Fujun Liu
2026
Detecting AI-Generated Content on Social Media with Multi-modal Language Models
Chenyang Yang | Shen Yan | Yibo Yang | Litao Hu | Yuchen Liu | Yuan Zeng | Hanchao Yu | Yinan Zhu | Sumedha Singla | Brian Vanover | Huijun Qian | Zihao Wang | Fujun Liu | Aashu Singh | Jianyu Wang | Xuewen Zhang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Chenyang Yang | Shen Yan | Yibo Yang | Litao Hu | Yuchen Liu | Yuan Zeng | Hanchao Yu | Yinan Zhu | Sumedha Singla | Brian Vanover | Huijun Qian | Zihao Wang | Fujun Liu | Aashu Singh | Jianyu Wang | Xuewen Zhang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Generative AI has enabled the creation of photorealistic images and videos that are increasingly disseminated on social media, often used for spam, misinformation, manipulation, and fraud. Existing AI-generated content (AIGC) detection methods face challenges including poor generalization to new generation models, reliance on single modalities, and lack of interpretable explanations. We present our pipeline that mitigates these issues by continuously curating diverse multi-modal social media data and training a compact vision-language model for detection and explanation. Our model achieves state-of-the-art detection performance on public benchmarks and demonstrates robust detection and explanation capabilities on internal social media datasets across multiple platforms. We deployed our model for post recommendation on social media platforms and observed positive downstream impacts on user engagement, demonstrating that it is feasible to perform effective AIGC detection in dynamic, real-world social media environments.
2025
Inference Compute-Optimal Video Vision Language Models
Peiqi Wang | ShengYun Peng | Xuewen Zhang | Hanchao Yu | Yibo Yang | Lifu Huang | Fujun Liu | Qifan Wang
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Peiqi Wang | ShengYun Peng | Xuewen Zhang | Hanchao Yu | Yibo Yang | Lifu Huang | Fujun Liu | Qifan Wang
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
This work investigates the optimal allocation of inference compute across three key scaling factors in video vision language models: language model size, frame count, and the number of visual tokens per frame. While prior works typically focuses on optimizing model efficiency or improving performance without considering resource constraints, we instead identify optimal model configuration under fixed inference compute budgets. We conduct large-scale training sweeps and careful parametric modeling of task performance to identify the inference compute-optimal frontier. Our experiments reveal how task performance depends on scaling factors and finetuning data size, as well as how changes in data size shift the compute-optimal frontier. These findings translate to practical tips for selecting these scaling factors.