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Joint Time Series Chain: Detecting Unusual Evolving Trend across Time Series

arXiv:2602.13649v1 Announce Type: new Abstract: Time series chain (TSC) is a recently introduced concept that captures the evolving patterns in large scale time series. Informally, a time series chain is a temporally ordered set of subsequences, in which consecutive subsequences in the chain are similar to one another, but the last and the first subsequences maybe be dissimilar. Time series chain has the great potential to reveal latent unusual evolving trend in the time series, or identify precursor of important events in a complex system. Unfortunately, existing definitions of time series chains only consider finding chains in a single time series. As a result, they are likely to miss unexpected evolving patterns in interrupted time series, or across two related time series. To address this limitation, in this work, we introduce a new definition called \textit{Joint Time Series Chain}, which is specially designed for the task of finding unexpected evolving trend across interrupted t

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Li Zhang, Nital Patel, Xiuqi Li, Jessica Lin
· · 1 min read · 4 views

arXiv:2602.13649v1 Announce Type: new Abstract: Time series chain (TSC) is a recently introduced concept that captures the evolving patterns in large scale time series. Informally, a time series chain is a temporally ordered set of subsequences, in which consecutive subsequences in the chain are similar to one another, but the last and the first subsequences maybe be dissimilar. Time series chain has the great potential to reveal latent unusual evolving trend in the time series, or identify precursor of important events in a complex system. Unfortunately, existing definitions of time series chains only consider finding chains in a single time series. As a result, they are likely to miss unexpected evolving patterns in interrupted time series, or across two related time series. To address this limitation, in this work, we introduce a new definition called \textit{Joint Time Series Chain}, which is specially designed for the task of finding unexpected evolving trend across interrupted time series or two related time series. Our definition focuses on mitigating the robustness issues caused by the gap or interruption in the time series. We further propose an effective ranking criterion to identify the best chain. We demonstrate that our proposed approach outperforms existing TSC work in locating unusual evolving patterns through extensive empirical evaluations. We further demonstrate the utility of our work with a real-life manufacturing application from Intel. Our source code is publicly available at the supporting page https://github.com/lizhang-ts/JointTSC .

Executive Summary

The article introduces the concept of Joint Time Series Chain (JTSC), an extension of the Time Series Chain (TSC) designed to detect unusual evolving trends across interrupted or related time series. The authors address the limitations of existing TSC definitions, which only consider single time series, by proposing a new definition and ranking criterion. The study demonstrates the effectiveness of JTSC through empirical evaluations and a real-life manufacturing application from Intel. The source code is publicly available, promoting reproducibility and further research.

Key Points

  • Introduction of Joint Time Series Chain (JTSC) to detect evolving trends across multiple or interrupted time series.
  • Proposal of a new definition and ranking criterion to mitigate robustness issues caused by gaps in time series.
  • Empirical evaluations and a real-life application from Intel demonstrate the effectiveness of JTSC.
  • Publicly available source code supports reproducibility and further research.

Merits

Innovative Approach

The introduction of JTSC addresses a significant gap in the existing literature by extending the TSC concept to multiple or interrupted time series, providing a more comprehensive tool for trend detection.

Practical Application

The real-life application from Intel demonstrates the practical utility of JTSC, showcasing its potential for industrial and real-world problem-solving.

Reproducibility

The availability of source code promotes transparency and encourages further research, which is crucial for the advancement of the field.

Demerits

Limited Scope of Empirical Evaluation

While the empirical evaluations are extensive, they may not cover all possible scenarios or industries, potentially limiting the generalizability of the findings.

Complexity of Implementation

The proposed method may be complex to implement in practice, requiring significant computational resources and expertise, which could be a barrier for some potential users.

Expert Commentary

The article presents a significant advancement in the field of time series analysis by introducing the Joint Time Series Chain (JTSC) concept. The authors effectively address the limitations of existing TSC definitions, which are confined to single time series, by proposing a new definition and ranking criterion. This extension is particularly valuable in scenarios involving interrupted or related time series, where detecting evolving trends is crucial. The empirical evaluations and the real-life application from Intel provide strong evidence of the method's effectiveness and practical utility. The availability of the source code further enhances the study's credibility and promotes reproducibility. However, the complexity of the implementation and the limited scope of empirical evaluations are notable limitations. Future research could explore the generalizability of JTSC across different industries and scenarios, as well as potential simplifications to make the method more accessible. Overall, this study makes a substantial contribution to the field and opens new avenues for research and application in time series analysis.

Recommendations

  • Future research should aim to expand the empirical evaluations to include a broader range of industries and scenarios to assess the generalizability of the JTSC method.
  • Efforts should be made to simplify the implementation process of JTSC to make it more accessible to practitioners with varying levels of expertise and computational resources.

Sources