• 제목/요약/키워드: Neighbourhood search

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The Dynamic Allocated Bees Algorithms for Multi-objective Problem

  • Lee, Ji-Young;Oh, Jin-Seok
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권3호
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    • pp.403-410
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    • 2009
  • The aim of this research is to develop the Bees Algorithm named 'the dynamic allocated Bees Algorithm' for multi-objective problem, especially in order to be suit for Pareto optimality. In addition two new neighbourhood search methods have been developed to produce enhanced solutions for a multi-objective problem named 'random selection neighbourhood search' and 'weighted sum neighbourhood search' and they were compared with the basic neighbourhood search in the dynamic allocated Bees Algorithm. They were successfully applied to an Environmental/Economic (electric power) dispatch (EED) problem and simulation results presented for the standard IEEE 30-bus system and they were compared to those obtained using other approaches. The comparison shows the superiority of the proposed dynamic allocated Bees Algorithms and confirms its suitability for solving the multi-objective EED problem.

지역 어메니티 촉진을 위한 마을만들기 운영사례 비교연구 (A comparative case study of neighbourhood making for promoting a local amenity)

  • 이영창;김근호
    • 농촌계획
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    • 제19권2호
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    • pp.129-138
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    • 2013
  • The aim of the research was to analyze programs, outcomes, promotion process, and operation methods of neighbourhood making to provide basic information for progressive improvement directions in the future. Buk-gu in Gwanju city, samdeok-dong in Daegu city and dongpirang in Tongyeong city were selected for a comparative analysis. The main bodies of neighbourhood making for promoting a local amenity were analysed for this research. The results indicated that a voluntary and continuous participation of residents was expected in the case of neighbourhood making led by the residents. However, a steady budget support from the outside was necessary for the continuous management and improvement of neighbourhood organization. For this, a voluntary agreement was required through the consultative group and committee formation. The member of civil organization has a limitation in the ability to develop and maintain continuos activities in the case of neighbourhood making led by a civil organization. This research found that operation methods including the constant checking, the search for new ideas through assessment of the resident's participation, local festivals for a community formation and real satisfactions of residents' desires were needed in the neighbourhood making led by a civil organization. A participation rate in neighbourhood making was low in the case of neighbourhood making led by administrative bodies. This result indicated that the long-term strategics for space renewal and community revitalization were important. Various easy ways of residents' participation to reflect their interests and operation systems were also needed. Finally, current local issues, active residents' participation and residents' opinions would be included in the process of neighbour making in the future.

Tabu Search와 Constraint Satisfaction Technique를 이용한 Job Shop 일정계획 (Job Shop Scheduling by Tabu Search Combined with Constraint Satisfaction Technique)

  • 윤종준;이화기
    • 산업경영시스템학회지
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    • 제25권2호
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    • pp.92-101
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    • 2002
  • The Job Shop Scheduling Problem(JSSP) is concerned with schedule of m different machines and n jobs where each job consists of a chain of operations, each of which needs to be processed during an uninterrupted time period of a given length on a given machine. The purpose of this paper is to develop the efficient heuristic method for solving the minimum makespan problem of the large scale job shop scheduling. The proposed heuristic method is based on a Tabu Search(TS) and on a Constraint Satisfaction Technique(CST). In this paper, ILOG libraries is used to embody the job shop model, and a CST is developed for this model to generate the increased solution. Then, TS is employed to overcome the increased search time of CST on the increased problem size md to refine the next-current solution. Also, this paper presents the new way of finding neighbourhood solution using TS. On applying TS, a new way of finding neighbourhood solution is presented. Computational experiments on well known sets of MT and LA problem instances show that, in several cases, our approach yields better results than the other heuristic procedures discussed In literature.

