← Search

Zhongkai Hao

24 accepted papers

2026

A$^2$Search: Ambiguity-Aware Question Answering with Reinforcement Learning

ICLR 2026poster

Recent advances in Large Language Models (LLMs) and Reinforcement Learning (RL) have led to strong performance in open-domain question answering (QA). However, existing models still struggle with questions that admit multiple valid answers. Standard QA benchmarks, which typically assume a single gol…

Cited by 0SourcecodeScholar
2026

Exploratory Diffusion Model for Unsupervised Reinforcement Learning

ICLR 2026oral

Unsupervised reinforcement learning (URL) pre-trains agents by exploring diverse states in reward-free environments, aiming to enable efficient adaptation to various downstream tasks. Without extrinsic rewards, prior methods rely on intrinsic objectives, but heterogeneous exploration data demand str…

Cited by 0SourcecodeScholar
2026

Helix: Evolutionary Reinforcement Learning for Open-Ended Scientific Problem Solving

ICLR 2026poster

Large language models (LLMs) with reasoning abilities have demonstrated growing promise for tackling complex scientific problems. Yet such tasks are inherently domain-specific, unbounded and open-ended, demanding exploration across vast and flexible solution spaces. Existing approaches, whether pure…

Cited by 0SourceScholar
2025

Accelerating PDE-Constrained Optimization by the Derivative of Neural Operators

ICML 2025poster

PDE-Constrained Optimization (PDECO) problems can be accelerated significantly by employing gradient-based methods with surrogate models like neural operators compared to traditional numerical solvers. However, this approach faces two key challenges: (1) **Data inefficiency**: Lack of efficient dat…

Cited by 0SourcePDFScholar
2025

AeroGTO: An Efficient Graph-Transformer Operator for Learning Large-Scale Aerodynamics of 3D Vehicle Geometries

AAAI 2025technical

Obtaining high-precision aerodynamics in the automotive industry relies on large-scale simulations with computational fluid dynamics, which are generally time-consuming and computationally expensive. Recent advances in operator learning for partial differential equations offer promising improvements…

2024

Accelerating Data Generation for Neural Operators via Krylov Subspace Recycling

ICLR 2024spotlight

Learning neural operators for solving partial differential equations (PDEs) has attracted great attention due to its high inference efficiency. However, training such operators requires generating a substantial amount of labeled data, i.e., PDE problems together with their solutions. The data genera…

2024

DPOT: Auto-Regressive Denoising Operator Transformer for Large-Scale PDE Pre-Training

ICML 2024poster

Pre-training has been investigated to improve the efficiency and performance of training neural operators in data-scarce settings. However, it is largely in its infancy due to the inherent complexity and diversity, such as long trajectories, multiple scales and varying dimensions of partial differen…

2024

Diffusion Models are Certifiably Robust Classifiers

NeurIPS 2024poster

Generative learning, recognized for its effective modeling of data distributions, offers inherent advantages in handling out-of-distribution instances, especially for enhancing robustness to adversarial attacks. Among these, diffusion classifiers, utilizing powerful diffusion models, have demonstrat…

2024

Improved Operator Learning by Orthogonal Attention

ICML 2024spotlight

This work presents orthogonal attention for constructing neural operators to serve as surrogates to model the solutions of a family of Partial Differential Equations (PDEs). The motivation is that the kernel integral operator, which is usually at the core of neural operators, can be reformulated wit…

2024

PAPM: A Physics-aware Proxy Model for Process Systems

ICML 2024poster

In the context of proxy modeling for process systems, traditional data-driven deep learning approaches frequently encounter significant challenges, such as substantial training costs induced by large amounts of data, and limited generalization capabilities. As a promising alternative, physics-aware…

2024

PEAC: Unsupervised Pre-training for Cross-Embodiment Reinforcement Learning

NeurIPS 2024poster

Designing generalizable agents capable of adapting to diverse embodiments has achieved significant attention in Reinforcement Learning (RL), which is critical for deploying RL agents in various real-world applications. Previous Cross-Embodiment RL approaches have focused on transferring knowledge ac…

2024

PINNacle: A Comprehensive Benchmark of Physics-Informed Neural Networks for Solving PDEs

