• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.70-71
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• 2014

In this paper, an advanced charging strategy for improving the charging performance of the Li-ion polymer battery is proposed, which is based on the battery characteristic. Simulation results show that the proposed charging current pattern can improve the charging speed of battery in comparison with the standard CC-CV (constant current - constant voltage) charging strategy and the pulse-charging strategy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.494-495
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• 2008

This paper shows the IUIa charging characteristics of charging pattern for industrial lead-acid battery. PSCAD/EMTDC simulation model is developed for studying the IUIa charging characteristics for micro-source, and control the charging current and charging voltage for each section of IUIa charging pattern.

• 조명전기설비학회논문지
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• 제29권9호
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• pp.96-102
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• 2015

This paper presents battery charging method using 3-phase AC-DC boost converter. General battery charging method is that charging the battery voltage to the reference voltage according to the constant current(CC) control, when it reaches the reference voltage, charging the battery fully according to the constant voltage(CV) control. However, battery chaging time is increased because of the battery impedance, constant current charging section which shoud take the large amount of charge is narrow, and constant voltage charging section which can generate insufficient charge is widen. To improve this problem, we proposes the method to reduce the charging time according to the SOC(State of Charge) estimation using battery impedance.

• 한국초전도ㆍ저온공학회논문지
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• 제17권3호
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• pp.18-22
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• 2015

This paper deals with high-Tc superconducting (HTS) power charging system with GdBCO magnet, photo-voltaic (PV) controller, and solar panels to charge solar energy. When combining the HTS magnet and the solar energy charging system, additional power source is not required therefore it is possible to obtain high power efficiency. Since there is no resistance in superconducting magnet carrying DC transport current the energy losses caused by joule heating can be reduced. In this paper, the charging characteristics of HTS power charging system was simulated by using PSIM. The charging current of HTS superconducting power charging system is measured and compared with the simulation results. Using the simulation of HTS power charging system, it can be applied to the solar energy applications.

• 한국수소및신에너지학회논문집
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• 제34권3호
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• pp.246-255
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• 2023

Due to lack of hydrogen charging stations and hydrogen supply compared to the supply of hydrogen vehicles, social phenomena such as 2-hour queues and restrictions on charging capacity are occurring, which negatively affects the spread of hydrogen vehicles. In order to resolve these problems, it is essential to have a strategic operation of the hydrogen charging stations. To establish operational strategies, it is necessary to derive customer demand patterns and characteristics through the analysis of sales data. This study derived the demand patterns and characteristics of customers visiting hydrogen charging stations through data analysis from various perspectives, such as charging volume, charging speed, number of visits, and correlation with external factors, based on the hydrogen sales data of off-site hydrogen charging stations located in domestic residential areas.

• 한국정보과학회논문지:정보통신
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• 제31권1호
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• pp.53-61
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• 2004

이 논문에서는 무선 LAN망과 이동통신망을 연동하는 통합 시스템에 적합한 과금 시스템 구현 방안을 제시한다. 기존의 무선 LAN망과 이동통신망의 과금 정보를 식별하는 방식이 서로 상이하여, 두 망을 연동하는 통합 시스템에서는 두 망의 과금 정보를 통합하여 식별할 수 있는 방법이 필요하다. 따라서, 이 논문에서는 무선 LAN망과 이동통신망의 서비스를 모두 사용하는 연동 시스템에서 통합된 과금 식별자를 사용하여 두 가지 망의 서비스 사용에 대한 과금 정보를 수집하는 방법을 제시한다. 또한 선불제, 후불제, 정액제와 같은 사용자의 과금 방식을 기반으로 과금 정보 수집 주기를 변경하는 방식을 제시하고, 제시된 방법을 통해서 과금 정보의 정확성을 높이고 과금 정보 수집에 필요한 통신 부하가 감소되는 것을 검증한다.

