Ir Prof. Byron Choi's Homepage

Ir Prof. Byron Choi (Koon Kau) in (Traditional Chinese and in Pinyin)

Associate Head (Teaching and Learning)

Programme Director of BSc (Hons) in Computer Science (JS2510)

Department of Computer Science (Map)
Faculty of Science and Technology
Hong Kong Baptist University

Fellow of the Hong Kong Institution of Engineers (FHKIE)

Member of Database Research Group

Office: Room 628

David C Lam Building (DLB628)

Hong Kong Baptist University

Kowloon Tong, Hong Kong

Tel: (+852) 3411 7638

Email: choi at hkbu.edu.hk

ORCID: https://orcid.org/0000-0002-8381-336X

SCOPUS: author profile HKBU scholars: profile

Google scholar profile DBLP entry
Semantic scholar profile

Short Biography:

I obtained my Ph.D and MSE degrees in Computer and Information Science from the University of Pennsylvania in 2006 and 2001, respectively, and my Bachelor of Engineering in Computer Engineering with first-class honours from the Hong Kong University of Science and Technology (HKUST). I was awarded the IEEE (Hong Kong Section) prize in 1999. Prior to joining the Hong Kong Baptist University, I was an Assistant Professor at School of Computer Engineering / Nanyang Technological University (NTU) for three years between 2005 and 2008. My prior research experience includes working as a research associate at the University of Edinburgh (2005), contributing to the Galax project at AT&T Labs Florham Park as a summer research intern, and visiting the HKUST theoretical computer science group at HKUST in 2003.

I have been elected as Fellow (FHKIE) of The Hong Kong Institution of Engineers (HKIE) - the Information discipline - and a standing committee member for Session 2026/27. I am a member of the Database Research Group at HKBU. I hold memberships with several professional associations, including professional member of ACM, senior member of IEEE, member of IEEE Computer Society and member of IEEE Technical Committee on Data Engineering (TCDE). I have been an associate editor of Distributed and Parallel Databases (DAPD) since March 2025. Since September 2021, I have been serving as the ACM SIGMOD information director. I have been recognized with several distinctions in roles throughout my career. In particular, I was the director of a Croucher Foundation Advanced Study Institute (ASI) titled "Frontiers in Big Data Graph Research" 2015. I have also served as a reviewer for the French Agence Nationale de Recherche (ANR) 2022, the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) 2022, and the Austrian Science Fund (FWF) 2014. I served as a supervisor of Hong Kong Scholars Program (香江學者計劃) 2020.

I have received several awards recognizing my contributions to research, teaching and service. In particular, I was awarded a distinguished program committee (PC) member from ACM SIGMOD 2023 and 2021, respectively, a distinguished reviewer award from PVLDB 2019, an outstanding program committee member for IEEE ICDE 2025, and the best reviewers award from ACM CIKM 2021. I received a silver ring from DASFAA 2014 after serving as a session chair for multiple sessions. I was the recipient of the HKBU President's Award for Outstanding Performance in Individual Teaching 2022 and the HKBU President's Award for Outstanding Young Researcher 2016, HKBU Faculty Performance Award for Service 2026, the Department's Best Teaching Award in AY2020-2021 and AY2014-2015, Best Research Award in AY2023-2024 and AY2013-14, and Best Service Award in AY2024-25, AY2019-2020 and AY2017-2018, respectively.

Teaching:

COMP3005 Design and Analysis of Algorithms
COMP4035 Database System Implementation

Always looking for strong applicants for Postdocs, PhD students, and research assistants:

Strong PhD applicants may contact me directly for Hong Kong PhD Fellowship Scheme (HKPFS).
Applicants should possess a strong background in (but not limited to) mathematics, algorithms and programming. Priority will be given to those with experience in graph data management or securities. The postdocs and research assistant positions are immediately available for one year and extensible for multiple years based on performance and availability of funds. In terms of research topics, the recent ones can be observed from my selected publications here. Possible research topics are graph-structured databases and time series analysis. Previous projects can be found here: Topic 1 and Topic 2. Our experience on providing secure subgraph query services can be found here. The general information of database research at HKBU can be found here.

