Research Interests
My statistical research is stimulated by real-world challenges and aims at addressing real-world problems in physical sciences including remote sensing science and climate science, engineering science, and medical science. My research interest is focused on developing statistical methods for understanding physical and environmental processes. It spans the following areas of statistics and machine learning:
- Uncertainty Quantification (UQ): Computer model validation, computer model emulation, model discrepancy, Bayesian calibration
- Bayesian Statistics: Nonparametric Bayes, objective Bayes, Bayesian hierarchical modeling and computation, Bayesian variable selection, model uncertainty
- Spatial and Spatio-Temporal Statistics: Random fields, nonstationary space-time processes, dynamic spatio-temporal models, multivariate models, data fusion
I work with climate scientists and ocean scientists to address data analytic problems in remote sensing and coastal flood hazard studies. Motivated by such interdisciplinary collaboration, I recently focus on developing statistical methods that allow flexible model structures and scalable computations for analyzing big and complex data with spatial dependence and understanding their use in complex real-world applications including environmental mapping, probabilistic assessment of remote sensing retrievals, and risk assessment of storm surges. More specifically, they can be summarized into three directions:
- Bayesian multi-scale methods and tree-based methods for Gaussian process modeling and their theoretical properties;
- Bayesian-frequentist theoretical foundations on constructing covariance function models and their practical usefulness;
- Bayesian methods for emulating, calibrating, and validating complex computer models with high-dimensional/functional input and massive functional/spatial outputs.
Research Projects
Uncertainty Quantification for Remote Sensing
- Ma, P. and Bhadra, A. (2022) "Beyond Matérn: On A Class of Interpretable Confluent Hypergeometric Covariance Functions." Journal of the American Statistical Association, Theory and Methods. DOI:10.1080/01621459.2022.2027775.
- Ma, P., Mondal, A., Konomi, B. A., Hobbs, J., Song, J. J., and Kang, E. L. (2021) "Computer Model Emulation with High-Dimensional Functional Output in Large-Scale Observing System Uncertainty Experiments." Technometrics. DOI:10.1080/00401706.2021.1895890.
- Ma, P., Kang, E. L., Braverman, A., and Nguyen, H. (2019) "Spatial Statistical Downscaling for Constructing High-Resolution Nature Runs in Global Observing System Simulation Experiments." Technometrics, 61(3), 322-340.
Uncertainty Quantification for Coastal Flood Hazard Studies
- Ma, P., Karagiannis, G., Konomi, B. A., Asher, T. G., Toro, G. R., and Cox, A. T. (2022) "Multifidelity Computer Model Emulation with High-Dimensional Output: An Application to Storm Surge." Journal of the Royal Statistical Society: Series C. DOI:https://doi.org/10.1111/rssc.12558.
- Ma, P. (2020) "Objective Bayesian Analysis of a Cokriging Model for Hierarchical Multifidelity Codes." SIAM/ASA Journal on Uncertainty Quantification, 8(4), 1358-1382.