• 산업경영시스템학회지
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• 제45권4호
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• pp.217-224
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• 2022

Due to the issue of the sustainability in transportation area, the number of electric vehicles has significantly increased. Most automakers have decided or planned to manufacture the electric vehicles rather than carbon fueled vehicles. However, there are still some problems to figure out for the electric vehicles such as long charging time, driving ranges, supply of charging stations. Since the speed of growing the number of electric vehicles is faster than that of the number of charging stations, there are lack of supplies of charging stations for electric vehicles and imbalances of the location of the charging stations. Thus, the location problem of charging stations is one of important issues for the electric vehicles. Studies have conducted to find the optimal locations for the charging stations. Most studies have formulated the problem with deterministic or hierarchical models. In this paper, we have investigated the fluctuations of locations and the capacity of charging stations. We proposed a mathematical model for the location problem of charging stations with the vehicle routing problem. Numerical examples provide the strategy for the location routing problems of the electric vehicles.

• 한국ITS학회 논문지
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• 제12권4호
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• pp.56-65
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• 2013

최근 계속되는 기후변화에 따른 위기감으로 인해 세계는 온실가스를 감축하기 위한 노력을 강화 하고 있다. 그중 수송분야에서는 온실가스를 줄이는 방안으로 현재의 내연기관 자동차를 전기자동차로 대체하고자 하고 있다. 한편 전기자동차를 보급하는데 있어서 중요한 충전설비는 완속충전설비와 급속충전설비로 나뉘는데, 전기 충전량 외에도 충전시간 역시 요금을 구성하는 중요 요소가 된다. 그러나 충전시간은 개인이 처한 상황에 따라 시간 기회비용이 같지 않으므로 이와 같은 현상을 정확히 이해하는 것은 충전설비의 보급이나 요금정책에 있어서 매우 중요하다고 생각한다. 따라서 본 연구는 상황에 따른 충전설비의 선택, 충전시간과 비용 지불의사가 어떻게 달라지는지를 밝히고자 로짓모형을 통해 충전설비 선택모형과 함께 상황별 시간가치를 제시하고 있다.

• 대한기계학회논문집
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• 제18권2호
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• pp.432-445
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• 1994

From a theoretical analysis point of view, the 2-stage precipitator is decomposed into two units: charging cell and collecting cell. Collection efficiency predictions of the two-stage parallel-plate electrostatic precipitator have been performed theoretically incorporating with the charging and the collecting cells. Particle trajectorise passing the charging cell have been modeled as a simple one. Particle charge distribution at the outlet of the charging cell is calculated through integration of the present unipolar combined charging rate along the entire particle trajectory, and average charge of particles at the outlet of the charging cell is obtained from the particle charge distribution. As for the collecting cell, the diminution of particle concentration along the longitudinal direction of the collecting cell is investigated considering the conventional Deutsch's theory and the laminar theory. One should note that the collection efficiency formula derived is based on monodisperse aerosols. It has been confirmed through the analysis that predictions of particle charge by applying White's unipolar diffusion charging theory overpredict actual cases in the continuum regime, while predictions by Fuch's unipolar diffusion charging theory indicate the reasonable result in the same regime. Theoretical predictions of collection efficiency are also compared with the available experimental results. Comparisons show that the experimental results are consistently located in the collection efficiency region bounded by the two limits, the Deutsch and the laminar collection efficiencies. Finally design parameters of the 2-stage electrostatic precipitator have been investigated systematically through the one-variable-at-a-time method in terms of collection efficiency. Applied voltages on the corona wire of the charging cell and the plate of the collecting cell, and the average air velocity have been selected as the design parameters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4301-4319
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• 2017

Adopting mobile chargers (MC) in rechargeable wireless sensors network (R-WSN) to recharge sensors can increase network efficiency (e.g., reduce MC travel distance per tour, reduce MC effort, and prolong WSN lifetime). In this study, we propose a mechanism to split the sensing field into partitions that may be equally spaced but differ in distance to the base station. Moreover, we focus on minimizing the MC effort by providing a new charging mechanism called the sector-based charging schedule (SBCS), which works to dispatch the MC in charging trips to the sector that sends many charging requests and suggesting an efficient sensor-charging algorithm. Specifically, we first utilize the high ability of the BS to divide the R-WSN field into sectors then it select the cluster head for each sector to reduce the intra-node communication. Second, we formulate the charging productivity as NP-hard problem and then conduct experimental simulations to evaluate the performance of the proposed mechanism. An extensive comparison is performed with other mechanisms. Experimental results demonstrate that the SBCS mechanism can prolong the lifetime of R-WSNs by increasing the charging productivity about 20% and reducing the MC effort by about 30%.