• 한국전자통신학회논문지
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• 제6권1호
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• pp.135-141
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• 2011

현재 전 세계적으로 신재생에너지에 대한 수요가 증가함에 따라, 국내의 풍력발전기 산업도 더욱 활발해지고 있다. 선진국에서는 이미 많은 풍력발전기를 보유하고 운영/제어하는 기술을 가지고 있지만, 우리나라의 풍력발전기과 관련된 기술은 많이 뒤져 있다. 따라서, 최근 국내에 설치되어 운용중인 대부분의 풍력발전기에서 활용 중인 운영 시스템은 대부분 외산 제품을 도입하여 사용하고 있는 실정이다. 선진국들은 이미 확보한 최적화된 운영 및 제어 기술력을 바탕으로 자국의 풍력발전기 산업을 보호하면서, 전 세계적으로 거대한 시장을 형성하고 있다. 본 연구에서는 풍력 발전기의 효율적인 운영과 제어를 지원하기 위한 풍력발전기 운영 프로토타입 시스템 HMI(Human Machine Interface)을 설계하였다.

• ETRI Journal
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• 제30권3호
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• pp.469-479
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• 2008

This study analyzes factors affecting the competitiveness of broadband over power line communication (BPLC) and predicts demand for the service, based on quantitative information about consumer preferences drawn from a survey of Korean consumers. Findings from the estimation suggest that, although consumers value some beneficial features of BPLC, to be competitive the speed and stability of its data transmission needs to be improved. Moreover, on the basis of a market simulation, we expect BPLC to occupy only a small portion of Korea's Internet access market in the future, a finding we expect would hold true for other developed countries whose Internet access markets are already mature.

• 에너지공학
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• 제11권2호
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• pp.142-148
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• 2002

경쟁적인 전력시장에서 실시간 전력가격의 변화는 전력소비자들의 전력소비에 영향을 주게된다. 서로 다른 특성을 가지는 가정용, 상업용, 산업용 부하들은 전력소비 성향의 변화에 따라 서로 다른 가지 탄력성을 가진다. 따라서, 본 논문에서는 계산된 각 용도별 부하에 대한 수요 탄력성을 적용하여 경쟁 전력시장에서 수요 탄력성에 따른 전력수요의 변화가 현물가격에 미치는 영향을 분석한다.

• 동력기계공학회지
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• 제3권4호
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• pp.28-35
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• 1999

An application of scroll compressor to the residential air conditioning and heat pump markets has generated many reliability problem, especially abnormal noise. Most of these noise problems is due to the check valve and compliance between FS(Fixed Scroll) and OS(Orbiting Scroll). FS and OS are the main parts of scroll compressor and are the main pumping part. But check valve has the role of protection of reverse rotation of OS when power is off. Check valve have several noise problems. Among them, shut down noise and valve movement noise is more than severe than any other problem. In this paper covers with these two noise problem.

• 한국태양광발전학회지
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• 제3권3호
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• pp.56-61
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• 2017

With the appearance of the climate change concerns, energy transition to renewable energy is accelerating over the world. Korea, a latecomer to the renewable energy sector, has also been unable to avoid energy transition. The government is promoting strong goals for expansion of renewable energy. However, switching from stable and controllable conventional generation to intermittent and uncontrollable renewable generation will be a big challenge for the electric power industry. Korea Power Exchange(KPX), which is responsible for the planning and operation of the electric power industry in Korea, is trying to improve measures in various fields such as the implementation of real-time unit commitment and additional real-time markets in order to cope with the volatility and intermittency of renewable energy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.524-526
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• 2001

The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers, with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper calculate the elasticity of each loads and analysis the effects of electric power demands and spot pricing as a function of elasticity in competitive electricity market.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1305-1325
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• 2008

As index option markets grow recently, many analysts and investors become interested in forecasting the volatility of KOSPI 200 Index to achieve portfolio's goal from the point of financial risk management and asset evaluation. To serve this purpose, we introduce NN and SVM integrated with other financial series models such as GARCH, EGARCH, and EWMA. Moreover, according to the empirical test, Integrating NN with GARCH or EWMA models improves prediction power in terms of the precision and the direction of the volatility of KOSPI 200 index. However, integrating SVM with financial series models doesn't improve greatly the prediction power. In summary, SVM-EGARCH was the best in terms of predicting the direction of the volatility and NN-GARCH was the best in terms of the prediction precision. We conclude with advantages of the integration process and the need for integrating models to enhance the prediction power.

• 대한전기학회논문지:전력기술부문A
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• 제51권7호
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• pp.311-316
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• 2002

It has been a basic model for the present electric power industry that more than two generators compete, and thereby the market clearing price and the generation schedules are determined through the bid process. In order for this paradigm to be applicable to real electric power systems and markets, it is necessary to reflect many physical and economic constraints related to frequency and transmission in the dispatching schedule. The paper presents an approach to deriving a Nash bargaining solution in a competitive electricity market where multiple generators are playing with the system operator who mitigates the transmission congestion to minimize the total transaction cost. In this study, we take the effect of the line flows and the role of system operator into the Game. Finally, a case study has been demonstrated to verify the proposed cooperative game.

• KIEE International Transactions on Power Engineering
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• 제5A권1호
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• pp.16-21
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• 2005

In this study, a new Unit Commitment (UC) algorithm is proposed to consider the uncertainty of a daily load profile. The proposed algorithm calculates the UC results with a lower load level than that generated by the conventional load forecast method and the greater hourly reserve allocation. In case of the worst load forecast, the deviation of the conventional UC solution can be overcome with the proposed method. The proposed method is tested with sample systems, which indicates that the new UC algorithm yields a completely feasible solution even when the worst load forecast is applied. Also, the effects of the uncertain hourly load demand are statistically analyzed, particularly by the consideration of the average over generation and the average under generation. Finally, it is shown that independent power producers participating in electricity spot-markets can establish bidding strategies by means of the statistical analysis. Therefore, it is expected that the proposed method can be used as the basic guideline for establishing bidding strategies under the deregulation power pool.

• 디지털산업정보학회논문지
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• 제12권3호
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• pp.231-257
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• 2016

Several efforts to replace the use of existing fossil energy resources have already been made around the world. As a result, a new industry of renewable energy has been created, and efficient energy distribution and storage has been promoted intensively. Among the newly explored renewable energy sources, the most widely used one is solar energy generation, which has a high market potential. An energy storage system (ESS) is a system as required. In this paper, the design and implementation of an ESS for the efficient use of power in stand-alone street lights is presented. In current ESS applied to stand-alone street lights, either 12V~24V DC (from solar power) or 110V~220V AC (from commercial power) is used to recharge power in systems with lithium batteries. In this study, an ESS that can support both solar power and commercial power was designed and implemented; it can also perform emergency recharge of portable devices from solar powered street lights. This system can maximize the scalability of ESSes using lithium batteries with efficient energy conversion, with the advantage of being an eco-friendly technology. In a ripple effect, it can also be applied to smart grids, electric vehicles, and new, renewable storage markets where energy storage technology is required.