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Researchers at UT Austin Introduce Panda: A Foundation Model for Nonlinear Dynamics Pretrained on 20,000 Chaotic ODE Discovered via Evolutionary Search
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德克萨斯大学奥斯汀分校的研究人员开发了Panda模型,这是一个预训练模型,专注于非线性动力学。Panda在20,000个算法生成的混沌系统上进行训练,展现出强大的零样本预测能力,即使在未见过的真实世界数据和偏微分方程上也能表现出色。该模型通过创新性的架构设计,如通道注意力机制和动态嵌入,捕捉动力学结构。Panda的性能随着训练系统多样性的增加而提高,并揭示了神经缩放定律。这项研究为理解和预测复杂动态系统开辟了新的道路。

🧠Panda模型是基于20,000个算法生成的混沌系统训练的预训练模型,这些系统是通过进化算法从已知的混沌常微分方程中生成的。

💡Panda模型在从未接触过偏微分方程的情况下,也能成功预测真实世界的实验数据和混沌偏微分方程,如Kuramoto-Sivashinsky和von Kármán涡街。

📈Panda模型在各种指标和预测范围上都优于Chronos-SFT等模型,展现出强大的零样本预测能力。

⚙️该模型采用了PatchTST架构,并增强了通道注意力、时间-通道注意力层以及动态嵌入,这些设计灵感来源于Koopman算子理论。

🔬Panda的性能与训练数据的多样性之间存在联系,揭示了一种神经缩放定律,并且在注意力模式中形成了可解释的结构,表明了模型对共振和吸引子的敏感性。

Chaotic systems, such as fluid dynamics or brain activity, are highly sensitive to initial conditions, making long-term predictions difficult. Even minor errors in modeling these systems can rapidly grow, which limits the effectiveness of many scientific machine learning (SciML) approaches. Traditional forecasting methods rely on models trained on specific time series or broad datasets lacking true dynamical structure. However, recent work has demonstrated the potential for local forecasting models to predict chaotic systems more accurately over longer timeframes by learning the numerical rules governing these systems. The real challenge is achieving out-of-domain generalization—creating models that can adapt and forecast new, previously unseen dynamical systems. This would require integrating prior knowledge with the ability to adapt locally. Still, the need for task-specific data constrains current methods and often overlooks key dynamical system properties such as ergodicity, channel coupling, and conserved quantities.

Machine learning for dynamical systems (MLDS) utilizes the unique properties of such systems as inductive biases. These include fixed relationships among system variables and invariant statistical measures, like strange attractors or conserved quantities. MLDS models use these properties to build more accurate and generalizable models, sometimes incorporating probabilistic or latent variable techniques. While datasets of dynamical systems have been curated and new systems are often generated by tweaking parameters or using symbolic methods, these approaches typically don’t ensure diverse or stable dynamics. Structural stability is a challenge—small changes may not yield new behaviors, while large ones can cause trivial dynamics. Foundation models aim to address this by enabling transfer learning and zero-shot inference. Still, most current models perform comparably to standard time series models or are limited in generating meaningful, dynamic variety. Some progress has been made through techniques like embedding spaces or symbolic discovery, but a richer, more diverse sampling of dynamical behaviors remains an open challenge. 

Researchers at the Oden Institute, UT Austin, introduce Panda (Patched Attention for Nonlinear Dynamics), a pretrained model trained solely on synthetic data from 20,000 algorithmically-generated chaotic systems. These systems were created using an evolutionary algorithm based on known chaotic ODEs. Despite training only on low-dimensional ODEs, Panda shows strong zero-shot forecasting on real-world nonlinear systems—including fluid dynamics and electrophysiology—and unexpectedly generalizes to PDEs. The model incorporates innovations like masked pretraining, channel attention, and kernelized patching to capture dynamical structure. A neural scaling law also emerges, linking Panda’s forecasting performance to the diversity of training systems. 

The researchers generated 20,000 new chaotic systems using a genetic algorithm that evolves from a curated set of 135 known chaotic ODEs. These systems are mutated and recombined using a skew product approach, with only truly chaotic behaviors retained through rigorous tests. Augmentations like time-delay embeddings and affine transformations expand the dataset while preserving its dynamics. A separate set of 9,300 unseen systems is held out for zero-shot testing. The model, Panda, is built on PatchTST and enhanced with features like channel attention, temporal-channel attention layers, and dynamic embeddings using polynomial and Fourier features, inspired by Koopman operator theory. 

Panda demonstrates strong zero-shot forecasting capabilities on unseen nonlinear dynamical systems, outperforming models like Chronos-SFT across various metrics and prediction horizons. Trained solely on 3D systems, it generalizes to higher-dimensional ones due to channel attention. Despite never encountering PDEs during training, Panda also succeeds on real-world experimental data and chaotic PDEs, such as the Kuramoto-Sivashinsky and von Kármán vortex street. Architectural ablations confirm the importance of channel attention and dynamics embeddings. The model exhibits neural scaling with increased dynamical system diversity and forms interpretable attention patterns, suggesting resonance and attractor-sensitive structure. This indicates Panda’s broad generalization across complex dynamical behaviors. 

In conclusion, Panda is a pretrained model designed to uncover generalizable patterns in dynamical systems. Trained on a large, diverse set of synthetic chaotic systems, Panda demonstrates strong zero-shot forecasting on unseen real-world data and even partial differential equations, despite only being trained on low-dimensional ODEs. Its performance improves with system diversity, revealing a neural scaling law. The model also shows emergent nonlinear resonance in attention patterns. While focused on low-dimensional dynamics, the approach may extend to higher-dimensional systems by leveraging sparse interactions. Future directions include alternative pretraining strategies to improve rollout performance forecasting chaotic behaviors. 


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The post Researchers at UT Austin Introduce Panda: A Foundation Model for Nonlinear Dynamics Pretrained on 20,000 Chaotic ODE Discovered via Evolutionary Search appeared first on MarkTechPost.

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Panda模型 混沌系统 机器学习 动力学系统
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