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Lang Feng

13 accepted papers

2026

AnomSeer: Reinforcing Multimodal LLMs to Reason for Time-Series Anomaly Detection

ICML 2026poster

Time-series anomaly detection (TSAD) with multimodal large language models (MLLMs) is an emerging area, yet a persistent challenge remains: MLLMs rely on coarse time-series heuristics but struggle with multi-dimensional, detailed reasoning, which is vital for understanding complex time-series data. …

Cited by 0SourceScholar
2026

Beyond Trajectory-Level Attribution: Graph-Based Credit Assignment for Agentic Reinforcement Learning

ICML 2026poster

Group-based reinforcement learning (RL) methods have achieved remarkable success in improving the performance of large language models (LLMs) and have been rapidly extended to agentic tasks. However, their credit assignment relies heavily on coarse-grained trajectory-level attribution according to f…

Cited by 0SourceScholar
2026

From Stimuli to Minds: Enhancing Psychological Reasoning in LLMs via Bilateral Reinforcement Learning

AAAI 2026technical

Large Language Models show promise in emotion understanding, social reasoning, and empathy, yet struggle with psychologically grounded tasks requiring inference of implicit mental states in complex, socially and contextually ambiguous settings. These limitations stem from lacking theory-aligned supe

Cited by 0SourcePDFScholar
2026

Generative Online Reinforcement Learning

ICML 2026poster

Reinforcement learning (RL) faces a persistent tension: policies that are stable to optimize (e.g., Gaussians) are often too simple to represent the multimodal action distributions required for complex control. Conversely, expressive generative policies—such as diffusion and flow matching—are freque…

Cited by 0SourceScholar
2026

Hierarchy-of-Groups Policy Optimization for Long-Horizon Agentic Tasks

ICLR 2026poster

Group-based reinforcement learning (RL), such as GRPO, has advanced the capabilities of large language models on long-horizon agentic tasks. To enable more fine-grained policy updates, recent research has increasingly shifted toward stepwise group-based policy optimization, which treats each step in…

Cited by 0SourcecodeScholar
2026

REAR: Test-time Preference Realignment through Reward Decomposition

ICML 2026poster

Aligning large language models (LLMs) with diverse user preferences is a critical yet challenging task. While post-training methods can adapt models to specific needs, they often require costly data curation and additional training. Test-time scaling (TTS) presents an efficient, training-free altern…

Cited by 0SourceScholar
2025

Generating Synthetic Data for Unsupervised Federated Learning of Cross-Modal Retrieval

AAAI 2025technical

Unsupervised federated learning for cross-modal retrieval has received increasing attention in recent years as it can free the requirement for annotations and avoid uploading original clients’ data to servers. Most existing methods focus on how to learn better local models and their aggregation to o…

Cited by 0SourcePDFScholar
2025

Policy Regularization on Globally Accessible States in Cross-Dynamics Reinforcement Learning

ICML 2025spotlight

To learn from data collected in diverse dynamics, Imitation from Observation (IfO) methods leverage expert state trajectories based on the premise that recovering expert state distributions in other dynamics facilitates policy learning in the current one. However, Imitation Learning inherently impos…

Cited by 0SourcePDFScholar
2025

Towards Efficient Online Tuning of VLM Agents via Counterfactual Soft Reinforcement Learning

ICML 2025poster

Online fine-tuning vision-language model (VLM) agents with reinforcement learning (RL) has shown promise for equipping agents with multi-step, goal-oriented capabilities in dynamic environments. However, their open-ended textual action space and non-end-to-end nature of action generation present sig…

2024

Resisting Stochastic Risks in Diffusion Planners with the Trajectory Aggregation Tree

ICML 2024spotlight

Diffusion planners have shown promise in handling long-horizon and sparse-reward tasks due to the non-autoregressive plan generation. However, their inherent stochastic risk of generating infeasible trajectories presents significant challenges to their reliability and stability. We introduce a novel…

2022

Event-Based Multimodal Spiking Neural Network with Attention Mechanism

ICASSP 2022accepted

Human brain can effectively integrate visual and auditory information. Dynamic Vision Sensor (DVS) and Dynamic Audio Sensor (DAS) are event-based sensors imitating the mechanism of human retina and cochlea. Since the sensors record the visual and auditory input as asynchronous discrete events, they…

Cited by 0SourceScholar
2022

Multi-Level Firing with Spiking DS-ResNet: Enabling Better and Deeper Directly-Trained Spiking Neural Networks

IJCAI 2022poster

Spiking neural networks (SNNs) are bio-inspired neural networks with asynchronous discrete and sparse characteristics, which have increasingly manifested their superiority in low energy consumption. Recent research is devoted to utilizing spatio-temporal information to directly train SNNs by backpro…