• 전기학회논문지P
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• 제67권3호
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• pp.131-136
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• 2018

Harmony search (HS) is a relatively recently developed meta-heuristic optimization method imitating the music improvisation process where musicians improvise their instruments' pitches searching for a perfect state of harmony. In the conventional HS algorithm, it is necessary to determine the maximum number of iterations with some algorithm parameters. However, there is no criterion for determining the number of iterations, which is a very difficult problem. To solve this problem, a new method is proposed to perform the algorithm without setting the maximum number of iterations in this paper. The new method allows the algorithm to be performed until the desired tuning is achieved. To do this, a new variable bandwidth is introduced. In addition, the types and probability of harmonies composed of variables is analyzed to help to decide the value of HMCR. The performance of the proposed method is investigated and compared with classical HS. The experiments conducted show that the new method generally outperformed conventional HS when applied to seven benchmark problems.

• Advances in Computational Design
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• 제2권1호
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• pp.1-13
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• 2017

This paper presents a variant of the Harmony Search Algorithm (HS) and its application to discrete optimization. The main proposed modifications regarding original HS are related to stopping criterion and reinitialization of population, called Harmony Memory. In order to investigate the efficiency of the algorithm, it was applied for obtaining optimal sections of reinforced concrete columns subjected to uniaxial flexural compression. To minimize the cost of the section, the amount and diameters of the reinforcement bars and the dimensions of the columns cross sections were considered as design variables. The obtained results were compared to those generated by other optimization methods. Since, to the examples, Harmony Search reached the same results achieved by Simulated Annealing, some additional analysis are presented in order to compare these methods regarding success rate and number of iterations to reach the optimum.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.359-366
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• 2005

Most engineering optimization are based on numerical linear and nonlinear programming methods that require substantial gradient information and usually seek to improve the solution in the neighborhood of a starting point. These algorithm, however, reveal a limited approach to complicated real-world optimization problems. If there is more than one local optimum in the problem, the result may depend on the selection of an initial point, and the obtained optimal solution may not necessarily be the global optimum. This paper describes a new harmony search(HS) meta-heuristic algorithm-based approach for structural size optimization problems with continuous design variables. This recently developed HS algorithm is conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary. Two classical space truss optimization problems are presented to demonstrate the effectiveness and robustness of the HS algorithm. The results indicate that the proposed approach is a powerful search and optimization technique that may yield better solutions to structural engineering problems than those obtained using current algorithms.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.304-315
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• 2018

화음탐색법은 근래에 개발된 메타휴리스틱 알고리즘 중 하나로, 다양한 분야의 최적화 문제에 적용되어 많은 연구자들에게 널리 알려진 바 있다. 하지만 최적화 문제의 복잡성이 날로 증가하여 기존 화음탐색법으로는 최적해를 효율적으로 탐색할 수 없는 경우가 증가하고 있다. 이를 개선하기 위해 기존 매개변수 설정의 변경 및 다른 메타휴리스틱 알고리즘의 특성과의 융합 등을 통해 화음탐색법의 성능을 향상시킨 연구가 다수 존재한다. 본 연구에서는 기존 화음탐색법의 매개변수설정 방법과 해탐색 성능을 개선한 모방 화음탐색법 (Copycat Harmony Search, CcHS)을 제시하였다. 모방 화음탐색법의 성능을 검증하기 위하여 대표적인 수학적 최적화 문제에 적용하여 기존에 개발되었던 향상된 형태의 화음탐색법 알고리즘들과 결과를 비교하였다. 모방 화음탐색법은 모든 수학적 최적화 문제에서 다른 알고리즘보다 전역해에 가까운 해를 찾음으로써 최적해 탐색의 효율성을 입증하였다. 또한, 알고리즘의 공학문제의 적용성을 분석하기 위하여 기존에 널리 적용되었던 상수도관망 최적설계 문제에 CcHS를 적용하였다. 그 결과 본 연구에서는 기존 화음탐색법이 제안한 최소 설계비용보다 약 21.91% 더 저렴한 비용을 제시하였다.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3665-3674
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• 2021

One of the important parts of the in-core fuel management is loading pattern optimization (LPO). The loading pattern optimization as a reasonable design of the in-core fuel management can improve both economic and safe aspects of the nuclear reactor. This work proposes the hybrid of fuzzy logic controller with harmony search algorithm (HS) for loading pattern optimization in a pressurized water reactor. The music improvisation process to find a pleasing harmony is inspiring the harmony search algorithm. In this work, the adjustment of the harmony search algorithm parameters such as the bandwidth and the pitch adjustment rate are increasing performance of the proposed algorithm which is done through a fuzzy logic controller. Hence, membership functions and fuzzy rules are designed to improve the performance of the HS algorithm and achieve optimal results. The objective of the method is finding an optimum core arrangement according to safety and economic aspects such as reduction of power peaking factor (PPF) and increase of effective multiplication factor (Keff). The proposed approach effectiveness has been tried in two cases, Michalewicz's bivariate function problem and NEACRP LWR core. The results show that by using fuzzy harmony search algorithm the value of the fitness function is improved by 15.35%. Finally, with regard to the new solutions proposed in this research it could be used as a trustworthy method for other optimization issues of engineering field.

