• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.466-471
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• 2017

Pantograph must be correctly attached to catenary to continuously supply stable power to railway vehicle, and the device used here is Auxiliary Air Compressor (ACM). The existing ACM used the DC motor that included commutator and brush. Since maintenance and repair by mechanical friction are essential for the DC motor, BLDC motor studies have been conducted to improve this. A three-phase BLDC motor does $120^{\circ}$ two-phase commutation through hall sensors in general. However, since hall sensor is vulnerable to heat and can run only when all three sensors work normally, sensorless control method has been studied to solve this. Using back EMF Zero Crossing Point (ZCP) detection method, this paper will introduce a stable switching sensing method that has a non-commutation area in a low speed zone.

• Journal of the Korean Regional Science Association
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• v.36 no.2
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• pp.3-12
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• 2020

Recently, metropolitanization and suburbization have been occurring mainly in large cities, and spatial miss-match between residential and employment areas has increased. Spatial miss-match is different in the metropolitan cities and other metropolitan cities in Korea. Seoul and other metropolitan cities have grown to become centers of business functions, while other metropolitan cities have been transformed into residential function centers. Accordingly, The reverse commuting phenomenon is occurring in the rural metropolitan. The reverse commuting phenomenon limits the employment opportunities of specific classes among urban residents, and cause various problems such as environmental pollution and traffic congestion. Therefore, many studies on spatial mismatch and reverse commuting have been conducted, but a number of studies have been conducted on the Seoul metropolitan area, and research on other metropolitan areas is insufficient. The purpose of this study is to analyze the cause of the commuting phenomenon in the metropolitan area of the non-metropolitan area by considering spatial mismatch and understanding the reverse commutation situation in the local metropolitan area. This study is analyzed by a multi-level model and suggests the need for management of industrial location and expansion of residence in suburban.