• Journal of Communications and Networks
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• v.14 no.6
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• pp.597-605
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• 2012

With the smart grid coming near, wide-area supervisory control and data acquisition (SCADA) becomes more and more important. However, traditional SCADA systems are not suitable for the openness and distribution requirements of smart grid. Distributed SCADA services should be openly composable and secure. Event-driven methodology makes service collaborations more real-time and flexible because of the space, time and control decoupling of event producer and consumer, which gives us an appropriate foundation. Our SCADA services are constructed and integrated based on distributed events in this paper. Unfortunately, an event-driven SCADA service does not know who consumes its events, and consumers do not know who produces the events either. In this environment, a SCADA service cannot directly control access because of anonymous and multicast interactions. In this paper, a distributed security framework is proposed to protect not only service operations but also data contents in smart grid environments. Finally, a security implementation scheme is given for SCADA services.

• Journal of Integrative Natural Science
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• v.9 no.3
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• pp.199-205
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• 2016

In this paper, we established ZIGBEE home network and combined smart-grid and u-Healthcare system. We assisted for amount of electricity management of household by interlocking home devices of wireless sensor, PLC modem, DCU and realized smart grid and u-Healthcare at the same time by verifying body heat, pulse, blood pressure change and proceeded living body signal by using SVM algorithm and variety of ZIGBEE network channel and enabled it to check real-time through IHD which is developed by user interface. In addition, we minimized the rate of energy consumption of each sensor node when living body signal is processed and realized Query Processor which is able to optimize accuracy and speed of query. We were able to check the result that is accuracy of classification 0.848 which is less accounting for average 17.9% of storage more than the real input data by using Mjoin, multiple query process and SVM algorithm.

• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.73-81
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• 2014

In this paper, high-speed Hybrid MAC (Medium Access Control layer) implementation suitable for smart grid applications is researched. MB-OFDM (Multi-Band Orthogonal Frequency Division Multiplexing) is considered for high-speed communication method in smart grid application. In this paper, the MAC adopts the distributed network managing method. Also, the MB-OFDM merit of high-speed transfer rate of up to 480Mbps must be supported. Hence, this paper presents an efficient hardware-software integration (co-design) method in order to realize a high- speed transmission, and a realizing method of distribution network. Finally, MAC performance and reliability based on MB-OFDM PHY (PHYsical layer) are confirmed through simulation and emulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1186-1192
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• 2012

In Jeju Smart Grid field test, Zigbee technology is being used as one of customer side solutions for AMI. Although Zigbee networks that provides effective connectivity and control among devices are advantages in ease of implementation and use, the data can be exposed to cyber attacks such as eavesdrop, unauthorized data dissemination and forgery. Currently authentication and confidentiality services are provided with the network and link keys generated based on public key pairs that are pre-installed in offline. However, the network is vulnerable once a hacker intrudes into a local network because operation and management policies for the generated keys are not well-established yet. In this paper, the vulnerability of the Zigbee security system in the customer side environment of Jeju Smart Grid field test is analyzed. Then, two-way authentication with the unique identifiers of devices and user-specific group management policies are proposed to resolve the vulnerability.

• Journal of Power Electronics
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• v.14 no.3
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• pp.421-431
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• 2014

A DSP-based self-adaptive proportional-integral (PI) controller to control a DC-DC converter is proposed in this paper. The full-bridge topology is adopted here to obtain higher power output capability and higher conversion efficiency. The converter adopts the zero-voltage-switching (ZVS) technique to reduce the conduction losses. A parallel secondary active clamp circuit is added to deal with the voltage overshoot and ringing effect on the transformer's secondary side. A self-adaptive PI controller is proposed to replace the traditional PI controller. Moreover, the designed converter adopts the constant-current and constant-voltage (CC-CV) output control strategy. The secondary active clamp mechanism is discussed in detail. The effectiveness of the proposed converter was experimentally verified by an IGBT-based 10kW prototype.

• Journal of Information Processing Systems
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• v.13 no.6
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• pp.1487-1495
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• 2017

With increasing interests in renewables, more consumers are installing an energy storage system (ESS) in their backyards, and thus, the ESS will play a critical role in the emerging smart grid. Due to mechanical properties, however its operational dynamics must be well understood before connecting the ESS to the smart grid (and eventually to an IT system). To this end, we investigate charging and discharging processes in detail. This paper, then, proposes methods for four type tests (state of charge test, conversion efficiency test, response time test, and ramp rate test) that can assess the dynamics of the ESS. The proposed methods can capture accurate delay values of mechanical processes in the ESS, and it is expected for those values to help design real-time communication systems in the smart grid involving the ESS.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.359-360
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• 2010

In smart grid system which uses photovoltaic system, fuel cells and so on, a program implemented with C language is used for control and measurement. When using programs implemented with C language GUI is difficult to watch control and monitor the smart grid system. But LabVIEW is a graphical programming language and it is easy to design GUI screen and to manage many variables such as real-time output of electric power including solar cell, wind power system and fuel cell. This paper suggests LabVIEW and C-language TCP/IP communication for smart grid monitoring system i mplemented with C-language.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.211-218
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• 2012

In this paper, we propose a system architecture of the AMI to be applied in the modern agricultural sector. Agricultural electricity costs in South Korea is very inexpensive compared with other industries. It is expected to increase oil prices to rise over the medium to long term so the facilities must to be installed for farmers in terms of energy savings and energy costs. The research and development of plant factory which can replace the ills of modern agriculture is very active. The technologies of smart grid and plat factory are good paradigm of next generation agricultural sector. Good use of smart grid technologies, the traditional energy consumption industries, agriculture sector can be self-sufficiency industry. In this article the AMI architecture is developed and it will be applicable for modern farmers plant factory.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.155-158
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• 2011

U-city구축에서 전기의 안전한 공급과 전기로 인한 화재 등 재난에 대한 통제가 가능해야 한다. U-city에 구축되어야 할 Smart Grid 네트워크와 Smart Grid 인프라 구축을 위해서 사용되는 전기IT기기에 대한 인증을 위한 인증설계와 인증방법에 대한 연구가 필요하다. 본 논문에서는 개발이 진행 중인 전기IT기기의 인증을 위하여 국내 국제표준화 기준을 연구한 후 국내에서 인증 받을 수 있는 인증설계를 연구한다. 인증설계는 Home Network Wall-Pad, 비접촉식 아크 검출기, 아크 안전진단, 아울렛, 저전압 배전반(MPNP) 블랙박스, 차단기이다. 그리고 인증기관에서 인증적용과 인증내용 및 평가기준과 전기IT기기의 인증심의 기관에서 기준 값 등에 관한 연구를 한다. 본 연구는 Smart Grid 네트워크와 인프라 구축을 위한 실무적인 연구 자료로 활용될 것이다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.720-721
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• 2011

본 논문에서는 제주 스마트그리드실증단지에서 진행중인 스마트그리드 5개 프로젝트 중 송배전분야의 전력망을 통합 운영하는 Smart Power Grid(SPG) 실증시스템의 설계와 구축 현황에 대해서 기술한다. 스마트그리드 프로젝트는 SPG외에도 ST(Smart Transportation), SP(Smart Place), SR(Smart Renewable), SES(mart Electric Service)가 있는데, SPG는 SES 프로젝트에서 운영하는 통합관제센터(TOC)를 거쳐 ST, SR, SP 시스템들과 운전 정보를 서로 교환하여 사용한다.