Air Quality Monitoring in Sparse Urban Networks: An Enhanced Fog Hierarchical Federated Learning Approach Satya Krishna Nunna A. Manju D. Jagadeesan C. S. P. Kumar ·. Satya K. Nunna J. Jegan ·. D. Jagadeesan Aug 2026 · SN Computer Science · Vol 7 · 0 citations · 61 references DOI Semantic Scholar Save View source Cite Copy APA Copied ✓ Copy MLA Copied ✓ Copy BibTeX Copied ✓ Share