Multilinear Domain Generalization for Low-Data Domain Shifts

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Solution Overview

Problem

Existing machine learning methods fail to effectively utilize multilinear indices structure in data domains, leading to inferior sample efficiency and generalized performance due to domain-shifts and limited data collection, especially in applications like distributed fiber optic sensing where comprehensive data coverage is costly and impractical.

Innovation Solution

A multilinear domain-specific domain generalization approach that utilizes tensor decomposition to train models jointly across observed domains, leveraging low-rank regularization and tensor completion for model assembly in unseen scenarios without additional training data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional i.i.d. assumption is used on the whole dataset, then training is simplified, but domain-shifts are not accommodated leading to poor generalization

Engineering Contradiction:
Improvetraining complexityVSAvoidgeneralization performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the dataset into multiple domains based on categorical factors (e.g., sensor type, environmental conditions, operating parameters). Each domain is treated separately with domain-specific training, allowing the model to learn domain-specific patterns while maintaining overall system performance. This segmentation enables accommodation of domain-shifts by creating domain-adaptive models rather than relying on a single global model under i.i.d. assumption.

Inventive Principle:
Principle #1Segmentation

2Reliability

If diverse data is collected to cover all domains, then domain-shifts are accommodated, but data collection cost becomes prohibitive

Engineering Contradiction:
Improvedomain coverageVSAvoiddata collection cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent creates a universal framework that can handle multiple domains using a common model architecture and training methodology. The domain generalization approach allows a single model to be trained on source domains and then adapted to multiple target domains without requiring extensive domain-specific data collection for each scenario. This multi-functionality enables the system to cover diverse domains while avoiding the prohibitive cost of collecting comprehensive data for every possible domain combination.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes parameter changes by varying domain description parameters (categorical factors) to define different domains. By representing domains through parameter combinations rather than requiring separate models for each domain, the system can generalize across multiple domains using limited training data. The domain generalization technique allows the model to adapt to new parameter combinations (domains) without retraining from scratch, reducing data collection requirements.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If limited sample size is used in each domain, then data collection cost is reduced, but sample efficiency and generalized performance deteriorate

Engineering Contradiction:
Improvedata collection costVSAvoidsample efficiency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent merges information across multiple domains through the domain generalization framework. By combining training data from multiple source domains and learning shared patterns, the model achieves better sample efficiency than training on single domains with limited data. The domain description parameters enable the model to leverage information from related domains, effectively increasing the usable sample size without requiring extensive data collection in each individual domain.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If multilinear indices structure is ignored, then processing is simplified, but information about domain relatedness is lost

Engineering Contradiction:
Improveprocessing complexityVSAvoiddomain relatedness information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent introduces another dimension by representing domains through multilinear indices based on categorical factors. This dimensional representation captures the hierarchical and relational structure of domains, enabling the model to understand domain relatedness. The multilinear indices organize domain information in a structured manner that preserves relationships between domains while remaining computationally tractable for the domain generalization algorithm.

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

Data Source

PatentUS12561841B2Multilinear domain-specific domain generalization
Publication Date: 2026.02.24 NEC CORP
  • US12561841B2 patent drawing
  • US12561841B2 patent drawing
  • US12561841B2 patent drawing

AI summary

A multilinear domain-specific domain generalization (MDSDG) approach that utilizes information stored in multilinear indices of data domains to improve machine learning. In particular—based on limited sample size(s) in observed scenarios—an array of models is jointly trained, which advantageously are generalized to a new, unseen scenario, where only domain descriptions in the form of multilinear indices are available.