At the Joint Technical Meeting on Systems and Control of Electrical Engineers of Japan (IEEJ), the paper titled “Application of an Improved Discrete Spider Monkey Optimization Method Using a Dynamic Penalty Function That Partially Tolerates Constraint Violations to the Vending Machine Column Optimization Problem, Taking Sales and Replenishment Periods into Account,” authored by HASEGAWA Riko, a fourth-year student in the Department of Network Design at the School of Interdisciplinary Mathematical Sciences, Professor FUKUYAMA Yoshikazu and others, received the 2025 IEEJ Electronics, Information and Systems Research Group Encouragement Award.
This award is presented at meetings organized by its technical committee to young researchers aged 35 years or younger for outstanding paper presentations befitting young engineers.
The number of beverage vending machines (hereinafter, “vending machines”) installed in Japan has reached approximately 2.19 million, making them a common sight in everyday life. Inside each vending machine, there are multiple storage compartments called columns, and the number of items that can be stored in each column is predetermined.
In this paper, they propose a method for optimizing vending machine columns based on the improved discrete spider monkey optimization (DSMO) approach, a prior study, by introducing a dynamic penalty function and a scheme that allows for solutions violating constraints under certain conditions. The effectiveness of the proposed method was verified through simulation comparisons with conventional methods using actual data from five vending machines.
Author: HASEGAWA Riko, FUKUYAMA Yoshikazu, WATANABE Takuya, ISHIBASHI Naoto, IIZAKA Tatsuya
Title: “Application of an Improved Discrete Spider Monkey Optimization Method Using a Dynamic Penalty Function That Partially Tolerates Constraint Violations to the Vending Machine Column Optimization Problem, Taking Sales and Replenishment Periods into Account,” ST-25-062, CT-25-097, November 2025