Sai Tej Paruchuri

Research Scientist in Plasma Control and Nonlinear Systems

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Publications

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Journal Articles

  1. Shabbir, Khadija; Leard, Brian; Wang, Zibo; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio MMMnet: A Neural Network Surrogate for Real-Time Transport Prediction Based on the Updated Multi-Mode Model, Plasma, Vol. 8, No. 3, 2025. DOI
  2. Paruchuri, Sai Tej; Ward, Ian; Rist, Nicholas; Graber, Vincent; Al Khawaldeh, Hassan; Wang, Zibo; Schuster, Eugenio; Pajares, Andres; Juhn, June-Woo Density Regulation with Disruption Avoidance in Next-Generation Tokamaks Using a Safe Reinforcement Learning-Based Controller, Fusion Engineering and Design, Vol. 216, p. 115064, 2025. DOI
  3. Paruchuri, Sai Tej; Pajares, Andres; Schuster, Eugenio Lyapunov-Based Nonlinear Control of Nonautonomous Systems with Individual Input Constraints, Automatica, Vol. 173, p. 111998, 2025. DOI
  4. Morosohk, Shira; Wang, Zibo; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Optimal Control of the Electron Temperature Profile in DIII-D Using Machine Learning Surrogate Models, Fusion Engineering and Design, Vol. 206, p. 114615, 2024. DOI
  5. Leard, Brian; Wang, Zibo; Paruchuri, Sai Tej; Schuster, Eugenio; Rafiq, Tariq Hybrid Model Predictive Control Techniques for Safety Factor Profile and Stored Energy Regulation While Incorporating NBI Constraints, Nuclear Fusion, Vol. 64, No. 8, p. 086052, 2024. DOI
  6. Niu, Shengyuan; Bouland, Ali; Wang, Haoran; Fotiadis, Filippos; Kurdila, Andrew; L’Afflitto, Andrea; Paruchuri, Sai Tej; Vamvoudakis, Kyriakos G. Convergence Rates of Online Critic Value Function Approximation in Native Spaces, IEEE Control Systems Letters, pp. 1–1, 2024. DOI
  7. Kurdila, Andrew J.; Paruchuri, Sai Tej; Powell, Nathan; Guo, Jia; Bobade, Parag; Estes, Boone; Wang, Haoran Approximation of Discrete and Orbital Koopman Operators over Subsets and Manifolds, Nonlinear Dynamics, Vol. 112, No. 8, pp. 6291–6327, 2024. DOI
  8. Paruchuri, Sai Tej; Pajares, Andres; Rafiq, Tariq; Schuster, Eugenio Nonlinear Control of the Minimum Safety Factor in Tokamaks by Optimal Allocation of Spatially Moving Electron Cyclotron Current Drive, Fusion Engineering and Design, Vol. 207, p. 114612, 2024. DOI
  9. Song, Xiao; Leard, Brian; Wang, Zibo; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Control-Oriented Free-Boundary Equilibrium Solver for Tokamaks, Plasma, Vol. 7, No. 4, pp. 842–857, 2024. DOI
  10. Paruchuri, Sai Tej; Graber, Vincent; Pajares, Andres; Schuster, Eugenio Static Actuator-Sharing Algorithm for Concurrent Control of Multiple Plasma Properties, Plasma Physics and Controlled Fusion, Vol. 67, No. 1, p. 015005, 2024. DOI
  11. Paruchuri, Sai Tej; Graber, V.; Khawaldeh, H. A.; Schuster, E. Dynamic Actuator Allocation via Reinforcement Learning for Concurrent Plasma Control Objectives, IEEE Transactions on Plasma Science, Vol. 52, No. 9, pp. 4140–4146, 2024. DOI
  12. Morosohk, S.; Wang, Z.; Paruchuri, Sai Tej; Rafiq, T.; Schuster, E. Simultaneous Control of the Electron Temperature and Safety Factor Profiles in DIII-D Using Model-Based Optimal Control Techniques, Plasma Physics and Controlled Fusion, Vol. 67, No. 1, p. 015012, 2024. DOI
