Dr. Sijie Ruan is an Assistant Professor, Special Research Associate at School of Computer Science and Technology, Beijing Institute of Technology.

His research interests include spatio-temporal data mining, volunteered geographic information and urban computing.

He was a visiting PhD student at Nanyang Technological University and research interns at Microsoft Research and JD.com.

He has published several papers in refereed journals and conferences, such as TKDE, KDD, AAAI, ICDE, WWW and UbiComp.

He also serves as a reviewer/PC member for several referred journals and conferences, e.g., TKDE, NeurIPS, KDD, WWW, AAAI and IMWUT.

Openings: We have openings of 2 master students annually. Please contact me via email if you have interest.

2026

• LeCDSR: Large Language Model Enhanced Cross-Domain Sequential Recommendation
  Shuliang Wang, Jiabao Zhu, Kaibo Wang and Sijie Ruan*
  Information Fusion (InfFus), 2026.
• A Gravity-informed Spatiotemporal Transformer for Human Activity Intensity Prediction
  Yi Wang, Zhenghong Wang, Fan Zhang, Chaogui Kang, Sijie Ruan, Di Zhu, Chengling Tang, Zhongfu Ma, Weiyu Zhang, Yu Zheng, Philip S. Yu, Yu Liu
  IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 2026.

2025

• Eulerian Neural Network Informed by Chemical Transport for Air Quality Forecasting
  Xukai Zhang, Shuliang Wang, Guangyin Jin, Ziqiang Yuan, Hanning Yuan* and Sijie Ruan*
  in Proceedings of the 39th Annual Conference on Neural Information Processing Systems (NeurIPS'25), 2025.
• FieldMapper: Automated Agricultural Field Delineation via Vision Foundation Model and Machinery Trajectories
  Shuliang Wang, Haoyu Han, Sijie Ruan*, Ziyu Wang, Ziqiang Yuan, Yeting Zhang, Hanning Yuan and Caicong Wu
  IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (JSTARS), 2025.
• Spatial Hierarchical Meta-Learning for Single-Point Map Matching
  Sijie Ruan, Yiqing Zou, Qianyu Yang, Haoyu Han, Yeting Zhang, Ziqiang Yuan, Hanning Yuan and Shuliang Wang
  in Proceedings of the 31st ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'25), 2025.
• Generative Human Trajectory Recovery via Embedding-Space Conditional Diffusion
  Kaijun Liu, Sijie Ruan*, Liang Zhang, Cheng Long, Shuliang Wang and Liang Yu
  in Proceedings of the 42nd International Conference on Machine Learning (ICML'25), 2025.
• AdaMove: Efficient Test-Time Adaptation for Human Mobility Prediction
  Huaxu Han, Shuliang Wang, Sijie Ruan*, Qianyu Yang, Yuxuan Liang, Ziqiang Yuan, Cheng Long, Hanning Yuan and Yu Zheng
  in Proceedings of the 41st IEEE International Conference on Data Engineering (ICDE'25), 2025.
• Hierarchical Gating Network for Cross-Domain Sequential Recommendation
  Shuliang Wang, Jiabao Zhu, Yi Wang, Chen Ma*, Xin Zhao, Yansen Zhang, Ziqiang Yuan and Sijie Ruan*
  ACM Transactions on Information Systems (TOIS), 2025.
• KITS: Inductive Spatio-Temporal Kriging with Increment Training Strategy
  Qianxiong Xu, Cheng Long, Ziyue Li, Sijie Ruan, Rui Zhao and Zhishuai Li
  in Proceedings of the 39th AAAI Conference (AAAI'25), 2025.
• Modeling On-road Trajectories with Multi-task Learning
  Kaijun Liu, Sijie Ruan*, Cheng Long and Liang Yu
  ACM Transactions on Knowledge Discovery from Data (TKDD), 2025.
• Spatial Meta Learning with Comprehensive Prior Knowledge Injection for Service Time Prediction
  Shuliang Wang, Qianyu Yang, Sijie Ruan*, Cheng Long, Ye Yuan, Qi Li, Ziqiang Yuan, Jie Bao and Yu Zheng
  IEEE Transactions on Knowledge and Data Engineering (TKDE), 2025.

