Haoyu Han
Graph-Centric AI: Scalable Graph Learning, LLM Reasoning, and AI for Social Good
Postdoctoral Fellow Β· Biomedical Informatics, Harvard Medical School
π On the 2026β27 academic job market β seeking faculty positions in Computer Science and related fields. View CV β Β· Email me β
About
I recently defended my Ph.D. in Computer Science at Michigan State University on October 2, 2026, advised by Professor Jiliang Tang in the DSE Lab. Starting October 2026, I will join the Department of Biomedical Informatics at Harvard Medical School as a Postdoctoral Research Fellow with Professor Marinka Zitnik. My research develops graph-centric AI systems, spanning scalable graph learning, reasoning with large language models over structured knowledge, and applications to scientific and real-world domains. My work has appeared at ICML, NeurIPS, ICLR, KDD, WWW, ACL and EMNLP, and I serve as an Area Chair for the KDD Datasets and Benchmarks Track. Before MSU, I earned my B.Eng. (2018) and M.S. (2021) from USTC, advised by Professors Enhong Chen and Qi Liu.
Research
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Graph Learning
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Graphs + Foundation Models
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Real-World Impact
Graph Learning Β· Scalability
Efficient optimization and propagation for learning on web-scale graphs.
- LazyGNN: Large-Scale Graph Neural Networks via Lazy Propagation ICML β23 Paper β LazyGNNCode β LazyGNN
- Alternately Optimized Graph Neural Networks ICML β23 Paper β ALT-OPTCode β ALT-OPT
- Inverse APPNP: Solution for OGB-LSC 2022 MAG240M NeurIPS β22 Β· Competition Paper β Inverse APPNPCode β Inverse APPNPResults β Inverse APPNP
Graph Learning Β· Adaptivity
Models that adapt to heterogeneous nodes, links, and graph spectra.
- Mixture of Link Predictors on Graphs NeurIPS β24 Paper β Link-MoECode β Link-MoE
- Demystifying Structural Disparity in Graph Neural Networks: Can One Size Fit All? NeurIPS β23 Paper β Structural DisparityCode β Structural Disparity
- Spectral-Aware Augmentation for Enhanced Graph Representation Learning CIKM β24 Paper β GASSER
- Node-wise Filtering in Graph Neural Networks: A Mixture of Experts Approach Preprint Β· 2026 Paper β Node-MoE
Graph Learning Β· Reliability
Understanding and mitigating bias, collapse, and generalization failures in graph learning.
- Structural Fairness-aware Active Learning for Graph Neural Networks ICLR β24 Paper β Structural FairnessCode β Structural Fairness
- Towards Label Position Bias in Graph Neural Networks NeurIPS β23 Paper β Label Position BiasCode β Label Position Bias
- Unveiling Mode Connectivity in Graph Neural Networks KDD β25 Paper β Mode Connectivity
- Enhancing Graph Representations Learning with Decorrelated Propagation KDD β23 Paper β DePropCode β DeProp
- An Embarrassingly Simple Graph Heuristic Reveals Shortcut-Solvable Benchmarks for Sequential Recommendation NeurIPS β26 Β· ED Paper β Benchmark Audit (TGH)Code β Benchmark Audit (TGH) Primarily Recommendation & E-Commerce
Graphs + Foundation Models Β· Structured LLM Reasoning
Explicit graph construction and exploration for reliable multi-step LLM reasoning.
- Reasoning by Exploration: A Unified Approach to Retrieval and Generation over Graphs WWW β26 Β· Oral Paper β Reasoning by ExplorationCode β Reasoning by Exploration
- Reasoning with Graphs: Structuring Implicit Knowledge to Enhance LLMs Reasoning ACL Findings β25 Paper β Reasoning with Graphs
- ConnectionMind: Leveraging Social Networks and Large Language Models for Personalized Recommendation at Meta CIKM β26 Β· Applied Paper β ConnectionMind Primarily Recommendation & E-Commerce
Graphs + Foundation Models Β· GraphRAG
Retrieval, filtering, integration, evaluation, and security over structured knowledge.
