Xi (Alex) Chen, PhD
Lead AI Researcher @ Proactive AI Lab, Inc.
Montreal, QC, Canada
Email: alex at proactiveailab dot com
Short Bio
Xi Chen is currently a Lead AI Researcher at Proactive AI Lab, working on agentic AI. Before that, he was a Senior Principle Researcher at Huawei Noah's Ark Lab, Montreal, and an NLP Research Scientist at Nuance Communications. He also served as an adjunct professor at School of Computer Science, McGill University, from 2020 to 2023. His experience and passion lie in a wide range of AI domains, including LLM agents, alignment, reasoning, decision making foundation models, 5G/6G foundation models, AI for communications, Integrated Sensing and Communications (ISAC), autonomous driving, smart IoT, smart homes, smart systems, vehicle-to-everything, etc. He achieved his PhD degree at School of Computer Science, McGill University. He received both M.Eng. and B.S. degrees from Department of Electronic Engineering, Shanghai Jiao Tong University.
News
[2024.01] Two of our papers "Latent Trajectory Learning for Limited Timestamps under Distribution Shift over Time", and "Less or More From Teacher: Exploiting Trilateral Geometry For Knowledge Distillation" accepted by ICLR 2024!
[2023.12] Our paper "Calibrated One Round Federated Learning with Bayesian Inference in the Predictive Space " accepted by AAAI 2024!
[2023.09] Our paper "FedSwarm: An Adaptive Federated Learning Framework for Scalable AIoT" accepted by Internet of Things Journal!
[2023.07] Our paper "Understanding Hessian Alignment for Domain Generalization" accepted by ICCV 2023!
[2023.03] Our paper "Eliminating Space Scanning: Fast mmWave Beam Alignment With UWB Radios" accepted by ACM Transactions on Sensor Networks!
[2023.02] Our paper "Dynamically Instance-Guided Adaptation: A Backward-free Approach for Test-Time Domain Adaptive Semantic Segmentation" accepted by CVPR 2023!
[2022.10] Our paper "Hyperspherical Quantization: Toward Smaller and More Accurate Models" accepted by WACV 2023!
[2022.10] Our paper on "Dynamic Consolidation for Continual Learning" accepted by Neural Computation Journal!
[2022.08] Two papers on 5G and aerial networks accepted by Globecom 2022!
[2022.08] Our survey "Gradient-based Bi-level Optimization for Deep Learning: A Survey" is available online!
[2022.08] Our survey "Encoder-Decoder Architecture for Supervised Dynamic Graph Learning: A Survey" is available online!
[2022.06] Our paper "Learning from FM Communications: Toward Accurate, Efficient, All-Terrain Vehicle Localization" was accepted by IEEE/ACM Trans. Networking!
[2022.03] Our paper "Fidora: Robust WiFi-based Indoor Localization via Unsupervised Domain Adaptation" was accepted by Internet of Thing Journal!
[2022.01] Two papers on transfer/continual learning for 5G traffic prediction accepted by ICC 2022!
Publications
Qiuhao Zeng, Changjian Shui, Long-Kai Huang, Peng Liu, Xi Chen, Charles Ling, Boyu Wang, "Latent Trajectory Learning for Limited Timestamps under Distribution Shift over Time", in International Conference on Learning Representations (ICLR 2024), 2024.
Chengming Hu, Haolun Wu, Xuan Li, Chen Ma, Xi Chen, Jun Yan, Boyu Wang, Xue Liu, "Less or More From Teacher: Exploiting Trilateral Geometry For Knowledge Distillation", in International Conference on Learning Representations (ICLR 2024), 2024.
Haizhou Du, Chengdong Ni, Chaoqian Cheng, Qiao Xiang, Xi Chen, and Xue Liu. "FedSwarm: An Adaptive Federated Learning Framework for Scalable AIoT." in IEEE Internet of Things Journal (IOTJ) 2023.
