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Kyungjae Lee

57 accepted papers

2026

Hybrid Deep Searcher: Scalable Parallel and Sequential Search Reasoning

ICLR 2026poster

Large reasoning models (LRMs) combined with retrieval-augmented generation (RAG) have enabled deep research agents capable of multi-step reasoning with external knowledge retrieval. However, previous methods that extend reasoning with single-query search steps struggle to scale to complex tasks dema…

Cited by 0SourceScholar
2026

INSIGHT Bench: Towards Grounded IN-SItu Guidance for Robotic ManipulaTion

CVPR 2026

Humans intuitively rely on text and symbols inscribed on objects (e.g. "PULL", "Squeeze and Turn") to perform tasks safely and correctly. In contrast, vision-language-action models excel at following external language commands, but remain largely unaware of this object-centric information. This capa

Cited by 0SourcecodeScholar
2026

LEGO: Latent-Space Exploration for Geometry-Aware Optimization of Humanoid Kinematic Design

ICRA 2026poster

Designing robot morphologies and kinematics has traditionally relied on human intuition, with little systematic foundation. Motion–design co-optimization offers a promising path toward automation, but two major challenges remain: (i) the vast, unstructured design space and (ii) the difficulty of con…

2026

Learning Social Navigation from Positive and Negative Demonstrations and Rule-Based Specifications

ICRA 2026poster

Mobile robot navigation in dynamic human environments requires policies that balance adaptability to diverse behaviors with compliance to safety constraints. We hypothesize that integrating data-driven rewards with rule-based objectives enables navigation policies to achieve a more effective balance…

2025

Assessing LLM Reasoning Steps via Principal Knowledge Grounding

EMNLP 2025

Step-by-step reasoning has become a standard approach for large language models (LLMs) to tackle complex tasks. While this paradigm has proven effective, it raises a fundamental question: How can we verify that an LLM’s reasoning is accurately grounded in knowledge? To address this question, we intr

2025

Bellman Unbiasedness: Toward Provably Efficient Distributional Reinforcement Learning with General Value Function Approximation

ICML 2025poster

Distributional reinforcement learning improves performance by capturing environmental stochasticity, but a comprehensive theoretical understanding of its effectiveness remains elusive. In addition, the intractable element of the infinite dimensionality of distributions has been overlooked. In this p…

Cited by 0SourcePDFScholar
2025

Learning to Explore and Select for Coverage-Conditioned Retrieval-Augmented Generation

NAACL 2025findings

Interactions with large language models (LLMs) often yield long and detailed responses, leveraging both parametric knowledge and retrieval-augmented generation (RAG). While these responses can provide rich insights, they often include redundant or less engaging content not aligned with user interest…

2025

Learning-Based Dynamic Robot-to-Human Handover

ICRA 2025

This paper presents a novel learning-based approach to dynamic robot-to-human handover, addressing the challenges of delivering objects to a moving receiver. We hypothesize that dynamic handover, where the robot adjusts to the receiver's movements, results in more efficient and comfortable interacti

Cited by 2SourcecodeScholar
2025

Pareto Optimal Risk-Agnostic Distributional Bandits with Heavy-Tail Rewards

NeurIPS 2025poster

This paper addresses the problem of multi-risk measure agnostic multi-armed bandits in heavy-tailed reward settings. We propose a framework that leverages novel deviation inequalities for the $1$-Wasserstein distance to construct confidence intervals for Lipschitz risk measures. The distributional…

Cited by 0SourceScholar
2025

Policy-labeled Preference Learning: Is Preference Enough for RLHF?

ICML 2025spotlight

To design reward that align with human goals, Reinforcement Learning from Human Feedback (RLHF) has emerged as a prominent technique for learning reward functions from human preferences and optimizing models using reinforcement learning algorithms. However, existing RLHF methods often misinterpret…

Cited by 0SourcePDFScholar
2025

Self-Corrective Task Planning by Inverse Prompting with Large Language Models

ICRA 2025

In robot task planning, large language models (LLMs) have shown significant promise in generating complex and long-horizon action sequences. However, it is observed that LLMs often produce responses that sound plausible but are not accurate. To address these problems, existing methods typically empl

Cited by 6SourceScholar
2025

The BiGGen Bench: A Principled Benchmark for Fine-grained Evaluation of Language Models with Language Models

NAACL 2025long

As language models (LMs) become capable of handling a wide range of tasks, their evaluation is becoming as challenging as their development. Most generation benchmarks currently assess LMs using abstract evaluation criteria-like helpfulness and harmlessness-which often lack the flexibility and granu…

