• Journal of the Optical Society of Korea
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• 제18권2호
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• pp.118-123
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• 2014

For multi parameter optimization of Raman Fiber Amplifier (RFA), a simple genetic algorithm is presented in the scenario of a 320 channel Dense Wavelength Division Multiplexed (DWDM) system at channel spacing of 25 GHz. The large average gain (> 22 dB) is observed from optimized RFA with the optimized parameters, such as 39.6 km of Raman length with counter-propagating pumps tuned to 205.5 THz and 211.9 THz at pump powers of 234.3 mW, 677.1 mW respectively. The gain flattening filter (GFF) has also been optimized to further reduce the gain ripple across the frequency range from 190 to 197.975 THz for broadband amplification.

• Journal of the Optical Society of Korea
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• 제18권5호
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• pp.442-448
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• 2014

For the first time, a novel analytical model of the net gain for a Raman-EDFA hybrid optical amplifier (HOA) is proposed and its various parameters optimized using a genetic algorithm. Our method has been shown to be robust in the simultaneous analysis of multiple parameters (Raman length, EDFA length, and pump powers) to obtain large gain. The optimized HOA is further investigated at the system level for the scenario of a 50-channel DWDM system with 0.2-nm channel spacing. With an optimized HOA, a flat gain of >17 dB is obtained over the effective ITU-T wavelength grid with a variation of less than 1.5 dB, without using any gain-flattening technique. The obtained noise figure is also the lowest value ever reported for a Raman-EDFA HOA at reduced channel spacing.

• 한국지능시스템학회논문지
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• 제20권6호
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• pp.820-824
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• 2010

유전 알고리즘은 비선형 전역 최적화 문제 해결에 효과적이라고 알려져 있다. 그러나 해답의 신뢰성을 높이려면 많은 양의 계산이 필요하여 온라인 방식에는 적합하지 않다. 본 논문에서는 집단 피드백 유전 알고리즘을 사용한 온라인 비선형 시스템 식별기 구성을 제안한다. 제안된 시스템 식별기의 유용성은 모의실험을 통해 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.485-487
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• 1995

This paper proposes a GAs-applied method for power system planning using series capacitors in order to control the flow of power as desired and utilize the existing transmission facilities to its transfer capacity limits. The control strategy problem is formulated as optimization problem. Also, in employing genetic algorithms to solve the optimization problems, real variable-based genetic algorithm is presented to save the coding processing time and obtain more accurate value of the variable. An application to IEEE 57-bus test system proves that the proposed method is effective for improvement of power system transfer capacity.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.354-360
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• 1998

In general, it is very difficult to find optimal fuzzy rules by experience when a system is dynamical and/or complex. Futhermore proper fuzzy partitioning is not deterministic and there is no unique solution. Therefore we propose a new design method of an optimal fuzzy logic controller, that is a co-evolutionary genetic algorithm finding optimal fuzzy rule and proper membership functions at the same time. We formalize the relation between fuzzy rules and membership functions in terms of fitness. We review the typical approaching methods to co-evolutionary genetic algorithms , and then classify them by fitness relation matrix. Applications of the proposed method to a path planning problem of autonomous mobile robots when moving objects exist are presented to demonstrate the performance and effectiveness of the method.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권3호
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• pp.157-163
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• 2000

In this paper, an Evolving Neural Network Controller(ENNC) which its structure and its connection weights are optimized simultaneously by Real Variable Elitist Genetic Algoithm(RVEGA) was presented for stabilization of an Inverter Pendulum(IP) system with nonlinearity. This proposed ENNC was described by a simple genetic chromosome. And the deletion of neuron, the determinations of input or output neuron, the deleted neuron and the activation functions types are given according to the various flag types. Therefore, the connection weights, its structure and the neuron types in the given ENNC can be optimized by the proposed evolution strategy. Through the simulations, we showed that the finally acquired optimal ENNC was successfully applied to the stabilization control of an IP system.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.58-61
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• 2003

A loop power system has a nonlinear characteristics. Also it is very hard to analyse through a equation if a discontinuous characteristic of the ULTC is added to a system. However, the problem which is hard to analyse by equations can acquire the useful result with what use the genetic algorithm (GA) which is a multi-point search program. In this paper, we proved through a simulation that the proposed method can reduce an operation frequency of tap changers and improving the quality of voltage of the buses by decreasing the deviation between the actual voltage and the reference voltage through the coordinated control of the ULTC that use GA in the loop power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2230-2232
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• 2003

One of the important problems in a control system design is the requirement that the system should have adequate relative stability. In this paper, We proposed a tuning algorithm PI controller for first order plus dead time system. It is determined the domain of the PI control parameters by Routh - Hurwitz criterion, and we tune parameters of the PI controller using genetic algorithm. A numerical example is also given to illustrate the method.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2007년도 추계학술대회
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• pp.592-601
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• 2007

In the conventional double auction approaches, two basic assumptions are usually applied - (1) each trader has a linear or quasi-linear utility function of price and quantity, (2) buyers as well as sellers have identical utility functions. However, in practice, these assumptions are unrealisitc. Therefore, a flexible and integrated double auction mechanism that can integrate all traders' diverse utility functions is necessary. We propose a double auction mechanism with resource allocation based on nonlinear utility functions, namely a flexible synchronous double auction system where each participant can express a diverse utility function on the price and quantity. In order to optimize the total market utility consists of multiple complex utility functions of traders, our study proposes a genetic algorithm (GA) We show the viability of the proposed mechanism through several simulation experiments.

• 국제강구조저널
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• 제18권5호
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• pp.1598-1606
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• 2018

An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.