• International Journal of Internet, Broadcasting and Communication
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• 제8권1호
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• pp.83-90
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• 2016

The emergence of cloud has been able to provide a variety of IT service to the user. As organizations and companies are increased that provide these cloud service, many problems arises on integration. However, with the advent of latest technologies such as big data, document-oriented database, and MapReduce, this problem can be easily solved. This paper is intended to design the Cloud Aggregator to provide them as a service to collect information of the cloud system providing each service. To do this, we use the DBaaS(DataBase as a Service) and MapReduce techniques. This makes it possible to maintain the functionality of existing system and correct the problem that may occur depending on the combination.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.630-632
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• 2003

This paper describes allocation strategies of controllable loads for load aggregator in power market with the direct load control (DLC) program, which is carried out the two-way confirmation procedure. So, it is needed to the priority among the controllable loads to perform effectively and quickly the confirmation task. In this paper, allocation strategies for market operator and/or load aggregator are proposed, which are based on the basic load patterns defined in this paper. To verify the soundness of proposed strategies. case study on a sample system is performed.

• 대한전기학회논문지:전력기술부문A
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• 제53권8호
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• pp.466-471
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• 2004

Electricity industries throughout the world are undergoing unprecedented changes. As a result, these changes lead to the separation of traditional integrated utilities and the introduction of competition in order that increase efficiency in electricity industry. Direct load control (DLC) system in competitive electricity market has a hierarchical interactive operation system, therefore, its control logic is also applied by bilateral interactive method that interchanges information related to interruptible load between operation hierarchies. Consequently, load curtailment allocation algorithm appropriate for new DLC system is required, and based on interchanged information, this algorithm should be implemented by most efficient way for each operation hierarchy. In this paper, we develop the load curtailment allocation algorithm in an emergency for new DLC system. Especially, the optimal algorithm for load aggregator (LA) that participates in competitive electricity market as a main operator for load management is developed.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.789-795
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• 2014

In a demand response (DR) market run by independent system operators (ISOs), load aggregators are important market participants who aggregate small retail customers through various DR programs. A load aggregator can minimize the allocation cost by efficiently allocating its demand response resources (DRRs) considering retail customers' characteristics. However, the uncertain response behaviors of retail customers can influence the allocation strategy of its DRRs, increasing the economic risk of DRR allocation. This paper presents a risk-based DRR allocation method for the load aggregator that takes into account not only the physical characteristics of retail customers but also the risk due to the associated response uncertainties. In the paper, a conditional value-at-risk (CVaR) is applied to deal with the risk due to response uncertainties. Numerical results are presented to illustrate the effectiveness of the proposed method.

• Asian review of World Histories
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• 제4권1호
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• pp.83-123
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• 2016

We describe a vision of historical analysis at the world scale, through the digital assembly of historical sources into a cloud-based database, where machine-learning techniques can be used to summarize the database into a time-integrated actor-to-actor complex network. Using this time-integrated network as a template, we then apply the method of automatic narratives to discover key actors ('who'), key events ('what'), key periods ('when'), key locations ('where'), key motives ('why'), and key actions ('how') that can be presented as hypotheses to world historians. We show two test cases on how this method works. To accelerate the pace of knowledge discovery and verification, we describe how historians would interact with these automatic narratives through an online, map-based knowledge aggregator that learns how scholars filter information, and eventually takes over this function to free historians from the more important tasks of verification, and stitching together coherent storylines. Ultimately, multiple coherent storylines that are not necessary compatible with each other can be discovered through human-computer interactions by the map-based knowledge aggregator.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1335-1341
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• 2015