2024

Conflict Area Prediction for Boosting Search-Based Multi-Agent Pathfinding Algorithms

ICRA 2024poster

We address the challenge of efficiently controlling multi-agent systems, crucial in fields like logistics and traffic management. We propose a novel approach that combines learning-based techniques with search-based methods, focusing on enhancing the conflict-based search (CBS). The CBS ensures opti…

Cited by 0SourceScholar
2024

Prometheus 2: An Open Source Language Model Specialized in Evaluating Other Language Models

EMNLP 2024main

Proprietary LMs such as GPT-4 are often employed to assess the quality of responses from various LMs. However, concerns including transparency, controllability, and affordability strongly motivate the development of open-source LMs specialized in evaluations. On the other hand, existing open evaluat…

2024

SPOTS: Stable Placement of Objects with Reasoning in Semi-Autonomous Teleoperation Systems

ICRA 2024poster

Pick-and-place is one of the fundamental tasks in robotics research. However, the attention has been mostly focused on the "pick" task, leaving the "place" task relatively unexplored. In this paper, we address the problem of placing objects in the context of a teleoperation framework. Particularly,…

Cited by 3SourcecodeScholar
2024

Spectral-Risk Safe Reinforcement Learning with Convergence Guarantees

NeurIPS 2024poster

The field of risk-constrained reinforcement learning (RCRL) has been developed to effectively reduce the likelihood of worst-case scenarios by explicitly handling risk-measure-based constraints. However, the nonlinearity of risk measures makes it challenging to achieve convergence and optimality. To…

2023

Exploring the Benefits of Training Expert Language Models over Instruction Tuning

ICML 2023poster

Recently, Language Models (LMs) instruction-tuned on multiple tasks, also known as multitask-prompted fine-tuning (MT), have shown capabilities to generalize to unseen tasks. Previous work has shown that scaling the number of finetuning datasets and instructions is the key component in making strong…

2023

Look Around for Anomalies: Weakly-Supervised Anomaly Detection via Context-Motion Relational Learning

CVPR 2023poster

Weakly-supervised Video Anomaly Detection is the task of detecting frame-level anomalies using video-level labeled training data. It is difficult to explore class representative features using minimal supervision of weak labels with a single backbone branch. Furthermore, in real-world scenarios, the…

Cited by 49SourcePDFScholar
2023

On Complementarity Objectives for Hybrid Retrieval

ACL 2023long

Dense retrieval has shown promising results in various information retrieval tasks, and hybrid retrieval, combined with the strength of sparse retrieval, has also been actively studied. A key challenge in hybrid retrieval is to make sparse and dense complementary to each other. Existing models have…

2023

Perturbation-Based Best Arm Identification for Efficient Task Planning with Monte-Carlo Tree Search

ICRA 2023poster

Combining task and motion planning (TAMP) is crucial for intelligent robots to perform complex and long-horizon tasks. In TAMP, many approaches generally employ Monte-Carlo tree search (MCTS) with upper confidence bound (UCB) for task planning to handle exploration-exploitation trade-off and find gl…

Cited by 1SourcecodeScholar
2023

Pitfall of Optimism: Distributional Reinforcement Learning by Randomizing Risk Criterion

NeurIPS 2023poster

Distributional reinforcement learning algorithms have attempted to utilize estimated uncertainty for exploration, such as optimism in the face of uncertainty. However, using the estimated variance for optimistic exploration may cause biased data collection and hinder convergence or performance. In t…

Cited by 4SourcePDFScholar
2023

PreWoMe: Exploiting Presuppositions as Working Memory for Long Form Question Answering

EMNLP 2023short main

Information-seeking questions in long-form question answering (LFQA) often prove misleading due to ambiguity or false presupposition in the question. While many existing approaches handle misleading questions, they are tailored to limited questions, which are insufficient in a real-world setting wit…

Cited by 7SourceScholar
2023

QASA: Advanced Question Answering on Scientific Articles

ICML 2023poster

Reasoning is the crux of intellectual thinking. While question answering (QA) tasks are prolific with various computational models and benchmark datasets, they mostly tackle factoid or shallow QA without asking deeper understanding. Dual process theory asserts that human reasoning consists of associ…

2023

Score-based Generative Modeling through Stochastic Evolution Equations in Hilbert Spaces

