Mobile and Spatial

Mobile and Ubiquitous Data Management

Portable and ubiquitous devices are changing our way of working, living and entertaining at an ever-increasing rate. So are they revealing the paradigm for future computing: autonomous devices interacting with servers, agents and peers. This new paradigm, however, poses tremendous challenges to our research community due to the large population, continuous movement, vulnerable network connectivity and bandwidth, scarce battery power, and limited screen size of these devices. While a huge body of research effort has been devoted to addressing the communication/networking aspect, especially at media access control and routing layer, less effort has been expended at the application layer to effectively manage resources and data. My research mostly falls in the category of context-aware data management, particularly in location-based services, which is one of the most distinguishing features in this new paradigm.

Selected Publications:

  • L. Chen, J. Xu, X. Lin, C. S. Jensen, and H. Hu. “Answering Why-Not Spatial Keyword Top-k Queries via Keyword Adaption.” Proc. of the 32nd IEEE International Conference on Data Engineering (ICDE ’16), Helsinki, Finland, May 2016, pp 697-708.
  • X. Lin, J. Xu, and H. Hu. “Reverse Keyword Search for Spatio-Textual Top-k Queries in Location-Based Services.” IEEE Transactions on Knowledge and Data Engineering (TKDE), 27(11): 3056-3069, Nov. 2015.
  • L. Chen, X. Lin, H. Hu, C. S. Jensen, and J. Xu. “Answering Why-not Questions on Spatial Keyword Top-k Queries.” Proc. the 31th IEEE International Conference on Data Engineering (ICDE ’15), Seoul, Korea, April 2015.
  • H. Hu and D. L. Lee. “Distance Indexing on Road Networks” Proc. of the 32th International Conference on Very Large Data Bases, Seoul, Korea, 2006, pp. 894-905.
  • H. Hu, D. L. Lee and J. Xu. “Fast Nearest Neighbor Search on Road Networks” Proc. of the 10th International Conference on Extending Database Technology, Munich, Germany, 2006, pp. 186-203.
  • H. Hu and D. L. Lee. “Range Nearest Neighbor Query.” IEEE Transactions on Data and Knowledge Engineering (TKDE), 18(1): 78-91, 2006.
  • H. Hu, J. Xu and D. L. Lee. “A Generic Framework for Monitoring Continuous Spatial Queries over Moving Objects” Proc. of the 24th ACM SIGMOD International Conference on Management of Data, Baltimore, Maryland, 2005, pp. 479-490.
  • H. Hu, J. Xu, W. S. Wong, B. Zheng and D. L. Lee. “Proactive Caching for Spatial Queries in Mobile Environments.” Proc. of the 21th IEEE International Conference on Data Engineering (ICDE ’05), Tokyo, Japan, pp. 403-414.

Externally Funded Projects:

  • Hybrid Geofencing Systems for Elderly and Child Care (PI: ITF/ITSP Tier 2, ITS/231/13FX, 2014-2016, HK$ $2,378,200)


  • J. Xu and H. Hu. “A System and Method for Providing Proximity Information.” US Patent No. 9,351,116 B2, May 2016.