Back to Repair: A Minimal Denoising Network for Time Series Anomaly Detection

arXiv cs.AI / 4/29/2026

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Key Points

  • The paper introduces JuRe (Just Repair), a minimal denoising neural network designed for time-series anomaly detection that emphasizes that model complexity is not required when the training objective follows the manifold-projection principle.
  • JuRe uses a single depthwise-separable convolutional residual block (hidden dimension 128) and performs detection at inference with a fixed, parameter-free structural discrepancy function.
  • Despite avoiding attention, latent variables, and adversarial training, JuRe achieved strong results, ranking second on TSB-AD and UCR benchmarks while outperforming neural baselines on AUC-PR and VUS-PR.
  • Ablation studies on TSB-AD show that corruption introduced during training is the most important driver of performance, with the denoising objective contributing more to detection quality than network capacity.
  • Statistical testing (pairwise Wilcoxon signed-rank) finds JuRe is significantly better than 21 out of 25 baselines on TSB-AD, and the authors provide released code on GitHub.

Abstract

We introduce JuRe (Just Repair), a minimal denoising network for time series anomaly detection that exposes a central finding: architectural complexity is unnecessary when the training objective correctly implements the manifold-projection principle. JuRe consists of a single depthwise-separable convolutional residual block with hidden dimension 128, trained to repair corrupted time series windows and scored at inference by a fixed, parameter-free structural discrepancy function. Despite using no attention, no latent variable, and no adversarial component, JuRe ranks second on the TSB-AD multivariate benchmark (AUC-PR 0.404, 180 series, 17 datasets) and second on the UCR univariate archive by AUC-PR (0.198, 250 series), leading all neural baselines on AUC-PR and VUS-PR. Component ablation on TSB-AD identifies training-time corruption as the dominant factor (\DeltaAUC-PR = 0.047 on removal), confirming that the denoising objective, not network capacity, drives detection quality. Pairwise Wilcoxon signed-rank tests establish statistical significance against 21 of 25 baselines on TSB-AD. Code is available at the URL https://github.com/iis-esslingen/JuRe.