• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.1-7
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• 2021

This study attempted to detect possible collapse and fire accidents in facilities for disaster monitoring of large facilities, and to develop a customized beacon to recognize the internal situation of an IoT-based facility when a disaster occurs. In the case of data measurement using the existing strain gauge sensor, the strain gauge sensor was connected by wire to measure it, but this study changed it to wireless so that the presence and absence of structural deformation can be monitored in real time. In this process, in order to use the Wheatstone bridge, a strain sensor module that can be connected to a customized beacon was manufactured, and a system configuration was conducted to remotely check the measurement data. To verify measurement data, 10 customized beacons and 2 gateways were installed on the 15th floor of the Advanced Institue of Convergence Technology, and as a result of analysis of measurement data, it was confirmed that the strain data values were distributed between 7 and 8.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.10
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• pp.825-829
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• 2015

Theoretical calculations suggest that the thermoelectric figure of merit (ZT) can be improved by introducing a core-shell heterostructure to a semiconductor nanowire because of the reduced thermal conductivity of the nanowire. To experimentally verify the decrease in thermal conductivity in core-shell nanowires, the thermal conductivity of Ge-SixGe1-x core-shell nanowires grown by chemical vapor deposition (CVD) was measured using suspended microdevices. The silicon composition (Xsi) in the shells was measured to be about 0.65, and the remainder of the germanium in the shells was shown to play a role in decreasing defects originating from the lattice mismatch between the cores and shells. In addition to the standard four-point current- voltage (I-V) measurement, the measurement configuration based on the Wheatstone bridge was attempted to enhance the measurement sensitivity. The measured thermal conductivity values are in the range of 9-13 W/mK at room temperature and are lower by approximately 30 than that of a germanium nanowire with a comparable diameter.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.77-82
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• 2017

In the splay manufacturing process, conveyor systems are widely used for conveying panels. In this conveyor, a large number of grounding lines are used in order to prevent a product failure due to static electricity. In many cases, the grounding line is disconnected due to the rotation of the transporting roller or curling, leading to product failure. In order to solve such a problem, there is a growing need for a system capable of detecting disconnection of a ground wire in real time. Therefore, in this paper, we propose a disconnection monitoring system of ESD (Electro-Static Discharge) ground wire caused by friction between the conveyor drive part and the panel. The proposed system is a monitoring system that can detect disconnection and disconnection of ground wire using ATmega 2560 and Wheatstone Bridge circuit. It can detect disconnection of ground wire immediately and can take measures to reduce the defect rate due to static electricity. The system proposed in this paper is expected to be applicable to the production and test equipments of all industries where the ground wire is used.