2024

• TrafCL: Robust Encrypted Malicious Traffic Detection via Contrastive Learning
  Xiaodu Yang, Sijie Ruan*, Jinyu Li, Yinliang Yue and Bo Sun*
  in Proceedings of the 33rd ACM International Conference on Information and Knowledge Management (CIKM'24), 2024.
• DiffCrime: A Multimodal Conditional Diffusion Model for Crime Risk Map Inference
  Shuliang Wang, Xinyu Pan, Sijie Ruan*, Haoyu Han, Ziyu Wang, Hanning Yuan, Jiabao Zhu and Qi Li
  in Proceedings of the 30th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'24), 2024.
• Towards Robust Trajectory Representations: Isolating Environmental Confounders with Causal Learning
  Kang Luo, Yuanshao Zhu, Wei Chen, Kun Wang, Zhengyang Zhou, Sijie Ruan and Yuxuan Liang
  in Proceedings of the 33rd International Joint Conference on Artificial Intelligence (IJCAI'24), 2024.
• A Lightweight Multi-Layer Perceptron for Efficient Multivariate Time Series Forecasting
  Zhenghong Wang^#, Sijie Ruan^#, Tianqiang Huang^#, Haoyi Zhou, Shanghang Zhang, Yi Wang, Leye Wang and Yu Liu
  Knowledge-Based Systems (KBS), 2024.
• DelvMap: Completing Residential Roads in Maps Based on Couriers' Trajectories and Satellite Imagery
  Shuliang Wang, Ziyu Wang, Sijie Ruan*, Haoyu Han, Keqin Xiong, Hannning Yuan, Ziqiang Yuan, Guoqing Li, Jie Bao and Yu Zheng
  IEEE Transactions on Geoscience and Remote Sensing (TGRS), 2024.[Code]
• Urban Sensing for Multi-Destination Workers via Deep Reinforcement Learning
  Shuliang Wang, Song Tang, Sijie Ruan*, Cheng Long, Yuxuan Liang, Qi Li, Ziqiang Yuan, Jie Bao and Yu Zheng
  in Proceedings of the 40th IEEE International Conference on Data Engineering (ICDE'24), 2024.[Code]
• Plaintext-aware Encrypted Traffic Detection Network for Identifying Cobalt Strike HTTPS Traffics
  Xiaodu Yang, Sijie Ruan*, Yinliang Yue and Bo Sun*
  Computer Networks, 2024.

2023

• A Novel Approach for Company Real Workplace Identification via E-commercial Data (Short Paper)
  Huimin Ren, Sijie Ruan*, Ye Yuan, Yanhua Li*, Jie Bao, Tianfu He, Huajun He, Chuishi Meng and Yu Zheng
  in Proceedings of the 31st ACM International Conference on Advances in Geographical Information Systems (SIGSPATIAL'23), 2023.
• A Survey of Urban Geographic Information Inference Driven by Crowdsourced Spatio-Temporal Data (in Chinese)
  Sijie Ruan, Keqin Xiong, Shuliang Wang, Jing Geng, Jie Bao and Yu Zheng
  in Acta Electronica Sinica, 2023.
• SAInf: Stay Area Inference of Vehicles using Surveillance Camera Records
  Zhipeng Ma, Chuishi Meng, Huimin Ren, Sijie Ruan, Jie Bao, Xiaoting Wang, Tianrui Li and Yu Zheng
  in Proceedings of the 29th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'23), 2023.
• Filling Delivery Time Automatically Based on Couriers' Trajectories
  Sijie Ruan, Xi Fu, Cheng Long, Zi Xiong, Jie Bao, Ruiyuan Li, Yiheng Chen, Shengnan Wu and Yu Zheng
  IEEE Transactions on Knowledge and Data Engineering (TKDE), 2023.
• TrajMesa: A Distributed NoSQL-Based Trajectory Data Management System
  Ruiyuan Li, Huajun He, Rubin Wang, Sijie Ruan, Tianfu He, Jie Bao, Junbo Zhang, Liang Hong and Yu Zheng
  IEEE Transactions on Knowledge and Data Engineering (TKDE), 2023.
• CD-BNN: Causal Discovery with Bayesian Neural Network
  Huaxu Han, Shuliang Wang, Hanning Yuan, Sijie Ruan
  in Proceedings of the 19th International Conference on Advanced Data Mining and Applications (ADMA'23), 2023.

