• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.93-108
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• 2016

Electric vehicle car sharing (EV-sharing) system is noted as an eco-friendly system of transportation in global warming crisis and has been practically implemented in some cities around the world. However, methodologies to find the efficient operation conditions of EV-sharing systems reflecting a typical characteristic 'charging' have not been fully investigated yet. In the paper a generalized model has been developed to identify optimal level of infrastructure for EV-sharing system which provides the optimum operation efficiency under service level constraints. From the simulation analysis based on the developed model the relationships between the operational variables to describe EV-sharing system have been identified and optimal capacity to maximize the operational efficiency have been found. From the analysis of simulation results it has been found that increases in the number of vehicles and chargers improve the service level until certain value beyond which increasing rate and the efficiency have been reduced. From the cost-revenue analysis the optimal numbers of vehicles and chargers have been identified which maximizes the annual operational profit.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.95-104
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• 2013

As global warming and depletion of fossil fuel are considered as urgent problems, the development of electric vehicle (EV) is getting more attention by automobile industry. However, the wide adoption of EVs is not coming yet, because of many issues such as long recharging time and high cost of batteries etc. As an alternative solution to the conventional battery charging EV, the idea of battery exchanging EV is introduced. To realize the battery exchanging business model, one should solve the issues of ownership and reliability of battery. To address such issues, the concept of battery sharing should be considered together with good traceability system. In this study, we studied RFID code structure to provide better visibility and traceability for shared EV batteries. The proposed RFID code and code generation system is based on GRAI-96 of EPCglobal and included factors such as chemical, physical, and manufacturing features. The designed code can be also used as the ID of each battery.

• The Journal of Industrial Distribution & Business
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• v.9 no.3
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• pp.57-68
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• 2018

Purpose - The purpose of this study is to classify that the quality factors for comparing the Visegrard Group with the Nordic Council have historical similarities against Germany and the Soviet Union. However, this is because in the integrated European market, the competitiveness possessed by the two groups of countries is invested in the priority order to grow. Research design, data, and methodology - The study was conducted on the research design, and the reason for trying to compare the competence of the automobile industry in the assessment of industrial capability is that the Visegrard Group focuses on automotive production and the Nordic Association focuses on the commercialization of the automobile(market). In this study, searching and quantifying indirect evidence was made through standards are more complementary in Europe since each country acts like the role of the European automotive industry for example, which is different from the realistic evaluation criteria, are more important than those of the United States(first in the world) or Germany(first in Europe). Results - The results of this study are as follows: In the global EV market U.S.(export: $ 2.62 billion /share: 36.7%), Germany($ 1.29 billion /18.1%), France($ 390 million /5.4%), United Kingdom($ 380 million /5.4%), and South Korea($ 320 million/ 4.4%). South Korea's share of the EV market is 4.4%, while TSI reaches at +0.9 which measures the comparative advantage of a specific commodity in the world trade market. There is great potential for evaluated as products processing in export competition. But, commercialization, standardization, and overall market expansion did not have a positive impact on global satisfaction. Conclusions - EVs put importance on various utilities. So this suggests that Korea's exports to the EU, including the Visegrard Group, should be more focused on marketability when illuminating with a sharing industrial system under the European Union. It is necessary to specialize in manufacturing and commercialization by country(region) to prepare sharing economy and blockchain in order to create a smart-sharing city linked on artificial intelligence, as the commercialization of electric vehicles, which will have a larger growth rate than that of manufacturing in the fourth revolutionary era.

