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Yuxin Chen

115 accepted papers

2026

AgentNoiseBench: Benchmarking Robustness of Tool-Using LLM Agents Under Noisy Condition

ICML 2026poster

As LLM-based agents are increasingly deployed in real-world workflows, existing agent benchmarks---often built on idealized, noise-free assumptions---fall short of characterizing agents' robustness under imperfect user instructions and unreliable tool feedback. To address this gap, we introduce **Ag…

Cited by 0SourceScholar
2026

AlphaAlign: Incentivizing Safety Alignment with Extremely Simplified Reinforcement Learning

ICLR 2026poster

Large language models (LLMs), despite possessing latent safety understanding from their vast pretraining data, remain vulnerable to generating harmful content and exhibit issues such as over-refusal and utility degradation after safety alignment. Current safety alignment methods often result in supe…

Cited by 0SourceScholar
2026

Beyond Semantic Search: Towards Referential Anchoring in Composed Image Retrieval

CVPR 2026

Composed Image Retrieval (CIR) has demonstrated significant potential by enabling flexible, multimodal queries that combine a reference image and modification text. However, CIR inherently prioritizes semantic matching, struggling to reliably retrieve a user-specified instance across contexts. In pr

Cited by 0SourceScholar
2026

CSG: Cognitive Structure Generation for Intelligent Education

ICML 2026poster

Cognitive structure (CS), a student's construction of concepts and inter-concept relations, has long been recognized as a foundational notion in psychology and intelligent education, yet remains largely unassessable in practice. Existing approaches such as knowledge tracing (KT) and cognitive diagno…

Cited by 0SourceScholar
2026

DexCtrl: Sim-To-Real Dexterity with Adaptive Controller Learning

ICRA 2026poster

Dexterous manipulation has advanced rapidly, with policies now capable of performing complex, contact-rich tasks in simulation. However, transferring these policies from simulation to real world remains a significant challenge. A key obstacle is the mismatch in low-level controller dynamics, where s…

Cited by 0Scholar
2026

Implicit Turn-Wise Policy Optimization for Proactive User-LLM Interaction

ICML 2026poster

Multi-turn human-AI collaboration is fundamental to deploying interactive services such as adaptive tutoring, conversational recommendation, and professional consultation. However, optimizing these interactions via reinforcement learning is hindered by the sparsity of verifiable intermediate rewards…

Cited by 0SourceScholar
2026

Internalizing Safety Understanding in Large Reasoning Models via Verification

ICML 2026poster

While explicit Chain-of-Thought (CoT) empowers large reasoning models (LRMs), it enables the generation of riskier final answers. Current alignment paradigms primarily rely on externally enforced compliance, optimizing models to detect malicious prompts rather than evaluating the safety of their own…

Cited by 0SourceScholar
2026

Learning to Reason in 4D: Dynamic Spatial Understanding for Vision Language Models

CVPR 2026

Vision-language models (VLM) excel at general understanding yet remain weak at dynamic spatial reasoning (DSR), i.e., reasoning about the evolvement of object geometry and relationship in 3D space over time, largely due to the scarcity of scalable 4D-aware training resources. To bridge this gap acro

Cited by 0SourcecodeScholar
2026

Learning to Self-Verify Makes Language Models Better Reasoners

ICML 2026poster

Recent large language models (LLMs) achieve strong performance in generating promising reasoning paths for complex tasks. However, despite powerful generation ability, LLMs remain weak at verifying their own answers, revealing a persistent capability asymmetry between generation and self-verificatio…

Cited by 0SourceScholar
2026

Look Back to Reason Forward: Revisitable Memory for Long-Context LLM Agents

ICLR 2026poster

Large language models face challenges in long-context question answering, where key evidence of a query may be dispersed across millions of tokens. Existing works equip large language models with a memory corpus that is dynamically updated during a single-pass document scan, also known as the "memor…

Cited by 0SourcecodeScholar
2026

MMhops-R1: Multimodal Multi-hop Reasoning

AAAI 2026technical

The ability to perform multi-modal multi-hop reasoning by iteratively integrating information across various modalities and external knowledge is critical for addressing complex real-world challenges. However, existing Multi-modal Large Language Models (MLLMs) are predominantly limited to single-ste

Cited by 0SourcePDFScholar
2026

Mean Flow Policy with Instantaneous Velocity Constraint for One-step Action Generation

ICLR 2026oral

Learning expressive and efficient policy functions is a promising direction in reinforcement learning (RL). While flow-based policies have recently proven effective in modeling complex action distributions with a fast deterministic sampling process, they still face a trade-off between expressiveness…