2022

• Traffic Speed Imputation with Spatio-Temporal Attentions and Cycle-Perceptual Training
  Qianxiong Xu, Sijie Ruan, Cheng Long, Liang Yu and Chen Zhang
  in Proceedings of the 31st ACM International Conference on Information and Knowledge Management (CIKM'22), 2022.
• Service Time Prediction for Delivery Tasks via Spatial Meta-Learning
  Sijie Ruan, Cheng Long, Zhipeng Ma, Jie Bao, Tianfu He, Ruiyuan Li, Yiheng Chen, Shengnan Wu and Yu Zheng
  in Proceedings of the 28th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'22), 2022.
• Modeling Trajectories with Multi-task Learning (Short Paper)
  Kaijun Liu, Sijie Ruan, Qianxiong Xu, Cheng Long, Nan Hu, Nan Xiao, Liang Yu and Sinno Pan
  in Proceedings of the 23rd IEEE International Conference on Mobile Data Management (MDM'22), 2022.
• Discovering Actual Delivery Locations from Mis-Annotated Couriers' Trajectories
  Sijie Ruan, Cheng Long, Xiaodu Yang, Tianfu He, Ruiyuan Li, Jie Bao, Yiheng Chen, Shengnan Wu, Jiangtao Cui and Yu Zheng
  in Proceedings of the 38th IEEE International Conference on Data Engineering (ICDE'22), 2022.
• TraSS: Efficient Trajectory Similarity Search Based on Key-Value Data Stores
  Huajun He, Ruiyuan Li, Sijie Ruan, Tianfu He, Jie Bao, Tianrui Li and Yu Zheng
  in Proceedings of the 38th IEEE International Conference on Data Engineering (ICDE'22), 2022.
• Fine-Grained Urban Flow Inference
  Kun Ouyang, Yuxuan Liang, Ye Liu, Zekun Tong, Sijie Ruan, Yu Zheng and David S. Rosenblum
  IEEE Transactions on Knowledge and Data Engineering (TKDE), 2022.

2021

• Distributed Spatio-Temporal k Nearest Neighbors Join
  Ruiyuan Li, Rubin Wang, Junwen Liu, Zisheng Yu, Huajun He, Tianfu He, Sijie Ruan, Jie Bao, Chao Chen, Fuqiang Gu, Liang Hong and Yu Zheng
  in Proceedings of the 29th ACM International Conference on Advances in Geographical Information Systems (SIGSPATIAL'21), 2021.
• SALON: A Universal Stay Point-Based Location Analysis Platform (Demo Paper) Best Demo Paper Award
  Yue Hu, Sijie Ruan*, Yuting Ni, Huajun He, Jie Bao*, Ruiyuan Li and Yu Zheng
  in Proceedings of the 29th ACM International Conference on Advances in Geographical Information Systems (SIGSPATIAL'21), 2021.
• ICFinder: A Ubiquitous Approach to Detecting Illegal Hazardous Chemical Facilities with Truck Trajectories (Short Paper)
  Zheng Zhu, Huimin Ren, Sijie Ruan, Boyang Han, Jie Bao, Ruiyuan Li, Yanhua Li and Yu Zheng
  in Proceedings of the 29th ACM International Conference on Advances in Geographical Information Systems (SIGSPATIAL'21), 2021.
• POI Alias Discovery in E-commerce Delivery Address Data using User Check-ins (Short Paper)
  Tianfu He, Guochun Chen, Chuishi Meng, Huajun He, Zheyi Pan, Yexin Li, Sijie Ruan, Huimin Ren, Ye Yuan, Ruiyuan Li, Junbo Zhang, Jie Bao, Hui He and Yu Zheng
  in Proceedings of the 29th ACM International Conference on Advances in Geographical Information Systems (SIGSPATIAL'21), 2021.
• TLDS: A Transfer-Learning-Based Delivery Station Location Selection Pipeline
  Chenyu Hou, Bin Cao, Sijie Ruan and Jing Fan
  in ACM Transactions on Intelligent Systems and Technology (TIST), 2021.
• MTrajRec: Map-Constrained Trajectory Recovery via Seq2Seq Multi-task Learning
  Huimin Ren, Sijie Ruan, Yanhua Li, Jie Bao, Chuishi Meng, Ruiyuan Li and Yu Zheng
  in Proceedings of the 27th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'21), 2021.