Research Interests (w. bibtex) (Selected Publications and Source Code):

PhD Graduates:

Rundong Zuo, 2026. (First appointment: Quant Researcher at China Merchants Securities)
Lyu Xu, 2024. (First appointment: Postdoc at Hong Kong PolyU)
Guozhong Li, 2021. [Webpage] (First appointment: Postdoc at HKBU)
Jiaxin Jiang, 2020. (Appointment after a Postdoc at HKBU: Research Fellow at National University of Singapore, Singapore)
Peipei Yi, 2018. (First appointment: Data Scientist, Machine Intelligence Center, Lenovo, Hong Kong SAR)
Zhe Fan, 2015. (First appointment: Big Data Analyst Engineer at Huawei, Shenzhen, China)
Yun Peng, 2013. (First appointment: Research Fellow at Nanyang Technological University, Singapore)

General Research Funds (GRF) in the capacity of Principal Investigator (PI):

Querying Large Networks of Cryptocurrencies (HKBU12203123, 2023-2024, on-going)
Semantic Indexing for Keyword Search on Graphs (HKBU12201119, 2020-2022, completed)
Exploring the Structural Critical Entities in Big Attributed Graphs (HKBU12201518, 2019-2021, transferred from Dr. Zhiwei Zhang, completed)
Privacy-preserving Linear Algebra Framework for Graph Query Algorithms for Massive Networks (HKBU12232716, 2017-2019, completed)
Exploratory Search on Graph Databases through Subgraph Query Feedback (HKBU12201315, 2016-2018, completed)
Adaptive Filtering for Efficient Subgraph Isomorphism in Graph Databases (HKBU210510, 2011-2012, completed)
Optimizations for the View Update Problem with Emerging Applications (HKBU210409, 2010-2011, completed)

Editorial Board:

Program Committee (Partial):

SIGMOD 2026-2023, 2021, and 2020, ICDE 2027-2026, PVLDB demo 2025 (meta reviewer), ICDE 2025 (with rapid response review duties), EDBT 2023 (senior PC), PVLDB 2022-2021, 2019-2018 and 2015, CIKM 2021 (senior PC), ICDE 2022-2021, AAAI 2022, ICDM 2021, PAKDD 2022-2020, ER 2019, 2015, CIKM (tutorial) 2015, WWW (demo) 2014, CloudDb 2014, IEEE Big Data Science and Engineering (BDSE 2014), IEEE BigData Congress 2014-2013, DASFAA 2013-2011, SIGMOD IDAR 2008,...

External Reviewer (Partial):

TODS, VLDBJ, TKDE, TKDD, TOIS, DAPD, Journal of Supercomputing, Information Sciences, Information Systems, ER, ...

Co-Organizer:

Selected Publications (full list at DBLP):

Quick Links by Topics: [Graphs] [Time Series] [Securities] [Visual Query] [Dynamic Data]

Y. Gong, L. Xu, Y. Peng, B. Choi, J. Xu and X. Huang. Gisma: Giant-Step-Small-Step Indexing for Approximate Similarity Search in Graph Databases. PVLDB 2027 (bibtex) [github site!]
R. Zuo, R. Cao, G. Li, B. Choi and S. S. Bhowmick. TSTUDIO: Efficient Discovery of Semantic Tokens for Long Time Series Transformers. ICDE 2027 (bibtex) [github site!]

