• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1259-1261
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• 1999

The paper proposes a simple method to calculate the portion of real power losses allocated to individual loads. The method is implemented by loss distribution factors, and analyses the share of loads in transmission line losses. Effectiveness of the algorithm is verified by a computer simulation. The results can be used to compute the cost of ancillary services under deregulated environment in electric power industries.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.869-871
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• 2005

As deregulated electricity markets are being implemented in different countries, the remuneration of reactive power which contribute to ancillary services is one of the key issues, so it is necessary to evaluate the generator's reactive. In this paper, we focus on the evaluation of reactive power which contributes to reactive power balance. The idea is that the main usages of the reactive power of generator can be divided into two components. First one is physically required amounts for transmitting the real power and the second one is the amounts contributed to support the system, that is, to maintain the voltage profiles. In this paper, the second component is used to evaluate the effective amounts of the reactive power contributed to ancillary service.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.377-382
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• 2016

In 2013, a total capacity of 591.3 MW of installed wind power generation was achieved in Korea, with a total of 1,139 MWh of wind energy generated that year. More wind power plants will be installed in the coming years, and it is important to develop methods to reduce the output variability of these resources so as to provide stable power to the power grid of Korea. In this regard, this paper proposes the use of energy storage system (ESS) as a means to stabilize the output variability of wind power plants. Presented in this paper is a method that uses Discrete Fourier Transform (DFT) to determine the ESS capacity needed to provide a stable power output for ancillary services such as frequency regulation, economic dispatch, and emergency reserves. In the first step of the proposed method, four regions (namely, Samdal, Yeongdeok, Yeongyang, and Gangwon) in Korea that had the most wind power generation capacity were selected for analysis. In the second step, the individual and aggregated wind power outputs of the selected regions in 2013 were obtained This information was then used in the third step, where DFT analysis of the power outputs was used to drive the magnitudes of the output variation. And finally, the ESS capacity requirements needed to provide different ancillary services were determined based on the magnitudes of the output variation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.692-694
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• 2004

As the electric power industry has gone for a deregulated environment from a vertically integrated structure, operations and controls of systems invite new challenges. In the past certain activities, such as voltage and frequency control, were considered as a part of integrated power supply. But now, these become parts of ancillary services which are independent and detailed, and have situations non-disregardable for operation of systems. This paper examines a management of reactive power services adopted in deregulated foreign and domestic markets.

• 노동경제논집
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• 제25권2호
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• pp.79-107
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• 2002

이 논문에서는 영국 노동당 정부의 공공부문 개혁정책의 내용과 그 추진 실태를 알아보고, 그에 대한 노동조합의 대응과 노사관계에 대한 그 영향을 검토하고, 여기서 추출되는 정책적 시사점을 검토하였다. 공공부문 개혁은 민영화가 진행 혹은 논의 중인 보건, 교육, 교통 및 교동소 등을 주된 대상으로 하여 검토하였다. 그리고 이 공공부문 개혁을 둘러싸고 전개되는 노조와 정부 간의 갈등을 알아보고, 여기서 얻을 수 있는 정책적 함의를 모색하였다.

• 한국병원경영학회지
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• 제10권4호
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• pp.23-50
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• 2005

