2025 7th International Symposium on Advanced Electrical and Communication Technologies (ISAECT), Mohali, India · December 2025
Charan Sai Ponnada, Divya Kothapalli, Karthik Goparaju, Sanath Pedapudi
This paper presents a real-time assistive system for outdoor navigation of visually impaired users in complex Indian urban environments. A BLIP vision-language model is fine-tuned through a 3-stage LoRA training strategy on a custom 427-scene dataset built from Google Street View API imagery, yielding a +15.6% improvement across BLEU, METEOR, ROUGE and semantic similarity metrics. The system is deployed on a Raspberry Pi through an edge-cloud hybrid architecture, and covers the full research pipeline: dataset curation, model training, evaluation framework and edge deployment. The trained model is released on HuggingFace and the code is open-sourced.
@inproceedings{ponnada2025vision,
title={Vision-Language Based Real-Time Assistive System for Outdoor Navigation of the Visually Impaired in Indian Urban Environments},
author={Ponnada, Charan Sai and Kothapalli, Divya and Goparaju, Karthik and Pedapudi, Sanath},
booktitle={2025 7th International Symposium on Advanced Electrical and Communication Technologies (ISAECT)},
year={2025},
doi={10.1109/ISAECT68904.2025.11318802}
}
IEEE International Conference on Computing, Communication and Intelligent Systems (InCODE) 2026 · April 2026 (under review)
Charan Sai Ponnada
This work proposes paraphrase variance across K=5 semantic-preserving rewrites as a label-free, unsupervised proxy for hallucination in large language model outputs, requiring no ground-truth answers at inference time. The signal is evaluated using BERTScore, NLI contradiction rate and AUC-ROC on the TriviaQA and Natural Questions benchmarks. Experiments run on Llama-3-8B-Instruct (BF16, FlashAttention-2) on 2x NVIDIA L40S, and extend to Llama-3-70B for a cross-scale validation claim.
@inproceedings{ponnada2026semantic,
title={Semantic Consistency as an Unsupervised Hallucination Signal in Large Language Models},
author={Ponnada, Charan Sai},
booktitle={Proceedings of IEEE InCODE 2026},
year={2026}
}