Cited by 0SourceScholar
2026

MemOCR: Layout-Aware Visual Memory for Efficient Long-Horizon Reasoning

ICML 2026poster

Long-horizon agentic reasoning necessitates effectively compressing growing interaction histories into a limited context window. Most existing memory systems serialize history as text, where token-level cost is uniform and scales linearly with length, often spending scarce budget on low-value detail…

Cited by 0SourceScholar
2026

On the Learning Dynamics of RLVR at the Edge of Competence

ICML 2026poster

Reinforcement Learning with Verifiable Rewards (RLVR) has been a main driver of recent breakthroughs in large reasoning models. Yet it remains a mystery how rewards based solely on final outcomes can help overcome the long-horizon barrier to extended reasoning. To understand this, we develop a theor…

Cited by 0SourceScholar
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
2026

Reasoning Can Be Restored by Correcting a Few Decision Tokens

ICML 2026poster

Large reasoning models (LRMs) substantially outperform their base LLM counterparts on challenging reasoning benchmarks, yet it remains poorly understood where base models go wrong during token-by-token generation and how to narrow this gap efficiently. We study the base–reasoning gap by quantifying …

Cited by 0SourceScholar
2026

Reimagination with Test-Time Observation Interventions: Distractor-Robust World Model Predictions for Visual Model Predictive Control

ICRA 2026poster

World models enable robots to “imagine” future observations given current observations and planned actions, and have been increasingly adopted as generalized dynamics models to facilitate robot learning. Despite their promise, these models remain brittle when encountering novel visual distractors su…

2026

Risk Awareness Injection: Calibrating Vision-Language Models for Safety without Compromising Utility

ICML 2026poster

Vision language models (VLMs) extend the reasoning capabilities of large language models (LLMs) to cross-modal settings, yet remain highly vulnerable to multimodal jailbreak attacks. Existing defenses predominantly rely on safety fine-tuning or \textit{aggressive} token manipulations, incurring subs…

Cited by 0SourceScholar
2026

Scaling Laws Revisited: Modeling the Role of Data Quality in Language Model Pretraining

ICLR 2026poster

Scaling laws for language model training traditionally characterize how performance scales with model size and dataset volume. Prior work has explored architecture variants and data treatments such as dataset filtering and noise injection in language model pretraining; however, these studies have no…

Cited by 0SourceScholar
2026

Tiny Brains, Giant Impact: Uncovering the Keystone Neurons of LLM with Just a Few Prompts

ICML 2026poster

Large language models (LLMs) display strong comprehensive abilities, yet the internal mechanisms that support these behaviors remain insufficiently understood. In this work, we show that across a wide range of open-weight Transformers, a subset of neurons remains consistently highly activated during…

Cited by 0SourceScholar
2026

Transport and Merge: Cross-Architecture Merging for Large Language Models

ICML 2026poster

Large language models (LLMs) achieve strong capabilities by scaling model capacity and training data, yet many real-world deployments rely on smaller models trained or adapted from low-resource data. This gap motivates the need for mechanisms to transfer knowledge from large, high-resource models to…

Cited by 0SourceScholar
2025

Adaptive Divergence Regularized Policy Optimization for Fine-tuning Generative Models

NeurIPS 2025poster

Balancing exploration and exploitation during reinforcement learning fine-tuning of generative models presents a critical challenge, as existing approaches rely on fixed divergence regularization that creates an inherent dilemma: strong regularization preserves model capabilities but limits reward o…

Cited by 0SourceScholar
2025

AnnaAgent: Dynamic Evolution Agent System with Multi-Session Memory for Realistic Seeker Simulation

ACL 2025finding

Constrained by the cost and ethical concerns of involving real seekers in AI-driven mental health, researchers develop LLM-based conversational agents (CAs) with tailored configurations, such as profiles, symptoms, and scenarios, to simulate seekers. While these efforts advance AI in mental health,…

2025

Constrained Multi-objective Bayesian Optimization through Optimistic Constraints Estimation

AISTATS 2025poster

Multi-objective Bayesian optimization has been widely adopted in scientific experiment design, including drug discovery and hyperparameter optimization. In practice, regulatory or safety concerns often impose additional thresholds on certain attributes of the experimental outcomes. Previous work has…

Cited by 0SourcecodeScholar
2025

DOGR: Towards Versatile Visual Document Grounding and Referring

ICCV 2025poster

With recent advances in Multimodal Large Language Models (MLLMs), grounding and referring capabilities have gained increasing attention for achieving detailed understanding and flexible user interaction. However, these capabilities still remain underdeveloped in visual document understanding due to…

