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Wei-Fang Sun

12 accepted papers

2026

VLM-AR3L: Vision-Language Models for Absolute and Relative Rewards in Reinforcement Learning

IJCAI 2026

Designing effective reward functions remains a major challenge in reinforcement learning (RL), particularly in open-ended environments where task goals are abstract and difficult to quantify. In this work, we present VLM-AR3L, a framework that leverages Vision-Language Models (VLMs) to provide both

Cited by 0Scholar
2025

3D Gaussian Splatting with Grouped Uncertainty for Unconstrained Images

ICASSP 2025accepted

3D Gaussian Splatting (3DGS) [1] is a promising method for 3D reconstruction and novel view synthesis. However, training it with unconstrained images presents challenges due to transient objects that cause undesired floaters and ghosting artifacts. Although related works using Neural Radiance Fields…

Cited by 0SourceScholar
2025

Beyond Masked and Unmasked: Discrete Diffusion Models via Partial Masking

NeurIPS 2025poster

Masked diffusion models (MDM) are powerful generative models for discrete data that generate samples by progressively unmasking tokens in a sequence. Each token can take one of two states: masked or unmasked. We observe that token sequences often remain unchanged between consecutive sampling steps;…

Cited by 0SourceScholar
2025

EDELINE: Enhancing Memory in Diffusion-based World Models via Linear-Time Sequence Modeling

NeurIPS 2025spotlight

World models represent a promising approach for training reinforcement learning agents with significantly improved sample efficiency. While most world model methods primarily rely on sequences of discrete latent variables to model environment dynamics, this compression often neglects critical visual…

Cited by 0SourcecodeScholar
2025

Retraining-free Merging of Sparse MoE via Hierarchical Clustering

ICML 2025poster

Sparse Mixture-of-Experts (SMoE) models represent a significant advancement in large language model (LLM) development through their efficient parameter utilization. These models achieve substantial performance improvements at reduced inference costs. However, the deployment of SMoE models faces cons…

2024

Expert Proximity as Surrogate Rewards for Single Demonstration Imitation Learning

ICML 2024poster

In this paper, we focus on single-demonstration imitation learning (IL), a practical approach for real-world applications where acquiring multiple expert demonstrations is costly or infeasible and the ground truth reward function is not available. In contrast to typical IL settings with multiple dem…

2024

Language-Guided Pattern Formation for Swarm Robotics with Multi-Agent Reinforcement Learning

IROS 2024poster

This paper explores leveraging the vast knowledge encoded in Large Language Models (LLMs) to tackle pattern formation challenges for swarm robotics systems. A new framework, named LGPF (Language-Guided Pattern Formation), is proposed to address these challenges. The framework breaks down the pattern…

Cited by 2SourceScholar
2024

Maximum Entropy Reinforcement Learning via Energy-Based Normalizing Flow

NeurIPS 2024poster

Existing Maximum-Entropy (MaxEnt) Reinforcement Learning (RL) methods for continuous action spaces are typically formulated based on actor-critic frameworks and optimized through alternating steps of policy evaluation and policy improvement. In the policy evaluation steps, the critic is updated to c…

2023

On Investigating the Conservative Property of Score-Based Generative Models

ICML 2023poster

Existing Score-Based Models (SBMs) can be categorized into constrained SBMs (CSBMs) or unconstrained SBMs (USBMs) according to their parameterization approaches. CSBMs model probability density functions as Boltzmann distributions, and assign their predictions as the negative gradients of some scala…

2023

Training Energy-Based Normalizing Flow with Score-Matching Objectives

NeurIPS 2023poster

In this paper, we establish a connection between the parameterization of flow-based and energy-based generative models, and present a new flow-based modeling approach called energy-based normalizing flow (EBFlow). We demonstrate that by optimizing EBFlow with score-matching objectives, the computati…

2022

Denoising Likelihood Score Matching for Conditional Score-based Data Generation

ICLR 2022poster

Many existing conditional score-based data generation methods utilize Bayes' theorem to decompose the gradients of a log posterior density into a mixture of scores. These methods facilitate the training procedure of conditional score models, as a mixture of scores can be separately estimated using a…

2021

DFAC Framework: Factorizing the Value Function via Quantile Mixture for Multi-Agent Distributional Q-Learning

ICML 2021spotlight

In fully cooperative multi-agent reinforcement learning (MARL) settings, the environments are highly stochastic due to the partial observability of each agent and the continuously changing policies of the other agents. To address the above issues, we integrate distributional RL and value function fa…