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Related papers: Improved off-policy training of diffusion samplers

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Offline reinforcement learning (RL), which aims to learn an optimal policy using a previously collected static dataset, is an important paradigm of RL. Standard RL methods often perform poorly in this regime due to the function…

Machine Learning · Computer Science 2023-08-29 Zhendong Wang , Jonathan J Hunt , Mingyuan Zhou

Diffusion models have been successfully adapted to text generation tasks by mapping the discrete text into the continuous space. However, there exist nonnegligible gaps between training and inference, owing to the absence of the forward…

Computation and Language · Computer Science 2023-05-09 Zecheng Tang , Pinzheng Wang , Keyan Zhou , Juntao Li , Ziqiang Cao , Min Zhang

Diffusion models have attained prominence for their ability to synthesize a probability distribution for a given dataset via a diffusion process, enabling the generation of new data points with high fidelity. However, diffusion processes…

Machine Learning · Computer Science 2024-11-25 Shervin Khalafi , Dongsheng Ding , Alejandro Ribeiro

Sample efficiency is crucial for imitation learning methods to be applicable in real-world applications. Many studies improve sample efficiency by extending adversarial imitation to be off-policy regardless of the fact that these off-policy…

Machine Learning · Computer Science 2022-04-14 Mingfei Sun , Sam Devlin , Katja Hofmann , Shimon Whiteson

As one of the most popular and sought-after generative models in the recent years, diffusion models have sparked the interests of many researchers and steadily shown excellent advantage in various generative tasks such as image synthesis,…

Computer Vision and Pattern Recognition · Computer Science 2024-10-17 Zhiyuan Ma , Yuzhu Zhang , Guoli Jia , Liangliang Zhao , Yichao Ma , Mingjie Ma , Gaofeng Liu , Kaiyan Zhang , Jianjun Li , Bowen Zhou

We explore the methodology and theory of reward-directed generation via conditional diffusion models. Directed generation aims to generate samples with desired properties as measured by a reward function, which has broad applications in…

Machine Learning · Computer Science 2023-07-17 Hui Yuan , Kaixuan Huang , Chengzhuo Ni , Minshuo Chen , Mengdi Wang

Guidance serves as a key concept in diffusion models, yet its effectiveness is often limited by the need for extra data annotation or classifier pretraining. That is why guidance was harnessed from self-supervised learning backbones, like…

Computer Vision and Pattern Recognition · Computer Science 2023-12-15 Vincent Tao Hu , Yunlu Chen , Mathilde Caron , Yuki M. Asano , Cees G. M. Snoek , Bjorn Ommer

We introduce Diffusion Active Learning, a novel approach that combines generative diffusion modeling with data-driven sequential experimental design to adaptively acquire data for inverse problems. Although broadly applicable, we focus on…

Machine Learning · Computer Science 2025-04-07 Luis Barba , Johannes Kirschner , Tomas Aidukas , Manuel Guizar-Sicairos , Benjamín Béjar

Imputation methods play a critical role in enhancing the quality of practical time-series data, which often suffer from pervasive missing values. Recently, diffusion-based generative imputation methods have demonstrated remarkable success…

Machine Learning · Computer Science 2025-10-03 Zeqi Ye , Minshuo Chen

Energy-based policies offer a flexible framework for modeling complex, multimodal behaviors in reinforcement learning (RL). In maximum entropy RL, the optimal policy is a Boltzmann distribution derived from the soft Q-function, but direct…

Machine Learning · Computer Science 2025-09-09 Vineet Jain , Tara Akhound-Sadegh , Siamak Ravanbakhsh

Geophysical inverse problems are often ill-posed and admit multiple solutions. Conventional discriminative methods typically yield a single deterministic solution, which fails to model the posterior distribution, cannot generate diverse…

Adversarial Imitation Learning (AIL) faces challenges with sample inefficiency because of its reliance on sufficient on-policy data to evaluate the performance of the current policy during reward function updates. In this work, we study the…

Machine Learning · Computer Science 2024-05-28 Yilei Chen , Vittorio Giammarino , James Queeney , Ioannis Ch. Paschalidis

Diffusion models are a class of flexible generative models trained with an approximation to the log-likelihood objective. However, most use cases of diffusion models are not concerned with likelihoods, but instead with downstream objectives…

Machine Learning · Computer Science 2024-01-08 Kevin Black , Michael Janner , Yilun Du , Ilya Kostrikov , Sergey Levine

We present a novel simulation-free framework for training continuous-time diffusion processes over very general objective functions. Existing methods typically involve either prescribing the optimal diffusion process -- which only works for…

Machine Learning · Computer Science 2025-06-24 Mengjian Hua , Eric Vanden-Eijnden , Ricky T. Q. Chen

We introduce a new paradigm for generative modeling built on Continuous Normalizing Flows (CNFs), allowing us to train CNFs at unprecedented scale. Specifically, we present the notion of Flow Matching (FM), a simulation-free approach for…

Machine Learning · Computer Science 2023-02-09 Yaron Lipman , Ricky T. Q. Chen , Heli Ben-Hamu , Maximilian Nickel , Matt Le

Sample efficiency is one of the most critical issues for online reinforcement learning (RL). Existing methods achieve higher sample efficiency by adopting model-based methods, Q-ensemble, or better exploration mechanisms. We, instead,…

Machine Learning · Computer Science 2023-05-31 Jiafei Lyu , Le Wan , Zongqing Lu , Xiu Li

Offline decision-making via diffusion models often produces trajectories that are misaligned with system dynamics, limiting their reliability for control. We propose Model Predictive Diffuser (MPDiffuser), a compositional diffusion…

Robotics · Computer Science 2026-02-02 Haldun Balim , Na Li , Yilun Du

We present a supervised learning framework of training generative models for density estimation. Generative models, including generative adversarial networks, normalizing flows, variational auto-encoders, are usually considered as…

Machine Learning · Computer Science 2023-10-24 Yanfang Liu , Minglei Yang , Zezhong Zhang , Feng Bao , Yanzhao Cao , Guannan Zhang

Imitation Learning presents a promising approach for learning generalizable and complex robotic skills. The recently proposed Diffusion Policy generates robot action sequences through a conditional denoising diffusion process, achieving…

Machine Learning · Computer Science 2024-12-03 Xiu Yuan

Diffusion models have achieved state-of-the-art synthesis quality on both visual and audio tasks, and recent works further adapt them to textual data by diffusing on the embedding space. In this paper, we conduct systematic studies of the…

Computation and Language · Computer Science 2024-04-23 Zhujin Gao , Junliang Guo , Xu Tan , Yongxin Zhu , Fang Zhang , Jiang Bian , Linli Xu