2025

Deployment Efficient Reward-Free Exploration with Linear Function Approximation

NeurIPS 2025poster

We study deployment-efficient reward-free exploration with linear function approximation, where the goal is to explore a linear Markov Decision Process (MDP) without revealing the reward function, while minimizing the number of distinct policies implemented during learning. By ``deployment efficient…

Cited by 0SourceScholar
2025

Designing Specialized Two-Dimensional Graph Spectral Filters for Spatial-Temporal Graph Modeling

AAAI 2025technical

Spatial-temporal graph modeling is challenging due to the diverse node interactions across spatial and temporal dimensions. Recent studies typically adopt Graph Neural Networks (GNNs) to perform node-level aggregation at different time steps, acting as a series of low-pass graph spectral filters, fo…

2025

EditInfinity: Image Editing with Binary-Quantized Generative Models

NeurIPS 2025poster

Adapting pretrained diffusion-based generative models for text-driven image editing with negligible tuning overhead has demonstrated remarkable potential. A classical adaptation paradigm, as followed by these methods, first infers the generative trajectory inversely for a given source image by image…

Cited by 0SourcecodeScholar
2025

Formal Models of Active Learning from Contrastive Examples

NeurIPS 2025poster

Machine learning can greatly benefit from providing learning algorithms with pairs of contrastive training examples---typically pairs of instances that differ only slightly, yet have different class labels. Intuitively, the difference in the instances helps explain the difference in the class labels…

Cited by 0SourceScholar
2025

Language Representations Can be What Recommenders Need: Findings and Potentials

ICLR 2025oral

Recent studies empirically indicate that language models (LMs) encode rich world knowledge beyond mere semantics, attracting significant attention across various fields. However, in the recommendation domain, it remains uncertain whether LMs implicitly encode user preference information. Contrary to…

2025

Leveraging Heterophily in Spatial-Temporal Graphs for Multivariate Time-Series Forecasting

ICASSP 2025accepted

Multivariate Time-Series (MTS) forecasting is challenging due to the complex spatial-temporal dependencies inherent in MTS data. Recent studies typically adopt spatial-temporal graph models to leverage this information. However, most of these approaches assume homophily in graphs and perform only im…

Cited by 0SourceScholar
2025

MEReQ: Max-Ent Residual-Q Inverse RL for Sample-Efficient Alignment from Intervention

CoRL 2025poster

Aligning robot behavior with human preferences is crucial for deploying embodied AI agents in human-centered environments. A promising solution is interactive imitation learning from human intervention, where a human expert observes the policy's execution and provides interventions as feedback. Howe…

Cited by 0SourceScholar
2025

Mamba-3VL: Taming State Space Model for 3D Vision Language Learning

ICCV 2025poster

3D vision-language (3D-VL) reasoning, connecting natural language with 3D physical world, represents a milestone in advancing spatial intelligence. While transformer-based methods dominate 3D-VL research, their quadratic complexity and simplistic positional embedding mechanisms severely limits effec…

2025

MindOmni: Unleashing Reasoning Generation in Vision Language Models with RGPO

NeurIPS 2025poster

Recent text-to-image systems face limitations in handling multimodal inputs and complex reasoning tasks. We introduce MindOmni, a unified multimodal large language model that addresses these challenges by incorporating reasoning generation through reinforcement learning. MindOmni leverages a three-p…

Cited by 0SourcecodeScholar
2025

Minimax Optimal Regret Bound for Reinforcement Learning with Trajectory Feedback

ICML 2025poster

In this work, we study reinforcement learning (RL) with trajectory feedback. Compared to the standard RL setting, in RL with trajectory feedback, the agent only observes the accumulative reward along the trajectory, and therefore, this model is particularly suitable for scenarios where querying the…

Cited by 0SourcePDFScholar
2025

Mono2Stereo: A Benchmark and Empirical Study for Stereo Conversion

CVPR 2025poster

With the rapid proliferation of 3D devices and the shortage of 3D content, stereo conversion is attracting increasing attention. Recent works introduce pretrained Diffusion Models (DMs) into this task. However, due to the scarcity of large-scale training data and comprehensive benchmarks, the optima…

Cited by 0SourcePDFScholar
2025

Online Reward-Weighted Fine-Tuning of Flow Matching with Wasserstein Regularization