Multi-objective optimal design of laminate composite shells and stiffened shells

  • Lakshmi, K.;Rama Mohan Rao, A.
    • Structural Engineering and Mechanics
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    • 제43권6호
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    • pp.771-794
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    • 2012
  • This paper presents a multi-objective evolutionary algorithm for combinatorial optimisation and applied for design optimisation of fiber reinforced composite structures. The proposed algorithm closely follows the implementation of Pareto Archive Evolutionary strategy (PAES) proposed in the literature. The modifications suggested include a customized neighbourhood search algorithm in place of mutation operator to improve intensification mechanism and a cross over operator to improve diversification mechanism. Further, an external archive is maintained to collect the historical Pareto optimal solutions. The design constraints are handled in this paper by treating them as additional objectives. Numerical studies have been carried out by solving a hybrid fiber reinforced laminate composite cylindrical shell, stiffened composite cylindrical shell and pressure vessel with varied number of design objectives. The studies presented in this paper clearly indicate that well spread Pareto optimal solutions can be obtained employing the proposed algorithm.

Optimal stacking sequence design of laminate composite structures using tabu embedded simulated annealing

  • Rama Mohan Rao, A.;Arvind, N.
    • Structural Engineering and Mechanics
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    • 제25권2호
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    • pp.239-268
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    • 2007
  • This paper deals with optimal stacking sequence design of laminate composite structures. The stacking sequence optimisation of laminate composites is formulated as a combinatorial problem and is solved using Simulated Annealing (SA), an algorithm devised based on inspiration of physical process of annealing of solids. The combinatorial constraints are handled using a correction strategy. The SA algorithm is strengthened by embedding Tabu search in order to prevent recycling of recently visited solutions and the resulting algorithm is referred to as tabu embedded simulated Annealing (TSA) algorithm. Computational performance of the proposed TSA algorithm is enhanced through cache-fetch implementation. Numerical experiments have been conducted by considering rectangular composite panels and composite cylindrical shell with different ply numbers and orientations. Numerical studies indicate that the TSA algorithm is quite effective in providing practical designs for lay-up sequence optimisation of laminate composites. The effect of various neighbourhood search algorithms on the convergence characteristics of TSA algorithm is investigated. The sensitiveness of the proposed optimisation algorithm for various parameter settings in simulated annealing is explored through parametric studies. Later, the TSA algorithm is employed for multi-criteria optimisation of hybrid composite cylinders for simultaneously optimising cost as well as weight with constraint on buckling load. The two objectives are initially considered individually and later collectively to solve as a multi-criteria optimisation problem. Finally, the computational efficiency of the TSA based stacking sequence optimisation algorithm has been compared with the genetic algorithm and found to be superior in performance.

A Reinforcement Learning with CMAC

  • Kwon, Sung-Gyu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제6권4호
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    • pp.271-276
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    • 2006
  • To implement a generalization of value functions in Adaptive Search Element (ASE)-reinforcement learning, CMAC (Cerebellar Model Articulation Controller) is integrated into ASE controller. ASE-reinforcement learning scheme is briefly studied to discuss how CMAC is integrated into ASE controller. Neighbourhood Sequential Training for CMAC is utilized to establish the look-up table and to produce discrete control outputs. In computer simulation, an ASE controller and a couple of ASE-CMAC neural network are trained to balance the inverted pendulum on a cart. The number of trials until the controllers are established and the learning performance of the controllers are evaluated to find that generalization ability of the CMAC improves the speed of the ASE-reinforcement learning enough to realize the cartpole control system.

Integrating Spatial Proximity with Manifold Learning for Hyperspectral Data

  • Kim, Won-Kook;Crawford, Melba M.;Lee, Sang-Hoon
    • 대한원격탐사학회지
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    • 제26권6호
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    • pp.693-703
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    • 2010
  • High spectral resolution of hyperspectral data enables analysis of complex natural phenomena that is reflected on the data nonlinearly. Although many manifold learning methods have been developed for such problems, most methods do not consider the spatial correlation between samples that is inherent and useful in remote sensing data. We propose a manifold learning method which directly combines the spatial proximity and the spectral similarity through kernel PCA framework. A gain factor caused by spatial proximity is first modelled with a heat kernel, and is added to the original similarity computed from the spectral values of a pair of samples. Parameters are tuned with intelligent grid search (IGS) method for the derived manifold coordinates to achieve optimal classification accuracies. Of particular interest is its performance with small training size, because labelled samples are usually scarce due to its high acquisition cost. The proposed spatial kernel PCA (KPCA) is compared with PCA in terms of classification accuracy with the nearest-neighbourhood classification method.