Xuelong Hu Yitian Zhao Guan Sun Jiujun Zhang Chao Jiang Xingfang Huang Evaluation of different DEWMA schemes for monitoring the ratio of two normal random variables. 115994 2024 449 J. Comput. Appl. Math. https://doi.org/10.1016/j.cam.2024.115994 db/journals/jcam/jcam449.html#HuZSZJH24 streams/journals/jcam