ICLR 2025poster

Recent advancements in reinforcement learning (RL) have achieved great success in fine-tuning diffusion-based generative models. However, fine-tuning continuous flow-based generative models to align with arbitrary user-defined reward functions remains challenging, particularly due to issues such as…

Cited by 0SourcePDFScholar
2025

Physics-Aware Robotic Palletization With Online Masking Inference

ICRA 2025

The efficient planning of stacking boxes, especially in the online setting where the sequence of item arrivals is unpredictable, remains a critical challenge in modern warehouse and logistics management. Existing solutions often address box size variations, but overlook their intrinsic and physical

Cited by 5SourcecodeScholar
2025

Robust Multi-fidelity Bayesian Optimization with Deep Kernel and Partition

AISTATS 2025poster

Multi-fidelity Bayesian optimization (MFBO) is a powerful approach that utilizes low-fidelity, cost-effective sources to expedite the exploration and exploitation of a high-fidelity objective function. Existing MFBO methods with theoretical foundations either lack justification for performance impro…

Cited by 0SourceScholar
2025

Taming Rectified Flow for Inversion and Editing

ICML 2025poster

Rectified-flow-based diffusion transformers like FLUX and OpenSora have demonstrated outstanding performance in the field of image and video generation. Despite their robust generative capabilities, these models often struggle with inversion inaccuracies, which could further limit their effectivenes…

2025

The Emergence of Abstract Thought in Large Language Models Beyond Any Language

NeurIPS 2025poster

As large language models (LLMs) continue to advance, their capacity to function effectively across a diverse range of languages has shown marked improvement. Preliminary studies observe that the hidden activations of LLMs often resemble English, even when responding to non-English prompts. This has…

Cited by 0SourceScholar
2025

Transformers Provably Learn Chain-of-Thought Reasoning with Length Generalization

NeurIPS 2025poster

The ability to reason lies at the core of artificial intelligence (AI), and challenging problems usually call for deeper and longer reasoning to tackle. A crucial question about AI reasoning is whether models can extrapolate learned reasoning patterns to solve harder tasks that require longer chain…

Cited by 0SourceScholar
2025

Versatile Loco-Manipulation through Flexible Interlimb Coordination

CoRL 2025oral

The ability to flexibly leverage limbs for loco-manipulation is essential for enabling autonomous robots to operate in unstructured environments. Yet, prior work on loco-manipulation is often constrained to specific tasks or predetermined limb configurations. In this work, we present einforcement Le…

Cited by 0SourceScholar
2025

VisionMath: Vision-Form Mathematical Problem-Solving

ICCV 2025poster

Mathematical problems in real-world scenarios are often presented in a purely vision-form, where textual problem statement and accompanying math figures, e.g., geometry figures and functional graphs, are integrated into a single image. This vision-form problem-solving task requires precise comprehen…

2024

Accelerating Convergence of Score-Based Diffusion Models, Provably

ICML 2024poster

Score-based diffusion models, while achieving remarkable empirical performance, often suffer from low sampling speed, due to extensive function evaluations needed during the sampling phase. Despite a flurry of recent activities towards speeding up diffusion generative modeling in practice, theoretic…

Cited by 80SourcePDFScholar
2024

Advancing Cross-domain Discriminability in Continual Learning of Vision-Language Models

NeurIPS 2024poster

Continual learning (CL) with Vision-Language Models (VLMs) has overcome the constraints of traditional CL, which only focuses on previously encountered classes. During the CL of VLMs, we need not only to prevent the catastrophic forgetting on incrementally learned knowledge but also to preserve the…

2024

Beyond Reverse KL: Generalizing Direct Preference Optimization with Diverse Divergence Constraints

ICLR 2024spotlight

The increasing capabilities of large language models (LLMs) raise opportunities for artificial general intelligence but concurrently amplify safety concerns, such as potential misuse of AI systems, necessitating effective AI alignment. Reinforcement Learning from Human Feedback (RLHF) has emerged as…

Cited by 79SourcePDFScholar
2024

Blending Imitation and Reinforcement Learning for Robust Policy Improvement

ICLR 2024spotlight

While reinforcement learning (RL) has shown promising performance, its sample complexity continues to be a substantial hurdle, restricting its broader application across a variety of domains. Imitation learning (IL) utilizes oracles to improve sample efficiency, yet it is often constrained by the qu…

Cited by 12SourcePDFScholar
2024

EA-VTR: Event-Aware Video-Text Retrieval

ECCV 2024poster

"Understanding the content of events occurring in the video and their inherent temporal logic is crucial for video-text retrieval. However, web-crawled pre-training datasets often lack sufficient event information, and the widely adopted video-level cross-modal contrastive learning also struggles to…

