Publications

2025
Dual-View Spectral-Temporal Graph Fusion with Adaptive Edge Learning and Divergence Scoring for Incipient Fault Detection
R. Wijethunga, A. Sadhu, J. Samarabandu
Information Fusion (IF ~15.5) — Under review
GNN Time-Series Anomaly Detection Information Fusion
Abstract

Graph neural networks have advanced unsupervised fault detection in industrial multivariate time series by modeling inter-sensor dependencies. However, existing methods operate exclusively in the time domain, relying on a single dependency graph that neither exploits complementary frequency-domain signatures nor captures structural disagreement across representation spaces. This paper proposes DualSTGF, an information fusion framework that jointly learns temporal and spectral dependency graphs for incipient fault detection. Jensen-Shannon divergence between dual-view attention distributions serves as both a structural training regularizer and an inference-time anomaly indicator.

2025
Robust and efficient dual-graph neural networks for structural damage detection
R. Wijethunga, J. Samarabandu, A. Sadhu
Engineering Structures, 2025
GNN Structural Health Anomaly Detection
Abstract

This paper presents a dual-graph neural network architecture for robust structural damage detection. The approach leverages both spatial and spectral graph representations to detect anomalies in structural health monitoring data, demonstrating improved robustness to noise and sensor failures compared to existing methods.

2025
Evaluating the Robustness of Counterfactual Generating Methods for Tree-based Ensembles
R. Wijethunga, V. Galwaduge, A. Sadhu, J. Samarabandu
IEEE Canadian Journal of Electrical and Computer Engineering (CJECE) — Minor revision
XAI Counterfactuals Tree Ensembles
Abstract

This work evaluates the robustness of counterfactual explanation methods designed for tree-based ensemble models. We propose metrics and benchmarks to assess how stable and actionable generated counterfactuals remain under perturbations and model updates.

2025
A Novel Objective Function for Counterfactual Explanations Using Conic Optimization
V. Galwaduge, R. Wijethunga, A. Sadhu, J. Samarabandu
7th International Conference on Advancements in Computing (ICAC), IEEE, 2025
XAI Counterfactuals Conic Optimization
Abstract

Counterfactual explanations are an effective method of explaining the decisions made by machine learning models to end-users. However, it is crucial to ensure that certain qualities of counterfactuals such as plausibility and proximity are satisfied. This paper proposes a novel objective function using conic optimization to generate high-quality counterfactual explanations that balance plausibility and proximity.

2025
Expert evaluation system for pothole defect detection
P. Singh, R. Wijethunga, A. Sadhu, J. Samarabandu
Expert Systems with Applications, 2025
Computer Vision Defect Detection Expert Systems
Abstract

An expert evaluation system for automated pothole defect detection using image analysis and machine learning. The system integrates domain expert knowledge with deep learning models to provide reliable assessment of road surface conditions.

2024
Precision leak detection in supermarket refrigeration systems integrating categorical gradient boosting
R. Wijethunga, H. Nouraei, C. Zych, J. Samarabandu, A. Sadhu
Energies, 2024
CatBoost Time-Series Anomaly Detection
Abstract

This study presents a precision leak detection framework for supermarket CO2 refrigeration systems using categorical gradient boosting. The method leverages multi-sensor time-series data to detect refrigerant leaks early, reducing environmental impact and maintenance costs.