The main objectives of this study are to compare the regional differences and to analyse the affecting factors of customer satisfaction. The subjects are 9 hospitals(5 Daegu region, 4 Seoul region) patient satisfaction index that were surveyed the 2004 Hospital Accreditation Program performed by KHIDI(Korea Health Industry Development Institute) and MOHW(Ministry of Health and Welfare). The sample used in this study consisted of 450 inpatients and 454 outpatients. The survey instrument is composed of physical environment items, physician factors, nursing staff factors, ancillary staff factors, administrative procedure items, and quality of hospital stay items. And overall satisfaction, intent to revisit, and intent to recommend as dependent variables are measured. Basically, the reliability and validity of survey items was evaluated. And the T-test was performed to compare regional differences of customer satisfaction. Finally to analyse the affecting factors on overall satisfaction, and customer loyalty(intent to revisit and intent to recommend), the multiple regression analysis was used. This study shows firstly, the Daegu region's patient satisfaction level of inpatients and outpatients is lower than Seoul region. Especially, nursing staff factors and quality of hospital stay items are very low on inpatient's satisfaction. Also all independent variables except the sufficiency of goods in hospital stand are very low on outpatient's satisfaction. Secondly, as a result of multiple regression analysis, ancillary staff factors(Beta=0.281) have a significant effect on overall satisfaction of inpatient cases in Daegu region. In regard to intent to revisit and intent to recommend, physical environment factors have a significant effect. Thirdly, in Seoul region, physical environment factors(Beta=0.430) have a significant effect on overall satisfaction of inpatient cases. In regard to intent to revisit and intent to recommend, administrative procedure items and nursing staff factors have a significant effect, respectively. In conclusion, these results indicate that hospitals in Daegu region make an effort to improve the customer satisfaction level, especially, of physical environment factors on inpatients and administrative procedure factors on outpatients

• 한국전자파학회논문지
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• 제23권11호
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• pp.1288-1296
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• 2012

최근 기존의 MSS(Mobile Satellite Service) 대역에 지상망과 위성망의 하이브리드 형태인 ATC(Ancillary Terrestrial Component) 서비스 도입이 추진되고 있다. 새로운 MSS/ATC 서비스 주파수 할당을 위해서는 기존의 지상망에 의한 인접 채널 간섭뿐만 아니라 시스템 자체 내의 인접 채널 간섭 분석이 중요하다. 이에 본 논문에서는 인접 채널 간섭에 의한 ACIR(Adjacent Channel Interference Ratio), 지상 이동국 및 위성 이동 지구국의 수를 파라미터로 하여 업링크에서는 지상 기지국 최소 허용 전력 및 시스템 용량(capacity) 손실, 다운링크에서는 1 빔(beam) 당 1 셀(cell)을 가정하여 MSS/ATC 시스템 용량 손실에 대한 시스템 성능을 평가하였다. MSS/ATC 서비스 주파수 배치에 따른 주파수 공유를 위해 두 가지 시나리오 즉, 5 MHz 및 10 MHz 주파수 간격에 대한 ACIR 기준값을 평가하였으며, 향후 이 기준값에 따른 ATC 서비스 커버리지 및 수신 필터 설계 등이 요구된다.

• 대한전기학회논문지:전력기술부문A
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• 제53권1호
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• pp.67-72
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• 2004

This paper addresses the bidding strategies of generating firms in a competitive market where the firms are provided with payment for generating reactive power. Reactive support for voltage control is an integral and critical part of power system operations. Since reactive support is unbundled in a competitive market under open access transmission, it is treated as one of ancillary services. The operation costs and opportunity costs for reactive support are compensated by payment to the firms, hence their bidding strategies will be affected. The opportunity costs are evaluated from the foregone profits of a generator in making sales in real power market by providing reactive support instead of real power. Game theory approach is used to analysis the transaction strategies of real power by the bimatrix method in this paper. Through computing the Nash equilibrium in a sample system, an incentive of a generator for improving the reactive generating capacity is found to be effective and the variations of the profits are analyzed as the demand power factor changes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.181-183
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• 1999

As one of ancillary services, voltage support and reactive power service should be compensed properly for its contribution. In this paper, a cost-based reactive power planning is presented. which minimizes the total cost of reactive power support of generators and VAR compensation facility installation. Reactive power support of generator is evaluated by the opportunity costs of reduced energy sale considering the varying SMP(system marginal price) in power market, Gradient projection method is applied to solve this reactive power planning using IEEE14 bus system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.182-184
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• 2001

This paper presents the application draft of system frequency and reserve criteria for Korean Wholesale Electricity Market. This application draft of system frequency and reserve criteria is based on frequecy, voltage control rules and technical rules for ancillary services agreements prepared by KEMA and the present conditions of KEPCO system operations and future directions.