PhD Student in Computer Science & Engineering (Language Agent Safety + LLM Alignment)
I am a first year PhD student in Computer Science & Engineering at The Ohio State University, with research interests in Language Agent Safety and Robustness of Large Language Models and Alignment. My work focuses on evaluating and mitigating the refusal behavior of LLMs, developing methods to improve the safety and reliability of language models in real-world applications.
Previously I have worked as an Applied Scientist Intern at Amazon and have collaborated with researchers at Stanford SALT Lab, Adobe Research, and Microsoft Research Lab – Asia, working on cutting-edge NLP research and applications.
Education
2025 — Present
Ph.D. in Computer Science
Advisor:
Yu Su, Co-advisor:
Huan Sun
Research focus: Language Agent Safety and Robustness of LLMs, Alignment
Advised by Prof. Yu Su and Prof. Huan Sun
2023 — 2024
M.S. in Computer Science
Research focus: Natural Language Processing
2019 — 2023
B.Eng. in Artificial Intelligence (Honor Class)
Honor Class in Artificial Intelligence
Industry Research Experience
Nov 2024 — Jun 2025
Work as an applied scientist intern on evaluating and mitigating the refusal behavior of LLMs.
Summer 2024
Research in multi-modal large language models and visual perception enhancement.
2023
Research in hierarchical table analysis and complex reasoning question answering over tabular data.
Academic Research Experience
2025 — Present
Mentor:
Yu Su
Research in Language Agent Safety and Robustness of LLMs, Alignment. Advised by Prof. Yu Su and Prof. Huan Sun.
2024
Mentor:
Diyi Yang
Research in Natural Language Processing, focusing on synthetic data and dynamic evaluation of large language models.
Honors and Awards
2025
Graduate Fellowship
awarded by Ohio State University
2025
COLM 2025 Travel Grant
2025
ICLR Notable Reviewer
2023-2025
Merit Scholarship
awarded by Dartmouth College
2019-2023
Zhiyuan Honor Scholarship and Merit Scholarship
awarded by SJTU
Publications
For the most up-to-date list of publications, please refer to my Google Scholar profile.
Selected: Latest & Greatest
Zhehao Zhang,
Weijie Xu,
Fanyou Wu,
Chandan K Reddy
Conference on Language Modeling (COLM). 2025.
@inproceedings{zhang2025falsereject,
title={Falsereject: A resource for improving contextual safety and mitigating over-refusals in llms via structured reasoning},
author={Zhang, Zhehao and Xu, Weijie and Wu, Fanyou and Reddy, Chandan K},
booktitle={Conference on Language Modeling (COLM)},
year={2025}
}
Zhehao Zhang,
Jiaao Chen,
Diyi Yang
Advances in Neural Information Processing Systems (NeurIPS). Vancouver, Canada, 2024.
@inproceedings{NEURIPS2024_f5198bc2,
author = {Zhang, Zhehao and Chen, Jiaao and Yang, Diyi},
booktitle = {Advances in Neural Information Processing Systems},
editor = {A. Globerson and L. Mackey and D. Belgrave and A. Fan and U. Paquet and J. Tomczak and C. Zhang},
pages = {135904--135942},
publisher = {Curran Associates, Inc.},
title = {DARG: Dynamic Evaluation of Large Language Models via Adaptive Reasoning Graph},
url = {https://proceedings.neurips.cc/paper_files/paper/2024/file/f5198bc255e1d5f959edd6d1d1a86fab-Paper-Conference.pdf},
volume = {37},
year = {2024}
}
Zhehao Zhang,
Ryan A. Rossi,
Tong Yu,
Franck Dernoncourt,
Ruiyi Zhang,
Jiuxiang Gu,
Sungchul Kim,
Xiang Chen,
Zichao Wang,
Nedim Lipka
arXiv preprint (arXiv). 2024.
@article{zhang2024vipact,
title={VipAct: Visual-Perception Enhancement via Specialized VLM Agent Collaboration and Tool-use},
author={Zhang, Zhehao and Rossi, Ryan A. and Yu, Tong and Dernoncourt, Franck and Zhang, Ruiyi and Gu, Jiuxiang and Kim, Sungchul and Chen, Xiang and Wang, Zichao and Lipka, Nedim},
journal={arXiv preprint arXiv:2410.16400},
year={2024}
}
Zhehao Zhang,
Weicheng Ma,
Soroush Vosoughi
Findings of the 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP). Miami, FL, USA, 2024.
