Efthymios (Themis) Tsaprazlis

About Me

I'm a Computer Science PhD student at University of Southern California and a graaduate research assistant at Signal Analysis and Interpretation Lab (SAIL) , under the supervision of Professor Shrikanth Narayanan. Previously, I did my Bachelors in the ECE Departement at National Technical University of Athens where I worked with Professor Petros Maragos. Also, I was an external collaborator of the Machine Learning Lab at Univerity of Texas at Austin, where I worked with Professor Alex Dimakis .

Research Interests

My research lies at the intersection of applied and theoretical machine learning, developing systems that learn efficiently, generalize across modalities, and remain trustworthy in real-world deployment.

Privacy-Preserving Machine Learning: Interested in unlearning, differential privacy, and risk auditing techniques while connecting them to broader optimization and system design challenges.
Multimodal & Representation Learning: Building models that jointly leverage vision, language, and speech to improve grounding, reasoning, and cross-domain transfer.
Self-Supervised & Contrastive Learning: Designing efficient objectives and training pipelines that enable robust, data-efficient representation learning at scale.
Generative AI: Leveraging LLMs and diffusion models to enable context-aware reasoning and controllable multimodal generation.

News

• [Sep 2025] Received a gift award from the USC-Amazon Center on Secure and Trusted Machine Learning for my research on explainable privacy understanding in multimodal AI.

• [Jan 2025] We got a paper accepted in ICRA 2025.

• [Aug 2024] I started my PhD at University of Southern California.

• [Jan 2024] I started a new position as Research Assistant in Robotics Unit of the Athena Research and Innovation Center (Athena RC) and CVSP Group.

• [Oct 2023] Our paper "Enhancing CLIP with a Third Modality" got accepted in NeurIPS 2023 Workshop: Self-Supervised Learning - Theory and Practice.

• [Oct 2023] I joined Workable as a Machine Learning Engineer intern.