• 조명전기설비학회논문지
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• 제27권11호
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• pp.69-75
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• 2013

This paper proposes a new algorithm for the optimal placement of a step voltage regulator(SVR) in distribution system with Distributed Generators(DG) using a Particle Swarm Optimization(PSO). The objective function of this algorithm is to find optimal placement for minimum loss while maintaining each node voltage fluctuations within upper and lower limits. In the objective function of proposed algorithm, the deviations to reference voltage and the distribution loss are considered. To verify effectiveness of the proposed method, simulation is implemented using MATLAB.

• 한국압력기기공학회 논문집
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• 제13권2호
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• pp.31-37
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• 2017

The heat transfer function or thermal performance is the most important function of the steam generator component in nuclear power plants. The declining of thermal performance, fouling does not affect the electric power of the nuclear power plant within a certain fouling level, but it affects the output when goes beyond the governor valve wide open of the turbine. The VWO steam pressure can be predicted through the thermal performance evaluation of steam generators in the nuclear power plant. In consideration of the fouling characteristics of the steam generator, methods of the thermal performance evaluation and fouling cases are reviewed, and also the critical VWO value is estimated through the actual thermal performance evaluation. It is necessary to apply the VWO theory based on the thermal performance of the steam generators.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1064-1072
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• 2017

The power of controlled generators in microgrids randomly fluctuate because of the stochastic volatility of the outputs of photovoltaic systems and wind turbines as well as the load demands. To address and dispatch these stochastic factors for daily operations, a dynamic economic dispatch model with the goal of minimizing the generation cost is established via chance-constrained programming. A Monte Carlo simulation combined with particle swarm optimization algorithm is employed to optimize the model. The simulation results show that both the objective function and constraint condition have been tightened and that the operation costs have increased. A higher stability of the system corresponds to the higher operation costs of controlled generators. These operation costs also increase along with the confidence levels for the objective function and constraints.

• 시멘트 심포지엄
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• 19호
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• pp.14-17
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• 1991

The electrostatic precipitator is known to the cement industry as the preferred dedusting equipment for the main dust emission sources. To understand the function better, a short description of the theory of precipitation is presented, with the factors in

• 조명전기설비학회논문지
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• 제12권2호
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• pp.69-76
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• 1998

본 논문에서는 배압터빈과 추기복수터빈으로 이루어진 열병합 발전플랜트의 최전운전을 결정할 수 있는 새로운 알고리즘을 제시한다. 제시한 알고리즘은 플랜트가 운전중에 직접 온 라인으로 취할 수 있는 증가량만을 파라메타로 하여 보일러와 터빈-발전기의 최적부하를 결정할 수 있다. 본 알고리즘은 비선형 경비함수와 해당 제한사항들로 이루어져 있으며 실제 운전중인 열병합 발전플랜트와 비교 시뮬레이션을 실시한 결과 만족할만한 결과를 얻었다. 즉 실제 운전 데이터와 비교해본 결과 공정의 증기 부하량에 따라 1.2∼4.5[%]의 운전경비 절감효과를 얻을 수 있었다. 또한 본 알고리즘은 필요한 입력 데이터를 공정으로부터 쉽게 온 라인으로 취할 수 있어 프로세스 컴퓨터로 용이하게 구현할 수 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권4호
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• pp.169-175
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• 2001

Ozone has been widely applied to many industrial fields because of its strong oxidation power, Therefore, the studies have been carried out for the methods on an effective and high concentration ozone generation. The silent or surface discharge type ozone generators have been mainly used for high concentration ozone generation in many fields of applications. But these two types of ozone generators have shortcomings to be improved. In this study, the ozone generator which improved the shortcomings of above ozone generators was proposed and fabricated for the high concentration ozone generation. And the proposed ozone generator could generate the surface and barrier discharge simultaneously. For this purpose, a mesh type discharge electrode was proposed and studied as a function of the widths output maximum ozone concentration of 2.96[vol%] was obtained at 5.6[kV], 830[mA], for 0.3[mm] width and 0.8[mm] vacancy of the mesh electrode and gap spacing of 0.65[mm] respectively.

