• 한국통신학회논문지
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• 제34권9C호
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• pp.887-895
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• 2009

본 논문은 다중 안테나를 가진 릴레이가 설치된 다중-셀 다중-사용자 시스템에서 부분 채널 정보를 이용하여 기지국과 릴레이 간 협력적으로 전력을 할당하는 기법을 제안한다. 이중-흡 MISO (Multi-Input Single-Output) 릴레이 채널에서, 릴레이 채널 용량(end-to-end capacity)을 최대화하기 위해 홉 간 송신 전력을 채널 상태에 따라 동적으로 할당할 필요가 있다. 제안된 기법은 목표 릴레이의 평균 채널 이득과 인접 릴레이로부터의 원하는 채널과 간섭 채널의 송신 상관 행렬의 주요한 고유벡터의 상대적인 각도 차이를 고려하여 릴레이 송신 전력을 동적으로 할당한다. 상향-경계치 분석을 통해서 릴레이 채널 용량은 원하는 채널과 간섭 채널의 주요한 고유벡터의 상대적인 각도 차이가 직교가 될 때 최대가 됨을 이론적으로 증명하였다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제11B권4호
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• pp.156-163
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• 2001

In this paper an optimal switching angle control of a switched reluctance motor (SRM) drive system is investigated for achieving maximum energy conversion ratio. A new magnetizing method is proposed with a low switching frequency. The proposed algorithm maximizes the positive energy conversion region, which is directly related to the mechanical output, and reduces the reactive power region with the same field energy region. As a consequence, a torque ripple is also sufficiently reduced compared with that of the conventional switching angle magnetizing method. Experimental results show that the proposed scheme provides a high efficiency and a low ripple drive.

• 대한전기학회논문지
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• 제34권5호
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• pp.193-200
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• 1985

Increased attention has been given in recent years to the use of pumped hydrostorage plant to meet the requirements for peak generation and bottom pumping. Once a pumped hydrostorage plant is installed, its economic operation as an integral component of a steam generating system requires the selection of a pumping and generating schedule which will result in the most effective use of the hydro generating capacity. The general object of coordination of pumped hydrostorage plants with electric power system is the minimization of the overall procduction cost and the maximization of generation reserves. This paper presents a method for the optimal scheduling of pumped hydrostorage plant and a computer program which determines weekly operating schedules for a pumped hydrostorage plant by dynamic programming method.

• 대한전기학회논문지:전력기술부문A
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• 제54권7호
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• pp.352-357
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• 2005

In competitive electricity markets, the System Operator (SO) coordinates the overall maintenance schedules when the collective maintenance schedule reported to 50 by Gencos not satisfy the specified operating criteria, such as system reliability or supply adequacy. This paper presented a method that divides generator maintenance scheduling of the 50 into a master-problem and a sub-problem. Master-problem is schedule coordination and sub-problem is DC-optimal power flow. If sub-problem is infeasible, we use the algorithm of modifying operating criteria of master-problem. And, the 50 should use the open information only, because the information such as cost function of a generator and bidding Price is highly crucial for the strategies of profit maximization.

• 대한전기학회논문지:전력기술부문A
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• 제53권9호
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• pp.521-528
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• 2004

The demise of the native franchise markets and the emergence of competitive markets in electricity generation service is substantially altering the way that operation and planning activity is conducted and is making it increasingly difficult for market participants such as generation firms to prospect the future electricity markets. Traditional generation expansion planning (GEP) problems which centrally determine the least-cost capacity addition plan that meets forecasted demand within pre-specified reliability criteria over a planning horizon (typically 10 to 20 years) is becoming no more valid in competitive market environments. Therefore, it requires to develop a new methodology for generation investments, which is applicable to the changed electric industry business environments and is able to address the post-privatization situation where individual generation firms seek to maximize their return on generation investments against uncertain market revenues. This paper formulates a new generation expansion planning problem and solve it in a market-oriented manner.

• Journal of Communications and Networks
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• 제12권5호
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• pp.459-465
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• 2010

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.55-58
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• 2009

화석연료의 문제점을 보완하고 있는 태양광발전 시스템은 태양전지 모듈의 온도에 따라 출력량이 급격히 변화하는 특성을 가지고 있다. 이러한 특성을 잘 이해하고 전력생산을 극대화 하기위해 태양전지의 온도를 낮추기 위한 방법을 고려하였다. 본 논문에서는 모듈의 전면과 후면에 똑같은 온도 감소 설비를 한 후 전 후면의 온도를 동시에 낮추는 것이 발전량에 더 큰 도움을 준다는 결론을 도출하였다.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.959-968
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• 2013

This paper presents a new approach with artificial immune system algorithm to solve the profit based unit commitment problem. The objective of this work is to find the optimal generation scheduling and to maximize the profit of generation companies (Gencos) when subjected to various constraints such as power balance, spinning reserve, minimum up/down time and ramp rate limits. The proposed hybrid method is developed through adaptive search which is inspired from artificial immune system and genetic algorithm to carry out profit maximization of generation companies. The effectiveness of the proposed approach has been tested for different Gencos consists of 3, 10 and 36 generating units and the results are compared with the existing methods.

• Journal of Biosystems Engineering
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• 제11권1호
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• pp.64-75
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• 1986

The objective of this study was to develop a mathematical model for optimum design of diversified farming systems which have the regional characteristics. For this purpose, the farming surveys were conducted for mainly 1984 agriculture. They were carried out on January and July 1985 for three villages of central region of Korea. The surveyed data were analyzed by systems analysis and the diversified farming systems were modeled. They consist of four and six croping patterns for paddy and upland, two and three kinds of fruit crop and livestock, and seven kinds of farm machinery for each work system. Then a mathematical model was developed by the multiple objective decision making (MODM) method in order to design optimum systems of diversified farming. It consists of 23 decision variables, two objective functions and nine constraint functions. The goals of objective function are maximization of agricultural incomes and power inputs of farm machinery, and the modeled factors for constraint function are arable land, available capital, labor, and land utilization.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.555-557
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• 2006

This paper represent improved On-line Turn off Angle control schemes for switched reluctance motors based on current control. For the purpose of the finding optimal commutation switching angle point, it is utilized him on and turn off position calculation with inductance vs. current vs. flux linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and maximizing efficiency and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated on a prototype experimental system.