4 papers
Label Less, Learn More: Resource-Efficient Active Semi-Supervised Learning for Onboard Satellite Image Annotation
Ahmed Abdelnaby, Mohamed Elmahallawy, Marius Bernahrndt +1
Large-scale pervasive sensing increasingly relies on high-resolution satellite imagery, yet task-specific onboard vision is constrained by costly annotation and limited computation…
Region-Level Black-Box Defense Against Stealthy Embedding-Space Backdoors in CLIP
Ahmed Abdelnaby, Mohamed Elmahallawy
Contrastive Language--Image Pretraining (CLIP) has emerged as a dominant vision backbone due to its strong transferability and zero-shot capabilities. However, recent studies revea…
When Clients Are Orchestrated: Strategic Gradient Manipulation to Defeat Federated Learning Servers with Efficient Defense
Mohamed Shaaban, Ahmed Abdelnaby, Mohamed Elmahallawy
Federated Learning enables decentralized model training by exchanging model updates--rather than raw data--with a central parameter server (PS). While most of the existing defenses…
Beyond Small Patches: Black-Box Detection and Purification of Diverse Backdoor Triggers
Ahmed Abdelnaby, Mohamed Elmahallawy
Deep neural networks (DNNs) are increasingly deployed in real-world vision systems, yet their predictions can be covertly manipulated by backdoor attacks, in which malicious trigge…