Leong Hou U, Ryan余亮豪
Associate Professor
Interim Head of Centre for Data Science

Academic Qualifications | Research | Teaching | Selected Publications | Professional Affiliations | Technical Activities | Supervisions | Contact Details

Academic Qualification

  • Ph.D. in Computer Science, The University of Hong Kong, Hong Kong (2010)
  • M.Sc. in E-Commerce Technology, University of Macau, Macau (2005)
  • B.Sc. in Computer Science and Information Engineering, National Chi Nan University, Taiwan (2003)


Research Interests

  • Spatial and spatio-temporal Databases
  • Crowdsourcing
  • Advanced Query Processing
  • Web Data Management
  • Information Retrieval
  • Data Mining
  • Optimization Problems
  • Mixture model

I am a member of data engineering research group.


M.Sc. Courses

  • CISC7015. Advanced Topics in Computer Science I – Blockchain Technology and Applications (Spring 2019)
  • COIS724. Big Data Processing and Analysis (Fall 2015, Fall 2016, Fall 2017)
  • COIS704. Current Development in Database (Fall 2014)
  • ECOM703. Distributed Database Management (Fall 2014)
  • ECOM706. Data Warehousing (Spring 2011, Spring 2012, Spring 2013)

B.Sc. Courses

  • The ACM-ICPC International Collegiate Programming Contest (ACM ICPC) Training (Coordinator and Coach, 2016-present)
  • CISB410. Final Year Project (Coordinator, 2010-present)
  • CISC7201. Introduction to Data Science Programming (Fall 2018)
  • CISB363. Information Retrieval and Web Mining (Spring 2014, Spring 2015, Spring 2016, Spring 2017, Spring 2018)
  • CISB359. Information Systems Analysis and Design (Fall 2011, Fall 2012, Fall 2013)

Selected Publications

Journal Articles

  1. Huaizhong Lin, Shanshan Wu, Leong Hou U, Ngai Meng Kou, Yunjun Gao, Dongming Lu: Finding the hottest item in data streams. Inf. Sci. 430: 314-330 (2018)
  2. Leong Hou U, Junjie Zhang, Kyriakos Mouratidis, Ye Li: Continuous Top-k Monitoring on Document Streams. IEEE Trans. Knowl. Data Eng. 29(5): 991-1003 (2017) [link]
  3. Yuhong Li, Leong Hou U, Man Lung Yiu, Zhiguo Gong: Efficient discovery of longest-lasting correlation in sequence databases. VLDB J. 25(6): 767-790 (2016) [link]
  4. Bailong Liao, Leong Hou U, Man Lung Yiu, Zhiguo Gong: Beyond Millisecond Latency kNN Search on Commodity Machine. IEEE Trans. Knowl. Data Eng. 27(10): 2618-2631 (2015) [link]
  5. Ngai Meng Kou, Leong Hou U, Yiyang Yang, and Zhiguo Gong: Travel Topic Analysis: A Mutually Reinforcing Method for Geo-tagged Photos, Geoinformatica, to appear. [pdf]
  6. Shen Ge, Leong Hou U, Nikos Mamoulis, David W. Cheung: Dominance relationship analysis with budget constraints. Knowl. Inf. Syst. (KAIS) 42(2):409-440 (2015)
  7. Yiyang Yang, Zhiguo Gong, Leong Hou U: Identifying Points of Interest using heterogenous Features. ACM TIST (TIST) 5(4):68 (2014). [pdf]
  8. Leong Hou U, Hong Jun Zhao, Man Lung Yiu, Yuhong Li, Zhiguo Gong: Towards Online Shortest Path Computation. IEEE Trans. Knowl. Data Eng. (TKDE) 26(4):1012-1025 (2014) [pdf]
  9. Shen Ge, Leong Hou U, Nikos Mamoulis, David W. Cheung: Efficient All Top-k Computation – A Unified Solution for All Top-k, Reverse Top-k and Top-m Influential Queries. IEEE Trans. Knowl. Data Eng. 25(5): 1015-1027 (2013)
  10. Leong Hou U, Kyriakos Mouratidis, Man Lung Yiu, and Nikos Mamoulis. Optimal Matching between Spatial Datasets under Capacity Constraints. ACM Transactions on Database Systems, 35(2):44 pages, April 2010.
  11. Leong Hou U, Kyriakos Mouratidis, and Nikos Mamoulis. Continuous Spatial Assignment of Moving Users. VLDB Journal, 19(2):141-160, 2010.
  12. Leong Hou U, Nikos Mamoulis, and Man Lung Yiu. Computation and Monitoring of Exclusive Closest Pairs. IEEE Trans. Knowl. Data Eng., 20(12):1641-1654, 2008.

