CV
My curriculum vitae. Click the PDF icon above to download a copy.
Contact Information
| Name | Xiangjun (Ethan) Fu |
| Professional Title | Graduate Researcher, University of Pennsylvania |
| xjf@seas.upenn.edu | |
| Phone | (858) 539-5848 |
| Location | Philadelphia, PA |
| Website | https://ethanfusion03.github.io |
Professional Summary
M.S.E. student in Computer & Information Science at the University of Pennsylvania. I work on latent reasoning for large language models — continuous chain-of-thought via normalizing flows — and previously on benchmarking LLMs as semantic encoders for retrieval and recommendation.
Experience
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2025 - present Philadelphia, PA
Graduate Researcher
GMLR Lab, University of Pennsylvania
Advised by Prof. Jiatao Gu.
- Designing a continuous latent chain-of-thought reasoning pipeline on a Qwen3-8B backbone that operates in a lower-dimensional space while preserving semantic structure.
- Fine-tuning an LLM-based VAE encoder to provide semantic guidance for latent thinking-token generation; using normalizing flows to autoregressively generate thinking tokens under an MSE objective against VAE-encoded latents.
- Computing step-wise log-likelihoods to enable reinforcement learning over reasoning trajectories, with evaluation protocols for trajectory selection.
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2024 - 2025 San Diego, CA
Undergraduate Researcher
McAuley Lab, UC San Diego
Advised by Prof. Julian McAuley and Yupeng Hou.
- Built an evaluation framework for benchmarking LLM text embeddings in retrieval and recommendation, including a public Amazon dataset with 2M+ training and 250K+ test instances.
- Benchmarked embeddings from SimCSE, E5-Mistral-7B, text-embedding-3-large, Qwen-7B, Gemini, and OpenAI across collaborative filtering, sequential recommendation, and product search; co-first-authored the resulting ACL 2026 paper.
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2023 - 2024 San Diego, CA
Undergraduate Researcher
Shang Data Lab, UC San Diego
Advised by Prof. Jingbo Shang and Letian Peng.
- Refined weakly supervised text classification, reaching 93% peak accuracy on AG News (vs. 78% baseline) via KL-divergence matching between token-level text and class-prompt distributions.
- Implemented the framework in PyTorch with BERT, RoBERTa, and Gemma across AG News and Rotten Tomatoes.
Education
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2025 - 2027 Philadelphia, PA
M.S.E. in Computer & Information Science
University of Pennsylvania
- GPA: 3.95 / 4.0
- Relevant coursework: Statistical NLP, Deep Learning, Deep Generative Modeling, Reinforcement Learning, Machine Learning, Recommender Systems & Web Mining, Probability & Statistics
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2021 - 2025 San Diego, CA
B.S. in Mathematics–Computer Science
University of California, San Diego
- GPA: 3.9 / 4.0 · Provost Honors
Publications
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2026 Bridging Language and Items for Retrieval and Recommendation: Benchmarking LLMs as Semantic Encoders
ACL 2026 Main Conference (Oral)
Yupeng Hou†, Jiacheng Li†, Xiangjun Fu†, Zhankui He, An Yan, Xiusi Chen, Julian McAuley. († equal contribution)
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2026 Latent Reasoning with Normalizing Flows
COLM 2026 Workshop on Efficient Reasoning · Under review at ICLR 2027
Xiangjun Fu†, Guancheng Tu†, Suhao Yu, Yao Tang, Haoqiang Kang, Lianhui Qin, Yizhe Zhang, Jiatao Gu. († equal contribution)
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2026 Decoupled Reading: Letting Demonstration-Conditioned Policies Follow Longer Compositions
CoRL 2026 Workshop on Compositional Generalization for Real-World Robot Learning
Cheng Yang, Xiangjun Fu, Jiatao Gu.
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2025 Larger Hausdorff Dimension in Scanning Pattern Facilitates Mamba-Based Methods in Low-Light Image Enhancement
Under review · arXiv:2510.26001
Xinhua Wang, Xiangjun Fu, Caibo Feng, Chunxiao Liu.
Teaching
- Supplemental Instruction Leader, Academic Achievement Hub, UC San Diego (2024–2025). Led weekly workshops for 50+ students in Physics and Calculus (~20 hrs/week), translating complex technical material into accessible, interactive lessons; iterated lesson design from student and faculty feedback and provided one-on-one mentorship.
Academic Service
- Reviewer: EMNLP 2026 (ACL Rolling Review, May cycle), NeurIPS 2026, ICLR 2027.