L V OngW L TeohM B C KhooZ L ChongW C Yeong2024-10-282024-10-282018-11https://doi.org/10.1088/1742-6596/1132/1/012084https://dspace-cris.utar.edu.my/handle/123456789/5090A study on the variable sampling interval EWMA bar chart when the process parameters are unknownjournal-article