This study investigates the opening force required for shucking farmed oysters to support the development of automated oyster-shucking systems. Oysters sourced from Yeosu and Tongyeong were tested for shell length, width, height, total weight, meat weight, and opening force. Results showed an average opening force of 8.1 kgf for one-year-old Yeosu oysters, 7.4 kgf for one-year-old Tongyeong oysters, and 8.7 kgf for two-year-old Tongyeong oysters, with correlations to shell width, height, and meat weight depending on production sea area and growing age. These findings highlight production sea area and growing age-based differences in oyster characteristics, contributing foundational data to advancing automation in oyster shucking.

In this study, the experiment was conducted on a fire door(W × H = 0.98 m × 2.19 m) installed on the vestibule. The effective leakage area for each opening angles and closing forces derived from the impulse-momentum equation was compared and analyzed with the experimental results. As a result of the experiment, the major factors affecting the door closing forces were the pressure difference and the area of the door. The difference of door closing forces between measured and calculated values by the impulse-momentum equation showed a deviation of less than ±15% at the opening angles of 5°to 10°. At the door opening angle of 2.5°, the dynamic pressure was much higher than the measured static pressure, and this pressure difference is estimated to be air resistance acting to prevent the door from being completely closed.