  13. Leard, Brian R.; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Fast Model-Based Scenario Optimization in NSTX-U Enabled by Analytic Gradient Computation, Fusion Engineering and Design, Vol. 192, p. 113606, 2023. DOI
  14. Paruchuri, Sai Tej; Schuster, Eugenio Nonlinear Control of Safety Factor Gradient in Tokamaks Using Spatially Variable Electron Cyclotron Current Drives, Fusion Engineering and Design, Vol. 194, p. 113914, 2023. DOI
  15. Al Khawaldeh, Hassan; Leard, Brian; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Model-Based Linear–Quadratic–Integral Controller for Simultaneous Regulation of the Current Profile and Normalized Beta in NSTX-U, Fusion Engineering and Design, Vol. 192, p. 113795, 2023. DOI
  16. Paruchuri, Sai Tej; Wang, Zibo; Rafiq, Tariq; Schuster, Eugenio Model Predictive Current Profile Control in Tokamaks by Exploiting Spatially Moving Electron Cyclotron Current Drives, Fusion Engineering and Design, Vol. 192, p. 113796, 2023. DOI
  17. Burns, John; Estes, Boone; Guo, Jia; Kurdila, Andrew; Paruchuri, Sai Tej; Powell, Nathan Kernel Methods for Regression in Continuous Time over Subsets and Manifolds, Nonlinear Dynamics, Vol. 111, No. 14, pp. 13165–13186, 2023. DOI
  18. Paruchuri, Sai Tej; Guo, J.; Kurdila, A. Sufficient Conditions for Parameter Convergence Over Embedded Manifolds Using Kernel Techniques, IEEE Transactions on Automatic Control, Vol. 68, No. 2, pp. 753–765, 2023. DOI
  19. Bouland, A.; Niu, S.; Paruchuri, Sai Tej; Kurdila, A.; Burns, J.; Schuster, E. Rates of Convergence in a Class of Native Spaces for Reinforcement Learning and Control, IEEE Control Systems Letters, pp. 1–1, 2023. DOI
  20. Guo, Jia; Kepler, Michael E.; Paruchuri, Sai Tej; Wang, Hoaran; Kurdila, Andrew J.; Stilwell, Daniel J. Adaptive Estimation of External Fields in Reproducing Kernel Hilbert Spaces, International Journal of Adaptive Control and Signal Processing, Vol. 36, No. 8, pp. 1931–1957, 2022. DOI
  21. Paruchuri, Sai Tej; Guo, Jia; Kurdila, Andrew Kernel Center Adaptation in the Reproducing Kernel Hilbert Space Embedding Method, International Journal of Adaptive Control and Signal Processing, Vol. 36, No. 7, pp. 1562–1583, 2022. DOI
  22. Paruchuri, Sai Tej; Guo, Jia; Kurdila, Andrew Reproducing Kernel Hilbert Space Embedding for Adaptive Estimation of Nonlinearities in Piezoelectric Systems, Nonlinear Dynamics, Vol. 101, No. 2, pp. 1397–1415, 2020. DOI
  23. Paruchuri, Sai Tej; Malladi, Vijaya V.N. Sriram; Tarazaga, Pablo A.; Kurdila, Andrew J. Expanding the Teaching of Single Frequency Vibration Absorption to Broadband Attenuation Using Subordinate Oscillator Arrays via Fettuccine Pasta, Engineering Structures, Vol. 224, p. 111201, 2020. DOI
  24. Sterling, John; Paruchuri, Sai Tej; Ryan, Teresa Jean; Vignola, Joseph; Kurdila, Andrew J Subordinate Oscillator Arrays: Physical Design and Effects of Error, engrxiv preprint https://doi.org/10.31224/osf.io/kpv3r, 2020. DOI
  25. Kurdila, Andrew J; Guo, Jia; Paruchuri, Sai Tej; Bobade, Parag Persistence of Excitation in Reproducing Kernel Hilbert Spaces, Positive Limit Sets, and Smooth Manifolds, arXiv preprint arXiv:1909.12274, 2019.
