People
XU Yunjian 徐云建
Associate Professor
yjxu@mae.cuhk.edu.hk
TEL: 852 - 3943 1333
Room 301A, 3/F, Academic Building No. 1

Yunjian Xu is an associate professor at the Mechanical and Automation Engineering department, the Chinese University of Hong Kong (CUHK). He was an assistant professor at the Singapore University of Technology and Design (SUTD) in 2013-2017, and a postdoctoral scholar at the Center for the Mathematics of Information of the California Institute of Technology (Caltech) in 2012-2013.

He completed his PhD degree at the Laboratory for Information and Decision Systems of Massachusetts Institute of Technology (MIT) in 2012. He obtained bachelor and master degrees in Electrical Engineering from Tsinghua University, Beijing, China. Dr. Xu was a recipient of the MIT-Shell Energy Fellowship.

Research Interests
  • Stochastic optimal control
  • Safe reinforcement learning
  • Power system optimization and control
  • Mechanism design for electricity markets
Teaching
Publications

Selective Conference Papers (* corresponding authors)

  1. Z. Yang, Y. Xu*, and Y. Zhang, Q-supervised contrastive representation: A state decoupling framework for safe offline reinforcement learning, The International Conference on Machine Learning (ICML), 2025.
  2. Z. Yang, X. Luo*, D. Han, Y. Xu*, and D. Li, 2025. Mitigating hallucinations in large vision-language models via DPO: On-policy data hold the key, The IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2025. (Oral presentation)
  3. Y. Li, S. Mao, J. Gao, N. Jiang, Y. Xu, Q. Cai, F. Pan, P. Jiang, and B. An, GAS: Generative auto-bidding with post-training search, International World Wide Web Conference 2025 (WWW2025).
  4. Z. Yang, and Y. Xu*, DMBP: Diffusion model-based predictor for robust offline reinforcement learning against state observation perturbations. The Twelfth International Conference on Learning Representations (ICLR). 2024.