NeurIPS 2023spotlight

Continuous-time score-based generative models consist of a pair of stochastic differential equations (SDEs)—a forward SDE that smoothly transitions data into a noise space and a reverse SDE that incrementally eliminates noise from a Gaussian prior distribution to generate data distribution samples—a…

Cited by 15SourcePDFScholar
2023

Sequential Preference Ranking for Efficient Reinforcement Learning from Human Feedback

NeurIPS 2023poster

Reinforcement learning from human feedback (RLHF) alleviates the problem of designing a task-specific reward function in reinforcement learning by learning it from human preference. However, existing RLHF models are considered inefficient as they produce only a single preference data from each human…

Cited by 11SourcePDFScholar
2023

Trust Region-Based Safe Distributional Reinforcement Learning for Multiple Constraints

NeurIPS 2023poster

In safety-critical robotic tasks, potential failures must be reduced, and multiple constraints must be met, such as avoiding collisions, limiting energy consumption, and maintaining balance. Thus, applying safe reinforcement learning (RL) in such robotic tasks requires to handle multiple constraints…

2023

When to Read Documents or QA History: On Unified and Selective Open-domain QA

ACL 2023findings

This paper studies the problem of open-domain question answering, with the aim of answering a diverse range of questions leveraging knowledge resources. Two types of sources, QA-pair and document corpora, have been actively leveraged with the following complementary strength. The former is highly pr…

2022

Domain Generalization by Mutual-Information Regularization with Pre-trained Models

ECCV 2022poster

"Domain generalization (DG) aims to learn a generalized model to an unseen target domain using only limited source domains. Previous attempts to DG fail to learn domain-invariant representations only from the source domains due to the significant domain shifts between training and test domains. Inst…

2022

Dynamics-Aware Metric Embedding: Metric Learning in a Latent Space for Visual Planning

RA-L 2022

In this letter, we consider vision-based control tasks of which the desired goals are given as target images. The problems are often addressed by an autonomous agent which optimizes a trajectory to minimize a manually designed cost function. However, it is challenging to design a suitable cost funct

Cited by 3SourceScholar
2022

Neural Markov Controlled SDE: Stochastic Optimization for Continuous-Time Data

ICLR 2022poster

We propose a novel probabilistic framework for modeling stochastic dynamics with the rigorous use of stochastic optimal control theory. The proposed model called the neural Markov controlled stochastic differential equation (CSDE) overcomes the fundamental and structural limitations of conventional…

Cited by 33SourcePDFScholar
2022

Plug-and-Play Adaptation for Continuously-updated QA

ACL 2022findings

Language models (LMs) have shown great potential as implicit knowledge bases (KBs). And for their practical use, knowledge in LMs need to be updated periodically. However, existing tasks to assess LMs’ efficacy as KBs do not adequately consider multiple large-scale updates. To this end, we first pro…

2022

Riemannian Neural SDE: Learning Stochastic Representations on Manifolds

NeurIPS 2022accept

In recent years, the neural stochastic differential equation (NSDE) has gained attention for modeling stochastic representations with great success in various types of applications. However, it typically loses expressivity when the data representation is manifold-valued. To address this issue, we su…

Cited by 2SourcePDFScholar
2022

Semi-Autonomous Teleoperation via Learning Non-Prehensile Manipulation Skills

ICRA 2022poster

In this paper, we present a semi-autonomous teleoperation framework for a pick-and-place task using an RGB-D sensor. In particular, we assume that the target object is located in a cluttered environment where both prehensile grasping and non-prehensile manipulation are combined for efficient teleope…

Cited by 7SourceScholar
2021

Robustifying Multi-hop QA through Pseudo-Evidentiality Training

ACL 2021long

This paper studies the bias problem of multi-hop question answering models, of answering correctly without correct reasoning. One way to robustify these models is by supervising to not only answer right, but also with right reasoning chains. An existing direction is to annotate reasoning chains to t…

Cited by 12SourcePDFScholar
2021

SWAD: Domain Generalization by Seeking Flat Minima

NeurIPS 2021poster

Domain generalization (DG) methods aim to achieve generalizability to an unseen target domain by using only training data from the source domains. Although a variety of DG methods have been proposed, a recent study shows that under a fair evaluation protocol, called DomainBed, the simple empirical r…

2020

Generalized Tsallis Entropy Reinforcement Learning and Its Application to Soft Mobile Robots

