• 조명전기설비학회논문지
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• 제21권10호
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• pp.22-28
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• 2007

본 논문은 지역 특성에 따른 각 피더의 정전비용 모델을 제시하였다. 수용가 형태별 정전비용은 한국전기연구원에서 실시한 국내 배전계통의 수용가 정전비용 조사결과를 이용하였다. 특정지역에 위치한 피더의 정전비용 산출을 위하여 주택용, 상업용, 공공용, 산업용의 비율을 고려하여 합성 정전비용 모델을 수립하였다. 제시한 기법은 수도권과 중소도시 지역의 한 피더에 대해 사례연구를 수행하여 결과를 제시하였다.

• 조명전기설비학회논문지
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• 제24권8호
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• pp.1-7
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• 2010

전력계통의 신뢰도와 배전계통의 유지보수는 매우 밀접한 관계가 있다. 본 논문에서는 정전비용의 최소화를 목적함수로 배전계통의 유지보수 계획을 수립하는 방안을 제시한다. 시변고장률을 이용하여 배전계통 내 특정설비의 고장으로 인한 정전비용을 수식화하고 공급구역의 정전비용을 목적함수로 최적화를 수행하며 경제성 분석을 통하여 투자비용 제약을 적용하여 유지보수를 위한 투자설비 우선순위를 결정한다. 제안한 방안을 검증할 모델계통은 국내의 도심지역 변전소를 통해 만들었으며, 제안된 방안의 신뢰도의 이득을 평가함으로서 그 타당성을 검증하였다.

• 전기학회논문지
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• 제60권5호
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• pp.929-935
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• 2011

Customers hardly change to electric prices in old days because electricity is essential commodity, while demand changes with price after deregulation. It's explained by price-based demand response with demand-elasticity matrix. Also all of the customers have had identical demand-price elasticity matrix till now. But in a practical power system, various customers are present with taking a variety of demand-price elasticity. Therefore this paper proposes demand-price sensitivity to represent different demand-price elasticity. Also as proposing demand-reliability sensitivity, it is modeling various customers' characteristics to reliability. And then this paper calculates total expected interruption cost of customer from the customer interruption cost and the demand-reliability sensitivity. A total expected interruption cost of system is shown as opportunity cost of a generation cost.

• 한국컴퓨터정보학회논문지
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• 제24권3호
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• pp.105-112
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• 2019

In this paper, we propose a technique to analyze similarity between SQL queries and to assist integrating similar tables. First, the table information was extracted from the SQL queries through the query structure analyzer, and the similarity between the tables was measured using the Jacquard index technique. Then, similar table clusters are generated through hierarchical cluster analysis method and the co-occurence probability of the table used in the query is calculated. The possibility of integrating similar tables is classified by using the possibility of co-occurence of similarity table and table, and classifying them into an integrable cluster, a cluster requiring expert review, and a cluster with low integration possibility. This technique analyzes the SQL query in practice and analyse the possibility of table integration independent of the existing business, so that the existing schema can be effectively reconstructed without interruption of work or additional cost.

• 전기학회논문지
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• 제66권3호
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• pp.513-521
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• 2017

Robust optimal operation of a microgrid is required since the increase of the penetration level of renewable generators in the microgrid raises uncertainty due to their intermittent power output. In this paper, an application of probabilistic optimization method to economical operation of a microgrid is studied. To simplify the treatment of the uncertainties of renewable generations and load, the new 'band of virtual equivalent load variation' is introduced considering their uncertainties. A simplified robust optimization methodology to generate the scenarios within the band of virtual equivalent load variation and to obtain the optimal solution for the worst scenario is presented based on Monte Carlo method. The microgrid to be studied here is composed of distributed generation system(DGs), battery systems and loads. The distributed generation systems include combined heat and power(CHP) and small generators such as diesel generators and the renewable energy generators such as photovoltaic(PV) systems and wind power systems. The modeling of the objective function for considering interruption cost by the penalty function is presented. Through the case study for a microgrid with uncertainties, the validity of proposed robust optimization methodology is evaluated.