The utilization of electric vehicles has been suggested to support the frequency regulation of power system. Assuming that an intermediate aggregator exists, this study suggests a decentralized vehicle-to-grid operation scheme in which each vehicle-to-grid aggregator can behave independently of the power system operator. To implement this type of decentralized operation, this study adopts a price-based operation that has been proposed by many researches as an alternative operation scheme for the power system. In this environment, each vehicle-to-grid aggregator can determine its participation in vehicle-to-grid service in consideration of its residual energy of aggregated system and real-time market price. Consequently, the main purpose of this study is to verify whether or not the vehicle-to-grid power can effectively support the current frequency regulation function within the price-based operation scheme. Specifically, a frequency regulation method is proposed based on the real-time price signal, and a feedback controller for battery management is designed for decentralized vehicle-to-grid operation.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.64-74
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• 2015

Because of the burgeoning demand of the energy, the countries are finding sustainable solutions for these emerging challenges. Demand Side Management is playing a significant role in managing the demand with an aim to support the electrical grid during the peak hours. However, advancement in controls and communication technologies, the aggregators are appearing as a third party entity in implementing demand response program. In this paper, a detailed mathematical framework is discussed in which the aggregator acts as an energy service provider between the utility and the consumers, and facilitate the consumers to actively participate in demand side management by introducing the new concept of demand reduction bidding (DRB) under constrained direct load control. Paper also presented an algorithm for the proposed framework and demonstrated the efficacy of the algorithm by considering few case studies and concluded with simulation results and discussions.

• 한국정보교육학회:학술대회논문집
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• 한국정보교육학회 2005년도 하계학술대회
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• pp.304-313
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• 2005

RSS와 같은 신디케이션 기술은 사용자가 스스로 웹사이트에 접근하지 않아도, 새롭게 업데이트 되는 정보가 있을 때마다 RSS Aggregator를 통해 사용자에게 알려줌으로써 편리성을 가져다준다. 이러한 기술을 이용한다면 학습자들은 새로운 웹 문서가 게시될 때마다 해당 사이트를 방문할 필요 없이, 자동으로 신규 정보만 얻어오는 학습 자료의 습득 도구로서 활용이 가능하다. 하지만, 정의가 새롭게 추가되는 여부만을 판단하는 기존의 RSS Aggregator의 경우에 등록된 채널수가 늘어갈수록 사용자는 자신이 원하는 정보를 찾기 위해, 정보를 분류하고 검색하는 작업에 많은 노력을 기울여야한다. 본 논문에서는 이러한 문제점을 해결하고 사용자에게 의다 효율적인 정보 전달을 위해, 사용자 스스로 관심분야를 생성하여, 사용자에게 전달되는 신규자료는 각 분야에 자동적으로 분류되며, 사용자가 지정해 놓은 조건에 적합하도록 콘텐츠를 제공 받을 수 있는 시스템을 설계하였다. 신규자료를 분야에 자동적으로 분류하기 위해 초기 분류된 문서로부터 분야별 색인어 추출 방안을 제안하고자 한다.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2157-2165
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• 2017

This study deals with the design of the mechanism in which demand response (DR) resources are traded in the power generation market. In general, a DR aggregator (DRA), which extends DR resources and provides technical support, is central to this mechanism. In this study, power users, called DR customer (DRC), participate in load reduction and are also modeled to participate directly in DR-related bidding. The DRA provides incentives to the DRC, indirectly impacting the market, and the DRC use the bid parameters strategically. We present the conditions for finding Nash Equilibrium (NE) in game problems of various participants including market operators, and analyze the characteristics of DRA and DRC related models. It also analyzes the impact of the participants on the market according to various types of competition and coalitions between DRA and DRC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.652-653
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• 2011

수요반응(DR : Demand Response)은 스마트 그리드(Smart Grid)를 구성하는 핵심 요소 중 하나이다. 본 논문에서는 스마트 그리드 환경 하에서 ISO(Independent System Operator)의 수요자원시장에 참여함과 동시에 말단 수용가들을 대상으로 다수의 DR 프로그램을 운영하는 LA(Load Aggregator)사업자의 DR자원 운영 시스템에 대한 전반적인 개념 및 흐름에 대하여 기술하였다. 또한, 스마트 그리드 하에서 LA사업자의 DR자원 운영 시스템 설계 중 LA사업자의 DR자원 최적배분 전략에 대한 개념 및 예시를 제시하였다.