• 정보보호학회논문지
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• 제7권3호
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• pp.11-22
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• 1997

출력 수열의 수가 스트림암호의 새로운 평가요소로서 제안된 바 있으나 일반적으로 발표된 대부분의 이진 수열 발생기는 출력 수열이 1개 뿐인 것으로 알려졌다. 본 논문에서는 출력 수열의 수가 여러 개인 다수열 출력 이진 수열 발생기를 2가지 유형으로 제안하였다. 첫 번째는 여러개의 feedback tap중 하나를 초기키에 따라 선택하는 Switched-Tap LESR(STLFSR)과 이를 이용한 일반형 모델 및 Geffe 발생기의 적용 예를 제안하였다. 나머지는 다수열 출력 수열로 이미 알려진 golic의 메모리 수열발생기(MEM-BSG)를 개선하여 대용량 메모리 사용이 가능하도록 일반화시킨 대용량 메모리형 다수열 출력 발생기(GMEM-BSG)를 제안하고, 이 발생기의 주기, 선형복잡도 및 출력 수열의 수를 분석하였다.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.234-240
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• 1999

This paper presents a new approach for large-scale generator maintenance scheduling optimizations. The generator preventive maintenance scheduling problems are typical discrete dynamic n-dimensional vector optimization ones with several inequality constraints. The considered objective function to be minimized a subset of{{{{ { R}^{n } }}}} space is the variance (i.g., second-order momentum) of operating reserve margin to levelize risk or reliability during a year. By its nature of the objective function, the optimal solution can only be obtained by enumerating all combinatorial states of each variable, a task which leads to computational explosion in real-world maintenance scheduling problems. This paper proposes a new priority search mechanism based on each generator's discrete sensitivity value which was analytically developed in this study. Unlike the conventional capacity-based priority search, it can prevent the local optimal trap to some extents since it changes dynamically the search tree in each iteration. The proposed method have been applied to two test systems (i.g., one is a sample system with 10 generators and the other is a real-world lage scale power system with 280 generators), and the results anre compared with those of the conventional capacith-based search method and combinatorial optimization method to show the efficiency and effectiveness of the algorithm.

• Journal of Power Electronics
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• 제19권6호
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• pp.1554-1565
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• 2019

When grid voltage is unbalanced, the grid-connected output current and power of Virtual Synchronous Generators (VSGs) are distorted and quadratic. In order to improve the power quality of a grid connected to a VSG when the grid voltage is unbalanced, a comprehensive coordinated control strategy is proposed. The strategy uses the positive sequence current reference command obtained by a VSG in the balanced current control mode to establish a unified negative sequence current reference command analytical expression for the three objectives of current balance, active power constant and reactive power constant. In addition, based on the relative value of each target's volatility, a comprehensive wave function expression is established. By deriving the comprehensive wave function, the corresponding negative sequence current reference value is obtained. Therefore, the VSG can achieve the minimum comprehensive fluctuation under the premise that the three targets meet the requirements of grid connection, and the output power quality is improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

• 한국산업정보학회논문지
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• 제7권5호
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• pp.67-72
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• 2002

출력 키수열의 사이클 수가 암호 분야에서 새로운 평가 요소로서 제안된 바 있으나 대부분의 이진 수열 발생기는 출력 사이클이 1개 뿐인 것으로 알려져 있다 본 논문에서는 다수 사이클을 갖는 발생기의 기본 함수로서 switching-tap LFSR과 이를 응용한 Rueppel 개선형 다수열 발생기를 제안하였다. 그리고 개선된 발생기에 대하여 주기, 선형 복잡도 및 출력 사이클 수에 대하여 안전성을 분석하였다.