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ZongZhang Zhang

50 accepted papers

2026

Learning Disentangled Multi-Agent World Model for Decentralized Control

ICML 2026poster

World models enable learning policies via latent imagination, offering benefits such as history compression and sample efficiency. The primary challenge in applying world models to multi-agent tasks is that modeling multi-agent dynamics in latent space requires integrating information from different…

Cited by 0SourceScholar
2026

Meta-Normalizing Flow for Data-Limited Offline Meta-Reinforcement Learning (Student Abstract)

AAAI 2026technical

Offline Meta-Reinforcement Learning (OMRL) leverages pre-collected data to adapt to new tasks. Context-based methods learn task representations from contexts. However, the context is influenced by both the task and the behavior policy. The mismatch between the behavior policy and the testing policy

Cited by 0SourcePDFScholar
2026

Multi-agent In-context Coordination via Decentralized Memory Retrieval

AAAI 2026technical

Large transformer models, trained on diverse datasets, have demonstrated impressive few-shot performance on previously unseen tasks without requiring parameter updates. This capability has also been explored in Reinforcement Learning (RL), where agents interact with the environment to retrieve conte

Cited by 0SourcePDFScholar
2026

Unleashing Humanoid Reaching Potential Via Real-World-Ready Skill Space

ICRA 2026poster

Humans possess a large reachable space in the 3D world, enabling interactions with objects at varying heights and distances. However, realizing such large-space reaching on humanoids is a complex whole-body control (WBC) problem. Learning from scratch often leads to optimization difficulty and poor …

2026

Unleashing Humanoid Reaching Potential via Real-World-Ready Skill Space

RA-L 2026

Humans possess a large reachable space in the 3D world, enabling interactions with objects at varying heights and distances. However, realizing such large-space reaching on humanoids is a complex whole-body control (WBC) problem. Learning from scratch often leads to optimization difficulty and poor

Cited by 23SourcecodeScholar
2025

Behavior-Regularized Diffusion Policy Optimization for Offline Reinforcement Learning

ICML 2025poster

Behavior regularization, which constrains the policy to stay close to some behavior policy, is widely used in offline reinforcement learning (RL) to manage the risk of hazardous exploitation of unseen actions. Nevertheless, existing literature on behavior-regularized RL primarily focuses on explicit…

Cited by 1SourcePDFScholar
2025

EvaLearn: Quantifying the Learning Capability and Efficiency of LLMs via Sequential Problem Solving

NeurIPS 2025poster

We introduce EvaLearn, a pioneering benchmark designed to evaluate large language models (LLMs) on their learning capability and efficiency in challenging tasks, a critical, yet underexplored aspect of model potential. EvaLearn contains 648 challenging problems across six task types, grouped into 18…

Cited by 0SourceScholar
2025

Focus-Then-Reuse: Fast Adaptation in Visual Perturbation Environments

NeurIPS 2025poster

Visual reinforcement learning has shown promise in various real-world applications. However, deploying policies in complex real-world environments with visual perturbations remains a significant challenge. We notice that humans tend to filter information at the object level prior to decision-making,…

Cited by 0SourcecodeScholar
2025

Lost in the Context: Insufficient and Distracted Attention to Contexts in Preference Modeling

ACL 2025long

In Reinforcement Learning from Human Feedback (RLHF), the reward model (RM) evaluates the response quality based on the given context and assigns a reward. It plays a crucial role in aligning RLHF with human preferences. Although the current RM training paradigm concatenates the context and response…

Cited by 0SourcePDFScholar
2025

Multi-Agent Imitation by Learning and Sampling from Factorized Soft Q-Function

NeurIPS 2025poster

Learning from multi-agent expert demonstrations, known as Multi-Agent Imitation Learning (MAIL), provides a promising approach to sequential decision-making. However, existing MAIL methods including Behavior Cloning (BC) and Adversarial Imitation Learning (AIL) face significant challenges: BC suffer…

Cited by 0SourcecodeScholar
2025

Q-Adapter: Customizing Pre-trained LLMs to New Preferences with Forgetting Mitigation

ICLR 2025poster

Large Language Models (LLMs), trained on a large amount of corpus, have demonstrated remarkable abilities. However, it may not be sufficient to directly apply open-source LLMs like Llama to certain real-world scenarios, since most of them are trained for \emph{general} purposes. Thus, the demands fo…

