Time-Series Embeddings Using Contrastive Learning for Classification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge of translating high-dimensional time-series data into lower-dimensional embeddings is exacerbated by non-linear relationships, making it difficult to identify relevant data links and classify electrical activity or behavioral patterns effectively.

Innovation Solution

A method involving contrastive learning is employed to select positive and negative samples from time-series data, mapping them into a common embedding space using deep neural networks, and optimizing the embedding space through a contrastive loss function to retain relevant information while reducing dimensionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If traditional dimensionality reduction methods are used on high-dimensional time-series data with non-linear relationships, then the data can be reduced to lower dimensions, but the relevant information links are lost or obscured making classification difficult

Engineering Contradiction:
Improveloss of relevant information linksVSAvoidcomplexity of identifying relevant links
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary embedding space that acts as a mediator between the high-dimensional input space and the classification task. This embedding space preserves relevant information links through carefully constructed positive and negative sample pairs, allowing the system to maintain information integrity while reducing dimensionality for effective classification.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If more dimensions are retained in the embedding space to preserve non-linear relationships, then classification accuracy improves, but the computational complexity and processing time increase

Engineering Contradiction:
Improveclassification accuracyVSAvoidprocessing speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the parameters of the embedding space by optimizing the dimensionality and the distribution of positive and negative samples. By adjusting these parameters, the system achieves a balance where the embedding space is sufficiently rich to capture non-linear relationships for accurate classification while remaining compact enough to enable efficient processing and maintain high productivity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the embedding space is optimized to separate dissimilar samples, then classification discrimination improves, but the risk of over-separating similarly labeled data increases

Engineering Contradiction:
Improvediscrimination precisionVSAvoidreliability of similarity preservation
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent implements feedback mechanisms through the contrastive learning objective function that continuously adjusts the embedding space based on the performance with respect to both positive and negative samples. This feedback loop ensures that the embedding space optimizes discrimination of dissimilar samples while maintaining appropriate separation for similarly labeled data, balancing discrimination precision with reliability of similarity preservation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS12499131B2Dimensionality reduction of time-series data, and systems and devices that use the resultant embeddings
Publication Date: 2025.12.16 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • US12499131B2 patent drawing
  • US12499131B2 patent drawing
  • US12499131B2 patent drawing

AI summary

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dimensionality reduction of time-series using contrastive learning. A method can include receiving multidimensional input time series data that includes data from a session or sessions that span time, selecting positive samples and negative samples from the multidimensional input time series data for respective reference samples from the multidimensional input time series data, wherein the positive samples and negative samples are each selected with a respective predetermined distribution across the time of the session or sessions of the multidimensional input time series, and mapping the reference samples, the positive samples, and negative samples into a common embedding space.