• 한국콘텐츠학회논문지
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• 제20권11호
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• pp.636-643
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• 2020

차분 진화 알고리즘은 연속적인 문제 공간인 실수 최적화 문제를 해결하기 위해 개발된 메타휴리스틱 기법 중에 하나이다. 본 연구에서는 차분 진화 알고리즘을 불연속적인 문제 공간인 외판원 문제 해결에 사용하기 위하여 차분 진화 알고리즘에 난수 키 표현법을 적용하였다. 차분 진화 알고리즘은 실수 공간을 탐색하고 오름 차순으로 정렬된 해의 인덱스의 순서를 도시 방문 순서로 하여 적합도를 구한다. TSPLIB에서 제공하는 표준 외판원 문제에 적용하여 실험한 결과 제안한 난수 키 표현법 기반 차분 진화 알고리즘이 외판원 문제 해결에 가능성을 가지고 있음을 확인하였다.

• 전기학회논문지
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• 제60권2호
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• pp.407-415
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• 2011

In this study, we propose the design of optimized fuzzy controller for the rotary inverted pendulum system by using differential evolution algorithm. The structure of the differential evolution algorithm has a simple structure and its convergence to optimal values is superb in comparison to other optimization algorithms. Also the differential evolution algorithm is easier to use because it have simpler mathematical operators and have much less computational time when compared with other optimization algorithms. The rotary inverted pendulum system is nonlinear and has a unstable motion. The objective is to control the position of the rotating arm and to make the pendulum to maintain the unstable equilibrium point at vertical position. The output performance of the proposed fuzzy controller is considered from the viewpoint of performance criteria such as overshoot, steady-state error, and settling time through simulation and practical experiment. From the result of both simulation and practical experiment, we evaluate and analyze the performance of the proposed optimal fuzzy controller from the comparison between PGAs and differential evolution algorithms. Also we show the superiority of the output performance as well as the characteristic of differential evolution algorithm.

• 한국지능시스템학회논문지
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• 제22권4호
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• pp.399-404
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• 2012

Evolutionary algorithms such as genetic algorithm (GA) have been proven their effectiveness when applying to the design of fuzzy models. However, it tends to suffer from computationally expensWive due to the slow convergence speed. In this study, we propose an approach to develop fuzzy models by means of an improved differential evolution (IDE) to overcome this limitation. The improved differential evolution (IDE) is realized by means of an orthogonal approach and differential evolution. With the invoking orthogonal method, the IDE can search the solution space more efficiently. In the design of fuzzy models, we concern two mechanisms, namely structure identification and parameter estimation. The structure identification is supported by the IDE and C-Means while the parameter estimation is realized via IDE and a standard least square error method. Experimental studies demonstrate that the proposed model leads to improved performance. The proposed model is also contrasted with the quality of some fuzzy models already reported in the literature.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.686-693
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• 2013

Generation Expansion Planning (GEP) is one of the most important decision-making activities in electric utilities. Least-cost GEP is to determine the minimum-cost capacity addition plan (i.e., the type and number of candidate plants) that meets forecasted demand within a pre specified reliability criterion over a planning horizon. In this paper, Differential Evolution (DE), and Opposition-based Differential Evolution (ODE) algorithms have been applied to the GEP problem. The original GEP problem has been modified by incorporating Virtual Mapping Procedure (VMP). The GEP problem of a synthetic test systems for 6-year, 14-year and 24-year planning horizons having five types of candidate units have been considered. The results have been compared with Dynamic Programming (DP) method. The ODE performs well and converges faster than DE.

• Journal of information and communication convergence engineering
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• 제19권3호
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• pp.155-160
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• 2021

Differential evolution is an efficient algorithm for solving continuous optimization problems. However, its performance deteriorates rapidly, and the runtime increases exponentially when differential evolution is applied for solving large-scale optimization problems. Hence, a novel cooperative coevolution differential evolution based on Spark (known as SparkDECC) is proposed. The divide-and-conquer strategy is used in SparkDECC. First, the large-scale problem is decomposed into several low-dimensional subproblems using the random grouping strategy. Subsequently, each subproblem can be addressed in a parallel manner by exploiting the parallel computation capability of the resilient distributed datasets model in Spark. Finally, the optimal solution of the entire problem is obtained using the cooperation mechanism. The experimental results on 13 high-benchmark functions show that the new algorithm performs well in terms of speedup and scalability. The effectiveness and applicability of the proposed algorithm are verified.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.665-666
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• 2022

미분 진화는 연속 최적화 문제에 대한 효율적인 알고리즘이다. 그러나 대규모 최적화 문제를 해결하기 위해 미분 진화를 적용하면 성능이 빠르게 저하되고 런타임이 기하급수적으로 증가한다. 이 문제를 극복하기 위해 Spark(SparkDECC라고 함)를 기반으로 하는 새로운 협력 공진화 미분 진화를 제안한다. 분할 정복 전략은 SparkDECC에서 사용된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.559-560
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• 2021

차등 진화는 연속 최적화 문제를 해결하기 위한 효율적인 알고리즘이다. 그러나 대규모 최적화 문제를 해결하기 위해 차등 진화를 적용하면 성능이 급격히 저하되고 런타임이 기하급수적으로 증가한다. 따라서 Spark(SparkDECC로 알려짐)를 기반으로 하는 새로운 협력 공진화 차동 진화가 제안된다. 분할 정복 전략은 SparkDECC에서 사용된다.

• Journal of applied mathematics & informatics
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• 제27권5_6호
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• pp.1235-1246
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• 2009

In this paper, we prove existence results for first order impulsive evolution differential inclusions with nonlocal condition by using a fixed point theorem for condensing multi-valued maps. An example is also given to illustrate the obtained results.

• 한국콘텐츠학회논문지
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• 제14권11호
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• pp.549-557
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• 2014

근래에 게임이론 분야에서 진화계산법을 사용한 교섭게임 분석은 중요한 이슈 중에 하나이다. 본 논문에서는 이질적인 두 인공 에이전트 간의 공진화를 활용하여 교섭게임을 관찰한다. 두 인공 에이전트를 모델링하기 위해 사용된 전략은 진화전략의 종류인 입자군집최적화와 차분진화알고리즘이다. 교섭게임에서 각 전략이 최선의 결과를 얻기 위한 알고리즘 모수들을 조사하고 두 전략의 공진화를 관찰하여 어느 알고리즘이 교섭게임에 더 우수한지 관찰한다. 컴퓨터 시뮬레이션 실험 결과 입자군집최적화 전략이 차분진화알고리즘 전략보다 교섭게임에서 더 우수한 성능을 보임을 확인하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제16권2호
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• pp.93-105
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• 2012

In this paper, we consider the controllability of a certain class of impulsive neutral evolution differential equations in Banach spaces. Sufficient conditions for controllability are obtained by using the Hausdorff measure of noncompactness and Monch fixed point theorem under the assumption of noncompactness of the evolution system.