Stefano Riva

Stefano Riva

Research Scientist specializing in Physics-Informed AI/ML for engineering and design. Proven track record in reduced-order models and data-driven state estimation, bridging traditional numerical solvers with machine learning to accelerate high-fidelity simulations.

Publications

In this page, you can find a selection of publications, including journal articles and conference contributions. In addition, the full list of journal articles, preprints and contributions to conferences and workshops is provided at the end of the page.

Selected Journal Articles

Selected Contributions to International Conferences

Common Task Framework For a Critical Evaluation of Scientific Machine Learning Algorithms

P. M. Wyder, J. A. Goldfeder, A. Yermakov, Y. Zhao, Stefano Riva, J. P. Williams, D. Zoro, A. S. Rude, M. Tomasetto, J. Germany, J. Bakarji, G. Maierhofer, M. Cranmer, J. N. Kutz ; The 39th Annual Conference on Neural Information Processing Systems (NeurIPS), Datasets and Benchmarks Track (2025)

This paper presents a common task framework for evaluating scientific machine learning algorithms, focusing on their application to complex dynamical systems.

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Selected Preprints

Full Lists

Full list of journal articles:

  1. Carolina Introini, Simone Cavalleri, Stefano Lorenzi, Stefano Riva, and Antonio Cammi, “Stabilization of Generalized Empirical Interpolation Method (GEIM) in presence of noise: A novel approach based on Tikhonov regularization,” Computer Methods in Applied Mechanics and Engineering, vol. 404, p. 115773, 2023. URL, doi:10.1016/j.cma.2022.115773.
  2. Carolina Introini, Stefano Riva, Stefano Lorenzi, Simone Cavalleri, and Antonio Cammi, “Non-intrusive system state reconstruction from indirect measurements: A novel approach based on Hybrid Data Assimilation methods,” Annals of Nuclear Energy, vol. 182, p. 109538, 2023. URL, doi:10.1016/j.anucene.2022.109538.
  3. Stefano Riva, Carolina Introini, Stefano Lorenzi, and Antonio Cammi, “Hybrid data assimilation methods, Part I: Numerical comparison between GEIM and PBDW,” Annals of Nuclear Energy, vol. 190, p. 109864, 2023. URL, doi:10.1016/j.anucene.2023.109864.
  4. Stefano Riva, Carolina Introini, Stefano Lorenzi, and Antonio Cammi, “Hybrid Data Assimilation methods, Part II: Application to the DYNASTY experimental facility,” Annals of Nuclear Energy, vol. 190, p. 109863, 2023. URL, doi:10.1016/j.anucene.2023.109863.
  5. Stefano Riva, Carolina Introini, and Antonio Cammi, “A finite element implementation of the incompressible Schrödinger flow method,” Physics of Fluids, vol. 36, no. 1, p. 017138, 2024. URL, doi:10.1063/5.0180356.
  6. Antonio Cammi, Stefano Riva, Carolina Introini, Lorenzo Loi, and Enrico Padovani, “Data-driven model order reduction for sensor positioning and indirect reconstruction with noisy data: Application to a Circulating Fuel Reactor,” Nuclear Engineering and Design, vol. 421, p. 113105, 2024. URL, doi:10.1016/j.nucengdes.2024.113105.
  7. Lorenzo Loi, Stefano Riva, Carolina Introini, Francesca Giacobbo, Xiang Wang, and Antonio Cammi, “OFELIA: An OpenMC-FEniCSx coupling for neutronic calculation with temperature feedback,” Nuclear Engineering and Design, vol. 428, p. 113480, 2024. URL, doi:10.1016/j.nucengdes.2024.113480.
  8. Stefano Riva, Carolina Introini, and Antonio Cammi, “Multi-physics model bias correction with data-driven reduced order techniques: Application to nuclear case studies,” Applied Mathematical Modelling, vol. 135, pp. 243-268, 2024. URL, doi:10.1016/j.apm.2024.06.040.