2020

• You Are How You Use: Catching Gas Theft Suspects among Diverse Restaurant Users
  Xiaodu Yang, Xiuwen Yi, Shun Chen, Sijie Ruan, Junbo Zhang, Yu Zheng and Tianrui Li
  in Proceedings of the 29th ACM International Conference on Information and Knowledge Management (CIKM'20), 2020.
• Doing in One Go: Delivery Time Inference Based on Couriers' Trajectories
  Sijie Ruan, Zi Xiong, Cheng Long, Yiheng Chen, Jie Bao, Tianfu He, Ruiyuan Li, Shengnan Wu, Zhongyuan Jiang and Yu Zheng
  in Proceedings of the 26th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'20), 2020.
• Discovering Real-time Reachable Area using Trajectory Connections
  Ruiyuan Li, Jie Bao, Huajun He, Sijie Ruan, Tianfu He, Liang Hong, Zhongyuan Jiang and Yu Zheng
  in Proceedings of the 25th International Conference on Database Systems for Advanced Applications (DASFAA'20), 2020.
• Dynamic Public Resource Allocation based on Human Mobility Prediction [Code&Data]
  Sijie Ruan, Jie Bao, Yuxuan Liang, Ruiyuan Li, Tianfu He, Chuishi Meng, Yanhua Li, Yingcai Wu and Yu Zheng
  in Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT/UbiComp'20), 2020.
• What is the Human Mobility in a New City? Transfer Mobility Knowledge Across Cities
  Tianfu He, Jie Bao, Ruiyuan Li, Sijie Ruan, Yanhua Li, Li Song, Hui He and Yu Zheng
  in Proceedings of the Web Conference 2020 (WWW'20), 2020.
• JUST: JD Urban Spatio-Temporal Data Engine
  Ruiyuan Li, Huajun He, Rubin Wang, Yuchuan Huang, Junwen Liu, Sijie Ruan, Tianfu He, Jie Bao and Yu Zheng
  in Proceedings of the 36th IEEE International Conference on Data Engineering (ICDE'20), 2020.
• Learning to Generate Maps from Trajectories
  Sijie Ruan, Cheng Long, Jie Bao, Chunyang Li, Zisheng Yu, Ruiyuan Li, Yuxuan Liang, Tianfu He and Yu Zheng
  in Proceedings of the 34th AAAI Conference (AAAI'20), 2020.
• Interactive Bike Lane Planning using Sharing Bikes' Trajectories
  Tianfu He, Jie Bao, Sijie Ruan, Ruiyuan Li, Yanhua Li, Hui He and Yu Zheng
  IEEE Transactions on Knowledge and Data Engineering (TKDE), 2020.
• TrajMesa: A Distributed NoSQL Storage Engine for Big Trajectory Data (Short Paper)
  Ruiyuan Li, Huajun He, Rubin Wang, Sijie Ruan, Yuan Sui, Jie Bao and Yu Zheng
  in Proceedings of the 36th IEEE International Conference on Data Engineering (ICDE'20), 2020.