- RAG vs. GraphRAG: A Systematic Evaluation and Key Insights KDD β26 Β· D&B Paper β RAG vs. GraphRAGCode β RAG vs. GraphRAG
- Retrieval-Augmented Generation with Graphs (GraphRAG) Preprint Β· 2025 Paper β GraphRAG SurveyResources β GraphRAG Survey
- Beyond Static Retrieval: Opportunities and Pitfalls of Iterative Retrieval in GraphRAG EMNLP β26 Β· Main Paper β Beyond Static Retrieval
- Why Retrieval-Augmented Generation Fails: A Graph Perspective KDD β26 Paper β Why RAG Fails
- Benchmarking Knowledge-Extraction Attack and Defense on Retrieval-Augmented Generation KDD β26 Β· D&B Β· Oral Paper β RAG Attack & DefenseCode β RAG Attack & DefenseDataset β RAG Attack & Defense
- Empowering GraphRAG with Knowledge Filtering and Integration EMNLP β25 Paper β GraphRAG-FI
- Mixture of Structural-and-Textual Retrieval over Text-rich Graph Knowledge Bases ACL Findings β25 Paper β MoRCode β MoR
- From Flat to Structural: Enhancing Automated Short Answer Grading with GraphRAG EDM β26 Paper β GraphRAG for Grading Primarily Education
- Enhancing LLM-Based Short Answer Grading with Retrieval-Augmented Generation EDM β25 Paper β RAG for Grading Primarily Education
Graphs + Foundation Models Β· Foundation Models for Graphs
Language and video models as graph annotators, encoders, and predictors.
- Graph2Video: Leveraging Video Models to Model Dynamic Graph Evolution AAAI β26 Paper β Graph2Video
- Label-free Node Classification on Graphs with Large Language Models (LLMs) ICLR β24 Paper β LLM-GNNCode β LLM-GNNarchived
- GT2VEC: Large Language Models as Multi-Modal Encoders for Text and Graph-Structured Data KDD SKnow-LLM Workshop β25 Paper β GT2VecCode β GT2Vec
- Understanding Graph Self-Supervised Pre-training under Distribution Shifts: A Scaling Law Perspective NeurIPS β26 Paper β Graph SSL Scaling
Real-World Impact Β· Recommendation & E-Commerce
Graph-based personalization, multimodal recommendation, and benchmark diagnostics.
- ConnectionMind: Leveraging Social Networks and Large Language Models for Personalized Recommendation at Meta CIKM β26 Β· Applied Paper β ConnectionMind Also connected to: Structured LLM Reasoning
- An Embarrassingly Simple Graph Heuristic Reveals Shortcut-Solvable Benchmarks for Sequential Recommendation NeurIPS β26 Β· ED Paper β Benchmark Audit (TGH)Code β Benchmark Audit (TGH) Also connected to: Reliability
- Enhancing ID and Text Fusion via Alternative Training in Session-based Recommendation IJCNLPβAACL β25 Paper β AlterRecCode β AlterRec
- Amazon-M2: A Multilingual Multi-locale Shopping Session Dataset for Recommendation and Text Generation NeurIPS β23 Β· D&B Paper β Amazon-M2Code β Amazon-M2Amazon Science β Amazon-M2Dataset β Amazon-M2
- STGCN: A Spatial-Temporal Aware Graph Learning Method for POI Recommendation ICDM β20 Paper β STGCN
Real-World Impact Β· Education
Knowledge-grounded assessment design and automated grading.
- From Flat to Structural: Enhancing Automated Short Answer Grading with GraphRAG EDM β26 Paper β GraphRAG for Grading Also connected to: GraphRAG
- Enhancing LLM-Based Short Answer Grading with Retrieval-Augmented Generation EDM β25 Paper β RAG for Grading Also connected to: GraphRAG
- Human-AI Collaboration for Knowledge-in-Use Assessment Design: Leveraging LLMs with RAG IEEE TALE β25 Paper β HumanβAI Assessment Design
- Constructing Educational Concept Maps with Multiple Relationships from Multi-source Data ICDM β19 Paper β Educational Concept Maps
Real-World Impact Β· AI for Science
Graph learning for multimodal single-cell data integration.
- Multimodal Single-Cell Data Integration Project Β· NeurIPS β21 Competition Β· 1st Competition page β DANCE Project repository β DANCE
Research overview β Browse all publications β
Recent News
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Oct 2026 Our workshop proposal Large Language Models (LLMs) for E-Commerce has been accepted as a half-day workshop at WSDM 2027 (9 of 24 proposals accepted)! The workshop will take place on February 19, 2027. Stay tuned for the call for papers.
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Oct 2026 I successfully defended my Ph.D. dissertation on October 2, 2026! Huge thanks to my advisor Prof. Jiliang Tang, my committee, and everyone in the DSE Lab. π
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Sep 2026 I have accepted an offer to join the Department of Biomedical Informatics at Harvard Medical School as a Postdoctoral Research Fellow, working with Prof. Marinka Zitnik, starting October 2026!
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Sep 2026 Our paper An Embarrassingly Simple Graph Heuristic Reveals Shortcut-Solvable Benchmarks for Sequential Recommendation is accepted by NeurIPS 2026 Evaluations and Datasets Track!
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Sep 2026 Our paper Understanding Graph Self-Supervised Pre-training under Distribution Shifts: A Scaling Law Perspective is accepted by NeurIPS 2026!
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Sep 2026 I will serve as an Area Chair for the GenAI4Health Workshop at NeurIPS 2026.