Cited by 3SourcePDFScholar
2024

Enhancing Instance-Level Image Classification with Set-Level Labels

ICLR 2024poster

Instance-level image classification tasks have traditionally relied on single-instance labels to train models, e.g., few-shot learning and transfer learning. However, set-level coarse-grained labels that capture relationships among instances can provide richer information in real-world scenarios. In…

Cited by 0SourcePDFScholar
2024

Federated Natural Policy Gradient and Actor Critic Methods for Multi-task Reinforcement Learning

NeurIPS 2024poster

Federated reinforcement learning (RL) enables collaborative decision making of multiple distributed agents without sharing local data trajectories. In this work, we consider a multi-task setting, in which each agent has its own private reward function corresponding to different tasks, while sharing…

Cited by 4SourcePDFScholar
2024

GTSinger: A Global Multi-Technique Singing Corpus with Realistic Music Scores for All Singing Tasks

NeurIPS 2024spotlight

The scarcity of high-quality and multi-task singing datasets significantly hinders the development of diverse controllable and personalized singing tasks, as existing singing datasets suffer from low quality, limited diversity of languages and singers, absence of multi-technique information and real…

2024

How to Make Cross Encoder a Good Teacher for Efficient Image-Text Retrieval?

CVPR 2024poster

Dominant dual-encoder models enable efficient image-text retrieval but suffer from limited accuracy while the cross-encoder models offer higher accuracy at the expense of efficiency. Distilling cross-modality matching knowledge from cross-encoder to dual-encoder provides a natural approach to harnes…

Cited by 2SourcePDFScholar
2024

Learning to Rank for Active Learning via Multi-Task Bilevel Optimization

UAI 2024poster

Active learning is a promising paradigm for reducing labeling costs by strategically requesting labels to improve model performance. However, existing active learning methods often rely on expensive acquisition functions, extensive model retraining, and multiple rounds of interaction with annotators…

Cited by 1SourcePDFScholar
2024

No-Regret Learning of Nash Equilibrium for Black-Box Games via Gaussian Processes

UAI 2024poster

This paper investigates the challenge of learning in black-box games, where the underlying utility function is unknown to any of the agents. While there is an extensive body of literature on the theoretical analysis of algorithms for computing the Nash equilibrium with *complete information* about t…

2024

On Softmax Direct Preference Optimization for Recommendation

NeurIPS 2024poster

Recommender systems aim to predict personalized rankings based on user preference data. With the rise of Language Models (LMs), LM-based recommenders have been widely explored due to their extensive world knowledge and powerful reasoning abilities. Most of the LM-based recommenders convert historica…

2024

Towards Non-Asymptotic Convergence for Diffusion-Based Generative Models

ICLR 2024poster

Diffusion models, which convert noise into new data instances by learning to reverse a Markov diffusion process, have become a cornerstone in contemporary generative modeling. While their practical power has now been widely recognized, the theoretical underpinnings remain far from mature. In this w…

Cited by 31SourcePDFScholar
2024

Transformers Implement Functional Gradient Descent to Learn Non-Linear Functions In Context

ICML 2024poster

Many neural network architectures are known to be Turing Complete, and can thus, in principle implement arbitrary algorithms. However, Transformers are unique in that they can implement gradient-based learning algorithms *under simple parameter configurations*. This paper provides theoretical and em…

Cited by 46SourcePDFScholar
2024

Wukong: Towards a Scaling Law for Large-Scale Recommendation

ICML 2024poster

Scaling laws play an instrumental role in the sustainable improvement in model quality. Unfortunately, recommendation models to date do not exhibit such laws similar to those observed in the domain of large language models, due to the inefficiencies of their upscaling mechanisms. This limitation pos…

Cited by 21SourcePDFScholar
2023

Active Policy Improvement from Multiple Black-box Oracles

ICML 2023poster

Reinforcement learning (RL) has made significant strides in various complex domains. However, identifying an effective policy via RL often necessitates extensive exploration. Imitation learning aims to mitigate this issue by using expert demonstrations to guide exploration. In real-world scenarios,…

2023

Efficient Online Decision Tree Learning with Active Feature Acquisition

IJCAI 2023poster

Constructing decision trees online is a classical machine learning problem. Existing works often assume that features are readily available for each incoming data point. However, in many real world applications, both feature values and the labels are unknown a priori and can only be obtained at a co…