2019

• Effective Recycling Planning for Dockless Sharing Bikes
  Cong Zhang, Yanhua Li, Jie Bao, Sijie Ruan, Tianfu He, Hui Lu, Zhihong Tian, Cong Liu, Chao Tian, Jianfeng Lin and Xianen Li
  in Proceedings of the 27th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL'19), 2019.
• UrbanFM: Inferring Fine-Grained Urban Flows [Code]
  Yuxuan Liang, Kun Ouyang, Lin Jing, Sijie Ruan, Ye Liu, Junbo Zhang and Yu Zheng
  in Proceedings of the 25th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'19), 2019.

2018

• Efficient Path Query Processing over Massive Trajectories on the Cloud
  Ruiyuan Li, Sijie Ruan, Jie Bao, Yanhua Li, Yingcai Wu, Liang Hong and Yu Zheng
  in IEEE Transactions on Big Data (TBD), 2018.
• Detecting Illegal Vehicle Parking Events using Sharing Bikes' Trajectories
  Tianfu He, Jie Bao, Ruiyuan Li, Sijie Ruan, Yanhua Li, Chao Tian and Yu Zheng
  in Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'18), 2018.
• CloudTP: A Cloud-based Flexible Trajectory Preprocessing Framework (Demo Paper)
  Sijie Ruan, Ruiyuan Li, Jie Bao, Tianfu He and Yu Zheng
  in Proceedings of the 34th IEEE International Conference on Data Engineering (ICDE'18), 2018.

2017

• Querying Massive Trajectories by Path on the Cloud (Short Paper)
  Ruiyuan Li, Sijie Ruan, Jie Bao, Yanhua Li, Yingcai Wu and Yu Zheng
  in Proceedings of the 25th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL'17), 2017.
• A Cloud-Based Trajectory Data Management System (Demo Paper) Best Demo Paper Award Runners-up
  Ruiyuan Li, Sijie Ruan, Jie Bao, Yu Zheng
  in Proceedings of the 25th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (SIGSPATIAL'17), 2017.
• Planning Bike Lanes based on Sharing-Bikes' Trajectories
  Jie Bao, Tianfu He, Sijie Ruan, Yanhua Li and Yu Zheng
  in Proceedings of the 23rd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'17), 2017.

• 2025.04-2028.03, Guizhou Provincial Key Technology R&D Program, (PA[2025]002), PI
• 2025.01-2025.12, Open Fund of Key Laboratory of Agricultural Machinery Monitoring and Big Data Applications, Ministry of Agriculture and Rural Affairs, Research on Resource Allocation for Field Operating of Agricultural Machinery (202405), PI
• 2023.12-2026.11, National Key Research and Development Program of China, Research on Intelligent Methods for Societal-Data-Driven Governance of Major Infectious Disease Transmission Risks (2023YFC2308703), Co-PI
• 2023.11-2026.10, National Key Research and Development Program of China, (2023YFC3321505), Co-PI
• 2024.01-2026.12, National Natural Science Foundation of China, Research on Methods for Fine-grained Geographical Information Collecting and Urban Space Modeling Driven by Spatio-temporal Big Data (62306033), PI
• 2022.07-2025.12, Beijing Institute of Technology Research Fund Program for Young Scholars, Research on Methods for Crowdsourced Spatio-temporal Data-centric Urban Geospatial Entity Understanding (6120220113), PI
• 2023.07-2024.07, Beijing Institute of Technology Library Research Fund (Key Program), Research on Algorithms of Personalized Article Recommendation Based on Multi-sourced Data Fusion, PI

• Data Science and Algorithms (100076218, in English), since 2023 Spring, Beijing Institute of Technology
• Computer Networks (100071011), since 2023 Spring, Beijing Institute of Technology
• Urban Computing (X19CS0250), 2017 Fall, Xidian University

• [2024.05.23] Applications of Artificial Intelligence in Infectious Desease Monitoring and Early Warnings, Pudong CDC.
• [2024.04.10] Crowdsourced Trajectory Data-Driven Urban Geospatial Entity Modeling: Opportunities, Challenges, and Methods, HKUST (GZ).
• [2023.12.26] Opportunities and Challenges of Large Models in Spatio-tempral Data Analytics, Software Development in the Era of Large Models: Opportunities and Challenges.
• [2023.12.01] Crowdsourced Trajectory Data Mining for Spatial Intelligent Decision-Making, The 2nd Spatial Data Intelligence Strategy Symposium of China.
• [2023.05.08] Classical Research Problems in Trajectory Data Mining, China Agricultural University.
• [2023.04.15] Research on Methods of Discovering and Understanding Urban Geospatial Entities Driven by Trajectory Data, SpatialDI 2023.
• [2022.10.31] Research on Methods of Discovering and Understanding Urban Geospatial Entities Driven by Trajectory Data, University of Chinese Academy of Sciences.