  9. M. Lo Verso, Stefano Riva, C. Introini, E. Cervi, F. Giacobbo, L. Savoldi, M. Di Prinzio, M. Caramello, L. Barucca, and A. Cammi, “Application of a non-intrusive reduced order modeling approach to magnetohydrodynamics,” Physics of Fluids, vol. 36, no. 10, p. 107167, 2024. URL, doi:10.1063/5.0230708.
  10. Stefano Riva, Carolina Introini, Enrico Zio, and Antonio Cammi, “Impact of Malfunctioning Sensors on Data-Driven Reduced Order Modelling: Application to Molten Salt Reactors,” EPJ Web Conf., vol. 302, p. 17003, 2024. URL, doi:10.1051/epjconf/202430217003.
  11. Matteo Lo Verso, Stefano Riva, Carolina Introini, Eric Cervi, Luciana Barucca, Marco Caramello, Matteo Di Prinzio, Francesca Giacobbo, Laura Savoldi, and Antonio Cammi, “Enhancing computational efficiency in nuclear fusion through reduced order modelling: Applications in magnetohydrodynamics,” Fusion Engineering and Design, vol. 216, p. 115080, 2025. URL, doi:10.1016/j.fusengdes.2025.115080.
  12. Stefano Riva, Carolina Introini, Antonio Cammi, and J. Nathan Kutz, “Robust state estimation from partial out-core measurements with Shallow Recurrent Decoder for nuclear reactors,” Progress in Nuclear Energy, vol. 189, p. 105928, 2025. URL, doi:10.1016/j.pnucene.2025.105928.
  13. Mahdi Nasr, Lorenzo Loi, Stefano Riva, AhmadReda Zolfaghari, Xiang Wang, and Antonio Cammi, “Enhancing multi-physics modeling in new-generation nuclear reactors using machine learning: Implementing Gaussian Process Regression for updating cross sections,” Annals of Nuclear Energy, vol. 224, p. 111720, 2025. URL, doi:10.1016/j.anucene.2025.111720.
  14. Stefano Riva, Sophie Deanesi, Carolina Introini, Stefano Lorenzi, and Antonio Cammi, “Real-Time State Estimation of Neutron Flux in Molten Salt Fast Reactors from Out-Core Sparse Measurements,” Nuclear Science and Engineering, vol. 0, pp. 1--14, 2025. URL, doi:10.1080/00295639.2025.2531477.
  15. Stefano Riva, Carolina Introini, Enrico Zio, and Antonio Cammi, “Data-driven reduced order modelling with malfunctioning sensors recovery applied to the Molten Salt Reactor case,” EPJ Nuclear Sci. Technol., vol. 11, p. 55, 2025. URL, doi:10.1051/epjn/2025054.
  16. Stefano Riva, Andrea Missaglia, Carolina Introini, In Cheol Bang, and Antonio Cammi, “A Comparative Study of Parametric Dynamic Mode Decomposition Algorithms on Thermal-Hydraulics Case Studies,” Nuclear Technology, vol. 0, pp. 1--25, 2026. URL, doi:10.1080/00295450.2025.2575701.
  17. Stefano Riva, Carolina Introini, and Antonio Cammi, “pyforce: Python Framework for data-driven model Order Reduction of multi-physiCs problems,” Journal of Open Source Software, vol. 11, no. 117, p. 6950, 2026. doi:10.21105/joss.06950.
  18. Matteo Lo Verso, Stefano Riva, Carolina Introini, Eric Cervi, Matteo Di Prinzio, Marco Caramello, Francesca Giacobbo, Laura Savoldi, and Antonio Cammi, “Parametric Dynamic Mode Decomposition for Nuclear Fusion: Applications to Magnetohydrodynamics,” IEEE Transactions on Plasma Science, pp. 1-6, 2026. doi:10.1109/TPS.2026.3682545.
  19. Mohammad Alrwashdeh, Carolina Introini, Stefano Riva, Xiang Wang, Francois Foulon, Khurrum Chaudri, Saeed Al Ameri, and Antonio Cammi, “Adaptive Parametric Reconstruction with the Generalised Empirical Interpolation Method on the DYNASTY Loop with Limited Instrumentation,” Nuclear Engineering and Technology, p. 104606, 2026. URL, doi:10.1016/j.net.2026.104606.
  20. Stefano Riva, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “Constrained Sensing and Reliable State Estimation with Shallow Recurrent Decoders on a TRIGA Mark II Reactor,” Chemical Engineering Science, p. 125037, 2026. URL, doi:10.1016/j.ces.2026.125037.