Cited by 3SourcePDFScholar
2023

Learning Human-Compatible Representations for Case-Based Decision Support

ICLR 2023poster

Algorithmic case-based decision support provides examples to help human make sense of predicted labels and aid human in decision-making tasks. Despite the promising performance of supervised learning, representations learned by supervised models may not align well with human intuitions: what models…

2023

Learning Regions of Interest for Bayesian Optimization with Adaptive Level-Set Estimation

ICML 2023poster

We study Bayesian optimization (BO) in high-dimensional and non-stationary scenarios. Existing algorithms for such scenarios typically require extensive hyperparameter tuning, which limits their practical effectiveness. We propose a framework, called BALLET, which adaptively filters for a high-confi…

Cited by 8SourcePDFScholar
2023

Order-Prompted Tag Sequence Generation for Video Tagging

ICCV 2023poster

Video Tagging intends to infer multiple tags spanning relevant content for a given video. Typically, video tags are freely defined and uploaded by a variety of users, so they have two characteristics: abundant in quantity and disordered intra-video. It is difficult for the existing multi-label class…

Cited by 4PDFScholar
2023

Reward-agnostic Fine-tuning: Provable Statistical Benefits of Hybrid Reinforcement Learning

NeurIPS 2023poster

This paper studies tabular reinforcement learning (RL) in the hybrid setting, which assumes access to both an offline dataset and online interactions with the unknown environment. A central question boils down to how to efficiently utilize online data to strengthen and complement the offline dataset…

Cited by 15SourcePDFScholar
2023

Scalable Batch-Mode Deep Bayesian Active Learning via Equivalence Class Annealing

ICLR 2023poster

Active learning has demonstrated data efficiency in many fields. Existing active learning algorithms, especially in the context of batch-mode deep Bayesian active models, rely heavily on the quality of uncertainty estimations of the model, and are often challenging to scale to large batches. In this…

2023

The Curious Price of Distributional Robustness in Reinforcement Learning with a Generative Model

NeurIPS 2023poster

This paper investigates model robustness in reinforcement learning (RL) via the framework of distributionally robust Markov decision processes (RMDPs). Despite recent efforts, the sample complexity of RMDPs is much less understood regardless of the uncertainty set in use; in particular, there exist…

Cited by 44SourcePDFScholar
2023

ViLEM: Visual-Language Error Modeling for Image-Text Retrieval

CVPR 2023poster

Dominant pre-training works for image-text retrieval adopt "dual-encoder" architecture to enable high efficiency, where two encoders are used to extract image and text representations and contrastive learning is employed for global alignment. However, coarse-grained global alignment ignores detailed…

Cited by 14SourcePDFScholar
2022

Explaining Why: How Instructions and User Interfaces Impact Annotator Rationales When Labeling Text Data

NAACL 2022long

In the context of data labeling, NLP researchers are increasingly interested in having humans select rationales, a subset of input tokens relevant to the chosen label. We conducted a 332-participant online user study to understand how humans select rationales, especially how different instructions a…

Cited by 9SourcePDFScholar
2022

Minimax-Optimal Multi-Agent RL in Markov Games With a Generative Model

NeurIPS 2022accept

This paper studies multi-agent reinforcement learning in Markov games, with the goal of learning Nash equilibria or coarse correlated equilibria (CCE) sample-optimally. All prior results suffer from at least one of the two obstacles: the curse of multiple agents and the barrier of long horizon, rega…

Cited by 31SourcePDFScholar
2022

Open-Vocabulary One-Stage Detection With Hierarchical Visual-Language Knowledge Distillation

CVPR 2022poster

Open-vocabulary object detection aims to detect novel object categories beyond the training set. The advanced open-vocabulary two-stage detectors employ instance-level visual-to-visual knowledge distillation to align the visual space of the detector with the semantic space of the Pre-trained Visual-…

Cited by 106PDFcodeScholar
2022

Pessimistic Q-Learning for Offline Reinforcement Learning: Towards Optimal Sample Complexity

ICML 2022spotlight

Offline or batch reinforcement learning seeks to learn a near-optimal policy using history data without active exploration of the environment. To counter the insufficient coverage and sample scarcity of many offline datasets, the principle of pessimism has been recently introduced to mitigate high b…

Cited by 116SourcePDFScholar
2022

These Maps are Made for Walking: Real-Time Terrain Property Estimation for Mobile Robots

RA-L 2022

The equations of motion governing mobile robots are dependent on terrain properties such as the coefficient of friction, and contact model parameters. Estimating these properties is thus essential for robotic navigation. Ideally any map estimating terrain properties should run in real time, mitigate