  26. Guo, J.; Dadashi, S.; Bender, M.; Paruchuri, Sai Tej; Powell, N.; Sharma, Y.; Kurdila, H.; McGlothlin, J. W.; Kurdila, A. J. Probabilistic Error Bounds on Constraint Violation for Empirical-Analytical Lagrangian Models of Motion, Nonlinear Dynamics, Vol. 98, No. 1, pp. 195–213, 2019. DOI
  27. Paruchuri, Sai Tej; Sterling, John; Malladi, Vijaya V N Sriram; Kurdila, Andrew; Vignola, Joseph; Tarazaga, Pablo Passive Piezoelectric Subordinate Oscillator Arrays, Smart Materials and Structures, Vol. 28, No. 8, p. 085046, 2019. DOI
  28. Sterling, John A.; Vignola, Joseph F.; Ryan, Teresa J.; Paruchuri, Sai Tej Analysis of Increased Damping in Arrays of Attached Resonators, The Journal of the Acoustical Society of America, Vol. 145, No. 3, pp. 1824–1824, 2019. DOI

Conference Proceedings

  1. Wang, Z.; Paruchuri, Sai Tej; Schuster, E. Safety Factor Profile Control in EAST via Reinforcement-Learning-Based Model Predictive Control, in 2025 IEEE Conference on Control Technology and Applications (CCTA), pp. 832–837, 2025. DOI
  2. Powell, N.; Paruchuri, Sai Tej; Bouland, A.; Niu, S.; Kurdila, A. Invariance and Approximation of Koopman Operators in Native Spaces, in 2024 American Control Conference (ACC), pp. 2871–2878, 2024. DOI
  3. Wang, Z.; Paruchuri, Sai Tej; Yang, L.; Schuster, E. Safety Factor Profile Regulation via Self-Triggered Model Predictive Control in the EAST Tokamak, in 2024 American Control Conference (ACC), pp. 2545–2550, 2024. DOI
  4. Paruchuri, Sai Tej; Pajares, Andres; Schuster, Eugenio Nonlinear Local Control of the Safety-Factor-Profile Gradient at Moving Spatial Locations in Tokamak Plasmas, in 2023 American Control Conference (ACC), pp. 1590–1595, 2023. DOI
  5. Burns, John A.; Guo, Jia; Kurdila, Andrew J.; Paruchuri, Sai Tej; Wang, Haoran Error Bounds for Native Space Embedding Observers with Operator-Valued Kernels, in 2023 American Control Conference (ACC), pp. 4796–4801, 2023. DOI
  6. Paruchuri, Sai Tej; Pajares, A.; Schuster, E. Lyapunov-Based Current-Profile Feedback Control in Tokamaks with Nonsymmetric Individual Actuator Saturation, in 2023 American Control Conference (ACC), pp. 1377–1382, 2023. DOI
  7. Paruchuri, Sai Tej; Schuster, Eugenio Distributed Regulation of the Safety Factor Profile in Tokamaks Using Nonlinear Infinite-dimensional Control, in 22nd IFAC World Congress, pp. 4466–4471, 2023. DOI
  8. Paruchuri, Sai Tej; Pajares, Andres; Schuster, Eugenio Minimum Safety Factor Control in Tokamaks via Optimal Allocation of Spatially Moving Electron Cyclotron Current Drive, in 2021 60th IEEE Conference on Decision and Control (CDC), pp. 454–459, 2021. DOI
  9. Aulisa, E.; Burns, J. A.; Gilliam, D. S.; Paruchuri, Sai Tej Accurate Approximate Regulation of Nonlinear Delay Differential Control Systems, in 2021 60th IEEE Conference on Decision and Control (CDC), pp. 422–427, 2021. DOI
  10. Burns, John A.; Paruchuri, Sai Tej; Schmidt, Michael Output Regulation of Systems Governed by Delay Differential Equations: Approximations and Robustness, in 24th International Symposium on Mathematical Theory of Networks and Systems MTNS 2020, pp. 422–427, 2021. DOI
  11. Guo, J.; Paruchuri, Sai Tej; Kurdila, A. J. Persistence of Excitation in Uniformly Embedded Reproducing Kernel Hilbert (RKH) Spaces, in 2020 American Control Conference (ACC), pp. 4539–4544, 2020. DOI
  12. Guo, J.; Paruchuri, Sai Tej; Kurdila, A. J. Approximations of the Reproducing Kernel Hilbert Space (RKHS) Embedding Method over Manifolds, in 2020 59th IEEE Conference on Decision and Control (CDC), pp. 1596–1601, 2020. DOI
  13. Paruchuri, Sai Tej; Guo, J.; Kepler, M.; Ryan, T.; Wang, H.; Kurdila, A. J.; Stilwell, D. Intrinsic and Extrinsic Approximation of Koopman Operators over Manifolds, in 2020 59th IEEE Conference on Decision and Control (CDC), pp. 1608–1613, 2020. DOI
  14. Sterling, John; Vignola, Joseph; Gietl, Jenna; Ryan, Teresa; Sonne, Noah; Paruchuri, Sai Tej Effect of Increased Damping in Subordinate Oscillator Arrays, in Journal of Physics: Conference Series, pp. 012006, 2018. DOI
  15. Paruchuri, Sai Tej; Kurdila, Andrew; Vignola, Joseph Estimation of Distribution Errors in Piezoelectric Subordinate Oscillator Arrays, in SMASIS2018, 2018. DOI
  16. Paruchuri, Sai Tej; Sterling, John; Kurdila, Andrew; Vignola, Joseph Piezoelectric Composite Subordinate Oscillator Arrays and Frequency Response Shaping for Passive Vibration Attenuation, in 2017 IEEE Conference on Control Technology and Applications (CCTA), pp. 702–707, 2017. DOI
  17. Paruchuri, Sai Tej; Kurdila, Andrew J.; Sterling, John; Vignola, Amelia; Judge, John; Vignola, Joe; Ryan, Teresa Thermodynamic Variational Formulations of Subordinate Oscillator Arrays (SOA) With Linear Piezoelectrics, in IDETC-CIE2017, 2017. DOI

Conference Abstracts

  1. Paruchuri, Sai Tej; Schuster, Eugenio Reference Governor for Plasma Scalar Control to Prevent Stability Limit Breaches in Tokamaks, 30th IAEA Fusion Energy Conference, Chengdu, China, 2025.
