• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.580-590
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• 2018

Active distribution system (ADS) considering distributed generation (DG) and electric vehicle (EV) is an effective way to cut carbon emission and improve system benefits. ADS is an evolving, complex and uncertain system, thus comprehensive model and effective optimization algorithms are needed. Battery swapping station (BSS) for EV service is an essential type of flexible load (FL). This paper establishes ADS planning model considering BSS firstly for the minimization of total cost including feeder investment, operation and maintenance, net loss and carbon tax. Meanwhile, immune binary firefly algorithm (IBFA) is proposed to optimize ADS planning. Firefly algorithm (FA) is a novel intelligent algorithm with simple structure and good convergence. By involving biological immune system into FA, IBFA adjusts antibody population scale to increase diversity and global search capability. To validate proposed algorithm, IBFA is compared with particle swarm optimization (PSO) algorithm on IEEE 39-bus system. The results prove that IBFA performs better than PSO in global search and convergence in ADS planning.

• 한국통신학회논문지
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• 제33권9A호
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• pp.891-899
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• 2008

cdma2000 1xEV-DO 시스템은 기지국이 전송하는 이진(binary) 정보와 간단한 확률모델에 의해 역방향 링크의 전송속도를 제어한다. 하지만, 이 트래픽 제어방식은 각 단말이 자율적으로 전송속도를 결정하기 때문에 역방향 링크를 효과적으로 제어하기 어렵고 역방향 링크의 안성성을 보장하기도 쉽지 않다. 본 논문에서는 역방향 링크의 안정성을 향상시키기 위하여 트래픽 부하에 따른 단계별 전송속도 제어방법을 제안하고, 이를 이산시간 마르코프 프로세스로 모델링하여 성능을 분석한다. 다양한 환경에서 실시한 분석 결과를 통해 제안한 방법이 기존의 방법과 비교하여 보다 높은 전송속도를 지원함을 확인할 수 있다. 더불어, 제안한 방식은 표준규격에서 정의한 물리계층 구조를 변경하지 않으므로 이미 구축되어 있는 1xEV-DO 시스템과 호환이 가능한 장점을 가진다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.551-569
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• 2024

With the rapid development of electric vehicles (EVs) industry, EV charging service becomes more and more important. Especially, in the case of suddenly drop of air temperature or open holidays that large-scale EVs seeking for charging devices (CDs) in a short time. In such scenario, inefficient EV charging scheduling algorithm might lead to a bad service quality, for example, long queueing times for EVs and unreasonable idling time for charging devices. To deal with this issue, this paper propose a Deep-Q-Network (DQN) based two-stage scheduling method for the large-scale EVs charging service. Fine-grained states with two delicate neural networks are proposed to optimize the sequencing of EVs and charging station (CS) arrangement. Two efficient algorithms are presented to obtain the optimal EVs charging scheduling scheme for large-scale EVs charging demand. Three case studies show the superiority of our proposal, in terms of a high service quality (minimized average queuing time of EVs and maximized charging performance at both EV and CS sides) and achieve greater scheduling efficiency. The code and data are available at THE CODE AND DATA.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권8호
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• pp.443-451
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• 2003

Many attempts have been made for the health and lives of patients at a remote site. but little attention has been given to emergency system using wireless or other intelligent networks. In this paper, shown is a remote emergency system which can be used in an ambulance. It possibly gives a great help to the patients who may lose their lives, in other words, gives pre-hospital cure to them being sent to the hospital. Doctors or specialists are able to give a quick help which may give a new life to patients. This system deal with very important patient's data-ECG, SpO$_2$, blood pressure, biomedical signal data etc. - as other emergency system. A good performance better than other system is many but shortly spoken as follows. First, this system is user friendly system activated in windows 2000 environment. Second, MPEG4 and ECG data sent to the other station for specilists can give a pre-hospital cure to patients in advance. Third, there exist effective algorithms to operate this system. Fourth, this system has been made with software mostly, so this system can be easily embedded in IBM compatible computer. In addition to this performance, for the better and reliable system, various tests were proceeded and recursively tested. Tests were made in EV-DO wireless network and Local Area Network. This mobile-fixed remote emergency system using wireless network like EV-DO network will give a great usage to needed area.

