Ihsan, M. et al. 2026. Hybrid random forest–catboost ensemble for heart disease prediction on imbalanced datasets: Toward applications in military health systems. International Journal of Applied Mathematics, Sciences, and Technology for National Defense. 4, 1 (Apr. 2026), 71–82. DOI:https://doi.org/10.58524/app.sci.def.v4i1.1148.