  2. Paruchuri, Sai Tej; Al Khawaldeh, Hassan; Graber, Vincent R.; Schuster, Eugenio; Pajares, Andres; Juhn, June-woo Nonlinear Adaptive Control of Deuterium-Tritium Density Ratio in ITER, Bulletin of the American Physical Society, Long Beach, California, USA, 2025.
  3. Paruchuri, Sai Tej; Al Khawaldeh, Hassan; Graber, Vincent; Wang, Zibo; Rist, Nicholas; Ward, Ian; Rafiq, Tariq; Schuster, Eugenio; Pajares, Andres; Juhn, June-woo Assessing Model-based and Learning-based Strategies for Active Density Regulation in ITER, Bulletin of the American Physical Society, Atlanta, Georgia, USA, 2024.
  4. Shabbir, Khadija; Leard, Brian; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio A Neural Network Version of the Multi-Mode Model for Fast Simulations in DIII-D, Bulletin of the American Physical Society, Atlanta, Georgia, USA, 2024.
  5. Rist, Nicholas; Paruchuri, Sai Tej; Schuster, Eugenio Reinforcement Learning-Based Control of the Safety Factor Profile and Normalized Beta in Tokamaks, Bulletin of the American Physical Society, Atlanta, Georgia, USA, 2024.
  6. Al Khawaldeh, Hassan; Paruchuri, Sai Tej; Graber, Vincent; Rafiq, Tariq; Schuster, Eugenio; Pajares, Andres; Juhn, June-woo Advanced Density Regulation for ITER-emulated Scenarios on DIII-D via Adaptive Control Techniques, Bulletin of the American Physical Society, Atlanta, Georgia, USA, 2024.
  7. Ward, Ian; Graber, Vincent; Rist, Nicholas; Paruchuri, Sai Tej; Schuster, Eugenio Burn Control in ITER Using a Reinforcement Learning Approach, Bulletin of the American Physical Society, Atlanta, Georgia, USA, 2024.
  8. Al Khawaldeh, Hassan; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Model-Based Control of the Dimensionless Gain in KSTAR by Leveraging Real-time Estimation of the Confinement Time, Bulletin of the American Physical Society, Denver, Colorado, USA, 2023.
  9. Wang, Zibo; Paruchuri, Sai Tej; Morosohk, Shira; Schuster, Eugenio Current Profile Control in EAST via Reinforcement-Learning-based Model Predictive Control, Bulletin of the American Physical Society, Denver, Colorado, USA, 2023.
  10. Morosohk, Shira; Wang, Zibo; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Simultaneous Regulation of the Electron Temperature and Safety Factor Profiles for DIII-D Using Optimal Control Methods, Bulletin of the American Physical Society, Denver, Colorado, USA, 2023.
  11. Paruchuri, Sai Tej; Schuster, Eugenio Incorporating Gas Puffing Delays into Density Control Synthesis in Tokamak Reactors By Combining Optimal Control and Reinforcement Learning Techniques, Bulletin of the American Physical Society, Denver, Colorado, USA, 2023.
  12. Leard, Brian; Wang, Zibo; Paruchuri, Sai Tej; Schuster, Eugenio; Rafiq, Tariq Incorporating Pulse Width Modulation Constraints Arising in Neutral Beam Injection, 29th IAEA Fusion Energy Conference, London, United Kingdom, 2023.
  13. Yang, Lixing; Al Khawaldeh, Hassan; Paruchuri, Sai Tej; Song, Xiao; Wang, Zibo; Schuster, Eugenio Towards Density Profile Regulation via Pellet Injection in Tokamaks Using Hybrid Model Predictive Control, 29th IAEA Fusion Energy Conference, London, United Kingdom, 2023.