• Executive Committee Member: CCF Expert Committee on Big Data, ACM SIGSPATIAL CHN Chapter, Health Statistics and Applications of Big Data of Beijing Association of Preventive Medicine
• Senior Area Chair: KDD (2026)
• Session Chair: ICDE (2024), UrbComp (2021)
• Publicity Chair: UrbComp (2024,2025)
• Journal Reviewer: IEEE Transactions on Knowledge and Data Engineering (TKDE); IEEE Transactions On Mobile Computing (TMC); The Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT); IEEE Transactions on Intelligent Transportation Systems (TITS); ACM Transactions on Knowledge Discovery from Data (TKDD); ACM Transactions on Intelligent Systems and Technology (TIST); ACM Transactions on Data Science (TDS); IEEE Transactions on Big Data (TBD)
• Conference Program Committee: KDD (2023-2026); NeurIPS (2024-2025); ICLR (2024-2026); ICML (2025); AAAI (2021, 2026); CIKM (2022-2025)

• [2025] Travel Planning Challenge 1st Place Award, IJCAI
• [2024] Doctoral Dissertation Incentive Program, Chinese Institute of Electronics
• [2023] Science and Technology Progress 1st Place Award, Chinese Institue of Command and Control
• [2023] Travel Grants, ACM SIGSPATIAL 2023
• [2022] ACM SIGSPATIAL China Doctoral Dissertation Award, ACM SIGSPATIAL China, 1st Place
• [2022] Outstanding Graduates, Education Department of Shaanxi Province, 1%
• [2021] Graduate Presidential Award Candidate, Xidian University, 0.1%
• [2021] Best Demo Paper Award, ACM SIGSPATIAL, 1/27
• [2021] The 3rd Prize in JD Outstanding Patent, JD Group, 4/436
• [2020] State Scholarship Fund, China Scholarship Council
• [2020] Outstanding Graduate Student, Xidian University
• [2020] National Scholarship, Ministry of Education of P.R.C.
• [2020] Student Travel Grants, KDD 2020
• [2020] Student Travel Grants, AAAI 2020
• [2020] The 2nd Prize in "TanSuo" Cup Patent Compitition, JD Digits, 2/434
• [2019] The 2nd Prize in JDD Hackathon, JD Digits, 2/238
• [2018] The 4th Prize in Global Optimization Challenge, JD Logistics, 4/46
• [2018] Outstanding Intern, JD iCity
• [2017] Best Demo Paper Award Runners-up, ACM SIGSPATIAL
• [2017] National Scholarship, Ministry of Education of P.R.C.
• [2017] Outstanding Graduates, Xidian University
• [2016] National Scholarship, Ministry of Education of P.R.C.

I am happy to work with my deligent and telented students:

Alumni

    Master Students

• 2023, Yeting Zhang (1st placement: Agricultural Bank of China), Song Tang (co-supervised with Prof. Shuliang Wang)
• 2022, Yiqing Zou (co-supervised with Assoc. Prof. Hanning Yuan)

    Visiting Students

• 2025, Songxin Lei (from HKUST(GZ))

• ACM Member:3594742
• IEEE Member: 97892443
• CIE Member: E190029979M
• CCF Member: 68501M

I am really honored to work with my best friends (in alphabetical order):

• Huajun He, Southwest Jiaotong University
• Tianfu He, JD.com
• Ruiyuan Li, Chongqing University
• Yuxuan Liang, HKUST (GZ)
• Huimin Ren, Li Auto
• Qianxiong Xu, Nanyang Technological University