Sobhan Hemati, Guojun Zhang, Amir Estiri, Xi Chen, "Understanding Hessian Alignment for Domain Generalization", in IEEE/CVF International Conference on Computer Vision (ICCV 2023), 2023, pp. 19004-19014.
Ju Wang, Xi Chen, Xue Liu, and Gregory Dudek. "Eliminating Space Scanning: Fast mmWave Beam Alignment with UWB Radios." in ACM Transactions on Sensor Networks 19, no. 4 (2023): 1-20.
Wei Wang, Zhun Zhong, Weijie Wang, Xi Chen, Charles Ling, Boyu Wang, and Nicu Sebe. "Dynamically Instance-Guided Adaptation: A Backward-Free Approach for Test-Time Domain Adaptive Semantic Segmentation." In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR 2023), pp. 24090-24099. 2023.
Guojun Zhang, Saber Malekmohammadi, Xi Chen, "Proportional Fairness in Federated Learning ", in Transactions on Machine Learning Research (01/2023).
Dan Liu, Xi Chen, Chen Ma, Xue Liu, "Hyperspherical Quantization: Toward Smaller and More Accurate Models", in IEEE/CVF Winter Conference on Applications of Computer Vision (WACV 2023), Waikoloa, HI, USA, 2023, pp. 5251-5261.
Hang Li, Chen Ma, Xi Chen, Xue Liu, "Dynamic Consolidation for Continual Learning", Neural Comput 2023; 35 (2): 228–248.
Can Chen, Xi Chen, Chen Ma, Zixuan Liu, Xue Liu, "Gradient-based Bi-level Optimization for Deep Learning: A Survey", arXiv preprint arXiv:2207.11719, 2022.
Yuecai Zhu, Fuyuan Lyu, Chengming Hu, Xi Chen, Xue Liu, "Encoder-Decoder Architecture for Supervised Dynamic Graph Learning: A Survey", arXiv preprint arXiv:2203.10480, 2022.
Xi Chen, Qiao Xiang, Linghe Kong, Huisan Xu, and Xue Liu, "Learning From FM Communications: Toward Accurate, Efficient, All-Terrain Vehicle Localization," in IEEE/ACM Transactions on Networking (TON), 2022.
Xi Chen, Hang Li, Chenyi Zhou, Xue Liu, Gregory Dudek, "Fidora: Robust WiFi-based Indoor Localization via Unsupervised Domain Adaptation," in IEEE Internet of Things Journal (IOTJ), 2022.
Hang Li, Ju Wang, Chengming Hu, Xi Chen, Xue Liu, Seowoo Jang, Gregory Dudek, "Communication Traffic Prediction with Continual Knowledge Distillation", IEEE International Conference on Communications (ICC), Seoul, Korea, Republic of, 2022, pp. 5481-5486.
Hang Li, Ju Wang, Xi Chen, Xue Liu, Gregory Dudek, "Data-Efficient Communication Traffic Prediction With Deep Transfer Learning", in IEEE International Conference on Communications, Seoul, Korea, Republic of, 2022, pp. 3190-3195.
Can Chen, Shuhao Zheng, Xi Chen, Erqun Dong, Xue Liu, Hao Liu, and Dejing Dou, "Generalized Data Weighting via Class-Level Gradient Manipulation ", in Proc. of Advances in Neural Information Processing Systems (NeurIPS 2021).
Hang Li, Xi Chen, Ju Wang, Di Wu, and Xue Liu, "DAFI: WiFi-based Device-free Indoor Localization via Domain Adaptation", in Proc. of ACM Interact. Mob. Wearable Ubiquitous Technol. (IMWUT/UbiComp) 5, 4, Article 167, pp. 1-21, Dec 2021.
Xi Chen, Ju Wang, Hang Li, Yi Tian Xu, Di Wu, Xue Liu, Gregory Dudek, Taeseop Lee, and Intaik Park, "One for All: Traffic Prediction at Heterogeneous 5G Edge with Data-Efficient Transfer Learning", in Proc. of IEEE Global Communications Conference 2021 (Globecom 2021) (Best Paper Award).
