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Wee Sun Lee

45 accepted papers

2026

From Backward Spreading to Forward Replay: Revisiting Target Construction in LLM Parameter Editing

ICML 2026poster

LLM parameter editing methods commonly rely on computing an ideal target hidden-state at a target layer (referred as anchor point) and distributing the target vector to multiple preceding layers (commonly known as backward spreading) for cooperative editing. Although widely used for a long time, its…

Cited by 0SourceScholar
2026

Rethinking the Trust Region in LLM Reinforcement Learning

ICML 2026poster

Reinforcement learning (RL) has become a cornerstone for fine-tuning Large Language Models (LLMs), with Proximal Policy Optimization (PPO) serving as the de facto standard algorithm. Despite its ubiquity, we argue that the core ratio clipping mechanism in PPO is structurally ill-suited for the large…

Cited by 0SourceScholar
2026

SPIRAL: Self-Play on Zero-Sum Games Incentivizes Reasoning via Multi-Agent Multi-Turn Reinforcement Learning

ICLR 2026poster

Recent advances in reinforcement learning have shown that language models can develop sophisticated reasoning through training on tasks with verifiable rewards, but these approaches depend on human-curated problem-answer pairs and domain-specific reward engineering. We introduce SPIRAL, a self-play…

Cited by 0SourcecodeScholar
2025

Approximation and Generalization Abilities of Score-based Neural Network Generative Models for Sub-Gaussian Distributions

NeurIPS 2025poster

This paper studies the approximation and generalization abilities of score-based neural network generative models (SGMs) in estimating an unknown distribution $P_0$ from $n$ i.i.d. observations in $d$ dimensions. Assuming merely that $P_0$ is $\alpha$-sub-Gaussian, we prove that for any time step $…

Cited by 0SourceScholar
2025

Continual Reinforcement Learning by Planning with Online World Models

ICML 2025spotlight

Continual reinforcement learning (CRL) refers to a naturalistic setting where an agent needs to endlessly evolve, by trial and error, to solve multiple tasks that are presented sequentially. One of the largest obstacles to CRL is that the agent may forget how to solve previous tasks when learning a…

Cited by 0SourcePDFScholar
2025

Optimizing Anytime Reasoning via Budget Relative Policy Optimization

NeurIPS 2025poster

Scaling test-time compute is crucial for enhancing the reasoning capabilities of large language models (LLMs). Existing approaches typically employ reinforcement learning (RL) to maximize a verifiable reward obtained at the end of reasoning traces. However, such methods optimize only the final perfo…

Cited by 0SourcecodeScholar
2025

SHIELD: Multi-task Multi-distribution Vehicle Routing Solver with Sparsity and Hierarchy

ICML 2025poster

Recent advances toward foundation models for routing problems have shown great potential of a unified deep model for various VRP variants. However, they overlook the complex real-world customer distributions. In this work, we advance the Multi-Task VRP (MTVRP) setting to the more realistic yet chall…

Cited by 9SourcePDFScholar
2025

Solving the Asymmetric Traveling Salesman Problem via Trace-Guided Cost Augmentation

NeurIPS 2025poster

The Asymmetric Traveling Salesman Problem (ATSP) ranks among the most fundamental and notoriously difficult problems in combinatorial optimization. We propose a novel continuous relaxation framework for the Asymmetric Traveling Salesman Problem (ATSP) by leveraging differentiable constraints that en…

Cited by 0SourceScholar
2024

Constrained Layout Generation with Factor Graphs

CVPR 2024poster

This paper addresses the challenge of object-centric layout generation under spatial constraints seen in multiple domains including floorplan design process. The design process typically involves specifying a set of spatial constraints that include object attributes like size and inter-object relati…

Cited by 6SourcePDFScholar
2024

On the Empirical Complexity of Reasoning and Planning in LLMs

EMNLP 2024finding

Chain-of-thought (CoT), tree-of-thought (ToT), and related techniques work surprisingly well in practice for some complex reasoning tasks with Large Language Models (LLMs), but why? This work seeks the underlying reasons by conducting experimental case studies and linking the performance benefits to…

2024

When Phrases Meet Probabilities: Enabling Open Relation Extraction with Cooperating Large Language Models

ACL 2024long

Current clustering-based open relation extraction (OpenRE) methods usually apply clustering algorithms on top of pre-trained language models. However, this practice has three drawbacks. First, embeddings from language models are high-dimensional and anisotropic, so using simple metrics to calculate…

2023

Differentiable Parsing and Visual Grounding of Natural Language Instructions for Object Placement

ICRA 2023poster

We present a new method, PARsing And visual GrOuNding (PARAGON), for grounding natural language in object placement tasks. Natural language generally describes objects and spatial relations with compositionality and ambiguity, two major obstacles to effective language grounding. For compositionality…

Cited by 11SourceScholar
2023

Efficient Offline Policy Optimization with a Learned Model

ICLR 2023poster

MuZero Unplugged presents a promising approach for offline policy learning from logged data. It conducts Monte-Carlo Tree Search (MCTS) with a learned model and leverages Reanalyze algorithm to learn purely from offline data. For good performance, MCTS requires accurate learned models and a large nu…

