Multimodal AI

Learning from video, vehicle sensors, and screens, from early video retrieval and vehicle behavior mining to agents that operate computers.

Today this thread runs through computer use, where agents operate full desktop environments: ChainWorld (Siu et al., 2026) composes atomic OSWorld tasks into long-horizon desktop workloads, and Spine-Branch (Zhang et al., 2026) coordinates teams of computer-use agents. See also Benchmarks and Evals and Agent Teams.

Back in college, I worked on our team’s entry to TRECVID 2007 (Yuan et al., 2007), an annual benchmark for content-based video retrieval run by the National Institute of Standards and Technology (NIST). The system covered three tasks. For shot boundary detection, it combined block-based color histograms with a motion detector that suppressed false alarms from camera and object motion, followed by a SIFT-based post-processing step. For high-level feature extraction (i.e., concept detection), it learned concept distributions over image regions with multi-label, multi-feature learning, added shape and spatial features, and fused scores both within and across concepts. For video search, it supported both automatic and interactive retrieval.

Back in college, in 2008, I worked on self-driving vehicles, mining vehicle behaviors from raw multi-sensor data (Liu et al., 2008). The resulting qualitative descriptions of vehicle state feed downstream tasks like scenario parsing, vehicle surveillance, and forward-collision warning. Earlier approaches either assumed the number of behavior categories was known in advance or had to rediscover it by hand whenever the training data changed. We instead treat behaviors as the hidden states of a hidden Markov model and choose the number of states by cross-validated likelihood with a complexity penalty, so the behavior categories and their number are learned together. Experiments on real sensor data bear out the approach.

Publications

2026

  1. Spine-Branch Coordination for Multi-agent Computer Use
    Mian Zhang, Manasi Sharma, Sheng Zhang, Minglai Yang, Kejian Shi, Ying Liu, Zhiyu Zoey Chen, and Daniel Yue Zhang
    arXiv preprint arXiv:2608.22077, Aug 2026
  2. ChainWorld: Composing Long-Horizon Desktop Workloads from Atomic OSWorld Tasks
    Vincent Siu, Manasi Sharma, Dawn Song, Daniel Yue Zhang, Chenguang Wang, and Ying Liu
    arXiv preprint arXiv:2606.21654, Jun 2026

2008

  1. Automatic Mining of Vehicle Behaviors with an Unknown Number of Categories
    Ying Liu, Hao Zhang, Huadong Meng, and Xiqin Wang
    In IEEE International Conference on Intelligent Transportation Systems (ITSC), Oct 2008

2007

  1. THU and ICRC at TRECVID 2007
    Jinhui Yuan, Zhishan Guo, Li Lv, Wei Wan, Teng Zhang, Dong Wang, Xiaobing Liu, Cailiang Liu, Shengqi Zhu, Duanpeng Wang, Yang Pang, Nan Ding, Ying Liu, Jiangping Wang, Xiujun Zhang, and 15 more authors
    In TREC Video Retrieval Evaluation (TRECVID) Workshop, Nov 2007