Chengming Hu, Xi Chen (corresponding author), Ju Wang, Hang Li, Jikun Kang, Yi Tian Xu, Xue Liu, Di Wu, Seowoo Jang, Intaik Park and Gregory Dudek, "AFB: Improving Communication Load Forecasting Accuracy with Adaptive Feature Boosting", in Proc. of IEEE Global Communications Conference 2021 (Globecom 2021) .
Dmitriy Rivkin, David Meger, Di Wu, Xi Chen, Xue Liu, and Gregory Dudek, "Learning Assisted Identification of Scenarios Where Network Optimization Algorithms Under-Perform", in Proc. of IEEE Global Communications Conference 2021 (Globecom 2021) .
Di Wu, Jikun Kang, Yi Tian Xu, Hang Li, Jimmy Li, Xi Chen, Dmitriy Rivkin, Michael Jenkin, Taeseop Lee, Intaik Park, Xue Liu, and Gregory Dudek, "Load Balancing for Communication Networks via Data-Efficient Deep Reinforcement Learning", in Proc. of IEEE Global Communications Conference 2021 (Globecom 2021) .
Jikun Kang, Xi Chen (corresponding author), Di Wu, Yi Tian Xu, Xue Liu, Gregory Dudek, Taeseop Lee, and Intaik Park, "Hierarchical Policy Learning for Hybrid Communication Load Balancing", in Proc. of IEEE 2021 International Conference on Communications (ICC 2021), Montreal, QC, Canada, 2021.
Ju Wang, Xi Chen, Xue Liu, and Gregory Dudek, "UWB-assisted Fast mmWave Beam Alignment", in Proc. of IEEE 2021 International Conference on Communications (ICC 2021), Montreal, QC, Canada, 2021.
Yi Tian Xu, Xi Chen (corresponding author), Steve Liu, Gregory Lewis Dudek, David Meger, "PresSense: Passive Respiration Sensing via Ambient WiFi Signals in Noisy Environments", in Proc. of 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2020), Las Vegas, NV, US, 2020.
Xi Chen, Hang Li, Chenyi Zhou, Xue Liu, Gregory Dudek, "FiDo: Ubiquitous Fine-Grained WiFi-based Localization for Unlabelled Users via Domain Adaptation", in Proc. of The World Wide Web Conference 2020 (WWW 2020), Taipei, China, 2020.
Xi Chen, Qiao Xiang, Linghe Kong, and Xue Liu, "RadioLoc: Learning Vehicle Locations with FM Signal in All-Terrain Environments", in Proc. of the 16th IEEE International Conference on Mobile Ad-Hoc and Smart Systems (IEEE MASS 2019) (Best Paper Award), Monterey, CA, USA, 2019.
Xi Chen, Chen Ma, Michel Allegue, and Xue Liu, "Taming the Inconsistency of Wi-Fi Fingerprints for Device-Free Passive Indoor Localization," in Proc. of the 36th Annual IEEE International Conference on Computer Communications (INFOCOM 2017), pp. 1-9, Atlanta, GA, 2017.(pdf) (ppt)
Linghe Kong, Xi Chen, Xue Liu, Qiao Xiang, Yi Gao, Noam Ben Baruch, Guihai Chen, "AdaSharing: Adaptive Data Sharing in Collaborative Robots", in IEEE Transactions on Industrial Electronics (TIE), vol. 64, no. 12, pp. 9569-9579, Dec. 2017.
Linghe Kong, Bowen Wang, Xi Chen, Xue Liu, Xiao-Yang Liu, Jiadi Yu, Guangtao Xue, Guihai Chen, "Joint adaptation framework in mobile ad hoc networks: A control theory perspective", in Elsevier Neurocomputing, vol. 270, pp. 66-74, 2017.
