• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.223-225
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• 2007

The contact-less inductive power transformer (IPT) uses principle of electromagnetic induction. Generally, there were many methods to improve the transfer performance of traditional transformer. But, though the principle of IPT is similar to that of general transformer, it is impossible to apply the methods because of large air-gap. Consequently, many linear numerical formulas for analysis of performance and design of traditional transformer cannot be used in development of IPT. The concept of the IPT for vehicle like PRT(Personal Rapid Transit) system is suggested and some suggestions for power collector(core & winding) design of IPT to improve power transfer performance arc presented in this paper. The characteristic of power delivery with these novel methods in design is presented by simulation and examination.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.172-183
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• 1998

The purpose of this study is to reduce the number of employees hired by Seoul Metropolitan Subway Corporation(SMSC) as a way of responding to deteriorating financial deficit problem. For the reduction, the personnel structure of Seoul Metro Rapid Transit Subway(SMRTS) newly founded in 1995 is benchmarked. Several assumptions are set for seeking the persuasive alternative; 1) no compulsory reduction of existing personnel, 2) raising the salary of SMSC to the same level of SMRTS for compensating intensified work burden, 3) hiring new employees to the amount of one-third of the reduced workforce for minimizing the problems associated with the reduction. The study suggests that the personnel reduction in relevant parts be planned in the following ways; 1) passenger transport part: from daily 3 shifts of 4 group to 2 shifts of 3 group, 2) fleet inspection, civil d: electric engineering, railtrack maintenance, signal parts: from 12 day-off to 10day-off, 3) architecture, AFC parts: from 2 shifts of 3 group to daily work, 4) fleet maintenance, architecture parts: expanding out-sourcing ＆ automation, and 5) headquarter part: 10% reduction of the total of office workers. The study finds, by implementing the plan, that 1,270 employee can be reduced, and that aggregate 106.8 billion won will be saved for the next 10 years.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1610-1612
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• 2005

In this paper, the inductive power collector using electromagnetic induction for vehicle such as the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. Also, a model of power collector and parallel winding structure and a model of concentration/decentralization winding are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.776-781
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• 2005

In this paper, using received channel information, we analyze performance in MIMO multiuser system in low-to-medium mobile speed by selecting each user's constellations, powers, and transmit antennas. Given a target of symbol error, we determine each user's constellations, powers, selected tranprobability smit antennas such that the required signal-to-noise(SNR) is minimized for MMSE, V-BLAST receiver according to each user's information and channel estimation information. When we do power control with antenna selection technique through uplink channels of MIMO system in low-to-medium mobile speed, we analyze system performance with wireless channel information from Base-Station(BS) to Users. By simulation, it has been shown that the proposed antenna selection scheme for transmitting data offer better performance improvement than all transmit antennas for transmitting data.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.188-193
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• 2011

In order to solve urban transportation problems, the various alternatives are presented to the public transportation system but the master plan of construction and operation is that there is no validity. PRT unlike other public transport system, is a new transport system that can respond appropriately, to solve the traffic demand, environmental and energy problems. Meanwhile, national and international PRT system was not commercially and the actual construction and operation of the PRT in case of base research is not well established. In this paper, PRT concept was established as the new transportation system, the target area(Nan-gok area) was selected to examine the feasibility of PRT systems and the corridor analysis method has been developed to predict the PRT demand as a basic material of planning process.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.83-96
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• 2010

The rapid spread of smart phone in recent years changes not only personal life but also work environment of organizations. Moreover, smart phone provoke service combination between industries and transit the digital paradigm in our society because of the character that anyone can develop or use the application of smart phone. Under these circumstances, the government hastens the construction of mobile-government in order to improve national services and communication with people. However, since security threats on smart phone become more critical recently, we should hurry the counter measures against mobile threats or we will face obstacles to the activation of mobile-government. On this article, we suggest the methods of information security and the Mobile-government Information Security Management System(M-ISMS) on the smart phone use environment for building up the secure and convenient mobile system in the national institution.