Harsh Sharma
I am a Postdoctoral Scholar working with Boris Krämer in the Department of Mechanical and Aerospace Engineering at UC San Diego. I am broadly interested in using ideas from mechanics and dynamical systems to develop computational analysis tools that can improve our understanding and prediction of complex dynamical systems. In my postdoctoral research, I am working on combining the perspectives of structure-preserving model reduction and machine learning to build physics-informed surrogate models of large-scale dynamical systems.
In August 2020, I completed my PhD in Aerospace Engineering at Virginia Tech, where I was jointly supervised by Mayuresh Patil and Craig Woolsey. My thesis developed a variety of structure-preserving algorithms for mechanical systems with external forcing and systems that evolve on non-Euclidean manifolds. I also obtained my MS in Mathematics at Virginia Tech where I worked under the guidance of Jeff Borggaard. During my graduate school, I spent two summers as a visiting research scholar at George Washington University working with Taeyoung Lee on developing structure-preserving methods on Lie groups. I obtained my dual degree (B.Tech + M.Tech) degree in Mechanical Engineering from IIT-Bombay in 2015.
Upcoming Events
January 06-10, 2025: I am excited to attend the ICERM workshop on Computational Learning for Model Reduction at Brown University in Providence, Rhode Island. Feel free to reach out if you are planning to attend the workshop and want to chat.
March 03-07, 2025: I look forward to attending the SIAM Conference on Computational Science and Engineering (CSE25) in Fort Worth, Texas where I will present my latest work on structure-preserving nonlinear model reduction via lifting transformations. I am also co-organizing a minisymposium on Structure-preserving Learning for Physical systems with Christine Allen-Blanchette from Princeton University.
Recent News
October 30, 2024: Our paper Data-driven Model Order Reduction for Soft Robots via Lagrangian Operator Inference (in collaboration with Michael Tolley's group from UC San Diego) is posted online. This work leverages the Lagrangian nature of soft robot models to derive structure-preserving reduced-order models via Lagrangian Operator Inference and compares their performance with prominent model reduction techniques through an anguilliform swimming soft robot model example with 231,336 degrees of freedom. The numerical results demonstrate that preserving the underlying Lagrangian mechanical structure leads to learned models with higher predictive accuracy and robustness to unseen inputs.
September 09-13, 2024: I presented our work on Lagrangian operator inference enhanced with structure-preserving machine learning for nonintrusive model reduction of mechanical systems at the Model Reduction and Surrogate Modeling (MORE) Conference in San Diego.
August 19-23, 2024: I attended the 26th International Symposium on Mathematical Theory of Networks and Systems (MTNS 2024) in Cambridge (UK) where I presented our recent work on Data-driven Model Order Reduction of Soft Robots via Lagrangian Operator Inference.
July 21-26, 2024: I had a great time at the 16th World Congress on Computational Mechanics in Vancouver where I presented our work on Symplectic Model Reduction of Hamiltonian Systems using Data-driven Quadratic Manifolds.
June 26-28, 2024: I attended a workshop on Mathematical and Statistical Foundations of Digital Twins in Chicago at the Institute for Mathematical and Statistical Innovation. We had great talks on foundational mathematical, statistical, and computational challenges to support complex applications of digital twins to scientific, engineering, medical, and societal problems.
June 21, 2024: Our paper Bayesian identification of nonseparable Hamiltonians with multiplicative noise using deep learning and reduced-order modeling has been accepted for publication in Computer Methods in Applied Mechanics and Engineering. This work presents a structure-preserving Bayesian framework for learning deep neural network parametrizations of complex mechanical systems from noisy data. This work is in collaboration with Alex Gorodetsky's group from the University of Michigan.
April 17, 2024: I presented our work on Data-driven Model Order Reduction for Soft Robots via Lagrangian Operator Inference at the Contextual Robotics Institute as part of the 7th IEEE-RAS International Conference on Soft Robotics (RoboSoft 2024).
March 14, 2024: Our paper Preserving Lagrangian structure in data-driven reduced-order modeling of large-scale dynamical systems (with Boris Kramer) is posted online at Physica D: Nonlinear Phenomena. This work presents a nonintrusive physics-preserving method to learn reduced-order models of Lagrangian mechanical systems and nonlinear wave equations. The numerical results demonstrate Lagrangian operator inference on an Euler-Bernoulli beam model, the sine-Gordon (nonlinear) wave equation, and a soft-robotic fishtail model with 779,232 degrees of freedom.
February 20, 2024: Our paper Lagrangian operator inference enhanced with structure-preserving machine learning for nonintrusive model reduction of mechanical systems has been accepted for publication in Computer Methods in Applied Mechanics and Engineering. This work presents an ML-enhanced model reduction method that learns structure-preserving ROMs of nonlinear mechanical systems from data in a nonintrusive manner. The proposed framework is well-suited for engineering applications where the data are generated from complicated high-fidelity computational models or experimental measurements. This work was done in collaboration with David Najera and Michael Todd from the Structural Engineering department at UCSD.
September 25- December 16, 2023: I had a great time teaching the graduate-level course on Numerical Methods for Linear Algebra and ODE Simulation (MAE 290A) during the Fall of 2023 at UC San Diego.
October 18, 2023: I gave a talk at the Optimization, Control, and Learning Seminar in the Electrical and Computer Engineering department at UCSD on the topic of "Structure-preserving Learning of Reduced-order Models for Large-scale Dynamical Systems".
September 14-15, 2023: I attended the Southern California Robotics Symposium 2023 at UC Irvine where Iman Adibnazari presented our work on Full-Body Optimal Control of a Swimming Soft Robot Enabled by Data-Driven Model Reduction. This work is based on our collaboration with Michael Tolley's group where we are using my work in data-driven structure-preserving model reduction for model predictive control of a soft anguilliform robot.
