Optimizing Biomarkers from Earbud Ballistocardiogram: Calibration and Calibration-Free Algorithms for Accelerometer Axis Selection and Fusion. - Yunzhi Li; Md. Mahbubur Rahman; Mehrab Bin Morshed; Md Saiful Islam; Hao Zhou; Weinan Wang; Holland Ernst; Li Zhu 004; Jilong Kuang (ICASSP, 2025)