Christian Uhl: Extracting Dynamical Systems-Based Signals from Noisy and Incomplete Datasets

Christian Uhl: Extracting Dynamical Systems-Based Signals from Noisy and Incomplete Datasets

🎙 Christian Uhl 👥 3K 📅 February 25, 2026 ⏱ 30 min 👁 39 📄 original study 🧭 2026-08-16
Available in: English (current) Français

Keywords

DyCAgeneralized eigenvalue problemKoopmandenoisingincomplete data

Summary

Christian Uhl presents Dynamical Component Analysis (DyCA), a new signal decomposition algorithm for extracting deterministic signals from noisy and incomplete multivariate data. The method is based on a Koopman operator approach, optimizing a least-squares cost function derived from a set of linear differential equations. This leads to a generalized eigenvalue problem involving correlation matrices of the signal and its time-shifted versions. The eigenvalues indicate the goodness of fit, allowing estimation of the number of linear equations. A singular value decomposition step removes redundancies and estimates the number of dynamical modes. The algorithm is demonstrated on simulated data (damped oscillator, Rössler attractor) and compared with PCA, ICA, and DMD, showing competitive or superior performance in certain scenarios. A robust version, robust DyCA, incorporates L2 regularization and variational denoising to handle additive noise and incomplete data, demonstrated on the Rössler attractor with up to 60% missing data. Application to real EEG data from epileptic seizures reveals clear phase-space structure, potentially linked to Shilnikov chaos. Limitations are acknowledged: DyCA works best when linear equations outnumber nonlinear ones and struggles with additive noise, which the robust version addresses. The talk concludes with a Q&A discussing potential control applications, such as seizure prediction.

198 words

Critical Evaluation

Value of the Information & Strength of the Argument

The talk provides a detailed derivation of the DyCA algorithm, including the optimization problem, the generalized eigenvalue formulation, and the mode selection procedure. The value lies in offering a new tool for signal decomposition that is theoretically grounded in dynamical systems theory. The argumentation is solid: the method is validated on synthetic examples with known ground truth, and comparisons with established methods (PCA, ICA, DMD) are presented. The speaker also honestly discusses limitations, such as the requirement for more linear than nonlinear equations and sensitivity to additive noise, which is addressed by the robust version. The real-world application to EEG data adds practical relevance. However, the presentation is dense and assumes familiarity with linear algebra and dynamical systems, which may limit accessibility.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high: the algorithm is derived from first principles, and the experimental setup is clearly described. The speaker references key publications and provides a GitHub link for implementation, but these are not explicitly listed in the talk. The title accurately reflects the content. The talk is a seminar presentation, so it does not include formal citations, but the methodology appears sound. The lack of peer-reviewed references in the talk itself is a minor weakness, but the technical depth and honest discussion of limitations compensate.

224 words

Title / Content Match

The title accurately reflects the content: the speaker presents a method to extract dynamical systems-based signals from noisy and incomplete data.

Quality & Reliability

8/10

The talk presents a novel algorithm (DyCA) with mathematical derivations, simulated examples, and applications to real EEG data. The methodology is clearly explained, and the results are compared with established methods (PCA, ICA, DMD). Limitations are acknowledged. The presentation is technical and appears rigorous, though the lack of peer-reviewed references in the talk itself limits verification.

Key Moments

Cited Sources

Concurring Sources

  • Koopman operator theory — The DyCA method is based on Koopman operator theory, which provides a linear representation of nonlinear dynamics.
  • Dynamic Mode Decomposition (DMD) — DyCA is compared with DMD, a widely used method for extracting spatiotemporal patterns from dynamical systems.

Dissenting Sources

Contribution & Novelties

The talk introduces Dynamical Component Analysis (DyCA), a novel algorithm that bridges signal processing and dynamical systems theory. Its key novelty is the formulation of signal decomposition as a generalized eigenvalue problem derived from a Koopman-based linear differential equation model, allowing extraction of deterministic components from noisy data. The robust version extends this to handle additive noise and incomplete data via L2 regularization and variational denoising. This is a significant contribution to the field of data-driven discovery of dynamical systems.

Pour aller plus loin :

119 words

Radar Profile

The radar profile shows high scores in technical level and information quality, indicating a dense, mathematically rigorous presentation. The lower score in quantity of information relative to technical depth suggests the talk is focused but may not cover a broad range of examples. Overall, the profile reflects a specialized seminar talk suitable for experts.

Reliability 8/10

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