Multi-View Contrastive Learning for Time Series Representation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Time series data analysis is challenging due to its high dimensionality and complexity, making labeling tasks expensive and requiring expert knowledge, especially in medical settings like cardiac abnormality identification from ECG data or emotion recognition through EEG and ECG signals, where labeled data is scarce.

Innovation Solution

A multi-view contrastive relational learning (MV-CRL) framework is introduced, which employs multiple parallel contrastive learning branches to generate auxiliary representations of time series data through specific transformations, using encoders to compute loss objectives based on inter-sample relationships, thereby learning effective representations even with limited labeled data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If supervised learning is used for time series classification, then classification accuracy can be improved, but labeling cost and expert knowledge requirements increase significantly

Engineering Contradiction:
Improveclassification accuracyVSAvoidlabeling cost
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The system performs self-supervised learning by automatically generating auxiliary views and contrastive labels from the time series data itself, without requiring external expert labeling. The multi-view contrastive relational learning framework enables the model to learn meaningful representations through self-generated supervision signals, eliminating the need for expensive manual annotation while maintaining high classification accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The time series data is segmented into multiple auxiliary views through different transformations (e.g., time warping, magnitude scaling, frequency domain transformations). Each view provides a different perspective on the same underlying pattern, allowing the system to learn robust representations without requiring labeled data for each view. This segmentation approach converts a single labeled dataset into multiple unlabeled auxiliary views that collectively provide rich supervision signals

Inventive Principle:
Principle #1Segmentation

2Reliability

If more labeled data is collected for training, then model performance improves, but data collection time and experimental complexity increase

Engineering Contradiction:
Improvemodel performanceVSAvoiddata collection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary transformations of the available time series data into multiple auxiliary views before training begins. By pre-processing the data into various transformed representations (time-warped, magnitude-scaled, frequency-transformed versions), the system prepares rich training material in advance that can be used for self-supervised learning, eliminating the need for time-consuming data collection experiments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies parameter transformations to generate auxiliary views, including time warping parameters, magnitude scaling factors, and frequency domain transformations. By changing these parameters systematically, the system generates diverse training samples from the same underlying data, improving model performance without requiring additional data collection experiments

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If traditional supervised learning is applied to high dimensional time series data, then classification tasks can be performed, but the requirement for expert knowledge and labeled data increases

Engineering Contradiction:
Improveclassification task executionVSAvoidexpert knowledge requirement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system introduces auxiliary views as intermediary representations between the raw time series data and the final classification task. These auxiliary views serve as mediators that capture different aspects of the underlying patterns without requiring expert interpretation. The multi-view contrastive learning framework uses these intermediaries to learn robust features that automatically transfer to the classification task, reducing the need for expert knowledge in both data preparation and model interpretation

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS20220261651A1Systems and methods for self supervised multi-view representation learning for time series
Publication Date: 2022.08.18 SALESFORCE INC
  • US20220261651A1 patent drawing
  • US20220261651A1 patent drawing
  • US20220261651A1 patent drawing

AI summary

A multi-view contrastive relational learning framework is provided. In the multi-view contrastive relational learning framework, contrastive learning is augmented with a multi-view learning signal. The auxiliary views guide an encoder of the underlying time series data's main view, by using an inter-sample similarity structure as a learning signal to learn representations which encode information from multiple views.