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Journal Papers 

  1. Y. Wang, W. Wang, K. Zhang, Y. Xu*, and R. Su, Risk-constrained linear quadratic control with one-step delayed sharing information pattern. Automatica, 174, p.112093, 2025.
  2. C. Wang, Y. Xu*, K. Pang, M. Shahidehpour, Q. Wang, G. Wang, and F. Wen, Imposing fine-grained synthetic frequency response rate constraints for IBR-rich distribution system restoration, IEEE Trans. on Power Systems, 40(3), pp. 2799-2802, 2025.
  3. Y. Wang, M. Lv, Z. Wu, Y. Xu, N. Guan, and R. Su, Risk-constrained LQR design framework for non-Gaussian interconnected systems defined over a digraph, IEEE Trans. on Automatic Control, 70(5), pp. 3510-3517, 2025.
  4. J. Jin, and Y. Xu, Optimal differentiated threshold characterization for multi-task stochastic deadline scheduling with queuing. Automatica, 163, p.111545, 2024.
  5. S. Mao, J. Jin, and Y. Xu, Routing and charging scheduling for EV battery swapping systems: Hypergraph-based heterogeneous multiagent deep reinforcement learning. IEEE Trans on Smart Grid, 15(5), pp. 4903-4916, 2024.
  6. W. Liu, Q. Wang, and Y. Xu*, Traffic toll design for dynamic wireless charging in coupled power-transportation networks: a tri-level optimization approach. IEEE Trans. on Smart Grid, 15(5), pp. 4877-4889, 2024.
  7. W. Liu, X. Wang, and Y. Xu*, Bilevel planning of wireless charging lanes in coupled transportation and power distribution networks, IEEE Trans. on Transportation Electrification, 10(2), pp. 2499-2510, 2024.
  8. W. Zhang, Y. Chen*, R. Xie, and Y. Xu*, A multi-timescale and chance-constrained energy dispatching strategy of integrated heat-power community with shared hybrid energy storage. Journal of Energy Storage, 97, p.112505, 2024.
  9. J. Jin, S. Mao, and Y. Xu*, Optimal priority rule enhanced deep reinforcement learning for charging scheduling in an electric vehicle battery swapping station, IEEE Trans. on Smart Grid, 14(6), pp. 4581-4593, 2023.
  10. S. Mao, Y. Wang, Q. Guan, and Y. Xu*, Structural charging and replenishment policies for battery swapping charging system operation under uncertainty, IEEE Trans. on Intelligent Transportation Systems, 24(12), pp. 14598-14609, 2023
  11. W. Liu, Y. Xu, J. Liu, W. Yin, Y. Hou, and Z. Yang, Energy and reserves haring considering uncertainty and communication resources, IEEE Internet of Things Journal, early access, 2023.
  12. L. Hao and Y. Xu*, Semi-supervised learning-based occupancy estimation for real-time energy management using ambient data, IEEE Internet of Things Journal, 10(20), pp. 18426-18437, 2023
  13. W. Zhang, Y. Chen*, Yi Wang, and Y. Xu*, Equilibrium analysis of a peer-to-peer energy trading market with shared energy storage in a power transmission grid, Energy, 274, 2023.
  14. Q. Huang, Y. Xu*, and C. A. Courcoubetis, Strategic production and trading in renewable energy certificate markets: Existence, uniqueness, and efficiency of market equilibria, IEEE Trans. on Network Science and Engineering, early access, 2023.
  15. J. Jin and Y. Xu*, Shortest path based deep reinforcement learning for EV charging routing under stochastic traffic condition and electricity prices, IEEE Internet of Things Journal, 9(22), pp. 22571-22581, 2022.
  16. T. Zhao, H. Yi, M. Chen, C. Wu, and Y. Xu, Efficient and robust equilibrium strategies of utilities in day-ahead market with load uncertainty, IEEE Systems Journal, 16(4), pp. 5246-5257, 2022.
  17. L. Hao, J. Jin, and Y. Xu*, Laxity differentiated pricing and deadline differentiated threshold scheduling for a public electric vehicle charging station, IEEE Trans. on Industrial Informatics, 18(9), pp. 6192-6202, 2022.
  18. J. Jin and Y. Xu*, Optimal policy characterization enhanced proximal policy optimization for multi-task scheduling in cloud computing, IEEE Internet of Things Journal, 9(9), pp. 6418-6433, 2022.
  19. L. Hao, Y. Xu*, and L. Tong, Asymptotically optimal index policies for deadline scheduling with processing rate limits, IEEE Trans. on Automatic Control, 67(1), pp. 236-250, 2022.
  20. J. Jin and Y. Xu*, Optimal policy characterization enhanced actor-critic approach for electric vehicle charging scheduling in a power distribution network, IEEE Trans. on Smart Grid, 12(2), pp. 1416-1428, 2021.
  21. J. Jin, L. Hao, Y. Xu*, J. Wu, and Q.-S. Jia, Joint scheduling of deferrable demand and storage with random supply and processing rate limits, IEEE Trans. on Automatic Control, 66(11), pp. 5506-5513, 2021.
  22. Q. Huang, Y. Xu*, and C. Courcoubetis, Strategic storage operation in wholesale electricity markets: A networked Cournot game analysis, IEEE Trans. on Network Science and Engineering, 8(2), pp. 1789-1801, 2021.
  23. J. Jin and Y. Xu*, Segregated linear decision rules for distributionally robust control with linear dynamics and quadratic cost, IEEE Systems Journal, 15(1), pp. 355-364, 2021.