• Current Photovoltaic Research
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• 제11권4호
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• pp.124-133
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• 2023

In order to deploy the large-scale energy storage (ES) service in the various industry, it is very important to develop a business model with high technological and economic feasibility through detailed valuation of cost and expected benefits. In relation to this, this paper established an optimal scheduling plan for electric vehicle charging stations connected with photovoltaic (PV) and ES technologies in Korea using the distributed energy resource valuation tool and analyzed the feasibility of the project. In addition, the impact of incentives such as REC (Renewable Energy Certificate) to be given to electric vehicle charging stations in accordance with the relevant laws to be revised in the future was analyzed. As a results, the methodology presented in this paper are expected to be used in various ways to analyze the feasibility of various business models linked to renewable energy and ES technologies as well as the electric vehicle market.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.69-72
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• 2022

This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1573-1582
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• 2015

This study was to investigate the effect of soyabean isoflavones (SIF) on onset of puberty, serum hormone concentration, and gene expression in hypothalamus, pituitary and ovary of female Bama miniature pigs. Fifty five, 35-days old pigs were randomly assigned into 5 treatment groups consisting of 11 pigs per treatment. Results showed that dietary supplementation of varying dosage (0, 250, 500, and 1,250 mg/kg) of SIF induced puberty delay of the pigs with the age of puberty of pigs fed basal diet supplemented with 1,250 mg/kg SIF was significantly higher (p<0.05) compared to control. Supplementation of SIF or estradiol valerate (EV) reduced (p<0.05) serum gonadotrophin releasing hormone and luteinizing hormone concentration, but increased follicle-stimulating hormone concentration in pigs at 4 months of age. The expression of KiSS-1 metastasis-suppressor (KISS1), steroidogenic acute regulatory protein (StAR) and 3-beta-hydroxysteroid dehydrogenase/delta-5-delta-4 isomerase ($3{\beta}-HSD$) was reduced (p<0.01) in SIF-supplemented groups. Expression of gonadotropin-releasing hormone receptor in the pituitary of miniature pigs was reduced (p<0.05) compared to the control when exposed to 250, 1,250 mg/kg SIF and EV. Pigs on 250 mg/kg SIF and EV also showed reduced (p<0.05) expression of cytochrome P450 19A1 compared to the control. Our results indicated that dietary supplementation of SIF induced puberty delay, which may be due to down-regulation of key genes that play vital roles in the synthesis of steroid hormones.

• Journal of electromagnetic engineering and science
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• 제3권1호
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• pp.50-56
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• 2003

This paper proposes a coding scheme of control channel for mobile packet communication to maximize the minimum Hamming distance, which is based on shifting of basis vectors of Reed Muller code with optimized dynamic puncturing and/or(partial) sequence repetition. Since the maximum likelihood decoding can be performed using the extremely simple FHT(Fast Hadamard Transformation), it is suitable for real time optimum decoding of control channel information with very little complexity. We show applications of the proposed coding method to TFCI(Transport Format Combination Indicator) code in split and normal modes of 3GPP W-CDMA system. We also discuss how this method can reduce rate indication error over AWGN(Additive White Gaussian Noise) as well as fading channels when the proposed coding scheme is applied to 1xEV-DV system of $3^{rd}$TEX> generation partnership project 2(3GPP2) to indicate the data rate transmitted on the reverse traffic channel by a Mobile Station(MS).

• 대한교통학회지
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• 제36권2호
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• pp.129-140
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• 2018

본 연구에서는 이항로짓모형 기반의 시장분할을 고려한 전기차 선택모형을 추정하여 전기차 잠재 수요층의 전기차 구매행태를 분석하였다. 모형 구축을 위하여 서울시에 거주하는 차량운전자를 대상으로 전기차 구매가격, 공용 충전인프라 구축 수준, 1회 충전 주행가능거리 등의 가상 시나리오에 대하여 전기차 선택여부를 조사하였다. 차급별로 구분하면 경 소형 차급 보유자는 차량 구매가격이 가장 큰 영향을 미치며, 중 대형 차급 보유자는 공용 충전인프라 구축 수준을 중요시하는 것으로 나타났다. 주택유형으로 분할한 경우 공동주택 거주자는 전기차 선택 시 공용 충전인프라 구축 수준을 가장 크게 고려하지만, 단독주택 거주자는 차량 구매가격에 가장 민감한 것으로 분석되었다. 이상의 결과를 토대로 자동차 제작사의 전기차 보급 전략이 전략적 구매층을 어디로 설정하느냐에 따라 달라져야 함을 보여주며, 정부의 전기차 보급정책으로는 공용 충전인프라의 확대가 가장 우선적으로 추진되어야 할 필요가 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1855-1860
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• 2010

Electric vehicles have reached a new level of development with introductions by Chrysler, Ford, Honda and Toyota. Today's charging technology includes conductive and inductive charging systems. There are three standardized charging levels: Level 1: charging can be done from a standard, grounded AC 120V, 3-prong outlet available in all homes; Level 2: charging is at AC 240V, 40 amp charging station with special consumer features to make it easy and convenient to plug in and charge EVs at home or at an EV charging station; Level 3: a high-powered charging "fast charge" technology currently under development that will provide a charge in less than 15 minutes. The incoming AC power is converted to DC and stored in the vehicle's batteries. In this paper, we investigated the application of urban railway DC electric power for electric car charging system.