Nghia H. Nguyen

PhD Student, University of Pennsylvania

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Philadelphia, PA

nghianhh@seas.upenn.edu

I am a PhD student in the Computer and Information Science Department at the University of Pennsylvania, advised by René Vidal. I did by B.S. in Computer Science at the University of Science, Vietnam National University – Ho Chi Minh City, advised by Minh-Triet Tran. Previously, I was in the AI Residency program at FPT Software AI Center, working with Thieu N. Vo and Tan M. Nguyen. In Summer 2020, I was a Research Intern at the Distributed Information Systems Laboratory (LSIR), EPFL, working on Graph Neural Networks for SQL query optimization.

My research focuses on leveraging optimization and algebraic structures (e.g., linear representations in LLMs) for trustworthy machine learning, specifically interpretability and adversarial robustness. I pursue two directions:

  • Algebraic structures for interpretability: Given that linear and hierarchical structures exist in the latent space of neural networks, how can we design algorithms that exploit this prior knowledge to recover semantic concepts that are more reliable and faithful to the model?
  • Emergence of structures via optimization: Why do these algebraic structures arise? I aim to prove their emergence from training objectives, connecting compositional structure in real-world data to geometry in representation space.

Updates

Nov 01, 2025 Our paper “Hierarchical Concept Embedding & Pursuit for Interpretable Image Classification” has been accepted to CVPR 2026! [arXiv].
Sep 27, 2025 New preprint: “SSD: Sparse Semantic Defense against Semantic Adversarial Attacks to Image Classifiers” is under review.
Dec 01, 2022 Our paper “Improving Neural Ordinary Differential Equations with Nesterov’s Accelerated Gradient Method” was accepted at NeurIPS 2022. [OpenReview]

Selected Work

  1. NeurIPS
    Improving Neural Ordinary Differential Equations with Nesterov’s Accelerated Gradient Method
    Nghia Nguyen, Tan Minh Nguyen, Vo Thi Khanh Huyen Vo, and 2 more authors
    In Advances in Neural Information Processing Systems, 2022
  2. CVPR
    Hierarchical Concept Embedding & Pursuit for Interpretable Image Classification
    Nghia Nguyen, Tianjiao Ding, and Rene Vidal
    In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2026

Blog Posts