• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.59-65
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• 2008

In security layer in the CDMA2000 1x EV-DO, a standard - C.S0024-a v2.0 is being accomplished under the project of 3GPP2(3rd Generation Partnership Project2). Therefore, a security device is needed to implement the security layer which is defined on the standard document for data transfer security between AT(Access Terminal) and AN(Access Network) on CDMA2000 1x EV-DO environment. This paper realizes the security layer system that can make safe and fast transfer of data between AT and AN. It could be applied to various platform environments by designing and implementing the Security Layer in the CDMA2000 1x EV-DO Security Layer to which applies C.S0024-A v2.0 of 3GPP2.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.119-127
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• 2020

As the electric vehicle (EV) market in South Korea grows, it is required to expand charging facilities to respond to rapidly increasing EV charging demand. In order to conduct a comprehensive facility planning, it is necessary to forecast future demand for electricity and systematically analyze the impact on the load capacity of facilities based on this. In this paper, we design and develop a Long Short-Term Memory (LSTM) neural network model that predicts the daily peak electric load at each charging station using the EV charging data of KEPCO. First, we obtain refined data through data preprocessing and outlier removal. Next, our model is trained by extracting daily features per charging station and constructing a training set. Finally, our model is verified through performance analysis using a test set for each charging station type, and the limitations of our model are discussed.

• Journal of Technology Innovation
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• v.23 no.3
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• pp.137-167
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• 2015

Based on the stakeholder theory, this paper analyzes a clash of standards in Korea's Electric Vehicle(EV) market, particularly between an EV charging standard and a smart grid communication standard in 2012~2013. For charging, EV is connected with the electric power grid and simultaneously exchanges data regarding the charging status. When EV is connected with the power grid, a clash between two standards may arise. It actually happened when BMW entered into the Korean EV market with the DC Combo charging system. In that course, the frequency interference occurred between the EV data communication technology adopted by BMW and the AMI(Advanced Metering Infrastructure) for the smart grid system in Korea. Standardization of Korea's EV charging systems was required to solve this problem. However, it had been delayed due to the confrontation between various stakeholders involved in the process of standardization. It lasted until the DC combo was accepted as one of the Korea EV charging standards(KSAE SAE 1772-2040, 2014.1) by KSAE(The Korea Society of Automotive Engineers) in January 2014. This is an interesting case in the age of convergence. As it deals with the standard competition not among EV standards, but a clash between the EV industry and the smart grid, i.e. electric power industry, it addresses the necessity to consider standardization processes between different industries. This study draws on the stakeholder theory to analyse the dynamics of the standard clash between EV charging systems and the smart grid system, which is a unique example of standard clash between different industries. We expect such clashes to increase in the age of convergence.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1105-1106
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• 2011

본 논문에서는 EV 구동용 유도전동기와 매입형 영구자석 동기전동기(IPMSM)의 동작특성과 효율을 비교하기 위하여 농형구조 유도전동기와 단층구조 IPMSM을 설계 하였다. EV 구동용 전동기는 정속운전 뿐만 아니라 가변속 운전이 필수적이므로 유도전동기는 V/f 제어, IPMSM은 약계자 제어를 사용하여 가변속 상태에서의 운전토크와 효율을 유한요소법을 이용하여 해석하였다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.316-317
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• 2010

본 논문에서는 전기 자동차 탑재형 충전기 모듈에 대하여 설명한다. 기존의 충전기와는 달리 저압 충전부를 겸비하고 있어 저압 배터리도 동시에 충전시킬 수 있는 절연형 3.3kW 충전기 모듈이다. 전기 자동차 탑재형으로 온도와 진동에 강한 전장용 부품을 사용하여 주요 하드웨어를 구성하였으며, 유로해석 및 PCB진동해석을 통해 외부 온도변화와 진동에 강인하도록 설계하였다.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.745-755
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• 2000

