OpenAI Blog

Nonlinear computation in deep linear networks

arXiv Machine Learning
1d ago

Circuit realization and hardware linearization of monotone operator equilibrium networks

The paper demonstrates that a resistor‑diode network’s port behavior solves a ReLU monotone operator equilibrium network, effectively realizing a neural network in analog hardware. It introduces hardware linearization to compute gradients directly in the circuit, enabling in‑hardware training demonstrated via device‑level simulation. The study also extends to cascaded networks for feedforward architectures and shows how different nonlinear elements yield distinct activation functions, including a novel diode ReLU from a non‑ideal diode model.

By Thomas Chaffey
arXiv AI
Jun 29

Derivation of effective gradient flow equations and dynamical truncation of training data in Deep Learning

arXiv:2501. 07400v2 Announce Type: replace-cross Abstract: We derive explicit equations governing the cumulative biases and weights in Deep Learning with ReLU activation function, based on gradient descent for the Euclidean loss in the input layer, and under the assumption that the weights are, in a precise sense, adapted to the coordinate system distinguished by the activations.

By Thomas Chen
arXiv AI
Aug 28

Physics-Informed Stochastic Configuration Machine: A Backpropagation-Free Neural Network with Fast Training for Nonlinear Differential Equations

The paper introduces the Physics-Informed Stochastic Configuration Machine (PI‑SCM), a backpropagation‑free neural network designed for solving nonlinear differential equations. By analytically evaluating local Jacobians, PI‑SCM linearizes the physical loss, enabling optimal weight determination through generalized linear least squares and avoiding iterative nonlinear optimization. The authors present a progressive algorithmic suite—PI‑SC‑I, PI‑SC‑II, and PI‑SC‑III—prove their universal approximation properties, and show through experiments that PI‑SCM achieves high‑fidelity predictions and parameter identification while accelerating training by orders of magnitude compared to standard PINNs.

By Yuehao Song (School of Automation, Central South University, Changsha, China), Zhong Chen (School of Automation, Central South University, Changsha, China), Lihui Cen (School of Automation, Central South University, Changsha, China), Liang Wu (Johns Hopkins University, Baltimore, USA), Kai Zhang (State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China)
arXiv Machine Learning
Sep 10

The Dynamics of Generalization in Deep Learning

arXiv:2504.16450v4 Announce Type: replace Abstract: We derive a differential equation that governs the evolution of the generalization gap when a model is trained by gradient descent-based methods. T...

By Rubing Yang, Pratik Chaudhari
arXiv Machine Learning
Sep 4

Linearized subspace refinement framework to expose hidden accuracy in trained neural networks

The paper introduces Linearized Subspace Refinement (LSR), a post‑training framework that uses the local linearized model of a trained neural network to compute a low‑dimensional correction via a reduced least‑squares problem. LSR is architecture‑agnostic and improves accuracy across tasks such as function approximation, operator learning, physics‑informed fine‑tuning, and noisy inverse problems, often achieving order‑of‑magnitude error reductions. The method reveals that standard training can leave significant accuracy plateaus due to numerical ill‑conditioning, and it offers a subspace rank that balances correction strength, stability, and noise sensitivity.

By Wenbo Cao, Weiwei Zhang