Unpikul, B., Khanapang, T., Pachsila, P., Auipako , W., & Junlabuddee, P. (2026). Design and Development of a Semi-Automatic Robusta Coffee Bean Sorting Machine with Optimal Operating Conditions Determined by Response Surface Methodology. Thai Industrial Engineering Network Journal, 12(1). retrieved from https://ph02.tci-thaijo.org/index.php/ienj/article/view/265032