• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.71-79
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• 2014

This paper discusses a method for the determination of frequency control reserve requirement with consideration of the interaction between ex-ante planning and real-time balancing. In proposed method, we consider the fact that the delivered energy for tertiary control reserve is determined based on required capacity for secondary control reserve and the expected amount of load errors. Uncertain load errors are derived by Brownian motion, an optimization method is suggested using a stochastic programming. In a short, we propose an interactive dependent method for determining secondary control reserve requirement based on the principle that it satisfies to minimize the total cost. As a result, this paper provides will analyze for an example model to demonstrate the capabilities of the method.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1397-1405
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• 2017

As the introduction of wind power is steadily increasing, negative effects of wind power become more important. To operate a power system more reliable, the system operator needs to recognize the maximum required capacity of available generators for a certain period. For recognizing the maximum capacity, this paper proposes a methodology to determine an optimal reserve requirement considering wind power, for the certain period in the mid-term perspective. As wind speed is predicted earlier, the difference of the forecasted and the actual wind speed becomes greater. All possible forecast errors should be considered in determining optimal reserve, and they are represented explicitly by the proposed matrix form in this paper. In addition, impacts of the generator failure are also analyzed using the matrix form. Through three main stages which are the scheduling, contingency and evaluation stages, costs associated with power generation, reserve procurement and the usage, and the reliability cost are calculated. The optimal reserve requirement is determined so as to minimize the sum of these costs based on the cost/reliability analysis. In case study, it is performed to analyze the impact of wind power penetration on the reserve requirement, and how major factors affect it.

• 한국비블리아학회지
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• 제32권1호
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• pp.199-221
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• 2021

우리나라 대학도서관에서는 미국과 달리 지정자료 및 e-Reserve 서비스 운영이 매우 저조한 실정이다. 본 연구는 국내 대학도서관의 e-Reserve 서비스 활성화를 위한 기초 자료를 제공하기 위하여 미국 131개 대학도서관의 e-Reserve 서비스 운영 사례를 살펴보았다. 운영 사례를 확인하기 위하여 131개의 대학도서관 웹사이트를 조사하였으며 중에서 7개 대학도서관의 e-Reserve 서비스 운영 방식을 비교 분석하고, 4개의 e-Reserve 지원 소프트웨어의 기능을 확인하였다. 연구결과는 국내 대학도서관에서 e-Reserve 서비스를 운영하는데 있어 참고자료로 활용될 수 있을 것이며 분석한 지원 소프트웨어의 기능은 시스템 도입 시 고려할 기능요건이 될 것으로 판단된다.

• 전기의세계
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• 제24권5호
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• pp.97-102
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• 1975

This paper describes the result of a Study for the Optimum Operating method with Spinning reserve in case of outage of large generator unit to improve the system stability and prevent the system frequency drop. This is usually done by governor free operation, so we focused our attention to the operating Char acteristics of spinning reserve. Nexy, a study was made to mesure the upper limit of Spinning reserve and when this upper limit cannot match the required power, a relationship between the amount of spinning reserve and that of the load shedding requirement was searched with regard to several system operating conditions to use it in our future system operation. By this study, the optimum system operating method was recommended for reliable operation of power system.

• Clinical and Experimental Reproductive Medicine
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• 제43권3호
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• pp.139-145
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• 2016

Measurements of ovarian reserve play an important role in predicting the clinical results of assisted reproductive technology (ART). The ideal markers of ovarian reserve for clinical applications should have high specificity in order to determine genuine poor responders. Basal follicle-stimulating hormone levels, antral follicle count, and serum anti-$M{\ddot{u}}llerian$ hormone (AMH) levels have been suggested as ovarian reserve tests that may fulfill this requirement, with serum AMH levels being the most promising parameter. Serum AMH levels have been suggested to be a predictor of clinical pregnancy in ART for older women, who are at a high risk for decreased ovarian response. We reviewed the prognostic significance of ovarian reserve tests for patients undergoing ART treatment, with a particular focus on the significance of serum AMH levels in patients at a high risk of poor ovarian response.