2025

Reinforced In-Context Black-Box Optimization

IJCAI 2025

Black-Box Optimization (BBO) has found successful applications in many fields of science and engineering. Recently, there has been a growing interest in meta-learning particular components of BBO algorithms to speed up optimization and get rid of tedious hand-crafted heuristics. As an extension, lea

2025

Reward Models in Deep Reinforcement Learning: A Survey

IJCAI 2025

In reinforcement learning (RL), agents continually interact with the environment and use the feedback to refine their behavior. To guide policy optimization, reward models are introduced as proxies of the desired objectives, such that when the agent maximizes the accumulated reward, it also fulfills

Cited by 0SourcePDFScholar
2024

ACT: Empowering Decision Transformer with Dynamic Programming via Advantage Conditioning

AAAI 2024technical

Decision Transformer (DT), which employs expressive sequence modeling techniques to perform action generation, has emerged as a promising approach to offline policy optimization. However, DT generates actions conditioned on a desired future return, which is known to bear some weaknesses such as the…

2024

Attention-Guided Contrastive Role Representations for Multi-agent Reinforcement Learning

ICLR 2024poster

Real-world multi-agent tasks usually involve dynamic team composition with the emergence of roles, which should also be a key to efficient cooperation in multi-agent reinforcement learning (MARL). Drawing inspiration from the correlation between roles and agent's behavior patterns, we propose a nove…

2024

Debiased Offline Representation Learning for Fast Online Adaptation in Non-stationary Dynamics

ICML 2024poster

Developing policies that can adapt to non-stationary environments is essential for real-world reinforcement learning applications. Nevertheless, learning such adaptable policies in offline settings, with only a limited set of pre-collected trajectories, presents significant challenges. A key difficu…

2024

Deep Demonstration Tracing: Learning Generalizable Imitator Policy for Runtime Imitation from a Single Demonstration

ICML 2024poster

One-shot imitation learning (OSIL) is to learn an imitator agent that can execute multiple tasks with only a single demonstration. In real-world scenario, the environment is dynamic, e.g., unexpected changes can occur after demonstration. Thus, achieving generalization of the imitator agent is cruci…

2024

Efficient and Stable Offline-to-online Reinforcement Learning via Continual Policy Revitalization

IJCAI 2024poster

In offline Reinforcement Learning (RL), the pre-trained policies are utilized for initialization and subsequent online fine-tuning. However, existing methods suffer from instability and low sample efficiency compared to pure online learning. This paper identifies these limitations stemming from dire…

2024

Focus-Then-Decide: Segmentation-Assisted Reinforcement Learning

AAAI 2024technical

Visual Reinforcement Learning (RL) is a promising approach to achieve human-like intelligence. However, it currently faces challenges in learning efficiently within noisy environments. In contrast, humans can quickly identify task-relevant objects in distraction-filled surroundings by applying previ…

2024

Generalizable Policy Improvement via Reinforcement Sampling (Student Abstract)

AAAI 2024technical

Current policy gradient techniques excel in refining policies over sampled states but falter when generalizing to unseen states. To address this, we introduce Reinforcement Sampling (RS), a novel method leveraging a generalizable action value function to sample improved decisions. RS is able to impr…

Cited by 0SourcePDFScholar
2024

Generalizable Task Representation Learning for Offline Meta-Reinforcement Learning with Data Limitations

AAAI 2024technical

Generalization and sample efficiency have been long-standing issues concerning reinforcement learning, and thus the field of Offline Meta-Reinforcement Learning (OMRL) has gained increasing attention due to its potential of solving a wide range of problems with static and limited offline data. Exist…

2024

Language Model Self-improvement by Reinforcement Learning Contemplation

ICLR 2024poster

Language model self-improvement (LMSI) techniques have recently gained significant attention as they improve language models without requiring external supervision. A common approach is reinforcement learning from AI feedback (RLAIF), which trains a reward model based on AI preference data and emplo…

Cited by 41SourcePDFScholar
2024

Multi-Agent Domain Calibration with a Handful of Offline Data

NeurIPS 2024poster

The shift in dynamics results in significant performance degradation of policies trained in the source domain when deployed in a different target domain, posing a challenge for the practical application of reinforcement learning (RL) in real-world scenarios. Domain transfer methods aim to bridge thi…