  14. Al Khawaldeh, Hassan; Paruchuri, Sai Tej; Wang, Zibo; Rafiq, Tariq; Schuster, Eugenio Simultaneous Optimal Regulation Of Kinetic+Magnetic Scalar Plasma Properties For Robust Sustainment Of Advanced Scenarios In NSTX-U, 29th IAEA Fusion Energy Conference, London, United Kingdom, 2023.
  15. Paruchuri, Sai Tej; Graber, Vincent; Pajares, Andres; Schuster, Eugenio Actuator-Sharing Algorithm For Simultaneous Regulation Of Multiple Plasma Properties With Coupled Dynamics, 29th IAEA Fusion Energy Conference, London, United Kingdom, 2023.
  16. Paruchuri, Sai Tej; Schuster, Eugenio Model-Based Safety-Factor-Profile Slope Control at Predefined Rational Surfaces in DIII-D, Bulletin of the American Physical Society, Spokane, Washington, USA, 2022.
  17. Al Khawaldeh, Hassan; Leard, Brian; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Model-Based Optimal Control of Core Kinetic+ Magnetic Profiles and Scalar Plasma Properties in NSTX-U, Bulletin of the American Physical Society, Spokane, Washington, USA, 2022.
  18. Wang, Haoran; Burns, John; Guo, Jia; Kurdila, Andrew; Paruchuri, Sai Tej; Powell, Nathan Koopman Operators and Inverse Problems, IEICE Proceedings Series, 2022.
  19. Morosohk, Shira; Paruchuri, Sai Tej; Wang, Zibo; Rafiq, Tariq; Schuster, Eugenio Robust Control of the Electron Temperature Profile in DIII-D, Bulletin of the American Physical Society, Spokane, Washington, USA, 2022.
  20. Yang, Lixing; Paruchuri, Sai Tej; Schuster, Eugenio Electron Density Profile Regulation with Pellet Injection Using Self-trigger Model Predictive Control, Bulletin of the American Physical Society, Spokane, Washington, USA, 2022.
  21. Elango, Murugappan; Annamalai, Adithyan; Paruchuri, Sai Tej Harmonic Analysis on Axial Turbine Blades, Recent Advances in Computational and Experimental Mechanics, Vol—I, Singapore, 2022.
  22. Leard, Brian; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Towards In-Between-Discharges Model-Based Scenario Planning in NSTX-U Via Fast Nonlinear Optimization, Bulletin of the American Physical Society, Pittsburgh, Pennsylvania, USA, 2021.
  23. Morosohk, Shira; Wang, Zibo; Pajares, Andres; Paruchuri, Sai Tej; Rafiq, Tariq; Schuster, Eugenio Simultaneous Electron Temperature and Safety Factor Profile Control for DIII-D, Bulletin of the American Physical Society, Pittsburgh, Pennsylvania, USA, 2021.
  24. Paruchuri, Sai Tej; Pajares, Andres; Rafiq, Tariq; Schuster, Eugenio Control of the Local Gradient and the Minimum Value of the Safety Factor Profile by Using Moving ECCD, Bulletin of the American Physical Society, Pittsburgh, Pennsylvania, USA, 2021.
  25. Neighborgall, Campbell R.; Kothari, Karan; Sriram Malladi, V. V. N.; Tarazaga, Pablo; Paruchuri, Sai Tej; Kurdila, Andrew Shaping the Frequency Response Function (FRF) of a Multi-Degree-of-Freedom (MDOF) Structure Using Arrays of Tuned Vibration Absorbers (TVA), Topics in Modal Analysis & Testing, Volume 8, Cham, 2020.
  26. Sterling, John; Paruchuri, Sai Tej; Tarazaga, Pablo; Vignola, Joseph; Kurdila, Andrew; Malladi, Vijaya V. N. Sriram; Ryan, Teresa Piezoelectric Subordinate Oscillator Arrays: Performance Recovery and Robustness to Uncertainty, IDETC-CIE2019, Volume 8: 31st Conference on Mechanical Vibration and Noise, 2019.
  27. Vignola, Joseph; Judge, John; Sterling, John; Ryan, Teresa; Kurdila, Andrew; Paruchuri, Sai Tej; Glean, Aldo On the Use of Shunted Piezo Actuators for Mitigation of Distribution Errors in Resonator Arrays, Proceedings of the 22nd International Congress on Acoustics, Buenos Aires, 2016.