  24. J. Jin, Y. Xu*, and Z. Yang, Optimal deadline scheduling for electric vehicle charging with energy storage and random supply, Automatica, 119, pp. 109096, 2020.
  25. Q. Huang, Y. Xu*, and C. Courcoubetis, Stackelberg competition between merchant and regulated storage investment in wholesale electricity markets, Applied Energy, 264, pp. 114669, 2020.
  26. S. Chen, Z. Gao, Z. Yang, Y. Xu, and R. Cheng, A game theoretic approach to phase balancing by plug-in electric vehicles in the smart grid, IEEE Trans. on Power Systems, 35(3), pp. 2232-2244, 2020.
  27. Q. Huang, Y. Xu*, and C. Courcoubetis, Financial incentives for joint storage planning and operation in energy and regulation markets, IEEE Trans. on Power Systems, 34(5), pp. 3326-3339, 2019.
  28. T. Wang, Y. Xu*, C. Withanage, L. Lan, S. Ahipasaoglu, and C. Courcoubetis, A fair and budget-balanced incentive mechanism for energy management in buildings, IEEE Trans. on Smart Grid, 9(4), pp. 3143- 3153, 2018.
  29. J. Jin, Y. Xu*, Y. Khalid, and N. Khan, Optimal Operation of Energy Storage with Random Renewable Generation and AC/DC Loads, IEEE Trans. on Smart Grid, 9(3), pp. 2314-2326, 2018.
  30. Q. Huang, Y. Xu*, and C. Courcoubetis, Market Mechanisms for Cooperative Operation of Pricemaker Energy Storage in a Power Network, IEEE Trans. on Power Systems, 33(3), pp. 3013-3028, 2018.
  31. Z. Yu, Y. Xu, and L. Tong, Deadline scheduling as restless bandits, IEEE Trans. on Automatic Control, 63(8), pp. 2343-2358, 2018.
  32. Y. Xu and L. Tong, Optimal Operation and Economic Value of Energy Storage at Consumer Locations, IEEE Trans. Automatic Control, 62(2), pp. 792-807, 2017. (A preliminary version was presented at the 53rd IEEE CDC, December 2014.)
  33. E. Bitar* and Y. Xu*, Deadline Differentiated Pricing of Deferrable Electric Loads, IEEE Trans. on Smart Grid, 8(1), pp. 13-25, 2017.
  34. J. Jin and Y. Xu*, Optimal Storage Operation under Demand Charge, IEEE Trans. on Power Systems, 32(1), pp. 795-808, 2017.
  35. Y. Xu and S. Low, An Efficient and Incentive Compatible Mechanism for Wholesale Electricity Markets, IEEE Trans. Smart Grid, 8(1), pp. 128-138, 2017.
  36. S. Kwon, Y. Xu*, and N. Gautam, Meeting Inelastic Demand in Systems with Storage and Renewable Sources, IEEE Trans. Smart Grid, 8(4), pp. 1619-1629, 2017. (A preliminary version was presented at the 5th IEEE SmartGridComm, November 2014.)
  37. Y. Xu and K. Ligett, Commitment in First-Price Auctions, Economic Theory, pp. 1-41, 2017.
  38. R. Thirumalaivasan, M. Janaki, and Y. Xu*, Kalman Filter Based Detection and Mitigation of Subsynchronous Resonance with SSSC, IEEE Trans. on Power Systems, 32(2), pp. 1400-1409, 2017.
  39. R. Thirumalaivasan, Y. Xu*, and M. Janaki, Power Control with Z-Source Converter based Unified Power Flow Controller, IEEE Trans. on Power Electronics, 32(12), pp. 9413-9423, 2017.
  40. T. Wang, Y. Xu*, S. Ahipasaoglu, and C. Courcoubetis, Ex-post Max-min Fairness of Generalized AGV Mechanisms, IEEE Trans. on Automatic Control, 62(10), pp. 5275-5281, 2017.
  41. W. Tushar, T. Wang, Y. Xu, C. Withanage, C. Yuen, and K. Wood, Policy Design for Controlling Set-point Temperature of ACs in Shared Spaces of Buildings, Energy and Buildings, 134, pp. 105-114, 2017.
  42. Y. Xu, N. Li, and S. Low, Demand Response with Capacity Constrained Supply Function Bidding, IEEE Trans. Power Systems, 31(2), pp. 1377-1394, 2016.
  43. Y. Xu, F. Pan, and L. Tong, Dynamic Scheduling for Charging Electric Vehicles: A Priority Rule, IEEE Trans. Automatic Control, 61(12), pp. 4094-4099, 2016. (A preliminary version was presented at the 51st IEEE CDC, December 2012.)
  44. S. Lakshminarayana, Y. Xu*, H. V. Poor, and T. Quek, Cooperation of Storage Operation in a Power Network with Renewable Generation, IEEE Trans. on Smart Grid, 7(4), pp. 2108-2122, 2016.
  45. Y. Xu, C. Shi, and I. Duenyas, Priority Rules for Multi-Task Due-date Scheduling Under Varying Processing Costs, Production and Operations Management, 25(12), pp. 2086-2102, 2016.
  46. J. N. Tsitsiklis and Y. Xu*, Pricing of Fluctuations in Electricity Markets, European Journal of Operational Research, 246(1), pp. 199-208, 2015. (A preliminary version was presented at the 51th IEEE CDC, December 2012.)
  47. S. Bose, C. Wu, Y. Xu, H. Mohsenian-Rad, and A. Wierman, Unifying Measure for Market Power in Deregulated Electricity Markets, IEEE Trans. Power Systems, 30(5), pp. 2338-2348, 2015.
  48. J. N. Tsitsiklis and Y. Xu*, Efficiency Loss in a Cournot Oligopoly with Convex Market Demand, Journal of Mathematical Economics, 53, pp. 46-58, 2014.
  49. J. Anselmi, D. Ardagna, J. C.S. Lui, A. Wierman, Y. Xu*, and Z. Yang, The Economics of the Cloud: Price Competition and Congestion, ACM SIGecom Exchanges, 13(1), pp. 58-63, 2014.
  50. J. N. Tsitsiklis and Y. Xu*, Profit Loss in Cournot Oligopolies, Operations Research Letters, 41(4), pp. 415-420, 2013.