Cited by 0SourcePDFScholar
2024

Multi-Expert Distillation for Few-Shot Coordination (Student Abstract)

AAAI 2024technical

Ad hoc teamwork is a crucial challenge that aims to design an agent capable of effective collaboration with teammates employing diverse strategies without prior coordination. However, current Population-Based Training (PBT) approaches train the ad hoc agent through interaction with diverse teammates…

2024

ODRL: A Benchmark for Off-Dynamics Reinforcement Learning

NeurIPS 2024poster

We consider off-dynamics reinforcement learning (RL) where one needs to transfer policies across different domains with dynamics mismatch. Despite the focus on developing dynamics-aware algorithms, this field is hindered due to the lack of a standard benchmark. To bridge this gap, we introduce ODRL,…

2024

Policy Rehearsing: Training Generalizable Policies for Reinforcement Learning

ICLR 2024poster

Human beings can make adaptive decisions in a preparatory manner, i.e., by making preparations in advance, which offers significant advantages in scenarios where both online and offline experiences are expensive and limited. Meanwhile, current reinforcement learning methods commonly rely on numerous…

Cited by 4SourcePDFScholar
2023

Anti-drifting Feature Selection via Deep Reinforcement Learning (Student Abstract)

AAAI 2023technical

Feature selection (FS) is a crucial procedure in machine learning pipelines for its significant benefits in removing data redundancy and mitigating model overfitting. Since concept drift is a widespread phenomenon in streaming data and could severely affect model performance, effective FS on concept…

Cited by 0SourcePDFScholar
2023

Deep Anomaly Detection and Search via Reinforcement Learning (Student Abstract)

AAAI 2023technical

Semi-supervised anomaly detection is a data mining task which aims at learning features from partially-labeled datasets. We propose Deep Anomaly Detection and Search (DADS) with reinforcement learning. During the training process, the agent searches for possible anomalies in unlabeled dataset to enh…

Cited by 1SourcePDFScholar
2023

Discovering Generalizable Multi-agent Coordination Skills from Multi-task Offline Data

ICLR 2023poster

Cooperative multi-agent reinforcement learning (MARL) faces the challenge of adapting to multiple tasks with varying agents and targets. Previous multi-task MARL approaches require costly interactions to simultaneously learn or fine-tune policies in different tasks. However, the situation that an ag…

Cited by 31SourcePDFScholar
2023

Learning Generalizable Batch Active Learning Strategies via Deep Q-networks (Student Abstract)

AAAI 2023technical

To handle a large amount of unlabeled data, batch active learning (BAL) queries humans for the labels of a batch of the most valuable data points at every round. Most current BAL strategies are based on human-designed heuristics, such as uncertainty sampling or mutual information maximization. Howev…

Cited by 0SourcePDFScholar
2023

Policy Regularization with Dataset Constraint for Offline Reinforcement Learning

ICML 2023poster

We consider the problem of learning the best possible policy from a fixed dataset, known as offline Reinforcement Learning (RL). A common taxonomy of existing offline RL works is policy regularization, which typically constrains the learned policy by distribution or support of the behavior policy. H…

2023

Policy-Independent Behavioral Metric-Based Representation for Deep Reinforcement Learning

AAAI 2023technical

Behavioral metrics can calculate the distance between states or state-action pairs from the rewards and transitions difference. By virtue of their capability to filter out task-irrelevant information in theory, using them to shape a state embedding space becomes a new trend of representation learnin…

Cited by 4SourcePDFScholar
2023

Retrosynthetic Planning with Dual Value Networks

ICML 2023poster

Retrosynthesis, which aims to find a route to synthesize a target molecule from commercially available starting materials, is a critical task in drug discovery and materials design. Recently, the combination of ML-based single-step reaction predictors with multi-step planners has led to promising re…

2023

Towards Deployment-Efficient and Collision-Free Multi-Agent Path Finding (Student Abstract)

AAAI 2023technical

Multi-agent pathfinding (MAPF) is essential to large-scale robotic coordination tasks. Planning-based algorithms show their advantages in collision avoidance while avoiding exponential growth in the number of agents. Reinforcement-learning (RL)-based algorithms can be deployed efficiently but cannot…