J. Jiang, Y. Zhao, L. Xu, B. Choi, B. He, Shixuan Sun, and Jia Chen. Efficient Densest Flow Queries in Transaction Flow Networks. TKDE 2026. (bibtex) [github site!]
J. Jiang, J. Zhan, L. Xu, B. Choi, Q. Wang, N. Liu, B. He and J. Xu. PPG: A Public-Private Graph Evaluation Framework for Efficient Querying and Analysis. The VLDB Journal, 2026. (bibtex) [github site!]
Y. Zhao, L. Xu, J. Jiang, B. Choi, J. Xu and B. He. ABFlow: Alert Bursting Flow Query in Streaming Temporal Flow Networks. Pro. ACM Manag. Data (SIGMOD) 2026. (bibtex) [github site!]
Z. Chen, W. K. Cheung, H-N Dai, B. Choi and J. Liu. Gated Variational Graph Autoencoders as Experts with Competition and Consensus for Multi-view Clustering. AAAI 2026. (bibtex) [github site!]
L. Xu, J. Jiang, B. Choi, J. Xu and B. He. Bursting Flow Query on Large Temporal Flow Networks. Pro. ACM Manag. Data (SIGMOD) 18:1-18:26, 2025. (bibtex) [github site!]
G. Li, B. Choi, R. Zuo, S. S. Bhowmick and J. Xu. leSAX Index: A Learned SAX Representation Index for Time Series Similarity Search. ICDE 2025. (bibtex) [github site!]
Z. Chen, Z. Wu, W. K. Cheung, H-N Dai, B. Choi and J. Liu. MSHTrans: Multi-Scale Hypergraph Transformer with Time-Series Decomposition for Temporal Anomaly Detection. SIGKDD 2025. (bibtex) [github site!]
R. Zuo, G. Li, R. Cao, B. Choi, J. Xu and S. S. Bhowmick. DARKER: Efficient Transformer with Data-driven Attention Mechanism for Time Series. PVLDB, 17(11):3229-3242, 2024. (bibtex) [github site!] [SDD: a demo at CIKM '2025]
J. Jiang, B. Choi, X. Huang, J. Xu and S. S. Bhowmick. DKWS: A Distributed System for Keyword Search on Massive Graphs. TKDE 39(5):1935-1950 2024. (bibtex) [pdf] [bitbucket repo!]

L. Xu, B. Choi, Y. Peng, J. Xu and S. S. Bhowmick. A Framework for Privacy Preserving Localized Graph Pattern Query Processing. Pro. ACM Manag. Data (SIGMOD) 1(2):129:1-239:27 (2023). (bibtex) [github site!]
Y. Peng, B. Choi, T. Chan, J. Yang and J. Xu. Efficient Approximate Nearest Neighbor Search in Multi-dimensional Databases. Pro. ACM Manag. Data (SIGMOD) 1:(1): 54:1-54:27 (2023). (bibtex) [github site!]
R. Zuo, G. Li, B. Choi, S. S. Bhowmick, D. N-Y. Mah and G. L-H. Wong. SVP-T: A Shape-level Variable-Position Transformer for Multivariate Time Series Classification. AAAI, 11497-11505, 2023. (bibtex) [github site!]

Y. Peng, B. Choi, T. Chan, and J. Xu. LAN: Learning-based Approximate k-Nearest Neighbor Search in Graph Databases. ICDE, 2022. Pages 2508-2521. (bibtex) [github site!]
G. Li, B. Choi, J. Xu, S. S. Bhowmick, D. N-Y. Mah and G. L-H. Wong. IPS: Instance Profile for Shapelet Discovery for Time Series Classification. ICDE, 2022. Pages 1781-1793.
G. Li, B. Choi, J. Xu, S. S. Bhowmick, K-P Chun and G. L-H. Wong. Efficient Shapelet Discovery for Time Series Classification. TKDE 34(3):1149-1163, 2022. [pdf] [Implementation!] [Visualet: a demo at CIKM '2020]
P. Yi , B. Choi, Z. Zhang, S. S. Bhowmick and J. Xu. GFocus: User Focus-based Graph Query Autocompletion. TKDE 34(4):1788-1802, 2022. [pdf]

L. Xu, J. Jiang, B. Choi, J. Xu, and S. S. Bhowmick. Privacy Preserving Strong Simulation Queries on Large Graphs. ICDE, 2021. Pages 1500-1511. [pdf] [github site!]
G. Li, B. Choi, J. Xu, S. S. Bhowmick, K-P Chun and G. L-H. Wong. ShapeNet: A Shapelet-Neural Network Approach for Multivariate Time Series Classification. AAAI, 2021. Pages 8375-8383. [Implementation!][Adopting the triplet loss function for clustering][Poster at J Hepatol 2021;75(2):S727][Urban Climate 2022;41:101034][Energy Reports 2022;8:12886-12904]
Y. Peng, B. Choi and J. Xu. Graph Edit Distance Learning via Modeling Optimum Matchings with Constraints. IJCAI, 2021. Pages 1534-1540.