September 8, 2023: Our paper Symplectic model reduction of Hamiltonian systems using data-driven quadratic manifolds has been accepted for publication in Computer Methods in Applied Mechanics and Engineering. This work combines the expressiveness of quadratic approximation manifolds with projection-based model reduction that enforces symplecticity. The proposed approaches constitute a first step towards the model reduction of dynamical systems on nonlinear manifolds using interpretable manifold constructions that ensure that the approximate solution satisfies key physical properties of the high-dimensional problem.
August 13, 2023: I successfully completed the summer course on An Introduction to Evidence-Based STEM Undergraduate Teaching offered by the Center for the Integration of Research, Teaching, and Learning. This eight-week course focused on the implementation of evidence-based teaching strategies in university classrooms as well as effective methods for assessing teaching and learning. It was a great learning experience and I am looking forward to making use of the strategies and techniques covered in my teaching.
May 22- May 26, 2023: I presented our work on Lagrangian operator inference at Workshop and Conference: Nonlinear Model Reduction for Control at Virginia Tech. It was a great experience to go back to my alma mater and interact with researchers working on model reduction for control.
April 22, 2023: I presented our work on Physics-preserving Learning of Reduced-order Models for Large-scale Dynamical Systems at the Southern California Applied Mathematics Symposium 2023.
March 17, 2023: I presented our work (in collaboration with Nick Galioto and Alex Gorodetsky from the University of Michigan) on Bayesian System Identification at the Scientific Machine Learning Symposium 2023.
February 26- March 3, 2023: I presented our work on Lagrangian operator inference at SIAM Conference on Computational Science and Engineering (CSE23). I also co-organized a two-part minisymposium with Silke Glas and Boris Kramer on Structure-Preserving Model Reduction for Lagrangian and Hamiltonian Systems.
December 6-9, 2022: I presented our work (in collaboration with Nick Galioto and Alex Gorodetsky from the University of Michigan) on Bayesian Identification of Nonseparable Hamiltonian Systems Using Stochastic Dynamic Models at the 61st IEEE Conference on Decision and Control (CDC).
September 26-30, 2022: I presented our work on Lagrangian operator inference at SIAM Conference on Mathematics of Data Science (MDS22). I also co-organized a minisymposium with Molei Tao (from Georgia Tech) on Exploiting Hamiltonian Structure in Learning Dynamical System Models for Prediction and Control.
September 2022: Our paper Bayesian Identification of Nonseparable Hamiltonian Systems Using Stochastic Dynamic Models (with Nick Galioto, Alex Gorodetsky, and Boris Kramer) has been accepted for publication at the 61st IEEE Conference on Decision and Control (CDC). In this paper, we propose a probabilistic Bayesian formulation for system identification (ID) and estimation of nonseparable Hamiltonian systems using stochastic dynamic models.
August 1- September 6, 2022: I taught an upper-division course on Computational Methods in Engineering (MAE 107) during Summer Session 2 at UC San Diego. I had a great time teaching this course and interacting with undergraduate students. In my Course and Professor Evaluations (CAPE), I received an instructor rating of 96.7% (the departmental average instructor rating for this course is 75.38%).
August 18-19, 2022: I presented our work on Bayesian identification of nonseparable Hamiltonian systems using stochastic dynamic models at the USACM Thematic Conference on Uncertainty Quantification for Machine Learning Integrated Physics Modeling (UQ-MLIP).
June 2022: Our paper Performance Assessment of Energy-preserving, Adaptive Time-Step Variational Integrators (with Jeff Borggaard, Mayuresh Patil, and Craig Woolsey) has been accepted for publication in Communications in Nonlinear Science and Numerical Simulation. This work presents a numerical and theoretical assessment of energy-preserving, adaptive time-step variational integrators.
May 2022: I presented our recent work on Data-driven reduced-order modeling of large-scale mechanical systems at Southern California Applied Mathematics Symposium at Harvey Mudd College.
April 2022: Our group along with the Triton Rocket Club at UCSD participated in the Barrio Logan Science & Art Expo on Saturday, April 16. We had a great time representing UCSD MAE and talking to students about our research. The UCSD School of Engineering Blog has written a nice article about our outreach event.
April 2022: I presented our recent work on Preserving Lagrangian structure in data-driven reduced-order modeling of large-scale mechanical systems at the 39th Southern California Control Workshop at UC Irvine.
January 2022: Our paper Hermite-based, One-step, Variational and Galerkin Time Integrators for Mechanical Systems (with Mayuresh Patil and Craig Woolsey) is up on arXiv. This work presents Hermite polynomial based one-step variational and Galerkin methods for mechanical systems with external forcing.
December 2021: Our paper Hamiltonian Operator Inference: Physics-preserving Learning of Reduced-order Models for Canonical Hamiltonian Systems (with Zhu Wang and Boris Kramer) is posted online at Physica D: Nonlinear Phenomena. The paper shows how to learn reduced-order models for Hamiltonian systems from data only, and demonstrates this on a variety of nonlinear Hamiltonian models.
September 2021: I am speaking at MMLDT-CSET 2021 on Hamiltonian Operator Inference: Physics-preserving Learning of Low-dimensional Models for Hamiltonian Systems. This is joint work with Zhu Wang and Boris Kramer.
August 2021: I was invited to give a Computational Mathematics Seminar at the University of Pittsburgh on August 31.
Contact
Harsh Sharma
Postdoctoral Scholar
Department of Mechanical and Aerospace Engineering
University of California San Diego
Jacobs Hall (EBU1) | Room 4205
9500 Gilman Drive | La Jolla | CA 92093-0411
Email: hasharma at ucsd dot edu