Cited by 0SourcePDFScholar
2022

Adapt to Environment Sudden Changes by Learning a Context Sensitive Policy

AAAI 2022technical

Dealing with real-world reinforcement learning (RL) tasks, we shall be aware that the environment may have sudden changes. We expect that a robust policy is able to handle such changes and adapt to the new environment rapidly. Context-based meta reinforcement learning aims at learning environment…

2022

Bayesian Optimistic Optimization: Optimistic Exploration for Model-based Reinforcement Learning

NeurIPS 2022accept

Reinforcement learning (RL) is a general framework for modeling sequential decision making problems, at the core of which lies the dilemma of exploitation and exploration. An agent failing to explore systematically will inevitably fail to learn efficiently. Optimism in the face of uncertainty (OFU)…

Cited by 11SourcePDFScholar
2022

Efficient Multi-Agent Communication via Shapley Message Value

IJCAI 2022poster

Utilizing messages from teammates is crucial in cooperative multi-agent tasks due to the partially observable nature of the environment. Naively asking messages from all teammates without pruning may confuse individual agents, hindering the learning process and impairing the whole system's performan…

2022

Efficient Multi-agent Communication via Self-supervised Information Aggregation

NeurIPS 2022accept

Utilizing messages from teammates can improve coordination in cooperative Multi-agent Reinforcement Learning (MARL). To obtain meaningful information for decision-making, previous works typically combine raw messages generated by teammates with local information as inputs for policy. However, neglec…

Cited by 35SourcePDFScholar
2022

Multi-Agent Concentrative Coordination with Decentralized Task Representation

IJCAI 2022poster

Value-based multi-agent reinforcement learning (MARL) methods hold the promise of promoting coordination in cooperative settings. Popular MARL methods mainly focus on the scalability or the representational capacity of value functions. Such a learning paradigm can reduce agents' uncertainties and pr…

2022

Multi-Agent Incentive Communication via Decentralized Teammate Modeling

AAAI 2022technical

Effective communication can improve coordination in cooperative multi-agent reinforcement learning (MARL). One popular communication scheme is exchanging agents' local observations or latent embeddings and using them to augment individual local policy input. Such a communication paradigm can reduce…

2022

Multi-agent Dynamic Algorithm Configuration

NeurIPS 2022accept

Automated algorithm configuration relieves users from tedious, trial-and-error tuning tasks. A popular algorithm configuration tuning paradigm is dynamic algorithm configuration (DAC), in which an agent learns dynamic configuration policies across instances by reinforcement learning (RL). However, i…

2021

Adaptive Online Packing-guided Search for POMDPs

NeurIPS 2021poster

The partially observable Markov decision process (POMDP) provides a general framework for modeling an agent's decision process with state uncertainty, and online planning plays a pivotal role in solving it. A belief is a distribution of states representing state uncertainty. Methods for large-scale…

2021

Cross-modal Domain Adaptation for Cost-Efficient Visual Reinforcement Learning

NeurIPS 2021poster

In visual-input sim-to-real scenarios, to overcome the reality gap between images rendered in simulators and those from the real world, domain adaptation, i.e., learning an aligned representation space between simulators and the real world, then training and deploying policies in the aligned represe…

2020

Efficient Deep Reinforcement Learning via Adaptive Policy Transfer

IJCAI 2020poster

Transfer learning has shown great potential to accelerate Reinforcement Learning (RL) by leveraging prior knowledge from past learned policies of relevant tasks. Existing approaches either transfer previous knowledge by explicitly computing similarities between tasks or select appropriate source pol…

2020

Triple-GAIL: A Multi-Modal Imitation Learning Framework with Generative Adversarial Nets

IJCAI 2020poster

Generative adversarial imitation learning (GAIL) has shown promising results by taking advantage of generative adversarial nets, especially in the field of robot learning. However, the requirement of isolated single modal demonstrations limits the scalability of the approach to real world scenarios…

Cited by 0SourcePDFScholar
2018

A Deep Bayesian Policy Reuse Approach Against Non-Stationary Agents

NeurIPS 2018poster

In multiagent domains, coping with non-stationary agents that change behaviors from time to time is a challenging problem, where an agent is usually required to be able to quickly detect the other agent's policy during online interaction, and then adapt its own policy accordingly. This paper studies…

Cited by 103SourcePDFScholar