J. Jiang, X. Huang, B. Choi, J. Xu, S. S. Bhowmick, and L. Xu. PPKWS: An Efficient Framework for Keyword Search on Public-Private Networks. ICDE 2020, Pages 457-468. [pdf] [Implementation!]

J. Jiang, B. Choi, S. S. Bhowmick and J. Xu. A Generic Ontology Framework for Indexing Keyword Search on Massive Graphs. TKDE, 2019. [pdf] [Implementation!]

P. Yi, B. Choi, S. S. Bhowmick and J. Xu. AutoG: A Visual Query Autocompletion Framework for Graph Databases. The VLDB Journal 26(3):347-372, 2017. (the demo at VLDB '16) (an extension to support a large graph -- a highlight in Chinese, 2022)

S. S. Bhowmick, B. Choi and C. Dyreson. Data-driven Visual Graph Query Interface Construction and Maintenance: Challenges and Opportunities [Vision]. PVLDB 9(13): 1505-1508, 2016.
Y. Peng, B. Choi, B. He, S. Zhou, R. Xu and X. Yu. VColor: A Practical Vertex-cut Based Approach for Coloring Large Graphs. ICDE 2016, Pages 97-108.
J. Jiang, P. Yi, B. Choi, Z. Zhang and X. Yu. Privacy-Preserving Reachability Query Services for Massive Networks. CIKM 2016, Pages 145-154.

+ Show selected publications before 2016

Z. Fan, B. Choi, J. Xu and S. S. Bhowmick. Asymmetric Structure-Preserving Subgraph Query for Large Graphs. ICDE 2015. Pages 339-350. [pdf] [Implementation!]

Z. Fan, B. Choi, Q. Chen, J. Xu, H. Hu and S. S. Bhowmick. Structure-Preserving Subgraph Query Services. TKDE 27(8): 2275-2290 (2015). [pdf]

Y. Peng, Z. Fan, B. Choi, J. Xu and S. S. Bhowmick. Authenticated Subgraph Similarity Search in Outsourced Graph Databases. TKDE 27(7): 1838-1860 (2015). [pdf]

D. Wu, B. Choi, J. Xu and C. S. Jensen. Authentication of Moving Top-k Spatial Keyword Queries. TKDE 27(4):922-935 (2015). [pdf]

Z. Fan, Y. Peng, B. Choi, J. Xu and S. S. Bhowmick. Towards Efficient Authenticated Subgraph Query Service in Outsourced Graph Databases. TSC 7(4):696-713, 2014. [pdf]

Y. Peng, B. Choi, J. Xu, H. Hu and S. S. Bhowmick. Side-Effect Estimation: A Filtering Approach to the View Update Problem. TKDE 26(9):2307-2322 (2014). [pdf]

J. Deng, B. Choi, J. Xu, H. Hu and S. S. Bhowmick. Incremental Maintenance of the Minimum Bisimulation of Cyclic Graphs. TKDE 25(11): 2536-2550 (2013). [pdf]

S. S. Bhowmick, B. Choi and S. Zhou. VOGUE: Towards a Visual Interaction-aware Graph Query Processing Framework. CIDR 2013.

L. Song, Y. Peng, B. Choi, J. Xu and B. He. Spectral Decomposition for Optimal Graph Index Prediction. PAKDD 2013. Pages 187-200.

Y. Peng, B. Choi and J. Xu. Selectivity Estimation of Twig Queries on Cyclic Graphs. ICDE 2011. Pages 960-971.

H. Hu, C. Ren, J. Xu and B. Choi. Processing Private Queries over Untrusted Data Cloud through Privacy Homomorphism. ICDE 2011. Pages 601-612.

L. Zhu, A. Sun and B. Choi. Detecting Spam-Blogs from Blog Search Results. IPM 2011 47(2): 246-262.

B. Choi, H. Hu, J. Xu, W. Cheung, C. H. Li and J. Liu. Data Engineering in Graph Databases. ISCIS 2010. Pages 127 - 132. (invited paper)

R. Bramandia, B. Choi and W-K. Ng. Incremental Maintenance of 2-hop Labeling of Large Graphs. TKDE 22(5): 682-698 (2010).

