• Title/Summary/Keyword: genetic algorithms (GAs).

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Discrete Optimization of Plane Frame Structures Using Genetic Algorithms (유전자 알고리즘을 이용한 뼈대구조물의 이산최적화)

  • 김봉익;권중현
    • Journal of Ocean Engineering and Technology
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    • v.16 no.4
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    • pp.25-31
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    • 2002
  • This paper is to find optimum design of plane framed structures with discrete variables. Global search algorithms for this problem are Genetic Algorithms(GAs), Simulated Annealing(SA) and Shuffled Complex Evolution(SCE), and hybrid methods (GAs-SA, GAs-SCE). GAs and SA are heuristic search algorithms and effective tools which is finding global solution for discrete optimization. In particular, GAs is known as the search method to find global optimum or near global optimum. In this paper, reinforced concrete plane frames with rectangular section and steel plane frames with W-sections are used for the design of discrete optimization. These structures are designed for stress constraints. The robust and effectiveness of Genetic Algorithms are demonstrated through several examples.

Optimal Identification of Nonlinear Process Data Using GAs-based Fuzzy Polynomial Neural Networks (유전자 알고리즘 기반 퍼지 다항식 뉴럴네트워크를 이용한 비선형 공정데이터의 최적 동정)

  • Lee, In-Tae;Kim, Wan-Su;Kim, Hyun-Ki;Oh, Sung-Kwun
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.6-8
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    • 2005
  • In this paper, we discuss model identification of nonlinear data using GAs-based Fuzzy Polynomial Neural Networks(GAs-FPNN). Fuzzy Polynomial Neural Networks(FPNN) is proposed model based Group Method Data Handling(GMDH) and Neural Networks(NNs). Each node of FPNN is expressed Fuzzy Polynomial Neuron(FPN). Network structure of nonlinear data is created using Genetic Algorithms(GAs) of optimal search method. Accordingly, GAs-FPNN have more inflexible than the existing models (in)from structure selecting. The proposed model select and identify its for optimal search of Genetic Algorithms that are no. of input variables, input variable numbers and consequence structures. The GAs-FPNN model is select tuning to input variable number, number of input variable and the last part structure through optimal search of Genetic Algorithms. It is shown that nonlinear data model design using Genetic Algorithms based FPNN is more usefulness and effectiveness than the existing models.

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An Efficient Method for Nonlinear Optimization Problems using Genetic Algorithms (유전해법을 이용한 비선형최적화 문제의 효율적인 해법)

  • 임승환;이동춘
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.44
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    • pp.93-101
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    • 1997
  • This paper describes the application of Genetic Algorithms(GAs) to nonlinear constrained mixed optimization problems. Genetic Algorithms are combinatorial in nature, and therefore are computationally suitable for treating discrete and integer design variables. But, several problems that conventional GAs are ill defined are application of penalty function that can be adapted to transform a constrained optimization problem into an unconstrained one and premature convergence of solution. Thus, we developed an improved GAs to solve this problems, and two examples are given to demonstrate the effectiveness of the methodology developed in this paper.

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Optimization of Truss Structure by Genetic Algorithms (유전자 알고리즘을 이용한 트러스 구조물의 최적설계)

  • 백운태;조백희;성활경
    • Korean Journal of Computational Design and Engineering
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    • v.1 no.3
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    • pp.234-241
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    • 1996
  • Recently, Genetic Algorithms(GAs), which consist of genetic operators named selection crossover and mutation, are widely adapted into a search procedure for structural optimization. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GAs are very simple in their algorithms and there is no need of continuity of functions(or functionals) any more in GAs. So, they can be easily applicable to wide territory of design optimization problems. Also, virtue to multi-point search procedure, they have higher probability of convergence to global optimum compared with traditional techniques which take one-point search method. The introduction of basic theory on GAs, and the application examples in combination optimization of ten-member truss structure are presented in this paper.

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Air-Borne Selection in Micro-Genetic Algorithms for Combinatorial Optimization

  • Kim, Yunyoung;Masahiro Toyosada;Koji Gotoh;Park, Jewoong
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.106.4-106
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    • 2001
  • The current research field to find near-optimum solutions explores in a small population, which is coined as Micro-Genetic Algorithms (${\mu}$GAs), with some genetic operators. Just as in the Simple-Genetic Algorithms (SGAs), the ${\mu}$GAs work with encoding population and are implemented serially. The major difference between SGAs and ${\mu}$GAs is how to make reproductive plan for more better searching strategy due to the population choice. This paper is conducted to implement ${\mu}$GAs in order to achieve fast searching for more better evolution and associated cost evaluation in global solution space. To achieve this implementation, the Air-Borne Selection (ABS) for a new reproductive plan is developed as new strategic conception for ${\mu}$GAs. In this paper, it is shown that the ${\mu}$GAs implementation reaches a near-optimal region much earlier than the SGAs implementation. The superior ...