Book Chapters

  1. Leong Hou U, Optimal Matching Between Spatial Datasets. Encyclopedia of GIS 2017: 1505-1511

Refereed Conference Proceedings

  1. T. N. Chan, M. L. Yiu, and L. H. U, KARL: Fast Kernel Aggregation Queries, Proceedings of the 35th IEEE International Conference on Data Engineering (ICDE), to appear, 2019. [pdf]
  2. Siyuan Wu, Leong Hou U, Sourav S. Bhowmick, Wolfgang Gatterbauer: PISTIS: A Conflict of Interest Declaration and Detection System for Peer Review Management. SIGMOD Conference 2018: 1713-1716. [project page]
  3. Yan Li, Ngai Meng Kou, Hao Wang, Leong Hou U, Zhiguo Gong: A Confidence-Aware Top-k Query Processing Toolkit on Crowdsourcing. PVLDB 10(12): 1909-1912 (2017). [project page]
  4. Ye Li, Leong Hou U, Man Lung Yiu, Ngai Meng Kou: An Experimental Study on Hub Labeling based Shortest Path Algorithms. PVLDB 11(4): 445-457 (2017) [project page]
  5. Yiyang Yang, Zhiguo Gong, Qing Li, Leong Hou U, Ruichu Cai, Zhifeng Hao: A Robust Noise Resistant Algorithm for POI Identification from Flickr Data. IJCAI 2017: 3294-3300.
  6. Ngai Meng Kou, Yan Li, Hao Wang, Leong Hou U, Zhiguo Gong: Crowdsourced Top-k Queries by Confidence-Aware Pairwise Judgments. SIGMOD Conference 2017: 1415-1430. [project page]
  7. Yuhong Li, Bo Tang, Leong Hou U, Man Lung Yiu, Zhiguo Gong: Fast Subsequence Search on Time Series Data. EDBT 2017: 514-517.
  8. Shanshan Wu, Huaizhong Lin, Leong Hou U, Yunjun Gao, Dongming Lu: Finding Frequent Items in Time Decayed Data Streams. APWeb (2) 2016: 17-29.
  9. Bo Tang, Man Lung Yiu, Yuhong Li, Leong Hou U: Exploit Every Cycle: Vectorized Time Series Algorithms on Modern Commodity CPUs. ADMS/IMDM@VLDB 2016: 18-39.
  10. Ngai Meng Kou, Leong Hou U, Nikos Mamoulis, Yuhong Li, Ye Li, and Zhiguo Gong: A Topicbased Reviewer Assignment System. In Proceedings of VLDB2015 (demo paper).
  11. Ngai Meng Kou, Leong Hou U, Nikos Mamoulis, and Zhiguo Gong: Weighted Coverage based Reviewer Assignment. In Proceedings of SIGMOD2015. [project page]
  12. Yuhong Li, Leong Hou U, Man Lung Yiu, and Zhiguo Gong: Quick-Motif: An Efficient and Scalable Framework for Exact Motif Discovery. In Proceedings of ICDE2015. [project page]
  13. Yuhong Li, Leong Hou U, Man Lung Yiu, Zhiguo Gong: Discovering Longest-lasting Correlation in Sequence Databases. PVLDB 6(14):1666-1677 (2013) [pdf]
  14. Yu Tang, Leong Hou U, Yilun Cai, Nikos Mamoulis, Reynold Cheng: Earth Mover’s Distance based Similarity Search at Scale. PVLDB 7(4):313-324 (2013) [pdf]
  15. Yiyang Yang, Zhiguo Gong, and Leong Hou U. Identifying points of interest by self-tuning clustering. In SIGIR, 2011.
  16. Man Lung Yiu, Leong Hou U, Simonas Saltenis, and Kostas Tzoumas. Efficient proximity detection among mobile users via self-tuning policies. PVLDB, 3(1):985–996, 2010.
  17. Leong Hou U, Nikos Mamoulis, Klaus Berberich, and Srikanta J. Bedathur. Durable top-k search in document archives. In SIGMOD Conference, pages 555–566, 2010.
  18. Leong Hou U, Nikos Mamoulis, and Kyriakos Mouratidis. A fair assignment algorithm for multiple preference queries. VLDB, 2(1):1054-1065, 2009.
  19. Leong Hou U, Nikos Mamoulis, and Kyriakos Mouratidis. Efficient evaluation of multiple preference queries. In ICDE, pages 1251-1254, 2009.
  20. Leong Hou U, Man Lung Yiu, Kyriakos Mouratidis, and Nikos Mamoulis. Capacity constrained assignment in spatial databases. In SIGMOD Conference, pages 15-28, 2008.