C. Jin, S. S. Bhowmick, X. Xiao, J. Cheng and B. Choi. GBLENDER: Towards Blending Visual Query Formulation and Query Processing in Graph Databases. SIGMOD 2010. Pages 111-122.

M. Cheng, B. Choi and W. Cheung. Hiding Emerging Patterns with Local Recoding Generalization. PAKDD 2010. Pages 158 - 170.

R. Bramandia, J. Cheng, B. Choi and J. X. Yu. Optimizing Updates of Recursive XML Views of Relations. The VLDB Journal 18(5):1313-1333, 2009.

R. Bramandia, B. Choi and W-K. Ng. On Incremental Maintenance of 2-hop Labeling of Graphs. WWW 2008. Pages 845-854. [pdf]

B. Choi, G. Cong, W. Fan and S. D. Viglas. Updating Recursive XML Views of Relations. JCST 23(4): 516-537 July 2008.

N. Tang, J. X. Yu, M. T. Ozsu, B. Choi and K-F. Wong. Multiple Materialized View Selection for XPath Query Rewriting. ICDE 2008. Pages 873-882.

B. He, Q. Luo and B. Choi. Adaptive Index Utilization in Memory-Resident Structural Joins. TKDE 19(6): 772 - 788 (2007).

B. Choi, G. Cong, W. Fan and S. D. Viglas. Updating Recursive XML Views of Relations. ICDE 2007. Pages 766 - 775.

B. He, Q. Luo and B. Choi. Cache-Conscious Automata for XML Filtering. TKDE 18(12): 1629-1644 (2006).

Z. Lin, B. He, and B. Choi. A Quantitative Summary of XML Structures. ER 2006. Pages 228-240. LNCS 4215. [pdf] Springer-Verlag.

B. Choi. Document Decomposition for XML Compression: A Heuristic Approach. DASFAA 2006. Pages 202-217. LNCS 3382

P. Buneman, B. Choi, W. Fan, R. Hutchison, R. Mann and S. D. Viglas. Vectorizing and Querying Large XML Repositories. ICDE 2005. Pages 261-272. [pdf]

B. He, Q. Luo and B. Choi. Cache-Conscious Automata for XML Filtering. ICDE 2005. Pages 878-889. [pdf]

P. Bohannon, B. Choi and W. Fan. Incremental Evaluation of Schema-Directed XML Publishing. SIGMOD 2004. Pages 503-514. [pdf]

B. Choi, W. Fan, X. Jia, and A. Kasprzyk. A Uniform System for Publishing and Maintaining XML Data. VLDB 2004 (demo). Pages 1301-1304.

B. Choi, M. Mahoui and D. Wood. On the Optimality of Holistic Algorithms for Twig Queries. DEXA 2003. Pages 28-37. LNCS 2736. [pdf] Springer-Verlag.

M. Fernandez, J. Simeon, B. Choi, A. Marian, G. Sur. Implementing Xquery 1.0: The Galax Experience. VLDB 2003 (demo). Pages 1077-1080.

B. Choi. What are Real DTDs Like? WebDB 2002. Pages 43-48. [pdf]

	S. S. Bhowmick and B. Choi. Plug-and-Play Visual Subgraph Query Interfaces. Synthesis Lectures on Data Managemnt, Morgan & Claypool Publishers, ISBN 3031161610, March, 2023. [Amazon Link]
	S. S. Bhowmick, B. Choi, and C. Li. Human Interaction with Graphs: A Visual Querying Perspective. Synthesis Lectures on Data Management, Morgan & Claypool Publishers, ISBN 9781681733784, Aug 2018. [Book Link] [Amazon Link]
	R. Chen, X. Weng, B. He, B. Choi and M. Yang. Network Performance Aware Graph Partitioning for Large Graph Processing Systems in the Cloud. Large Scale and Big Data: Processing and Management. S. Sakr and M. M. Gaber (Eds.), to be published by CRC Press, 2013 [an earlier version published in SoCC '12]. [Book Link] [Amazon Link]