Yuan Yao, Xi Chen, Lei Rao, Xue Liu, and Xingshe Zhou, "LORA: Loss Differentiation Rate Adaptation Scheme for Vehicle-to-Vehicle Safety Communications", in IEEE Transactions on Vehicular Technology (TVT), vol. 66, no. 3, pp. 2499-2512, 2017.
Xi Chen, Lei Rao, Qiao Xiang, Xue Liu, and Fan Bai, "DRIVING: Distributed Scheduling for Video Streaming in Vehicular Wi-Fi Systems," in Proc. of ACM Multimedia Conference 2016 (ACM MM 2016), pp. 858-867, Amsterdam, Netherlands, 2016. (pdf)(ppt)
Xi Chen, Linghe Kong, Xue Liu, Lei Rao, Fan Bai and Qiao Xiang, "How Cars Talk Louder, Clearer and Fairer: Optimizing the Communication Performance of Connected Vehicles via Online Synchronous Control," in Proc. of the 35th Annual IEEE International Conference on Computer Communications (INFOCOM 2016), pp. 1-9, San Francisco, CA, U.S.A., 2016. (pdf)(ppt)
Landu Jiang, Xi Chen, and Wenbo He, "SafeCam: Analyzing Intersection-Related Driver Behaviors using Multi-Sensor Smartphones," in Proc. of the 14th IEEE International Conference on Pervasive Computing and Communications (PerCom 2016), pp. 1-9, Sydney, Australia, 2016. (pdf)
Hang Luo, Xue Liu, Xi Chen, Ting Long, and Ronghua Jiang, "Software Reliability Analysis Using Weakest Preconditions in Linear Assignment Programs", in IEEE Transactions on Software Engineering (TSE) vol. 42, no. 9, pp. 866-885, Sep. 1, 2016.
Qiao Xiang, Xi Chen, Linghe Kong, Lei Rao and Xue Liu, "Data Preference Matters: A New Perspective of Safety Data Dissemination in Vehicular Ad Hoc Networks," in Proc. of the 34th Annual IEEE International Conference on Computer Communications (INFOCOM 2015) , pp. 1149 - 1157, Hong Kong, China, 2015. (pdf)
Linghe Kong, Xi Chen, Xue Liu and Lei Rao, “FINE: Frequency-divided Instantaneous Neighbors Estimation System in Vehicular Networks,” in Proc. of the 13rd IEEE International Conference on Pervasive Computing and Communications (PerCom 2015) , pp. 172 - 177, St. Louis, Missouri, USA, 2015.
Qiao Xiang, Fanxin Kong, Xue Liu, Xi Chen, Linghe Kong and Lei Rao, "Auc2Charge: An Online Auction Framework for Eectric Vehicle Park-and-Charge," in Proc. of the 2015 ACM Sixth International Conference on Future Energy Systems (E-energy 2015), pp. 151-160, Bangalore, India, 2015.
Kai Xiong, Xi Chen, Lei Rao, Xue Liu and Yuan Yao, “Solving the Performance Puzzle of DSRC Multi-Channel Operations,” in Proc. of IEEE International Conference on Communications 2015 (ICC 2015), pp.3843-3848, 8-12, London, UK, 2015.
Xue Liu, Xi Chen and Fanxin Kong, "Utilization Control and Optimization of Real-Time Embedded Systems", Foundations and Trends® in Electronic Design Automation: Vol. 9: No. 3, pp 211-307, 2015.
Xi Chen, Lei Rao, Yuan Yao, Xue Liu and Fan Bai, "The Answer is Rolling on Wheels: Modeling and Performance Evaluation of In-cabin Wi-Fi Communications," in Elsevier Journal of Vehicular Communications, vol. 2, no. 1, pp. 13-26, Jan. 2015. (pdf)
Xi Chen, Lei Rao, Xue Liu, Hongxing Li and Xinbing Wang, “Right Time in Right Place: Taming Workload Balancing Oscillations in Internet Data Center Cost Management,” in Proc. of the 5th IEEE International Green Computing Conference (IGCC 2014), pp. 1 - 10, Dallas, TX, 2014.
