• Journal of IKEEE
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• v.26 no.2
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• pp.265-270
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• 2022

This paper proposes the detection algorithm for switch open fault of asymmetric 6-phase PMSM based on stationary reference frame dq-axis currents. In this paper, target motor has an asymmetric structure in which two upper three windings have an electrical phase difference of 30° and a neutral point is separated. As a result, dual 3-phase PWM inverters and the detection techniques due to open failures of switch are definitely required. In this paper, the dual dq-axis current control method is used for driving the asymmetric 6-phase PMSM and the open fault switch should be detected by using variable all pass filter and low pass filter in order to detect the current amplitude. The effectiveness and usefulness of the proposed method is verified by several experiments.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.249-259
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• 2014

This study has analyzed the factors that influence the safety consciousness of school bus drivers at Child Care Centers. To achieve this, 276 directors and drivers of owner-operator who drives the school bus at Child Care Centers in Chungnam, Chungbuk and Daejeon area were selected as study subjects. For the data analysis, PASW Statistics 18.0 was used. The main results of this study are as follows. The level of safety consciousness of directors and drivers of owner-operator were 6.46 and 6.82 respectively showing that drivers of owner-operator were significantly higher. Second, the factors that influence the safety consciousness were shown to be significantly different for each group. The factors that influence the safety consciousness of directors were shown in the order of whether or not the accident was experienced, safety-seeking motivation, sensation-seeking disposition, safety consciousness of caregivers, perception-motor skill. The factors that influence the safety consciousness of drivers of owner-operator were shown in the order of safety-seeking motivation, health status, daily driving hours, economic status, safety consciousness of caregivers. Based on these results, several ways were suggested to improve the safety consciousness of school bus drivers at Child Care Centers and prevent the traffic accidents.

• Journal of IKEEE
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• v.25 no.3
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• pp.485-492
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• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.