Full list of preprints:

  1. Stefano Riva, Andrea Missaglia, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “From Models To Experiments: Shallow Recurrent Decoder Networks on the DYNASTY Experimental Facility,” submitted to Nuclear Engineering and Design, 2026. arXiv:2503.08907.
  2. Stefano Riva, Carolina Introini, Antonio Cammi, Dean Price, Alexey Yermakov, Yue Zhao, Philippe M. Wyder, Judah A. Goldfeder, Jan P. Williams, Amy Sara Rude, Matteo Tomasetto, Joe Germany, Joseph Bakarji, Georg Maierhofer, Miles Cranmer, and J. Nathan Kutz, “CTF4Nuclear: Common Task Framework for Nuclear Fission and Fusion Models,” 2026. arXiv:2605.15549.
  3. Stefano Riva, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “Multi-Fidelity Learning with Shallow Recurrent Decoders for Multi-Physics Applications,” 2026. arXiv:2606.05202.
  4. Claudio Scardino, Stefano Riva, Carolina Introini, Matteo Lo Verso, Eric Cervi, Antonio Cammi, and Laura Savoldi, “Real-Time Monitoring of MHD Liquid Metal Flows with Shallow Recurrent Decoders,” 2026. arXiv:2608.28366.

Full list of contributions to international conferences:

