model provides feedback to the student model during the learning process, guiding the student to maintain consistency with source domain representations while adapting to application domain characteristics. This feedback mechanism ensures that adaptation does not come at the cost of forgetting previous knowledge.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4703974A1Learning device, training method, and training program
Publication Date: 2026.03.04 MITSUBISHI ELECTRIC CORP
  • EP4703974A1 patent drawingFigure 1~2
  • EP4703974A1 patent drawingFigure 3
  • EP4703974A1 patent drawingFigure 4

AI summary

A learning device (100) includes an acquisition unit (110) that acquires a clean signal, a mixture signal and a source domain teacher learned model (11), an extraction unit (130) that extracts a clean feature value by using the clean signal, an estimation unit (140) that estimates a teacher vector representation by using the source domain teacher learned model (11) and the clean feature value, an extraction unit (150) that extracts a mixture feature value by using the mixture signal, an estimation unit (160) that estimates a student vector representation by using a student learning model (12) and the mixture feature value, a calculation unit (170) that calculates a value based on the teacher vector representation and the student vector representation, and a learning unit (180) that learns the student learning model (12) by using the value so that estimation by the student learning model (12) becomes closer to estimation by the source domain teacher learned model (11).