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The Shape Optimization Design of Space Trusses Using Genetic Algorithms (퍼지-유전자 알고리즘에 의한 공간 트러스의 형상 최적화)

  • Park, Choon-Wook;Kim, Su-Won;Kang, Moon-Myung
    • Journal of Korean Association for Spatial Structures
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    • v.2 no.3 s.5
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    • pp.61-70
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    • 2002
  • The objective of this study is the development of a size and shape discrete optimum design algorithms, which is based on the genetic algorithms and the fuzzy theory. This algorithms can perform both size and shape optimum designs of plane and space trusses. The developed fuzzy shape-GAs (FS-GAs) was implemented in a computer program. For the optimum design, the objective function is the weight of structures and the constraints are limits on loads and serviceability. This study solves the problem by introducing the FS-GAs operators into the genetic.

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Effective Gas Identification Model based on Fuzzy Logic and Hybrid Genetic Algorithms

  • Bang, Yonug-Keun;Byun, Hyung-Gi;Lee, Chul-Heui
    • Journal of Sensor Science and Technology
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    • v.21 no.5
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    • pp.329-338
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    • 2012
  • This paper presents an effective design method for a gas identification system. The design method adopted the sequential combination between the hybrid genetic algorithms and the TSK fuzzy logic system. First, the sensor grouping method by hybrid genetic algorithms led the effective dimensional reduction as well as effective pattern analysis from a large volume of pattern dimensions. Second, the fuzzy identification sub-models allowed handling the uncertainty of the sensor data extensively. By these advantages, the proposed identification model demonstrated high accuracy rates for identifying the five different types of gases; it was confirmed throughout the experimental trials.

Optimal Configuration of Distribution Network using Genetic Algorithms

  • Kim, Intaek;Wonhyuk Cho
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.625-628
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    • 1998
  • This paper presents an application of genetic algorithms(GAs) for optimal configuration of distribution network. Three problems have been used to show how genetic algorithms are modified and applied. Solutions to the problems are found by minimizing the cost function which is directly related with balancing the loads. Simulation results show that genetic algorithms are technically feasible if they are tailored to meet the needs of real problems.

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Design of Genetic Algorithms-based Fuzzy Polynomial Neural Networks Using Symbolic Encoding (기호 코딩을 이용한 유전자 알고리즘 기반 퍼지 다항식 뉴럴네트워크의 설계)

  • Lee, In-Tae;Oh, Sung-Kwun;Choi, Jeoung-Nae
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.270-272
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    • 2006
  • In this paper, we discuss optimal design of Fuzzy Polynomial Neural Networks by means of Genetic Algorithms(GAs) using symbolic coding for non-linear data. One of the major subject of genetic algorithms is representation of chromosomes. The proposed model optimized by the means genetic algorithms which used symbolic code to represent chromosomes. The proposed gFPNN used a triangle and a Gaussian-like membership function in premise part of rules and design the consequent structure by constant and regression polynomial (linear, quadratic and modified quadratic) function between input and output variables. The performance of the proposed model is quantified through experimentation that exploits standard data already used in fuzzy modeling. These results reveal superiority of the proposed networks over the existing fuzzy and neural models.

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Component Map Generation of a Gas Turbine Engine Using Genetic Algorithms and Scaling Method (유전자 알고리즘과 스케일링 기법을 이용한 가스터빈 엔진 구성품 성능선도 개선에 관한 연구)

  • Kho Seong-Hee;Kong Chang-Duk
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.299-303
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    • 2005
  • In the present study, in order to improve precision of the component characteristic maps generated by the scaling method, a map generation method which can produce a compressor map from some experimental performance data using GAs(Genetic Algorithms) was proposed. However, in case of the proposed map generation method only using GAs, because it has a drawback for estimating correctly the surge points and the choke points of the compressor map, a modified GAs method was additionally proposed through complementally use of the scaling method to determine obviously those points of the compressor map.

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