• 전기학회논문지
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• 제57권8호
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• pp.1318-1326
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• 2008

This paper proposes an alternative methodology for deciding an optimum deterministic reliability level (IRR; Installed Reserve Rate) by using probabilistic reliability criterion (LOLE; Loss of Load Expectation). Additionally, case studies using the proposed method induce the characteristics of relationship between the probabilistic reliability index (LOLE) and deterministic reliability index (IRR) for 2008 and 2010 years in Korea power system. The case study presents a possibility that an optimum IRR level in Korea can be assessed using the proposed method. Korea power system has been using the LOLE criterion to determine the adequacy of installed capacity (ICAP) requirement. The criterion in Korea is that the loss of load expectation shall not exceed the available capacity more than five day in ten years (=0.5[days/year]), The probabilistic reliability evaluation and production cost simulation program which is called PRASim is used in order to evaluate the relationship and optimum IRR in this paper.

• 수산경영론집
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• 제42권3호
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• pp.95-107
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• 2011

The Comprehensive Measures for a soft landing of Household Debts affecting the credit service of Fisheries Cooperative (FC) have been known to the public in June 2011. Its essential points are as follows: 1) Abolition of Tax-free Regulation, 2) Set limit of loans, etc. per person, 3) Introduce leverage regulations for credit-specialized financial sector i. e. FC, 4) Gradually strengthen loan-loss reserve requirements for card-loan and other credit loans. However, the Financial Policy Measures seem to pay no attention to the Cooperative's Values, Principles and Identity. In this paper, emphasis is be placed on the task of the regulators i. e. Financial Services Commission and Financial Supervice Service to lift the Financial Measures negatively affecting the operation of fund of FCs, and on the establishment of Cooperative identity in order to further develop FCs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.173-175
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• 2007

This paper introduces the characteristics of relationship between probabilistic reliability (LOLE; Loss of Load Expectation) and deterministic reliability (SRR; supply reserve rate) for 2008 year in Korea power system. Korea power system has been using the LOLE criterion to determine the adequacy of installed capacity (ICAP) requirement. The criterion is that load shall not exceed the avaliable capacity, on the average, more than five day in ten years. The probabilistic reliability evaluation and production cost simulation program which is called PPHFHT was used in order to obtain the relationship in this paper.

• 전기학회논문지
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• 제61권11호
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• pp.1565-1570
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• 2012

Nuclear power generation is increasing domestic power supply ratio by lower CO2 emission and fuel prices. Currently, nuclear power generator has been operated with maximum power output. Therefore, nuclear power generator could be no effect to managing the reactive power reserve on power system. The reactive power reserve is calculated to the difference between maximum facility and operation generation capacity of the power system. This paper was proposed that load following of nuclear power is control by using 15-bus power system model. In the simulation result, power system is shown to safety state by operating load following of nuclear power generator. This method has be improved the supplied reliability through economic and efficient operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.46-47
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• 2008

전력산업은 국가경제 및 국민생활의 기반이 되는 기간산업으로서 그 역할이 중대하므로 계통운영자는 적정 예비력을 확보하여 양질의 전기를 안정적이고 효율적으로 공급해야 한다. 그러나, 계통규모의 지속적인 증가와 전력수급의 지역적 편중 가속화로 국내 여건은 갈수록 악화되고 있는 실정이다. 또한, 현행 예비력 기준은 계통규모와는 상관없이 정량적으로 확보하게 되어 있으며 예비력 소진시 재 확보해야 할 기준도 마련되어 있지 않다. 따라서, 본 논문에서는 지역적 계통특성을 반영하고 항목별 예비력 기준을 세분화하여 보다 체계적인 예비력 운영기준을 제시하고자 한다.