The dam operation system of KOWACO for flood control doesn't have capability to account for the downstream hydrologic conditions and any feasible index to decide the pre-release from the forecasted rainfall and inflow. In this study, a dam operation model for flood control was developed to account for the flood flow condition of its downstream to give users the dam release schedules. Application test of EV ROM to Keum River showed that EV ROM is superior to the Rigid ROM and Technical ROM which are currently used by KOWACO. EV ROM developed in this study provides a release schedule accounting for the cumulative lateral flow hydrograph at the downstream control points where the discharge does not depend only on the dam operation. but also on lateral inflow from the tributaries. In order to reduce the peak discharge at the control points, it suggests the preliminary release during the early rising phase of the predicted hydrograph, holding the flood flow inside the dam during a peak phase, and afterward resuming the release. Three case studies of flood control by the operation of Daechung Multipurpose Dam in Geum River Basin show that the EV ROM is superior to the Rigid ROM and Technical ROM. This must be due to its nature to account for the downstream flow condition as well as the inflow and water level of the dam. It was also conceived that further case studies of EV ROM and more accurate rainfall prediction would improve the dam operation for flood control.ontrol.

• Journal of Korea Trade
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• v.27 no.4
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• pp.77-100
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• 2023

Purpose - Using the Model of Goal-Directed Behavior (MGB), this study identifies the critical factors that influence consumer intention to purchase an electric vehicle (EV). This study also provides differentiated policy implications to the Korean and Chinese governments and EV-related companies for the expansion of the EV market in both countries by comparing consumers' perceptions of EV purchase intentions. Design/methodology - Our extended MGB model adds to the standard model consideration of financial incentives, perceived risks, and environmental concerns. An online survey was conducted of Korean and Chinese consumers. Based on the collected responses, all tested hypotheses were verified using PLS-SEM (Partial Least Squares-Structural Equation Modeling). Differences in the path analysis results between Korea and China were compared and verified using Henseler's MGA (multi-group analysis), the parametric test, and the Welch-Satterthwaite test. Findings - The most critical factor that influences the intent to purchase an EV in consumers from both countries is personal desire. PBC and SN were identified as the critical factors that respectively increase personal desire in Korea and China. In addition, in Korea, among the three factors EC, FIP, and PR, environmental concerns were found to have the most significant impact on attitudes and purchase intention. In contrast, in China, economic factors (specifically financial incentives) had greater importance than environmental issues. Originality/value - This study has academic contributions in that it presents a new research model that includes financial incentive policies, environmental concerns, and perceived risk variables based on the MGB to explore consumers' purchase intentions. This study can also make a practical contribution in that it provides some meaningful implications to the governments and EV-related companies of both countries based on the differences in the analysis results of the Korean and Chinese markets.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.39-48
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• 2020

Recently, the study and development of environment-friendly energy technique have increased in worldwide due to environmental pollution and energy resources problems. In vehicle industry, the development of electric vehicle(EV) is now on progress, and also, many other governments support the study and development and make an effort for EV to become widely available. In addition, though they strive to construct the EV infra such as a charge station for EV, the techniques related to managing charge demand and peak power are not enough. The standard of EV communication has been already established as ISO/IEC 15118, however, most of implemented EVs and EV charge stations do not support any communication between each of them. In this paper, an improved slow charge scheme for non-communication EVs is proposed and designed by using predicting charge demand. The proposed scheme consists of distributed charge model and charge demand prediction. The distributed charge model is designed to manage to distribute charge power depending on available charge power and charge demand. The charge demand prediction is designed to be used in the distributed charge model. The proposed scheme is based on the collected data which were from EV slow charge station in business building during the past 1 year. The system-level simulation results show that the waiting time of EV and the charge fee of the proposed scheme are better than those of the conventional scheme.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.38-43
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• 2020

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 ㎍/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 ㎍/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 ㎍/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.845-850
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• 2021

In this study, the energy conversion characteristics and design of electric vehicle (EV: Electric Vehicle) powertrain were performed. An interior permanent magnet synchronous motor (IPMSM) was targeted as a power source for the EV powertrain, and control was performed. In order to drive the IPMSM, two regions are considered: a constant torque and a constant output (field-weakening) region. The design of the control system for IPMSM was constructed based on the d-q reference frame (vector control). To determine the static characteristics of motor torque appearing in two areas of IPMSM, a torque control system and a d axis current control system of IPMSM were implemented and proposed. Matlab-Simulink software was used for characteristic analysis. Finally, by applying IPMSM to the powertrain model under the actual EV vehicle level conditions, simulation results of the proposed control system were performed and characteristics were analyzed.