Cited by 30SourcecodeScholar
2021

Breaking the Sample Complexity Barrier to Regret-Optimal Model-Free Reinforcement Learning

NeurIPS 2021spotlight

Achieving sample efficiency in online episodic reinforcement learning (RL) requires optimally balancing exploration and exploitation. When it comes to a finite-horizon episodic Markov decision process with $S$ states, $A$ actions and horizon length $H$, substantial progress has been achieved toward…

Cited by 64SourcePDFScholar
2021

Channel-Wise Topology Refinement Graph Convolution for Skeleton-Based Action Recognition

ICCV 2021poster

Graph convolutional networks (GCNs) have been widely used and achieved remarkable results in skeleton-based action recognition. In GCNs, graph topology dominates feature aggregation and therefore is the key to extracting representative features. In this work, we propose a novel Channel-wise Topology…

Cited by 872PDFcodeScholar
2021

Generating Continuous Motion and Force Plans in Real-Time for Legged Mobile Manipulation

ICRA 2021poster

Manipulators can be added to legged robots, allowing them to interact with and change their environment. Legged mobile manipulation planners must consider how contact forces generated by these manipulators affect the system. Current planning strategies either treat these forces as immutable during p…

Cited by 24SourceScholar
2021

Learning to Make Decisions via Submodular Regularization

ICLR 2021poster

Many sequential decision making tasks can be viewed as combinatorial optimization problems over a large number of actions. When the cost of evaluating an action is high, even a greedy algorithm, which iteratively picks the best action given the history, is prohibitive to run. In this paper, we aim t…

Cited by 14SourcePDFScholar
2021

Sample-Efficient Reinforcement Learning Is Feasible for Linearly Realizable MDPs with Limited Revisiting

NeurIPS 2021poster

Low-complexity models such as linear function representation play a pivotal role in enabling sample-efficient reinforcement learning (RL). The current paper pertains to a scenario with value-based linear representation, which postulates linear realizability of the optimal Q-function (also called the…

Cited by 36SourcePDFScholar
2021

Teaching via Best-Case Counterexamples in the Learning-with-Equivalence-Queries Paradigm

NeurIPS 2021poster

We study the sample complexity of teaching, termed as "teaching dimension" (TD) in the literature, for the learning-with-equivalence-queries (LwEQ) paradigm. More concretely, we consider a learner who asks equivalence queries (i.e., "is the queried hypothesis the target hypothesis?"), and a teacher…

Cited by 1SourcePDFScholar
2021

Tightening the Dependence on Horizon in the Sample Complexity of Q-Learning

ICML 2021spotlight

Q-learning, which seeks to learn the optimal Q-function of a Markov decision process (MDP) in a model-free fashion, lies at the heart of reinforcement learning. Focusing on the synchronous setting (such that independent samples for all state-action pairs are queried via a generative model in each it…

Cited by 23SourcePDFScholar
2020

An Online Learning Framework for Energy-Efficient Navigation of Electric Vehicles

IJCAI 2020poster

Energy-efficient navigation constitutes an important challenge in electric vehicles, due to their limited battery capacity. We employ a Bayesian approach to model the energy consumption at road segments for efficient navigation. In order to learn the model parameters, we develop an online learning f…

Cited by 0SourcePDFScholar
2020

Breaking the Sample Size Barrier in Model-Based Reinforcement Learning with a Generative Model

NeurIPS 2020poster

We investigate the sample efficiency of reinforcement learning in a $\gamma$-discounted infinite-horizon Markov decision process (MDP) with state space S and action space A, assuming access to a generative model. Despite a number of prior work tackling this problem, a complete picture of the trade-…

Cited by 152SourcePDFScholar
2020

Communication-Efficient Distributed Optimization in Networks with Gradient Tracking and Variance Reduction

AISTATS 2020poster

Due to the imminent need to alleviate the communication burden in multi-agent and federated learning, the investigation of communication-efficient distributed optimization algorithms for empirical risk minimization has flourished recently. A large fraction of existing algorithms are developed for th…

2020

Sample Complexity of Asynchronous Q-Learning: Sharper Analysis and Variance Reduction

NeurIPS 2020poster

Asynchronous Q-learning aims to learn the optimal action-value function (or Q-function) of a Markov decision process (MDP), based on a single trajectory of Markovian samples induced by a behavior policy. Focusing on a $\gamma$-discounted MDP with state space S and action space A, we demonstrate tha…

Cited by 107SourcePDFScholar
2020

Uncertainty quantification for nonconvex tensor completion: Confidence intervals, heteroscedasticity and optimality

