What Makes Our Approach Distinctive
Physical AI systems operate through continuous interaction with the real world. They must understand human intent, perceive uncertain environments, predict future states, plan reliable actions, execute them through physical actuators, and continuously monitor whether their behavior remains safe.
Many Physical AI studies focus on robot architectures, demonstrations, or task-specific performance. We approach Physical AI safety from both modern learning theory and mathematical systems analysis.
Reliable perception from noisy, incomplete, corrupted or adversarial sensor observations supporting Physical AI under sensor degradation, communication failure, unfamiliar environments and deliberate attack.
Selected Publications
Kim et al., Local Geometry Attention for Time Series Forecasting under Realistic Corruptions, ICLR, 2026
Kim et al., Towards Undetectable Adversarial Attack on Time Series Classification, Information Sciences, 2025
Lee et al., Variational Cycle-Consistent Imputation Adversarial Networks for General Missing Patterns, Pattern Recognition, 2022
Kim and Lee, Nonlinear Dynamic Projection for Noise Reduction of Dispersed Manifolds, IEEE TPAMI, 2014
Learning temporal dynamics to predict future states and generate realistic trajectories supporting scenario synthesis, state reconstruction and simulation-based safety evaluation.
Selected Publications
Park et al., TimeBridge: Better Diffusion Prior Design with Bridge Models for Time Series Generation, KDD, 2026
Kim et al., Are Self-Attentions Effective for Time Series Forecasting?, NeurIPS, 2024
Park et al., Fast Sharpness-Aware Training for Periodic Time Series Classification and Forecasting, Applied Soft Computing, 2023
Kim et al., Self-Correcting Ensemble Using a Latent Consensus Model, Applied Soft Computing, 2016
Learning algorithms whose decisions stay dependable under adversarial perturbation, uncertainty and distribution shift — the learning theoretic foundation for reliable planning and risk-aware decisions.
Selected Publications
Kim et al., Fantastic Robustness Measures: The Secrets of Robust Generalization, NeurIPS, 2023
Lee et al., Implicit Jacobian Regularization Weighted with Impurity of Probability Output, ICML, 2023
Lee et al., GradDiv: Adversarial Robustness of Randomized Neural Networks via Gradient Diversity Regularization, IEEE TPAMI, 2022
Kim et al., Understanding Catastrophic Overfitting in Single-Step Adversarial Training, AAAI, 2021
Mathematical foundations for safe physical behavior: stability regions, unstable equilibria, nonlinear systems, trajectory-based optimization, homotopy methods and global optimization. This is what lets us state safe operating regions and failure boundaries mathematically.
Selected Publications
Lee et al., Trajectory-Based Method for Multiple Solutions in Nonlinear Programming, IEEE TAC, 2004
Lee, Optimization Framework for Computing the Controlling UEP, IEEE TAC, 2004
Lee et al., Stability Regions of Non-Hyperbolic Dynamical Systems, IEEE TCAS-I, 2002
Lee et al., Constructive Homotopy for Multiple DC Operating Points, IEEE TCAS-I, 2001
Lee, Trajectory-Informed Search for Global Optimization, Journal of Global Optimization, 2007
Monitoring deployed systems, identifying abnormal or unsafe behavior, explaining model decisions, and defending against security and privacy threats. The point is to connect detection and explanation to recovery, replanning and human oversight.
Selected Publications
Jeong et al., JoCE: Joint Counterfactual Explanations for Interpretable Time Series Anomaly Detection, Pattern Recognition, 2026
Choi et al.,Differentially Private Upsampling for Imbalanced Anomaly Detection , Engineering Applications of Artificial Intelligence, 2026
Byun et al., Privacy-Preserving Inference Resistant to Model Extraction Attacks, Expert Systems with Applications, 2024
From Robust Learning to Stable Physical Intelligence
Trustworthy AI is a system-wide layer supporting every stage of Physical AI: learning from sensitive data, reducing algorithmic bias, protecting deployed systems, adapting to new environments, and maintaining stable representations.
Our research develops the learning algorithms and mathematical foundations required to make this closed-loop intelligence robust, stable, privacy-preserving, explainable, and verifiable. We focus particularly on reliable perception under realistic corruption, predictive and generative modeling, robust and certifiable decision intelligence, dynamical-system stability, global optimization, and runtime safety assurance.
Physical AI collects sensitive visual, acoustic, behavioral, spatial and industrial data. We develop privacy preserving learning and inference based on differential privacy and homomorphic encryption, alongside fair learning that reduces group level disparity.
Selected Publications
Park et al., Multi-Class SVM with Differential Privacy, NeurIPS, 2025
Choi et al., Safeguarding Retrieval Data against Membership Inference Attacks, EMNLP, 2025
Park et al., Public Data Synthesis for Differentially Private Image Classification, CVPR, 2024
Choi et al., Fair Sampling in Diffusion Models, AAAI, 2024
Park et al., Differentially Private Sharpness-Aware Training, ICML, 2023
Mathematical and algorithmic methods that produce stable representations, robust cluster structures, transferable models, and reliable learning from limited or partially labeled data.
Selected Publications
Kim et al., Voronoi Cell-Based Clustering Using a Kernel Support, IEEE TKDE, 2015
Lee et al., Constructing Sparse Kernel Machines Using Attractors, IEEE TNN, 2009
Kim and Lee, Clustering Based on Gaussian Processes, Neural Computation, 2007
Lee and Lee, Equilibrium-Based SVM for Semi-Supervised Classification, IEEE TNN, 2007
Lee et al., Dynamic Characterization of Cluster Structures for Robust SVC, IEEE TPAMI, 2006
Earlier work in ensemble learning, large-scale data mining, Bayesian modeling, multimodal clustering, recommendation and information integration methodological foundations for heterogeneous-data analysis and data-driven decision support.
Selected Publications
Park et al., Inductive Ensemble Clustering Using Kernel Support Matching, Electronics Letters, 2017
Kim et al., Improved Churn Prediction by Analyzing a Large Network, Expert Systems with Applications, 2014
Park et al., Transductive Bayesian Regression via Manifold Learning, Expert Systems with Applications, 2012
Heo et al., Credit Delinquent Prediction Using Locally Transductive MLP, Neurocomputing, 2009
Cho et al., A Tandem Clustering Process for Multimodal Datasets, European Journal of Operational Research, 2006