• 제목/요약/키워드: Heuristic Search Algorithm

검색결과 391건 처리시간 0.022초

Parameter Calibration of the Nonlinear Muskingum Model using Harmony Search

  • Geem, Zong-Woo;Kim, Joong-Hoon;Yoon, Yong-Nam
    • 한국수자원학회논문집
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    • 제33권S1호
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    • pp.3-10
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    • 2000
  • A newly developed heuristic algorithm, Harmony Search, is applied to the parameter calibration problem of the nonlinear Muskingum model. The Harmony Search could, mimicking the improvisation of music player, find better parameter values for in the nonlinear Muskingum model than five other methods including another heuristic method, genetic algorithm, in the aspect of SSQ(the sum of the square of the deviations between the observed and routed outflows) as well as in the aspects of SAD(the sum of the absolute value of the deviations), DPO(deviations of peak of routed and actual flows) and DPOT(deviatios of peak time of routed and actual outflow). Harmony Search also has the advantage that it does not require the process of asuming the initial values of desing parameters. The sensitivity analysis of Harmony Memory Considering Rate showed that relatively large values of Harmony Memory Considering Rate makes the Harmony Search converge to a better solution.

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Parameter Calibration o fthe Nonlinear Muskingum Model using Harmony Search

  • Geem, Jong-Woo;Kim, Joong-Hoon;Yoon, Yong-Nam
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2000년도 학술발표회 논문집
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    • pp.3-10
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    • 2000
  • A newly developed heuristic algorithm, Harmony Search, is applied to the parameter calibration problem of the nonlinear Muskingum model. The Harmony Search could, mimicking the improvisation of music players, find better parameter values for in the nonlinear Muskingum model than five other methods including another heuristic method, genetic algorithm, in the aspect of SSQ (the sum of the square of the deviations between the observed and routed outflows) as well as in the aspects of SAD (the sum of the absolute value of the deviations), DPO (deviations of peak of routed and actual flows) and DPOT (deviations of peak time of rented and actual outflow). Harmony Search also has the advantage that it does not require the process of assuming the initial values of design parameters. The sensitivity analysis of Harmony Memory Considering Rate showed that relatively large values of Harmony Memory Considering Rate makes the Harmony Search converse to a better solution.

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휴리스틱 유전 알고리즘 경로 탐색에 광선 추적 알고리즘을 활용한 경로 최적화 연구 (Path Optimize Research used Ray-Tracing Algorithm in Heuristic-based Genetic Algorithm Pathfinding)

  • 고정운;이동엽
    • 한국게임학회 논문지
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    • 제19권6호
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    • pp.83-90
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    • 2019
  • 휴리스틱 기반의 유전 알고리즘 경로 탐색(H-GAP)은 노드, 에지 정보를 필요로 하지 않기 때문에 기존 경로 탐색 알고리즘의 단점을 보완하고 빠른 속도로 경로 탐색을 수행할 수 있다. 하지만 H-GAP를 이용해 탐색한 경로는 비 노드 기반이기 때문에 불필요한 경로 정보가 포함되어 탐색된 경로가 최적의 경로가 아닐 때도 있다. 본 논문에서는 H-GAP를 이용해 탐색한 경로를 최적화하는 알고리즘을 제안한다. 제안하는 알고리즘은 H-GAP의 경로 탐색이 완료된 후 광선 추적 알고리즘을 이용해 불필요한 경로 정보를 제거하여 경로를 최적화한다.

A Geometrical Center based Two-way Search Heuristic Algorithm for Vehicle Routing Problem with Pickups and Deliveries

  • Shin, Kwang-Cheol
    • Journal of Information Processing Systems
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    • 제5권4호
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    • pp.237-242
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    • 2009
  • The classical vehicle routing problem (VRP) can be extended by including customers who want to send goods to the depot. This type of VRP is called the vehicle routing problem with pickups and deliveries (VRPPD). This study proposes a novel way to solve VRPPD by introducing a two-phase heuristic routing algorithm which consists of a clustering phase and uses the geometrical center of a cluster and route establishment phase by applying a two-way search of each route after applying the TSP algorithm on each route. Experimental results show that the suggested algorithm can generate better initial solutions for more computer-intensive meta-heuristics than other existing methods such as the giant-tour-based partitioning method or the insertion-based method.

Probabilistic Model for Performance Analysis of a Heuristic with Multi-byte Suffix Matching

  • Choi, Yoon-Ho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권4호
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    • pp.711-725
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    • 2013
  • A heuristic with multi-byte suffix matching plays an important role in real pattern matching algorithms. By skipping many characters at a time in the process of comparing a given pattern with the text, the pattern matching algorithm based on a heuristic with multi-byte suffix matching shows a faster average search time than algorithms based on deterministic finite automata. Based on various experimental results and simulations, the previous works show that the pattern matching algorithms with multi-byte suffix matching performs well. However, there have been limited studies on the mathematical model for analyzing the performance in a standard manner. In this paper, we propose a new probabilistic model, which evaluates the performance of a heuristic with multi-byte suffix matching in an average-case search. When the theoretical analysis results and experimental results were compared, the proposed probabilistic model was found to be sufficient for evaluating the performance of a heuristic with suffix matching in the real pattern matching algorithms.