• 한국도로학회논문집
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• 제20권3호
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• pp.59-64
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• 2018

PURPOSES : We propose a parameter-setting-free harmony-search (PSF-HS) algorithm to determine the individual sound power levels of noise sources in the cases of industrial or road noise environment. METHODS :In terms of using methods, we use PSF-HS algorithm because the optimization parameters cannot be fixed through finding the global minimum. RESULTS:We found that the main advantage of the PSF-HS heuristic algorithm is its ability to find the best global solution of individual sound power levels through a nonlinear complex function, even though the parameters of the original harmony-search (HS) algorithm are not fixed. In an industrial and road environment, high noise exposure is harmful, and can cause nonauditory effects that endanger worker and passenger safety. This study proposes the PSF-HS algorithm for determining the PWL of an individual machine (or vehicle), which is a useful technique for industrial (or road) engineers to identify the dominant noise source in the workplace (or road field testing case). CONCLUSIONS : This study focuses on providing an efficient method to determine sound power levels (PWLs) and the dominant noise source while multiple machines (or vehicles) are operating, for comparison with the results of previous research. This paper can extend the state-of-the-art in a heuristic search algorithm to determine the individual PWLs of machines as well as loud machines (or vehicles), based on the parameter-setting-free harmony-search (PSF-HS) algorithm. This algorithm can be applied into determining the dominant noise sources of several vehicles in the cases of road cross sections and congested housing complex.

• 전기학회논문지
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• 제58권7호
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• pp.1287-1293
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• 2009

This paper presents an application of Harmony Search (HM) meta-heuristic optimization algorithm for optimal operation of microgrid system. The microgrid system considered in this paper consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile which divided 20 minute data and wind resource for wind turbine generator were used for the study. In optimization, the HS algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch and having its nature of fast convergency time as compared to other optimization method.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.61-73
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• 2021

메타휴리스틱 탐색법은 주어진 정보의 부족 및 시간의 제약을 받는 상황에서 다양한 목적함수를 가진 문제를 해결하기 위해 개발되었다. 본 연구에서는 기존의 최적화 알고리즘인 Vision Correction Algorithm(VCA)의 성능을 강화한 Hybrid Vision Correction Algorithm(HVCA)을 개발하였다. HVCA는 기존의 알고리즘의 성능을 개선하기 위해 두 가지 방법을 적용하였다. 첫 번째 방법으로 사용자가 입력해야 하는 매개변수를 자가적응형 매개변수로 개선하였다. 두 번째 방법으로 Exponential Bandwidth Harmony Search With Centralized Global Search(EBHS-CGS)의 CGS 구조를 HVCA에 추가하였다. CGS 구조의 추가로 인해 HVCA 내부는 CGS와 VCA의 두 가지 구조로 구성되어 있다. 두 가지 구조를 효율적으로 사용하기 위해 반복시산을 진행하면서 최적값이 나오는 구조의 선택확률을 증가시키는 방법을 적용하였다. 제안된 HVCA의 성능을 확인하기 위해 최적화 문제에 적용하고, 그 결과를 Harmony Search(HS), Improved Harmony Search(IHS) 및 VCA와 비교하여 나타내었다. 적용결과 수학문제와 공학문제에서 HVCA는 HS, IHS 및 VCA보다 최적값 및 100번의 반복실행 중 최적값을 찾는 횟수가 많았으며, 최적값에 수렴하는 반복시산횟수도 낮았다. 이를 통해 HVCA가 성능이 개선되었다는 것을 확인할 수 있었다. 제안된 HVCA는 적용한 수학문제 및 공학문제 이외에도 많은 분야에 대해 좋은 결과를 나타낼 것으로 기대된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.351-358
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• 2005

Many methods have been developed and are in use for structural size optimization problems, In which the cross-sectional areas or sizing variables are usually assumed to be continuous. In most practical structural engineering design problems, however, the design variables are discrete. This paper proposes an efficient optimization method for structures with discrete-sized variables based on the harmony search (HS) meta-heuristic algorithm. The recently developed HS algorithm was conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary In this paper, a discrete search strategy using the HS algorithm is presented in detail and its effectiveness and robustness, as compared to current discrete optimization methods, are demonstrated through a standard truss example. The numerical results reveal that the proposed method is a powerful search and design optimization tool for structures with discrete-sized members, and may yield better solutions than those obtained using current method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.648-649
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• 2011

This Paper presents an efficient approach for solving the economic dispatch (ED) problems with valve-point effects using an combination of particle swarm optimization and harmony search. To reduce a premature convergence effect of PSO algorithm, We proposed PSO-HS algorithm considering evolutionary using harmony search algorithm. To prove the ability of the PSO-HS in solving nonlinear optimization problems, ED problems with non-convex solution spaces are solved with three different approach(PSO, HS, combination of PSO and HS)