• Journal of the Korean Mathematical Society
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• v.58 no.1
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• pp.29-44
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• 2021

The set D of column vectors of a generator matrix of a linear code is called a defining set of the linear code. In this paper we consider the problem of constructing few-weight (mainly two- or three-weight) linear codes from defining sets. It can be easily seen that we obtain an one-weight code when we take a defining set to be the nonzero codewords of a linear code. Therefore we have to choose a defining set from a non-linear code to obtain two- or three-weight codes, and we face the problem that the constructed code contains many weights. To overcome this difficulty, we employ the linear codes of the following form: Let D be a subset of ��2n, and W (resp. V ) be a subspace of ��2 (resp. ��2n). We define the linear code ��D(W; V ) with defining set D and restricted to W, V by $${\mathcal{C}}_D(W;V )=\{(s+u{\cdot}x)_{x{\in}D^{\ast}}|s{\in}W,u{\in}V\}$$. We obtain two- or three-weight codes by taking D to be a Vasil'ev code of length n = 2m - 1(m ≥ 3) and a suitable choices of W. We do the same job for D being the complement of a Vasil'ev code. The constructed few-weight codes share some nice properties. Some of them are optimal in the sense that they attain either the Griesmer bound or the Grey-Rankin bound. Most of them are minimal codes which, in turn, have an application in secret sharing schemes. Finally we obtain an infinite family of minimal codes for which the sufficient condition of Ashikhmin and Barg does not hold.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.328-338
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• 2017

In this paper, a zero torque control scheme adopting current sharing function (CSF) used in integrated Switched Reluctance Motor (SRM) drive with DC battery charger is proposed. The proposed control scheme is able to achieve the keeping position (KP), zero torque (ZT) and power factor correction (PFC) at the same time with a simple novel current sharing function algorithm. The proposed CSF makes the proper reference for each phase windings of SRM to satisfy the total charging current of the battery with zero torque output to hold still position with power factor correction, and the copper loss minimization during of battery charging is also achieved during this process. Based on these, CSFs can be used without any recalculation of the optimal current at every sampling time. In this proposed integrated battery charger system, the cost effective, volume and weight reduction and power enlargement is realized by function multiplexing of the motor winding and asymmetric SR converter. By using the phase winding as large inductors for charging process, and taking the asymmetric SR converter as an interleaved converter with boost mode operation, the EV can be charged effectively and successfully with minimum integral system. In this integral system, there is a position sliding mode controller used to overcome any uncertainty such as mutual inductance or DC offset current sensor. Power factor correction and voltage adaption are obtained with three-phase buck type converter (or current source rectifier) that is cascaded with conventional SRM, one for wide input and output voltage range. The practicability is validated by the simulation and experimental results by using a laboratory 3-hp SRM setup based on TI TMS320F28335 platform.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.184-186
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• 2020

본 논문은 전기 자동차의 DC-DC 컨버터 공유형 유·무선통합 충전 시스템의 고효율 동작을 고려한 최적의 DC-link 전압을 설계한다. DC-DC 컨버터의 입력 DC-link 전압 크기에 따라 유·무선 충전 방식 간 효율 특성이 상이하므로 DC-link 전압 크기별 유·무선 충전 시스템의 손실 분석을 진행한다. 손실 분석 결과를 바탕으로 유·무선 통합 충전 시스템의 고효율 동작을 위한 최적 DC-link 전압을 제안한다.

• The Journal of Korean Obstetrics and Gynecology
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• v.27 no.4
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• pp.25-42
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• 2014

Objectives: To observe the effects of Herb medication on Polycystic Ovary (PCO) in rats. Methods: Riss (Research Information Sharing Service) was searched for Oriental medicine about PCO on 2000~2014. So, Experimental studies using PCO model induced by Estradiol Valerate (EV) was selected to analyze how effects they were. Consequently, 10 studies published on 2000~2014 were selected to analyze about weight of model and both ovaries, the number aries, the number of follicle and corpus of follicle and corpus luteum, the level of serum Androstenedione (ADD) and total estrogen, the level of Nerve Growth Factor (NGF) and Corticotropin Releasing Factor (CRF), the crossover rate and the number of implantation. Results: Among them, there was significantly difference between treatment group and control group in weight of both ovaries, the number of follicle and corpora lutea, the crossover rate and the number of implantation. Conclusions: The effects of Herb medication was observed on making weight of ovaries with PCO to promote. The study about effect of Herb medication on NGF and CRF with PCOS had to be conducted. The further research have to focus on treatment of subfertility and infertility, that is field showing the advantage of Oriental medicine.