적합성 함수를 이용한 2차원 저장소 적재 문제의 휴리스틱 알고리즘 (A Heuristic Algorithm for the Two-Dimensional Bin Packing Problem Using a Fitness Function)

  • 연용호;이선영;이종연
    • 정보처리학회논문지B
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    • 제16B권5호
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    • pp.403-410
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    • 2009
  • 2차원 저장소 적재는 NP-hard 문제로서 그 문제의 정확한 해를 구하는 것이 어려운 것으로 알려져 있으며, 이의 더 좋은 해를 얻기 위해 유전자(genetic) 알고리즘, 시뮬레이티드 어닐링(simulated annealing), 타부서치(tabu search)등과 같은 근사적 접근법이 제안되어 왔다. 하지만 분지한계(branch-and-bound)나 타부서치 기법들을 이용한 기존의 대표적인 근사 알고리즘들은 휴리스틱 알고리즘의 해에 기반을 둠으로 효율성이 낮고 반복수행에 의한 계산시간이 길다. 따라서 본 논문에서는 이러한 근사 알고리즘의 복잡성을 간소화하고, 알고리즘의 효율성을 높이기 위해 적재가능성을 판단하는 적합성 함수(fitness function)를 정의하고 이를 이용하여 어떤 특정 개체의 적재영역을 판단하는데 영향을 주는 적재영역의 수를 계산한다. 또한, 이들을 이용한 새로운 휴리스틱 알고리즘을 제안하였다. 끝으로 기존의 휴리스틱 또는 메타휴리스틱 기법과의 비교실험을 통해 기존의 휴리스틱 알고리즘인 FFF와 FBS에 비해 97%의 결과가 같거나 우수하였으며, 타부서치 알고리즘에 비해 86%의 결과가 같거나 우수한 것으로 나타났다.

A hybrid tabu-simulated annealing heuristic algorithm for optimum design of steel frames

  • Degertekin, S.O.;Hayalioglu, M.S.;Ulker, M.
    • Steel and Composite Structures
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    • 제8권6호
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    • pp.475-490
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    • 2008
  • A hybrid tabu-simulated annealing algorithm is proposed for the optimum design of steel frames. The special character of the hybrid algorithm is that it exploits both tabu search and simulated annealing algorithms simultaneously to obtain near optimum. The objective of optimum design problem is to minimize the weight of steel frames under the actual design constraints of AISC-LRFD specification. The performance and reliability of the hybrid algorithm were compared with other algorithms such as tabu search, simulated annealing and genetic algorithm using benchmark examples. The comparisons showed that the hybrid algorithm results in lighter structures for the presented examples.

물류 센터 위치 선정 및 대리점 할당 모형에 대한 휴리스틱 해법 (Meta-heuristic Method for the Single Source Capacitated Facility Location Problem)

  • 석상문;이상욱
    • 한국콘텐츠학회논문지
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    • 제10권9호
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    • pp.107-116
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    • 2010
  • 시설물 입지 선정 문제(FLP)는 전통적인 최적화 문제중에 하나이다. FLP에 공급제약과 하나의 고객은 하나의 시설물에서만 제품을 공급받을 수 있다는 제약을 추가하면 단일 시설물 공급제약을 가지는 시설물 위치 설정 문제(SSFLP)가 된다. SSFLP는 NP-hard 문제로 알려져 있으며 진화 알고리즘과 같은 휴리스틱 알고리즘을 사용하여 해결하는 것이 일반적이다. 본 논문에서는 SSFLP를 위한 효율적인 진화 알고리즘을 제안한다. 제안하는 알고리즘은 적응형 링크 조절 진화 알고리즘과 3가지 휴리스틱 해 개선 방법을 조합하여 고안되었다. 제안하는 알고리즘을 벤치마크 문제에 적용하여 다른 알고리즘과 성능을 비교분석해 본 결과, 제안하는 알고리즘은 중간 크기의 문제에서 대부분 최적해를 찾았으며 큰 문제에서도 안정된 결과를 보여주었다.

HS 최적화 알고리즘을 이용한 계단응답과 연속시스템 인식 (Identification of Continuous System from Step Response using HS Optimization Algorithm)

  • 이태봉;손진근
    • 전기학회논문지P
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    • 제65권4호
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    • pp.292-297
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    • 2016
  • The first-order plus dead time(FOPDT) and second-order plus dead time(SOPDT), which describes a linear monotonic process quite well in most chemical and industrial processes and is often sufficient for PID and IMC controller tuning. This paper presents an application of heuristic harmony search(HS) optimization algorithm to the identification of linear continuous time-delay systems from step response. 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. The effectiveness of the proposed identification method has been demonstrated through a number of simulation examples.

A new hybrid meta-heuristic for structural design: ranked particles optimization

  • Kaveh, A.;Nasrollahi, A.
    • Structural Engineering and Mechanics
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    • 제52권2호
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    • pp.405-426
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    • 2014
  • In this paper, a new meta-heuristic algorithm named Ranked Particles Optimization (RPO), is presented. This algorithm is not inspired from natural or physical phenomena. However, it is based on numerous researches in the field of meta-heuristic optimization algorithms. In this algorithm, like other meta-heuristic algorithms, optimization process starts with by producing a population of random solutions, Particles, located in the feasible search space. In the next step, cost functions corresponding to all random particles are evaluated and some of those having minimum cost functions are stored. These particles are ranked and their weighted average is calculated and named Ranked Center. New solutions are produced by moving each particle along its previous motion, the ranked center, and the best particle found thus far. The robustness of this algorithm is verified by solving some mathematical and structural optimization problems. Simplicity of implementation and reaching to desired solution are two main characteristics of this algorithm.