2023

Tell2Design: A Dataset for Language-Guided Floor Plan Generation

ACL 2023long

We consider the task of generating designs directly from natural language descriptions, and consider floor plan generation as the initial research area. Language conditional generative models have recently been very successful in generating high-quality artistic images. However, designs must satisfy…

2022

PF-GNN: Differentiable particle filtering based approximation of universal graph representations

ICLR 2022poster

Message passing Graph Neural Networks (GNNs) are known to be limited in expressive power by the 1-WL color-refinement test for graph isomorphism. Other more expressive models either are computationally expensive or need preprocessing to extract structural features from the graph. In this work, we pr…

2020

Contrastive Variational Reinforcement Learning for Complex Observations

CoRL 2020

Deep reinforcement learning (DRL) has achieved significant success in various robot tasks: manipulation, navigation, etc. However, complex visual observations in natural environments remains a major challenge. This paper presents Contrastive Variational Reinforcement Learning (CVRL), a model-based m

2020

Discriminative Particle Filter Reinforcement Learning for Complex Partial observations

ICLR 2020poster

Deep reinforcement learning is successful in decision making for sophisticated games, such as Atari, Go, etc. However, real-world decision making often requires reasoning with partial information extracted from complex visual observations. This paper presents Discriminative Particle Filter Reinfor…

Cited by 45SourcecodeScholar
2019

DESPOT-Alpha: Online POMDP Planning with Large State and Observation Spaces

RSS 2019poster

State-of-the-art sampling-based online POMDP solvers compute near-optimal policies for POMDPs with very large state spaces. However, when faced with large observation spaces, they may become overly optimistic and compute sub-optimal policies, because of particle divergence. This paper presents a new…

Cited by 73SourcePDFScholar
2019

Differentiable Algorithm Networks for Composable Robot Learning

RSS 2019poster

This paper introduces the Differentiable Algorithm Network (DAN), a composable architecture for robot learning systems. A DAN is composed of neural network modules, each encoding a differentiable robot algorithm and an associated model; and it is trained end-to-end from data. DAN combines the streng…

Cited by 81SourcePDFScholar
2019

Factored Contextual Policy Search with Bayesian optimization

ICRA 2019poster

Scarce data is a major challenge to scaling robot learning to truly complex tasks, as we need to generalize locally learned policies over different task contexts. Contextual policy search offers data-efficient learning and generalization by explicitly conditioning the policy on a parametric context…

Cited by 8SourceScholar
2019

LeTS-Drive: Driving in a Crowd by Learning from Tree Search

RSS 2019poster

Autonomous driving in a crowded environment, e.g., a busy traffic intersection, is an unsolved challenge for robotics. The robot vehicle must contend with a dynamic and partially observable environment, noisy sensors, and many agents. A principled approach is to formalize it as a Partially Observabl…

Cited by 40SourcePDFScholar
2018

Convolutional Sequence to Sequence Model for Human Dynamics

CVPR 2018poster

Human motion modeling is a classic problem in com- puter vision and graphics. Challenges in modeling human motion include high dimensional prediction as well as extremely complicated dynamics.We present a novel approach to human motion modeling based on convolutional neural networks (CNN). The hiera…

2018

HyP-DESPOT: A Hybrid Parallel Algorithm for Online Planning under Uncertainty

RSS 2018poster

Planning under uncertainty is critical for robust robot performance in uncertain, dynamic environments, but it incurs high computational cost. State-of-the-art online search algorithms, such as DESPOT, have vastly improved the computational efficiency of planning under uncertainty and made it a valu…

2018

PORCA: Modeling and Planning for Autonomous Driving Among Many Pedestrians

RA-L 2018

This letter presents a planning system for autonomous driving among many pedestrians. A key ingredient of our approach is Pedestrian Optimal Reciprocal Collision Avoidance, a pedestrian motion prediction model that accounts for both a pedestrian's global navigation intention and local interactions w

Cited by 191SourceScholar
2017

Intention-Net: Integrating Planning and Deep Learning for Goal-Directed Autonomous Navigation

CoRL 2017

How can a delivery robot navigate reliably to a destination in a new office building, with minimal prior information? To tackle this challenge, this paper introduces a two-level hierarchical approach, which integrates model-free deep learning and model-based path planning. At the low level, a neural

Cited by 0SourcePDFScholar
2017

QMDP-Net: Deep Learning for Planning under Partial Observability

NeurIPS 2017poster

This paper introduces the QMDP-net, a neural network architecture for planning under partial observability. The QMDP-net combines the strengths of model-free learning and model-based planning. It is a recurrent policy network, but it represents a policy for a parameterized set of tasks by connecting…

2015

Intention-aware online POMDP planning for autonomous driving in a crowd

ICRA 2015poster

This paper presents an intention-aware online planning approach for autonomous driving amid many pedestrians. To drive near pedestrians safely, efficiently, and smoothly, autonomous vehicles must estimate unknown pedestrian intentions and hedge against the uncertainty in intention estimates in order…

Cited by 432SourceScholar