• Korea Trade Review
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• v.46 no.2
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• pp.193-212
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• 2021

This study investigates the structural relationship among 11 latent factors that potentially influence the intention of Chinese consumers to purchase electrical vehicles (EV) by applying the MGB and TAM models, both based on well-established socio-psychological theories. For this research, we conducted an online survey using a Chinese platform collecting 287 valid responses to our questionnaire. The analysis reveals that 10 out of the 12 hypotheses were adopted while 2 were rejected. Specifically, it was found that EC (environment concern) and PEV (perceived environment value) had a positive effect on the PEU (perceived environmental usefulness) of electric vehicles. In addition, ATT (attitude), PAE (positive anticipated emotion), and PBC (perceived behavior control) were confirmed to have a significant positive relationship with DES (desire) for EV purchase. At the same time, the results of the analysis show a statistically significant relationship between PEU, ATT as well as PI (purchase intention). This study further analyzed and presented the results of the moderating effects of gender, based on the adopted relationship hypotheses. This study is novel in that it is the first attempt in the literature to apply both the MGB model and the TAM simultaneously to predict EV purchasing behavior.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1618-1628
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• 2011

The Train Diagnostic and Control System(TDCS) has been equipped on the modern Metro Vehicle, Locomotive and High Speed Train. The main purpose of this system is to support the identification of train status by real-time, the fast action against such failure events during revenue service and the fast convenient maintenance processes. Some of newest TCMS, a kind of control and monitoring system, has participated in the main control functions such as pantograph up and down, powering and braking command and so on. But these kind of control functions of the high speed train which has the operating speed over 300km/h are conducted by the train electrical logic circuits. The KTX-I and KTX-II - the local high speed train, are the typical example. The next generation TDCS for the ongoing project of distributed high speed train(HEMU) is designing with the target to increase main train control functions, to increase the reliability/avalibility and to increase the convenient driving. This paper introduces the overall configurations and functions of the new generation TDCS.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.1-7
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• 2017

Aluminum alloys have been widely used in many fields such as electronic, structure, aero-space and vehicle industries due to their outstanding thermal and electrical conductivity as well as low cost. However, they have some difficulties for using in brazing process because of the strong oxide layer of $Al_2O_3$ on the surface of Al alloy. In addition, their melting point is similar to that of brazing filler metal resulting in thermal damage of Al alloys. Therefore, it is very important to understand the brazing principles, filler metal and its properties such as wetting, capillary flow and dissolution of base metal in the Al brazing process. This paper reviews the brazing principles, aluminum alloys, and brazing fillers. In the case of brazing principle, some formula was used for calculation of capillary force and the dissolution to obtain the best condition of Al brazing. In addition, the advanced research trends in Al brazing were introduced including thermal treatment, additive for improving property and decreasing melting point in Al brazing process.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.7
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• pp.535-540
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• 2016

The braking device in railway vehicles decelerates or stops the train by dissipating the thermal energy converted from kinetic energy into the air. Therefore, the brake system is crucial for safety. In this paper, we performed a study on an electromechanical brake actuator using an electrical motor as an alternative to pneumatic air cylinders to reduce the idle running time in braking, which subsequently increases braking distance, and to ensure reliable response characteristics. Especially, to analyze the response characteristics of the electromechanical brake actuator, we measure the delay time, response time and power consumption compared to the air cylinder. It is confirmed that the electromechanical brake actuator can reduce reaction time by 0.1 seconds (Braking Action) and 0.46 seconds (Brake Release) compared to the air cylinder.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.411-417
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• 2016

Theoretical IPMSM control technique is complicated, and reliability is low because of the changing parameters. Further, in case of general look-up table designing method which obtains torque characteristics (according to current and speed) or torque characteristics (according to magnetic flux through the entire control region), obtaining a precise result can be difficult and has the disadvantage taking too much time to establish a current look-up table. In this paper, the new auto maximum torque point tracking (MTPT) algorithm that automatically finds the optimum stator d - q axis electric current reference through the entire speed region is devised; consequently, it could establish a 3D look-up table with torque characteristics according to current and speed. In case of using the devised auto MTPT algorithm, the result value detailed was obtained in comparison with the generalized look-up design technique, and checked to reduce the current look-up table establishment time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2841-2860
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• 2018

Vehicular networks play an important role in current intelligent transportation networks and have gained much attention from academia and industry. Vehicular networks can be enhanced by Long Term Evolution-Vehicle (LTE-V) technology, which has been defined in a series of standards by the 3rd Generation Partnership Project (3GPP). LTE-V technology is a systematic and integrated V2X solution. To guarantee secure LTE-V communication, security and privacy issues must be addressed before the network is deployed. The present study aims to improve the security functionality of vehicular LTE networks by proposing an efficient and secure ID-based message authentication scheme for vehicular networks, named the ESMAV. We demonstrate its ability to simultaneously support both mutual authentication and privacy protection. In addition, the ESMAV exhibit better performance in terms of overhead computation, communication cost, and security functions, which includes privacy preservation and non-frameability.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.146-148
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• 2006

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications. This paper proposes efficiency optimization control of IPMSM drive using AFLC-FNN(Adaptive Fuzzy Learning Control Fuzzy Neural Network)controller. In order to maximize the efficiency in such applications, this paper proposes the optimal control method of the armature current. The optimal current can be decided according to the operating speed and the load conditions. This paper proposes speed control of IPMSM using AFLC-FNN and estimation of speed using ANN controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled AFLC-FNN controller, the operating characteristics controlled by efficiency optimization control are examined in detail.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.115-120
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• 2003

In a motor driving, the current rate is directly related to the rate of a switching device and in cost reduction, the parallel switching operation is the alternatives because it has the smaller current rate through current division. There are many investigations for the parallel switching operations to equaling the current division. However it remains many problems for practical usage. The reason is that the switching characteristics are mainly relied on the different saturation voltage of each device etc. and these factors are not altered by circuit designer. In order to compensate this problem, a proper resistance is experimently inserted to the switching device. But this method can not be the optimal solution. Therefore this paper proposes a new parallel operation which uses a parallel phase winding to remove the traditional effect of switching device such as saturation voltage according to the division of current. Also the reliable and stable driving is improved through experiments and the detailed principles.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.103-110
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• 2005

Fuel cell systems are consisted of various parts, for example fuel cell stack, fuel supplier, electrical converters, controllers and so on. Each components of system should have appropriate specification for their applications as well as simplicity. Because thermal load can be managed simply by using fans without any water cooling system, the air-cooled PEMFC is widely used in sub kW and around 1kW systems. The performance of an air-cooled system is highly dependent on ambient temperature and humidity. In this paper, the air-cooled PEMFC systems are developed and investigated to study the operating characteristics in the aspect of the thermal and water coupled management by the control of the axial fans and compressors. Various experiments were also conducted to get the cell voltage distribution, the relative humidity of the reactant gas and the thermal management by axial cooling fans, which cannot be observed in single cell experiment. After then, as practical applications, portable fuel cell system and a hybrid electric cart were successfully integrated and operated by using this air-cooled stack.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.773-782
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• 2016

Recently, Energy Industry is in the face of such sustained Low-Growth, Energy Depletion, Climate Warming and Energy Companies bankruptcy, Various methods have been tried to break through it. In this paper, We propose Business Model of Energy New Industry in Electric Power Market after analyze background of Energy New Industry and Technology Trends. The proposed Business Model introduces Energy of Things(: EoT) Service based Advanced Metering Infrastructure, Energy Storage System(: ESS) for Frequency Regulation, Energy Prosumer using Vehicle and Grid(: VnG) and Smart City.