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Ziang Chen

14 accepted papers

2026

Aegis: Automated Error Generation and Identification for Multi-Agent Systems

ICLR 2026poster

Large language model based multi-agent systems (MAS) have unlocked significant advancements in tackling complex problems, but their increasing capability introduces a structural fragility that makes them difficult to debug. A key obstacle to improving their reliability is the severe scarcity of larg…

Cited by 0SourceScholar
2026

CCAHCL: Multi-Level Hypergraph Contrastive Learning for Connected Component Awareness

AAAI 2026technical

Hypergraph contrastive learning has emerged as a powerful unsupervised paradigm for hypergraph representation learning. Traditional hypergraph contrastive learning methods typically leverage neighbor aggregation strategy to obtain entity (node and hyperedge) representations within each connected com

Cited by 0SourcePDFScholar
2025

Evaluating Generalization Capabilities of LLM-Based Agents in Mixed-Motive Scenarios Using Concordia

NeurIPS 2025poster

Large Language Model (LLM) agents have demonstrated impressive capabilities for social interaction and are increasingly being deployed in situations where they might engage with both human and artificial agents. These interactions represent a critical frontier for LLM-based agents, yet existing eval…

Cited by 0SourceScholar
2025

Expressive Power of Graph Neural Networks for (Mixed-Integer) Quadratic Programs

ICML 2025poster

Quadratic programming (QP) is the most widely applied category of problems in nonlinear programming. Many applications require real-time/fast solutions, though not necessarily with high precision. Existing methods either involve matrix decomposition or use the preconditioned conjugate gradient metho…

Cited by 2SourcePDFScholar
2025

On Designing General and Expressive Quantum Graph Neural Networks with Applications to MILP Instance Representation

ICLR 2025poster

Graph-structured data is ubiquitous, and graph learning models have recently been extended to address complex problems like mixed-integer linear programming (MILP). However, studies have shown that the vanilla message-passing based graph neural networks (GNNs) suffer inherent limitations in learning…

Cited by 1SourcePDFScholar
2024

Certified Machine Unlearning via Noisy Stochastic Gradient Descent

NeurIPS 2024poster

``The right to be forgotten'' ensured by laws for user data privacy becomes increasingly important. Machine unlearning aims to efficiently remove the effect of certain data points on the trained model parameters so that it can be approximately the same as if one retrains the model from scratch. We p…

2024

Langevin Unlearning: A New Perspective of Noisy Gradient Descent for Machine Unlearning

NeurIPS 2024spotlight

Machine unlearning has raised significant interest with the adoption of laws ensuring the ``right to be forgotten''. Researchers have provided a probabilistic notion of approximate unlearning under a similar definition of Differential Privacy (DP), where privacy is defined as statistical indistingui…

2024

Rethinking the Capacity of Graph Neural Networks for Branching Strategy

NeurIPS 2024poster

Graph neural networks (GNNs) have been widely used to predict properties and heuristics of mixed-integer linear programs (MILPs) and hence accelerate MILP solvers. This paper investigates the capacity of GNNs to represent strong branching (SB), the most effective yet computationally expensive heuris…

Cited by 4SourcePDFScholar
2023

HeteRSGD: Tackling Heterogeneous Sampling Costs via Optimal Reweighted Stochastic Gradient Descent

AISTATS 2023poster

One implicit assumption in current stochastic gradient descent (SGD) algorithms is the identical cost for sampling each component function of the finite-sum objective. However, there are applications where the costs differ substantially, for which SGD schemes with uniform sampling invoke a high samp…

Cited by 0SourcePDFScholar
2023

On Representing Linear Programs by Graph Neural Networks

ICLR 2023top-25%

Learning to optimize is a rapidly growing area that aims to solve optimization problems or improve existing optimization algorithms using machine learning (ML). In particular, the graph neural network (GNN) is considered a suitable ML model for optimization problems whose variables and constraints a…

2023

On Representing Mixed-Integer Linear Programs by Graph Neural Networks

ICLR 2023poster

While Mixed-integer linear programming (MILP) is NP-hard in general, practical MILP has received roughly 100--fold speedup in the past twenty years. Still, many classes of MILPs quickly become unsolvable as their sizes increase, motivating researchers to seek new acceleration techniques for MILPs. W…