@inproceedings{zhang2024gpt4v,
title={Is GPT-4V (ision) All You Need for Automating Academic Data Visualization? Exploring Vision-Language Models' Capability in Reproducing Academic Charts},
author={Zhang, Zhehao and Ma, Weicheng and Vosoughi, Soroush},
booktitle={Findings of the 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2024}
}
Zhehao Zhang,
Ryan A. Rossi,
Branislav Kveton,
Yijia Shao,
Diyi Yang,
Hamed Zamani,
Franck Dernoncourt,
Joe Barrow,
Tong Yu,
Sungchul Kim,
Ruiyi Zhang,
Jiuxiang Gu,
Tyler Derr,
Hongjie Chen,
Junda Wu,
Xiang Chen,
Zichao Wang,
Subrata Mitra,
Nedim Lipka,
Nesreen Ahmed,
Yu Wang
Transactions on Machine Learning Research (TMLR). 2025.
@article{zhang2024personalization,
title={Personalization of Large Language Models: A Survey},
author={Zhang, Zhehao and Rossi, Ryan A. and Kveton, Branislav and Shao, Yijia and Yang, Diyi and Zamani, Hamed and Dernoncourt, Franck and Barrow, Joe and Yu, Tong and Kim, Sungchul and Zhang, Ruiyi and Gu, Jiuxiang and Derr, Tyler and Chen, Hongjie and Wu, Junda and Chen, Xiang and Wang, Zichao and Mitra, Subrata and Lipka, Nedim and Ahmed, Nesreen and Wang, Yu},
journal={arXiv preprint arXiv:2411.00027},
year={2024}
}
Zhehao Zhang,
Yan Gao,
Jian-Guang Lou
Proceedings of the 2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics (NAACL). Mexico City, Mexico, 2024.
@inproceedings{zhang2024e5,
title={E5: Zero-shot Hierarchical Table Analysis using Augmented LLMs via Explain, Extract, Execute, Exhibit, and Extrapolate},
author={Zhang, Zhehao and Gao, Yan and Lou, Jian-Guang},
booktitle={Proceedings of the 2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics (NAACL)},
year={2024}
}
Zhehao Zhang,
Xitao Li,
Yan Gao,
Jian-Guang Lou
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP). Singapore, 2023.
@inproceedings{zhang2023crt,
title={CRT-QA: A Dataset of Complex Reasoning Question Answering over Tabular Data},
author={Zhang, Zhehao and Li, Xitao and Gao, Yan and Lou, Jian-Guang},
booktitle={Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2023}
}
Zhehao Zhang,
Jiaao Chen,
Diyi Yang
Findings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP). Singapore, 2023.
@inproceedings{zhang2023hate,
title={Mitigating Biases in Hate Speech Detection from A Causal Perspective},
author={Zhang, Zhehao and Chen, Jiaao and Yang, Diyi},
booktitle={Findings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2023}
}
Caleb Ziems,
William Held,
Omar Shaikh,
Jiaao Chen,
Zhehao Zhang,
Diyi Yang
Computational Linguistics (CL). 2023.
@article{ziems2023llm,
title={Can Large Language Models Transform Computational Social Science?},
author={Ziems, Caleb and Held, William and Shaikh, Omar and Chen, Jiaao and Zhang, Zhehao and Yang, Diyi},
journal={Computational Linguistics},
volume={50},
number={1},
pages={237--280},
year={2023}
}
Conference
C6
Zhehao Zhang,
Weijie Xu,
Fanyou Wu,
Chandan K Reddy
Conference on Language Modeling (COLM). 2025.
@inproceedings{zhang2025falsereject,
title={Falsereject: A resource for improving contextual safety and mitigating over-refusals in llms via structured reasoning},
author={Zhang, Zhehao and Xu, Weijie and Wu, Fanyou and Reddy, Chandan K},
booktitle={Conference on Language Modeling (COLM)},
year={2025}
}
C5
Zhehao Zhang,
Jiaao Chen,
Diyi Yang
Advances in Neural Information Processing Systems (NeurIPS). Vancouver, Canada, 2024.
@inproceedings{NEURIPS2024_f5198bc2,
author = {Zhang, Zhehao and Chen, Jiaao and Yang, Diyi},
booktitle = {Advances in Neural Information Processing Systems},
editor = {A. Globerson and L. Mackey and D. Belgrave and A. Fan and U. Paquet and J. Tomczak and C. Zhang},
pages = {135904--135942},
publisher = {Curran Associates, Inc.},
title = {DARG: Dynamic Evaluation of Large Language Models via Adaptive Reasoning Graph},
url = {https://proceedings.neurips.cc/paper_files/paper/2024/file/f5198bc255e1d5f959edd6d1d1a86fab-Paper-Conference.pdf},
volume = {37},
year = {2024}
}
C4
Zhehao Zhang,
Weicheng Ma,
Soroush Vosoughi
Findings of the 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP). Miami, FL, USA, 2024.
@inproceedings{zhang2024gpt4v,
title={Is GPT-4V (ision) All You Need for Automating Academic Data Visualization? Exploring Vision-Language Models' Capability in Reproducing Academic Charts},
author={Zhang, Zhehao and Ma, Weicheng and Vosoughi, Soroush},
booktitle={Findings of the 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2024}
}
C3
Zhehao Zhang,
Yan Gao,
Jian-Guang Lou
Proceedings of the 2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics (NAACL). Mexico City, Mexico, 2024.