  1. Stefano Riva, Antonio Cammi, Carolina Introini, and Stefano Lorenzi, “Hybrid Data Assimilation Methods: Application to the DYNASTY Experimental Facility,” in 13th International Topical Meeting of Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS), (Taipei, Taiwan), pp. 505-518, September 2022.
  2. Stefano Riva, Antonio Cammi, and Carolina Introini, “Inviscid Fluid Simulation through Incompressible Schrödinger Flow: a Finite Element approach,” in 31st International Conference Nuclear Energy for New Europe (NENE2022), (Portoroz, Slovenia), September 2022.
  3. Antonio Cammi, Stefano Riva, Carolina Introini, Lorenzo Loi, and Enrico Padovani, “Indirect Field Reconstruction and Sensor Positioning in Circulating Fuel Reactors using Data-Driven Model Order Reduction,” in 2023 International Congress on Advances in Nuclear Power Plants, (Gyeongju, Korea), April 2023.
  4. Stefano Riva, Carolina Introini, and Antonio Cammi, “Multi-Physics Model Correction with Data-Driven Reduced Order Modelling,” in 32nd International Conference Nuclear Energy for New Europe (NENE2023), (Portoroz, Slovenia), September 2023.
  5. Stefano Riva, Lorenzo Loi, Carolina Introini, Antonio Cammi, and Xiang Wang, “FEniCSx-OpenMC Coupling for Neutronic Calculation with Temperature Feedback,” in 32nd International Conference Nuclear Energy for New Europe (NENE2023), (Portoroz, Slovenia), September 2023.
  6. Lorenzo Loi, Stefano Riva, Carolina Introini, Antonio Cammi, and Enrico Padovani, “OpenMC Analysis of TRIGA Mark II Reactor Void and Temperature Reactivity Coefficients,” in 32nd International Conference Nuclear Energy for New Europe (NENE2023), (Portoroz, Slovenia), September 2023.
  7. Stefano Riva, Sophie Deanesi, Carolina Introini, Stefano Lorenzi, and Antonio Cammi, “Neutron Flux Reconstruction from Out-Core Sparse Measurements using Data-Driven Reduced Order Modelling,” in Proceedings of the International Conference on Physics of Reactors, PHYSOR 2024, pp. 1632 – 1641, 2024. doi:10.13182/PHYSOR24-43444.
  8. Lorenzo Loi, Stefano Riva, Carolina Introini, Enrico Padovani, Francesca Giacobbo, and Antonio Cammi, “An Alternative Approach for Group Constants Regression Based on Supervised Learning Techniques,” in Proceedings of the International Conference on Physics of Reactors, PHYSOR 2024, pp. 1674 – 1683, 2024. doi:10.13182/PHYSOR24-43521.
  9. Stefano Riva, Andrea Missaglia, Carolina Introini, In Cheol Bang, and Antonio Cammi, “A Novel Approach for Parametric Dynamic Mode Decomposition: Application to the DYNASTY Experimental Facility,” in The 14th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation, and Safety (NUTHOS-14), (Vancouver, Canada), August 2024. doi:10.13182/NUTHOS14-231.
  10. Cyrille De Lurion De L''Egouthail, Lorenzo Loi, Stefano Riva, Carolina Introini, and Antonio Cammi, “Shadowing Effect Correction for the Pavia TRIGA Reactor Using Monte Carlo Data and Reduced Order Modelling Techniques,” in The 33rd International Conference Nuclear Energy for New Europe (NENE2024), (Portoroz, Slovenia), September 2024.
  11. Riccardo Boccelli, Lorenzo Loi, Stefano Riva, Carolina Introini, Stefano Lorenzi, and Antonio Cammi, “Analysis of KRUSTY reactor behaviour with OFELIA environment,” in The 33rd International Conference Nuclear Energy for New Europe (NENE2024), (Portoroz, Slovenia), September 2024.
  12. Stefano Riva, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “Shallow Recurrent Decoders for State Estimation in Parametric Accidental Scenarios of Circulating Fuel Nuclear Reactors,” in 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21), (Busan, Korea), September 2025.
  13. Stefano Riva, Andrea Missaglia, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “Verification and Validation of Shallow Recurrent Decoders for State Estimation in the DYNASTY facility,” in 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21), (Busan, Korea), September 2025.
  14. Yifan Xu, Carolina Introini, Stefano Riva, Xiaobo Zeng, Minjun Peng, Yuanhui Wang, Genglei Xia, and Antonio Cammi, “Parametric Reduced-Order Modeling of Once-Through Steam Generators using Proper Orthogonal Decomposition and LSTM Neural Networks,” in 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21), (Busan, Korea), September 2025.
  15. Matteo Lo Verso, Stefano Riva, Carolina Introini, Eric Cervi, Francesca Giacobbo, Matteo Di Prinzio, Marco Caramello, Laura Savoldi, and Antonio Cammi, “Parametric Model Discovery in Magneto-Hydrodynamics,” in 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21), (Busan, Korea), September 2025.
  16. Philippe M. Wyder, Judah A. Goldfeder, Alexey Yermakov, Yue Zhao, Stefano Riva, Jan P. Williams, David Zoro, Amy Sara Rude, Matteo Tomasetto, Joe Germany, Joseph Bakarji, Georg Maierhofer, Miles Cranmer, and J. Nathan Kutz, “Common Task Framework For a Critical Evaluation of Scientific Machine Learning Algorithms,” in The 39th Annual Conference on Neural Information Processing Systems (NeurIPS), Datasets and Benchmarks Track, November 2025. URL: link.
  17. Alexey Yermakov, Yue Zhao, Marine Denolle, Yiyu Ni, Philippe M. Wyder, Judah A. Goldfeder, Stefano Riva, Jan P. Williams, David Zoro, Amy Sara Rude, Matteo Tomasetto, Joe Germany, Joseph Bakarji, Georg Maierhofer, Miles Cranmer, and J. Nathan Kutz, “The Seismic Wavefield Common Task Framework,” accepted, 2025. URL: link.
  18. Stefano Riva, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “State Estimation during Different Accidental Scenarios in a Molten Salt Fast Reactor with Shallow Recurrent Decoders from Out-Core Temperature Measurements,” in International Conference on the Physics of Reactors, PHYSOR 2026, (Turin, Italy), April 2026. doi:10.5281/zenodo.20804138.
  19. Stefano Riva, Carolina Introini, J. Nathan Kutz, and Antonio Cammi, “Multi-Fidelity Learning with Shallow Recurrent Decoders for Reactor Physics,” in International Conference on the Physics of Reactors, PHYSOR 2026, (Turin, Italy), April 2026. doi:10.5281/zenodo.20804140.
  20. Yantao Luo, Carolina Introini, Mahdi Nasr, Lorenzo Loi, Wang Xiang, Stefano Riva, and Antonio Cammi, “Verification and Validation of FVM-based Neutronic Solvers against TRIGA Mark II Reactor,” in International Conference on the Physics of Reactors, PHYSOR 2026, (Turin, Italy), April 2026. doi:10.5281/zenodo.20803584.
  21. Yantao Luo, Carolina Introini, Lorenzo Loi, Mahdi Nasr, Wang Xiang, Stefano Riva, and Antonio Cammi, “Preliminary Research on Spatial and Energy-group MGXS Homogenization for the TRIGA Mark II reactor,” in International Conference on the Physics of Reactors, PHYSOR 2026, (Turin, Italy), April 2026. doi:10.5281/zenodo.20803757.
  22. Sophie Deanesi, Davide Pizzocri, Stefano Riva, and Stefano Lorenzi, “A Perturbation Theory Based Analysis of Reactivity Feedbacks during a ULOHS Transient in Molten Salt Reactors,” in International Conference on the Physics of Reactors, PHYSOR 2026, (Turin, Italy), April 2026. doi:10.5281/zenodo.20803347.