RSS 2020poster

In this paper, we present a new class of Markov decision processes (MDPs), called Tsallis MDPs, with Tsallis entropy maximization, which generalizes existing maximum entropy reinforcement learning (RL). A Tsallis MDP provides a unified framework for the original RL problem and RL with various types…

2020

Hierarchical 6-DoF Grasping with Approaching Direction Selection

ICRA 2020poster

In this paper, we tackle the problem of 6-DoF grasp detection which is crucial for robot grasping in cluttered real-world scenes. Unlike existing approaches which synthesize 6-DoF grasp data sets and train grasp quality networks with input grasp representations based on point clouds, we rather take…

Cited by 8SourceScholar
2020

Learning to Walk a Tripod Mobile Robot Using Nonlinear Soft Vibration Actuators With Entropy Adaptive Reinforcement Learning

RA-L 2020

Soft mobile robots have shown great potential in unstructured and confined environments by taking advantage of their excellent adaptability and high dexterity. However, there are several issues to be addressed, such as actuating speeds and controllability, in soft robots. In this letter, a new vibra

Cited by 17SourceScholar
2020

MixGAIL: Autonomous Driving Using Demonstrations with Mixed Qualities

IROS 2020poster

In this paper, we consider autonomous driving of a vehicle using imitation learning. Generative adversarial imitation learning (GAIL) is a widely used algorithm for imitation learning. This algorithm leverages positive demonstrations to imitate the behavior of an expert. In this paper, we propose a…

Cited by 25SourceScholar
2020

No-Regret Shannon Entropy Regularized Neural Contextual Bandit Online Learning for Robotic Grasping

IROS 2020poster

In this paper, we propose a novel contextual bandit algorithm that employs a neural network as a reward estimator and utilizes Shannon entropy regularization to encourage exploration, which is called Shannon entropy regularized neural contextual bandits (SERN). In many learning-based algorithms for…

Cited by 2SourceScholar
2020

Task Agnostic Robust Learning on Corrupt Outputs by Correlation-Guided Mixture Density Networks

CVPR 2020oral

In this paper, we focus on weakly supervised learning with noisy training data for both classification and regression problems. We assume that the training outputs are collected from a mixture of a target and correlated noise distributions. Our proposed method simultaneously estimates the target dis…

Cited by 9PDFScholar
2018

Sparse Markov Decision Processes With Causal Sparse Tsallis Entropy Regularization for Reinforcement Learning

RA-L 2018

In this letter, a sparse Markov decision process (MDP) with novel causal sparse Tsallis entropy regularization is proposed. The proposed policy regularization induces a sparse and multimodal optimal policy distribution of a sparse MDP. The full mathematical analysis of the proposed sparse MDP is pro

Cited by 70SourceScholar
2018

Uncertainty-Aware Learning from Demonstration Using Mixture Density Networks with Sampling-Free Variance Modeling

ICRA 2018poster

In this paper, we propose an uncertainty-aware learning from demonstration method by presenting a novel uncertainty estimation method utilizing a mixture density network appropriate for modeling complex and noisy human behaviors. The proposed uncertainty acquisition can be done with a single forward…

Cited by 138SourceScholar
2017

Scalable robust learning from demonstration with leveraged deep neural networks

IROS 2017poster

In this paper, we propose a novel algorithm for learning from demonstration, which can learn a policy function robustly from a large number of demonstrations with mixed qualities. While most of the existing approaches assume that demonstrations are collected from skillful experts, the proposed metho…

Cited by 4SourceScholar
2016

Robust learning from demonstration using leveraged Gaussian processes and sparse-constrained optimization

ICRA 2016

In this paper, we propose a novel method for robust learning from demonstration using leveraged Gaussian process regression. While existing learning from demonstration (LfD) algorithms assume that demonstrations are given from skillful experts, the proposed method alleviates such assumption by allow

Cited by 30SourceScholar
2016

Robust modeling and prediction in dynamic environments using recurrent flow networks

IROS 2016poster

To enable safe motion planning in a dynamic environment, it is vital to anticipate and predict object movements. In practice, however, an accurate object identification among multiple moving objects is extremely challenging, making it infeasible to accurately track and predict individual objects. Fu…

Cited by 5SourceScholar
2015

Leveraged non-stationary Gaussian process regression for autonomous robot navigation

ICRA 2015poster

In this paper, we propose a novel regression method that can incorporate both positive and negative training data into a single regression framework. In detail, a leveraged kernel function for non-stationary Gaussian process regression is proposed. With this new kernel function, we can vary the corr…

Cited by 14SourceScholar