@inproceedings{zhang2024e5,
title={E5: Zero-shot Hierarchical Table Analysis using Augmented LLMs via Explain, Extract, Execute, Exhibit, and Extrapolate},
author={Zhang, Zhehao and Gao, Yan and Lou, Jian-Guang},
booktitle={Proceedings of the 2024 Annual Conference of the North American Chapter of the Association for Computational Linguistics (NAACL)},
year={2024}
}
C2
Zhehao Zhang,
Xitao Li,
Yan Gao,
Jian-Guang Lou
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP). Singapore, 2023.
@inproceedings{zhang2023crt,
title={CRT-QA: A Dataset of Complex Reasoning Question Answering over Tabular Data},
author={Zhang, Zhehao and Li, Xitao and Gao, Yan and Lou, Jian-Guang},
booktitle={Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2023}
}
C1
Zhehao Zhang,
Jiaao Chen,
Diyi Yang
Findings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP). Singapore, 2023.
@inproceedings{zhang2023hate,
title={Mitigating Biases in Hate Speech Detection from A Causal Perspective},
author={Zhang, Zhehao and Chen, Jiaao and Yang, Diyi},
booktitle={Findings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year={2023}
}
Journal
J2
Zhehao Zhang,
Ryan A. Rossi,
Branislav Kveton,
Yijia Shao,
Diyi Yang,
Hamed Zamani,
Franck Dernoncourt,
Joe Barrow,
Tong Yu,
Sungchul Kim,
Ruiyi Zhang,
Jiuxiang Gu,
Tyler Derr,
Hongjie Chen,
Junda Wu,
Xiang Chen,
Zichao Wang,
Subrata Mitra,
Nedim Lipka,
Nesreen Ahmed,
Yu Wang
Transactions on Machine Learning Research (TMLR). 2025.
@article{zhang2024personalization,
title={Personalization of Large Language Models: A Survey},
author={Zhang, Zhehao and Rossi, Ryan A. and Kveton, Branislav and Shao, Yijia and Yang, Diyi and Zamani, Hamed and Dernoncourt, Franck and Barrow, Joe and Yu, Tong and Kim, Sungchul and Zhang, Ruiyi and Gu, Jiuxiang and Derr, Tyler and Chen, Hongjie and Wu, Junda and Chen, Xiang and Wang, Zichao and Mitra, Subrata and Lipka, Nedim and Ahmed, Nesreen and Wang, Yu},
journal={arXiv preprint arXiv:2411.00027},
year={2024}
}
J1
Caleb Ziems,
William Held,
Omar Shaikh,
Jiaao Chen,
Zhehao Zhang,
Diyi Yang
Computational Linguistics (CL). 2023.
@article{ziems2023llm,
title={Can Large Language Models Transform Computational Social Science?},
author={Ziems, Caleb and Held, William and Shaikh, Omar and Chen, Jiaao and Zhang, Zhehao and Yang, Diyi},
journal={Computational Linguistics},
volume={50},
number={1},
pages={237--280},
year={2023}
}
Preprint
1
Zhehao Zhang,
Ryan A. Rossi,
Tong Yu,
Franck Dernoncourt,
Ruiyi Zhang,
Jiuxiang Gu,
Sungchul Kim,
Xiang Chen,
Zichao Wang,
Nedim Lipka
arXiv preprint (arXiv). 2024.
@article{zhang2024vipact,
title={VipAct: Visual-Perception Enhancement via Specialized VLM Agent Collaboration and Tool-use},
author={Zhang, Zhehao and Rossi, Ryan A. and Yu, Tong and Dernoncourt, Franck and Zhang, Ruiyi and Gu, Jiuxiang and Kim, Sungchul and Chen, Xiang and Wang, Zichao and Lipka, Nedim},
journal={arXiv preprint arXiv:2410.16400},
year={2024}
}
Service
| Reviewer |
EMNLP 2023, 2024; NeurIPS 2023, 2024, 2025; NAACL 2024; ACL 2024, 2025; COLM 2024
CIKM 2024, 2025; ICLR 2025; COLING 2025; IJCAI 2025; IEEE TNNLS Journal |
| Volunteer |
EMNLP 2023; NAACL 2024 |
References
Prof. Yu Su
Associate Professor, Computer Science & Engineering
The Ohio State University
ysu@cse.ohio-state.edu
Prof. Huan Sun
Associate Professor, Computer Science & Engineering
The Ohio State University
sun.397@osu.edu
Prof. Diyi Yang
Assistant Professor, Computer Science
Stanford University
diyiy@stanford.edu
Dr. Ryan Rossi
Principal Research Scientist
Adobe Research
rrossi@adobe.com