Zhonghao Sun, Fanxin Kong, Xue Liu, Xingshe Zhou and Xi Chen, "Intelligent Joint Spatio-temporal Management of Electric Vehicle Charging and Data Center Power Consumption", in Proc. of the 5th IEEE International Green Computing Conference (IGCC 2014), pp. 1-8, Dallas, TX, 2014.
Zhenzhi Qian, Xiaohua Tian, Xi Chen, Wentao Huang, and Xinbing Wang, "Multicast Capacity in MANET with Infrastructure Support," in IEEE Transactions on Parallel and Distributed Systems (TPDS), vol.25, no.7, pp.1808 - 1818, July 2014.
Xi Chen, Wentao Huang, Xinbing Wang, and Xiaojun Lin, “Multicast Capacity in Mobile Wireless Ad Hoc Network with Infrastructure Support,” in Proc. of the 31st Annual IEEE International Conference on Computer Communications (INFOCOM 2012), Orlando, FL, 2012, pp. 271-279.
Xi Chen, Haike Yi, Hanwen Luo, Hui Yu, and Hailong Wang, "A novel CQI calculation scheme in LTELTE-A systems," in Proc. of 2011 International Conference on Wireless Communications and Signal Processing (WCSP), Nanjing, China, pp. 1-5, 2011.
Community Services
TPC member of INFOCOM 2021, 2022, 2023, 2024
TPC member of AAAI 2023
TPC member of NeurIPS 2023
TPC member of ICC 2020, 2021, 2022, 2023, 2024
TPC member of Globecom 2020, 2021, 2022, 2023
TPC member of PerCom 2022
TPC member of ICDCS 2021
Publicity Chair of IWQoS 2020.
Local Chair of the 2019 CPS-IoT week.
Projects involved
Decision-making foundation models, Superalignment
AI for net: Deep ML solutions for intelligent networks (2021-present, Huawei Noah's Ark Lab)
AI-5G: Deep RL solutions for smart 5G networks (2019-2021, Samsung AI Center)
AI-IoT: Deep ML solutions for smart IoT and indoor localization (2019-present, Samsung AI Center)
NLP: Deep NLP solutions for voice control on automobiles and IoT devices (2017-2019, Nuance Communication Inc.)
DSRC: Performance enhancement of vehicular communications (Dedicated Short Range Communication and mobile Wi-Fi) (2012 - 2017, McGill and General Motors);
Wi-Fi on wheels: Mobile Wi-Fi APs for In-vehicle Infotainment (2013 - 2017, McGill and General Motors);
Aerial: Device-free human activity recognition via wireless signals (2015 - 2017, Tandemlaunch, Aerial.ai and McGill);
Electric Vehicles: Optimization of energy-efficient EVs (2014 - 2017, CPS lab, McGill);
Cloud Energy: Energy/cost management for cloud computing systems in smart grid (2012 - 2015, CPS lab, McGill);
Skysensor: Real-time virtual link scheduling in AFDX network (2012 - 2013, McGill and Sponsors);
Limited feedback design of LTE/LTE-A system (2009-2012, SJTU and Sharp Co.);
Capacity scaling in mobile Ad Hoc network (2011-2012, SJTU).
Testbeds and demos
VSmart is a DSRC-enabled smart vehicle testbed established at CPS Lab, McGill University, and is partially supported by General Motors Company. (Testbed website, YouTube videos and slides)
Aerial can tell who you are, where you are and what you are doing, even if you don't carry any wearable devices, smartphones, nor cameras. As long as there are standard Wi-Fi signals in the air, aerial is good to go. (Check our Project website and YouTube video to see the magic!)
Miscellaneous
Prof. Luc Devroye's library (open to all McGill students)