Full list of contributions to workshops and other conferences:

  1. Stefano Riva, Carolina Introini, Luca Marocco, Laura Savoldi, and Antonio Cammi, “Inclusion of the buoyancy forces in the Incompressible Schrödinger Flow algorithm to simulate inviscid fluids,” in 41st UIT International Heat Transfer Conference, (Naples, Italy), June 2024.
  2. Stefano Riva, Carolina Introini, Xiang Wang, and Antonio Cammi, “Advection-Diffusion of Scalars with the Incompressible Schrödinger Flow,” in The 14th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation, and Safety (NUTHOS-14), (Vancouver, Canada), August 2024.
  3. Carolina Introini, Stefano Riva, Lorenzo Loi, Xiang Wang, and Antonio Cammi, “Learning the dynamics of un-observable fields from out-core measurements of simple fields using Supervised Learning,” in The 11th International Symposium on Symbiotic Nuclear Power: AI Application in Nuclear Systems (ISSNP2024), (Harbin, Heilongjiang, China), September 2024.
  4. Carolina Introini, Stefano Riva, Lorenzo Loi, Xiang Wang, and Antonio Cammi, “State estimation in the DYNASTY experimental facility using Supervised Learning,” in The 11th International Symposium on Symbiotic Nuclear Power: AI Application in Nuclear Systems (ISSNP2024), (Harbin, Heilongjiang, China), September 2024.
  5. Philippe M. Wyder, Judah A. Goldfeder, Alexey Yermakov, Yue Zhao, Stefano Riva, Jan P. Williams, David Zoro, Amy Sara Rude, Matteo Tomasetto, Joe Germany, Joseph Bakarji, Georg Maierhofer, Miles Cranmer, and J. Nathan Kutz, “Common Task Framework For a Critical Evaluation of Scientific Machine Learning Algorithms,” in Championing Open-source DEvelopment in ML Workshop @ ICML25, 2025. URL: link.
  6. Carolina Introini, Claudio Stecchetti, Stefano Riva, Antonio Cammi, Francois Foulon, and Mohammad Alrwashdeh, “Dynamics of the Molten Salt Fast Reactor Through Parametric Dynamic Mode Decomposition,” in The 2nd Saudi International Conference on Nuclear Power Engineering (SCOPE), (Dhahran, Saudi Arabia), November 2025.
  7. Stefano Riva, Carolina Introini, Antonio Cammi, Xiang Wang, Francois Foulon, and Mohammad Alrwashdeh, “Development of a Buoyancy-Driven Incompressible Schrodinger Flow Algorithm for Inviscid Flows,” in The 2nd Saudi International Conference on Nuclear Power Engineering (SCOPE), (Dhahran, Saudi Arabia), November 2025.
  8. Antonio Cammi, Carolina Introini, Stefano Riva, Xiang Wang, Francois Foulon, and Mohammad Alrwashdeh, “Robust Model Identification for Pressurized Water Reactor Systems using Sparse Identification of Nonlinear Dynamics,” in The 2nd Saudi International Conference on Nuclear Power Engineering (SCOPE), (Dhahran, Saudi Arabia), November 2025.
  9. Carolina Introini, Stefano Riva, Antonio Cammi, Xiang Wang, Francois Foulon, and Mohammad Alrwashdeh, “The Data-Driven Reduced Order Modelling Framework: Application on the DYNASTY Experimental Facility,” in The 2nd Saudi International Conference on Nuclear Power Engineering (SCOPE), (Dhahran, Saudi Arabia), November 2025.
  10. Stefano Riva, Carolina Introini, Matteo Lo Verso, J. Nathan Kutz, and Antonio Cammi, “Robust Monitoring of Nuclear Reactors from Sparse Sensors using Shallow Recurrent Decoders,” in The 17th World Congress on Computational Mechanics & 10th European Congress on Computational Methods in Applied Sciences and Engineering, July 2026.
  11. Matteo Lo Verso, Carolina Introini, Stefano Riva, J. Nathan Kutz, and Antonio Cammi, “Application of Shallow Recurrent Decoder Networks for parametric state reconstruction of magnetohydrodynamic flows in liquid metal blankets of fusion reactors,” in The 17th World Congress on Computational Mechanics & 10th European Congress on Computational Methods in Applied Sciences and Engineering, July 2026.
  12. Yantao Luo, Carolina Introini, Stefano Riva, Xiang Wang, and Antonio Cammi, “Reduced-Order Modeling for Sensor Placement in the TRIGA Mark II Research Reactor under Region Accessibility Constraints,” in 10th International Conference on Reliability Engineering (ICRE2026), (Hangzhou, China), July 2026.
  13. Paolo Conti, Elisea \"Ozalp, Stefano Riva, and J. Nathan Kutz, “Data-driven reduced-order modeling with latent geometry encoding for inverse design,” These authors contributed equally to this work and are listed in alphabetical order, 2026.