• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.4
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• pp.344-350
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• 2015

A battery management system requires accurate information on the battery state of charge (SOC) to achieve efficient energy management of electric vehicle and renewable energy systems. Although correct SOC estimation is difficult because of the changes in the electrical characteristics of the battery attributed to ambient temperature, service life, and operating point, various methods for accurate SOC estimation have been reported. On the basis of piecewise linear (PWL) modeling technique, this paper proposes a simple SOC observer for lithium-polymer batteries. For performance evaluation, the SOC estimated by the PWL SOC observer, the SOC measured by the battery-discharging experiment and the SOC estimated by the extended Kalman filter (EKF) estimator were compared through a PSIM simulation study.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.3
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• pp.236-241
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• 1996

This paper presents a new eddy current testing system for inspecting tubes of steam generator in nuclear power plant. The proposed system adopted embedded expert system concept to automate tasks of the inspection such as inspection planning and flaw signal interpretation, and integrated all the tasks into a client/server type computing architecture using database management system. Therefore, human factor errors occurred during inspection could be minimized and the inspection data could be transferred in real-time. As a result, we can increase the level of inspection confidence and the productivity of a personal inspector. A prototype of the proposed system has been developed for 5 years and the test operation has been performed in domestic nuclear power plants.

• Journal of Power System Engineering
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• v.21 no.4
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• pp.84-93
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• 2017

This study was carried out to improve the electric power consumption of HVAC in the blow mold machine(BMM) and work environment. The experiment was conducted with the simulated HVAC system of 1/15 of the actual BMM. The temperature of main facility and two preheaters was fixed at 200 and $60^{\circ}C$ respectively in all test conditions. The measured points of temperature were chosen as critical locations considering the work environment. The tendency of temperature distributions decreases as the duct was closed to the main facility. The reduction rate of power consumption of HVAC increases up to 32.3% when both duct and cooling systems are operated. Also the efficiency of HVAC is improved about 9% through the modified design of duct system. It notes that the electric power consumption of HVAC can be reduced by the optimum design and operating condition of duct and cooling system.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.147-152
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• 2018

This study investigates the demand management and energy saving plan of the apartment house based on the ESS (: Energy Storage System), which is the main equipment in the field of electric power energy efficiency, and suggests standardization for various technical factors and operation. It contributes to the spread of ESS industry. In addition, to create ESS market for apartment houses and smart homes, housing IoT technology is used to integrate apartment houses with smart home-based ESS and it is possible to achieve use efficiency and economic feasibility of power users, We will study a business model that can reconsider the acceptability of power users.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.113-118
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• 2011

Fuel Cell Hybrid Vehicle (FCHV) is one of the most promising candidates for the next generation of transportation. It has many outstanding advantages such as higher energy efficiency and much lower emissions than internal combustion engine vehicles. It also has the ability of recovering braking energy. In order to design an FCHV drive train, we need to determine the size of the electric motor, the Fuel Cell System (FCS), and the battery. In this paper, the methodology for the sizing of these components is introduced based on the driveability constraints of the FCHV. A power management strategy is also presented because the battery energy capacity depends on it. The warm-up time of the FCS is also considered in the power management strategy and the simulation result is compared to that without considering the warm-up time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1321-1326
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• 2015

The amount of smart phones has increased exponentially. Due to the periodic release of high-performance smart phones and upgraded operating system, new smart phones become out-dated over 1 or 2 years. In order to solve environmental constraints of these smart phones, virtualization technology using Thin-Client terminal has been developed. However, in the case of Virtual Machine(VM), the applications associated with sensors and a GPS device can not run because they are not included. In this paper, by implementing the device driver for Android running in a virtual machine in the x86-based systems, it is to provide Android virtualization capabilities such as using the latest smart phones in the virtual machine environment. It would like to propose a method that the virtual device driver receives sensors and GPS information from the old Android smart phones(Thin-Client) that actually work and run as if the real device exists.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.40-45
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• 2014

This study examines the system and process of battery stored energy in vehicles and suggest the effective area for the use of V2G(vehicle-to-grid) from Jeju Smart Grid Demonstration Project. V2G means technology of electric power transmission from the battery of electric-drive vehicles to state grid. As for the increasing of effectiveness for demand-side control, V2G is a very good alternative. In the U.S., the utilization of electric vehicles is under 40% on average. In this case, we can use he battery of electric vehicle as role of frequency regulation or generator of demand-side resource. V2G, which is the element of Smart Transportation, consists of electric vehicle battery, BMS(battery management system), OBC(on-board charger), charging infrastructure, NOC(network operating center) and TOC(total operation center). V2G application has been tested for frequency regulation to secure the economical efficiency in the United States. In this case, the battery cycle life is not verified its disadvantage. On the other hand, Demand Response is required by low c-rate of battery in electric vehicle and It can be small impact on the battery cycle life. This paper concludes business area of demand response is more useful than frequency regulation in V2G application of electric vehicles in Korea. This provides the opportunity to create a new business for power grid administrator with VPP(virtual power plant).

• Proceedings of the KIEE Conference
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• 2006.07e
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• pp.85-86
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• 2006

최근 정부에서는 고효율 기기 개발과 ESCO 사업 등을 통해 낭비되고 있는 에너지를 절감하기 위해 노력하고 있고, 산업 패러다임 변화에 따른 전력 IT 기술 중요성이 상승하고 있어 디지털 멀티미디어 기술과 융합된 지능형 전원 관리시스템 개발이 필요한 실정이다. 따라서 본 연구에서는 리모콘 및 인체감지에 의한 스위치 및 콘센트의 개별/동시 제어기법을 이용한 지능형 전원 관리 시스템 개발하고 특성실험을 통해 우수성을 입증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.482-485
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• 2010

정부의 신성장 동력산업으로 스마트 그리드 분야가 대두되고 있다. 전기사용량 절약, 전력 예비율 확보와 전력망의 신뢰성 확보를 통해 에너지 자원의 효율적 이용이 필요한 시대이다. 산업현장의 차단기를 디지털화하고, 각각의 전력 정보를 자동으로 수집하여 모니터링 시스템으로 설계함으로써 효율적인 전력 관리 및 긴급상황에 대처할 수 있게 된다. 산업현장의 전력 에너지 모니터링 시스템 설계를 바탕으로 타 분야에서도 응용할 수 있도록 설계하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.129-136
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• 2019

In this study, we proposed a model for forecasting power energy demand by investigating how outside temperature at a given time affected power consumption and. To this end, we analyzed the time series of power consumption in terms of the power spectrum and found the periodicities of one day and one week. With these periodicities, we investigated two time series of temperature and power consumption, and found, for a given hour, an approximate linear relation between temperature and power consumption. We adopted an exponential smoothing model to examine the effect of the linearity in forecasting the power demand. In particular, we adjusted the exponential smoothing model by using the variation of power consumption due to temperature change. In this way, the proposed model became a mixture of a time series model and a regression model. We demonstrated that the adjusted model outperformed the exponential smoothing model alone in terms of the mean relative percentage error and the root mean square error in the range of 3%~8% and 4kWh~27kWh, respectively. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric energy together with the outside temperature.