ICML 2020poster

We study the distribution and uncertainty of nonconvex optimization for noisy tensor completion — the problem of estimating a low-rank tensor given incomplete and corrupted observations of its entries. Focusing on a two-stage nonconvex estimation algorithm proposed by (Cai et al., 2019), we characte…

Cited by 28SourcePDFScholar
2020

Understanding the Power and Limitations of Teaching with Imperfect Knowledge

IJCAI 2020poster

Machine teaching studies the interaction between a teacher and a student/learner where the teacher selects training examples for the learner to learn a specific task. The typical assumption is that the teacher has perfect knowledge of the task---this knowledge comprises knowing the desired learning…

Cited by 0SourcePDFScholar
2019

A General Framework for Multi-fidelity Bayesian Optimization with Gaussian Processes

AISTATS 2019poster

How can we efficiently gather information to optimize an unknown function, when presented with multiple, mutually dependent information sources with different costs? For example, when optimizing a physical system, intelligently trading off computer simulations and real-world tests can lead to signif…

Cited by 149SourcePDFScholar
2019

Batched Stochastic Bayesian Optimization via Combinatorial Constraints Design

AISTATS 2019poster

In many high-throughput experimental design settings, such as those common in biochemical engineering, batched queries are often more cost effective than one-by-one sequential queries. Furthermore, it is often not possible to directly choose items to query. Instead, the experimenter specifies a set…

Cited by 25SourcePDFScholar
2019

Pixel Level Data Augmentation for Semantic Image Segmentation Using Generative Adversarial Networks

ICASSP 2019accepted

Semantic segmentation is one of the basic topics in computer vision, it aims to assign semantic labels to every pixel of an image. Unbalanced semantic label distribution could have a negative influence on segmentation accuracy. In this paper, we investigate using data augmentation approach to balanc…

Cited by 0SourceScholar
2019

Preference-Based Batch and Sequential Teaching: Towards a Unified View of Models

NeurIPS 2019poster

Algorithmic machine teaching studies the interaction between a teacher and a learner where the teacher selects labeled examples aiming at teaching a target hypothesis. In a quest to lower teaching complexity and to achieve more natural teacher-learner interactions, several teaching models and comple…

Cited by 39SourcePDFScholar
2019

Teaching Multiple Concepts to a Forgetful Learner

NeurIPS 2019poster

How can we help a forgetful learner learn multiple concepts within a limited time frame? While there have been extensive studies in designing optimal schedules for teaching a single concept given a learner's memory model, existing approaches for teaching multiple concepts are typically based on heur…

Cited by 29SourcePDFScholar
2018

Implicit Regularization in Nonconvex Statistical Estimation: Gradient Descent Converges Linearly for Phase Retrieval and Matrix Completion

ICML 2018oral

Recent years have seen a flurry of activities in designing provably efficient nonconvex optimization procedures for solving statistical estimation problems. For various problems like phase retrieval or low-rank matrix completion, state-of-the-art nonconvex procedures require proper regularization (e…

Cited by 334SourcePDFScholar
2018

Near-Optimal Machine Teaching via Explanatory Teaching Sets

AISTATS 2018poster

Modern applications of machine teaching for humans often involve domain-specific, non- trivial target hypothesis classes. To facilitate understanding of the target hypothesis, it is crucial for the teaching algorithm to use examples which are interpretable to the human learner. In this paper, we pro…

Cited by 0SourcePDFScholar
2018

Teaching Categories to Human Learners With Visual Explanations

CVPR 2018poster

We study the problem of computer-assisted teaching with explanations. Conventional approaches for machine teaching typically only provide feedback at the instance level e.g., the category or label of the instance. However, it is intuitive that clear explanations from a knowledgeable teacher can…

Cited by 86SourcePDFScholar
2018

Understanding the Role of Adaptivity in Machine Teaching: The Case of Version Space Learners

NeurIPS 2018poster

In real-world applications of education, an effective teacher adaptively chooses the next example to teach based on the learner’s current state. However, most existing work in algorithmic machine teaching focuses on the batch setting, where adaptivity plays no role. In this paper, we study the case…

Cited by 53SourcePDFScholar
2017

Near-optimal Bayesian Active Learning with Correlated and Noisy Tests

AISTATS 2017poster

We consider the Bayesian active learning and experimental design problem, where the goal is to learn the value of some unknown target variable through a sequence of informative, noisy tests. In contrast to prior work, we focus on the challenging, yet practically relevant setting where test outcomes…

Cited by 27SourcePDFScholar