NeurIPS 2024poster

While significant progress has been made on Physics-Informed Neural Networks (PINNs), a comprehensive comparison of these methods across a wide range of Partial Differential Equations (PDEs) is still lacking. This study introduces PINNacle, a benchmarking tool designed to fill this gap. PINNacle pro…

2024

Reference Neural Operators: Learning the Smooth Dependence of Solutions of PDEs on Geometric Deformations

ICML 2024poster

For partial differential equations on domains of arbitrary shapes, existing works of neural operators attempt to learn a mapping from geometries to solutions. It often requires a large dataset of geometry-solution pairs in order to obtain a sufficiently accurate neural operator. However, for many in…

Cited by 2SourcePDFScholar
2023

Bi-level Physics-Informed Neural Networks for PDE Constrained Optimization using Broyden's Hypergradients

ICLR 2023poster

Deep learning based approaches like Physics-informed neural networks (PINNs) and DeepONets have shown promise on solving PDE constrained optimization (PDECO) problems. However, existing methods are insufficient to handle those PDE constraints that have a complicated or nonlinear dependency on optim…

Cited by 19SourcePDFScholar
2023

Equivariant Energy-Guided SDE for Inverse Molecular Design

ICLR 2023poster

Inverse molecular design is critical in material science and drug discovery, where the generated molecules should satisfy certain desirable properties. In this paper, we propose equivariant energy-guided stochastic differential equations (EEGSDE), a flexible framework for controllable 3D molecule ge…

2023

Full-Atom Protein Pocket Design via Iterative Refinement

NeurIPS 2023spotlight

The design of \emph{de novo} functional proteins that bind with specific ligand molecules is crucial in various domains like therapeutics and bio-engineering. One vital yet challenging step is to design the protein pocket, the cavity region of protein where the ligand binds with. Existing methods su…

2023

GNOT: A General Neural Operator Transformer for Operator Learning

ICML 2023poster

Learning partial differential equations' (PDEs) solution operators is an essential problem in machine learning. However, there are several challenges for learning operators in practical applications like the irregular mesh, multiple input functions, and complexity of the PDEs' solution. To address t…

2023

MultiAdam: Parameter-wise Scale-invariant Optimizer for Multiscale Training of Physics-informed Neural Networks

ICML 2023poster

Physics-informed Neural Networks (PINNs) have recently achieved remarkable progress in solving Partial Differential Equations (PDEs) in various fields by minimizing a weighted sum of PDE loss and boundary loss. However, there are several critical challenges in the training of PINNs, including the la…

Cited by 22SourcePDFScholar
2023

NUNO: A General Framework for Learning Parametric PDEs with Non-Uniform Data

ICML 2023poster

The neural operator has emerged as a powerful tool in learning mappings between function spaces in PDEs. However, when faced with real-world physical data, which are often highly non-uniformly distributed, it is challenging to use mesh-based techniques such as the FFT. To address this, we introduce…

2023

On the Reuse Bias in Off-Policy Reinforcement Learning

IJCAI 2023poster

Importance sampling (IS) is a popular technique in off-policy evaluation, which re-weights the return of trajectories in the replay buffer to boost sample efficiency. However, training with IS can be unstable and previous attempts to address this issue mainly focus on analyzing the variance of IS. I…

2022

A Unified Hard-Constraint Framework for Solving Geometrically Complex PDEs

NeurIPS 2022accept

We present a unified hard-constraint framework for solving geometrically complex PDEs with neural networks, where the most commonly used Dirichlet, Neumann, and Robin boundary conditions (BCs) are considered. Specifically, we first introduce the "extra fields'' from the mixed finite element method t…

2022

Cluster Attack: Query-based Adversarial Attacks on Graph with Graph-Dependent Priors

IJCAI 2022poster

While deep neural networks have achieved great success in graph analysis, recent work has shown that they are vulnerable to adversarial attacks. Compared with adversarial attacks on image classification, performing adversarial attacks on graphs is more challenging because of the discrete and non-dif…

Cited by 18SourcePDFScholar
2022

GSmooth: Certified Robustness against Semantic Transformations via Generalized Randomized Smoothing

ICML 2022spotlight

Certified defenses such as randomized smoothing have shown promise towards building reliable machine learning systems against $\ell_p$ norm bounded attacks. However, existing methods are insufficient or unable to provably defend against semantic transformations, especially those without closed-form…

Cited by 31SourcePDFScholar