• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.295-302
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• 2002

This study addresses some solutions of the technical problem of using e-money systems. The solutions are on/off line e-money, one card, ordering system, and card-card settlement system etc. The alternatives are described as source code in the example of Angel Plus e-money. E-money is classified as IC card(off-line) type and net work(on-line) type. But, They should be integrated. End-users want to use the combined card for its conveniences. This research introduces on/off line e-money with a case study. On the basis of this paper, future research is to be further conducted on the Customer-oriented e-money with multiple functions.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.22-33
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• 2013

Currently average daily traffic using Hi-pass has increased over 3 times that of 2008 and more than half of highway traffic now uses High-pass. At this juncture, reassessment on the overall operation of Hi-pass is required to improve the safety aspect of toll booths and the flow of traffic. Although existing Hi-pass operation manual presents the methods of alignment, they do not reflect actual forms of vehicles and do not properly take the safety of toll booth and flow of the traffic into consideration. In order to compensate these problems, this study classifies highway tollbooths into two categories of mainline type and interchange type, and establishes the standard of lane alignment by traffic conflict analysis based on the types divided according to geometric structure or environment around the tollbooths. In addition, traffic flows around the tollbooths were reflected with the stage to arrange Hi-pass lanes according to the volume of traffic on the lanes for Hi-pass.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.