Check here for my DBLP record.

I am looking for research assistants, PhD students, and postdocs who intend to study on premier research (cf. Arnetminer or CCF) in Data Engineering.

Professional Affiliations

  • Member of ACM
  • Member of IEEE

Technical Activities

Reviewer for journals

  • IEEE Transactions on Knowledge and Data Engineering (IEEE TKDE)
  • Very Large Data Base Journal (VLDBJ)
  • ACM Transactions on Spatial Algorithms and Systems (ACM TSAS)
  • IEEE Transactions on Mobile Computing
  • Information Systems (Inf. Syst.)

International Conference Steering/Organization Committee

International Conference Technical Program/Review Committee and Session Chair

  • 2019: DASFAA
  • 2018: WISE, PAKDD, WAIM
  • 2017: VLDB Demo, WAIM
  • 2016: CIKM (KM Track)
  • 2015: DASFAA, APWEB, CIKM (KM Track), SIGMOD/PODS PhD Symposium
  • 2014: CIKM (KM Track), DASFAA, WAIM, MobiGIS, WebDB
  • 2013: SIGMOD, CIKM (KM Track), WAIM
  • 2012: KDD, ER, MobiGIS


Reserach Students

  • Ye LI (PhD)
  • Yan LI (PhD)
  • Pei ZHANG (MSc)
  • Siyuan WU (MSc)
  • Yuhao YOU (MSc)
  • Changyi MA (MSc, Graduated 2017), Functional Region based Daily-life Activity Recommendation
  • Xuan Liu RU (MSc, Graduated 2016), Link prediction in time-aware graphs
  • Yan LI (MSc, Graduated 2015), Crowdsourcing Object Ranking by Pairwise Comparisons
  • Jian WANG (MSc, Graduated 2015), Multidimensional Similarity Join using MapReduce
  • Junjie ZHANG (MSc, Graduated 2015), A Scalable Framework for Continuous Keyword Search Queries
  • Nana PAN (MSc, Graduated 2014), On Dynamic Top-k Influence Maximization
  • Bailong LIAO (MSc, Graduated 2014), Compact Main Memory Indexing for Efficient Spatial Network Queries
  • Bohan ZHAN (MSc, Graduated 2014), Influence Maximization on MapReduce

Final Year Projects

  • Wai Lon FAN and Ka Chon WONG, Big Data for Smart Transport – Augmented Reality based Transportation System (2016) One of 5 best projects of CIS in 2016
  • Renjie GOU and Jlio Mamad Bald Quina, Big Data for Smart Transport – Public Transportation Planning (2016)
  • Chi Lap PUN and Weng un IONG, Travel Route Recommendation System (2015) The best project of CIS in 2015
  • Kit NG, Mei Keong U, and Kin Fei WONG, Interactive TV System on Mobile Devices (2013)
  • Kun YAO, G-PathSim (2013) The runner-up project of CIS in 2013
  • Wai Kuan CHEANG, Keng Fai LEI, and Man Cheng HO, StallKet – Open your stall at anytime and anywhere (2012)
  • Mao Teng LAM and Ka Chon UN, A Study on Search and Visualization in DBLP (2012)

Contact Details

Faculty of Science and Technology
University of Macau, E11
Avenida da Universidade, Taipa,
Macau, China

Room: E11-4021
Telephone: (853) 8822-4493
Fax: (853) 8822-2426
Email: ryanlhu