• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.665-672
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• 2023

Purpose: Underground utility tunnel is facility that is jointly house infrastructure such as electricity, water and gas in city, causing condensation problems due to lack of airflow. This paper aims to prevent electricity leakage fires caused by condensation by detecting whether the control panel door in the underground utility tunnel is open using a deep learning model. Method: YOLO, a deep learning object recognition model, is trained to recognize the opening and closing of the control panel door using video data taken by a robot patrolling the underground utility tunnel. To improve the recognition rate, image augmentation is used. Result: Among the image enhancement techniques, we compared the performance of the YOLO model trained using mosaic with that of the YOLO model without mosaic, and found that the mosaic technique performed better. The mAP for all classes were 0.994, which is high evaluation result. Conclusion: It was able to detect the control panel even when there were lights off or other objects in the underground cavity. This allows you to effectively manage the underground utility tunnel and prevent disasters.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.70-73
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• 2013

Solubility of oil contaminants in surfactant solutions plays an important role in selecting a suitable surfactant type for soil remediation. Solubility measurement procedures consist of making an equilibrium between surfactant solution and oil, solvent extraction using dichloromethane, and condensation for gas chromatography analysis. Solubility measurement requires time consumption and lots of materials. Interfacial tension is the contracting force between two immiscible liquids, surfactant solution and oil, and also closely related to solubility of oil. This study established a relationship between the interfacial tension and solubility of diesel fuel in surfactant solution and suggested a quick method to estimate solubility of oil in a surfactant solution by measuring its interfacial tension. The results of this study showed that the solubility of diesel fuel in surfactant solution was exponentially increased by decreasing the interfacial tension between two immiscible liquids. The solubility of diesel fuel was significantly increased under the interfacial tension conditions below 1 dyne/cm, while the solubility change was not apparent under the interfacial tension conditions beyond 5 dyne/cm. Interfacial tension measurements may allow us to quickly select an efficient surfactant and its concentration for soil remediation.