In recent years, the increasing number of indiscriminate attacks on passengers aboard trains has prompted many railway operators to install onboard inside-car monitoring cameras for security purposes. Detecting abnormal passenger scenarios from videos captured through these cameras is critical for enhancing railway safety. In this paper, we present a method to detect abnormal passenger scenarios using onboard camera footage. To evaluate the proposed method, we conducted filming tests on an operational train, simulating abnormal scenarios involving a knife-wielding individual. Performance evaluation results demonstrate the effectiveness of the proposed method.

In high-speed railways, the contact strips and horns mounted on the pantographs of trains are consumables because they wear down through contact with overhead wires, which requires frequent visual inspections. If an automatic inspection device to measure the thickness of contact strips and horns can be installed on the main line, such as at stations, it not only reduces labor but also significantly increases inspection frequency. Given this background, we developed a highly accurate method to measure the thickness of the contact strips on the pantographs of high-speed trains. The developed method employs a laser-based optical cutting technique and enables the device to conduct measurements while maintaining the required insulation distance from the overhead wires. In addition, we developed a noise-reduction algorithm to improve data quality, which confirms that our method achieves sufficient accuracy even at higher speeds (70km/h) compared to those of conventional methods. A prototype device installed at the entrance of a Tokaido Shinkansen station track demonstrated the effectiveness of the method.

This paper discusses the voltage-sharing characteristics of series-connected MOSFETs based on circuit analysis and experimental verification, focusing on the relationship between the load current and voltage deviation. The analysis reveals that the occurrence of the Miller plateau depends on the amount of the load current during the turn-on and/or -off. However, independent of the Miller plateau, the voltage deviation is related to the difference in the output capacitance between series-connected MOSFETs as well as in the other stray capacitance around the circuit. Therefore, a higher voltage is always applied across the lower MOSFET in the upper arm even when the MOSFETs are simultaneously turned off. Furthermore, the analysis derives the gate timing for suppressing the voltage deviation as a function of the load current. Experimental results verify the analysis using a buck converter consisting of two series-connected MOSFETs.