• Title/Summary/Keyword: Evolutionary Strategies

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Strategic Coalition for Improving Generalization Ability of Multi-agent with Evolutionary Learning (진화학습을 이용한 다중에이전트의 일반화 성능향상을 위한 전략적 연합)

  • 양승룡;조성배
    • Journal of KIISE:Software and Applications
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    • v.31 no.2
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    • pp.101-110
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    • 2004
  • In dynamic systems, such as social and economic systems, complex interactions emerge among its members. In that case, their behaviors become adaptive according to Changing environment. In many cases, an individual's behaviors can be modeled by a stimulus-response system in a dynamic environment. In this paper, we use the Iterated Prisoner's Dilemma (IPD) game, which is simple yet capable of dealing with complex problems, to model the dynamic systems. We propose strategic coalition consisting of many agents and simulate their emergence in a co-evolutionary learning environment. Also we introduce the concept of confidence for agents in a coalition and show how such confidences help to improve the generalization ability of the whole coalition. Experimental results are presented to demonstrate that co-evolutionary learning with coalitions and confidence allows better performing strategies that generalize well.

International Comparative Study on the Government Policy and Corporate Strategy in the Aerospace Industry (항공우주산업의 기업전략 및 정부정책에 대한 국제비교연구)

  • Lee, Yun-Cheol;Lim, Sang-Min
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.14 no.2
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    • pp.56-70
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    • 2006
  • Since the 90's, the world's aerospace industry have been experienced the era of radical changes. We make a comparative study about the 10 countries government policies and corporate strategies changes in this era. In this study, we figure out aerospace industry's evolutional patterns and factors through evolutionary perspective, and then, proposed development strategies and implications for Korea's aerospace industry.

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The Implications for Science Education of the Evolutionary Perspective on Education (교육에 대한 진화론적 관점이 과학교육에 주는 시사점)

  • Jang, Myoung-Duk
    • Journal of the Korean Society of Earth Science Education
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    • v.9 no.2
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    • pp.107-122
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    • 2016
  • The purpose of this study is to review the literatures on the evolutionary perspective on education and to draw the educational implications for science education. This study addresses on several topics as follows: our common misunderstandings about the evolutionary perspective on education; children's inherent knowledge and abilities, their learning about the evolutionarily novel knowledge and abilities in school, their difficulties in academic learning, and the instructional strategies to cope with the difficulties; and the implications for science education from the evolutionary perspective. The evolutionary perspective on education has provided new insights how culturally important information is transmitted across generations in the past hunting-gathering societies and the modern societies, and how children's inherent motivational and behavioral dispositions affect their academic learning. In addition, the new perspective on education can be used to generate empirical hypotheses about children's science learning, and with the further research, could lead to useful implications and ultimately improve educational outcomes.

Development of a Multi-objective function Method Based on Pareto Optimal Point (Pareto 최적점 기반 다목적함수 기법 개발에 관한 연구)

  • Na, Seung-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.2 s.140
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    • pp.175-182
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    • 2005
  • It is necessary to develop an efficient optimization technique to optimize the engineering structures which have given design spaces, discrete design values and several design goals. As optimization techniques, direct search method and stochastic search method are widely used in designing of engineering structures. The merit of the direct search method is to search the optimum points rapidly by considering the search direction, step size and convergence limit. And the merit of the stochastic search method is to obtain the global optimum points by spreading point randomly entire the design spaces. In this paper, a Pareto optimal based multi-objective function method (PMOFM) is developed by considering the search direction based on Pareto optimal points, step size, convergence limit and random search generation . The PMOFM can also apply to the single objective function problems, and can consider the discrete design variables such as discrete plate thickness and discrete stiffener spaces. The design results are compared with existing Evolutionary Strategies (ES) method by performing the design of double bottom structures which have discrete plate thickness and discrete stiffener spaces.

Improved marine predators algorithm for feature selection and SVM optimization

  • Jia, Heming;Sun, Kangjian;Li, Yao;Cao, Ning
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.4
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    • pp.1128-1145
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    • 2022
  • Owing to the rapid development of information science, data analysis based on machine learning has become an interdisciplinary and strategic area. Marine predators algorithm (MPA) is a novel metaheuristic algorithm inspired by the foraging strategies of marine organisms. Considering the randomness of these strategies, an improved algorithm called co-evolutionary cultural mechanism-based marine predators algorithm (CECMPA) is proposed. Through this mechanism, search agents in different spaces can share knowledge and experience to improve the performance of the native algorithm. More specifically, CECMPA has a higher probability of avoiding local optimum and can search the global optimum quickly. In this paper, it is the first to use CECMPA to perform feature subset selection and optimize hyperparameters in support vector machine (SVM) simultaneously. For performance evaluation the proposed method, it is tested on twelve datasets from the university of California Irvine (UCI) repository. Moreover, the coronavirus disease 2019 (COVID-19) can be a real-world application and is spreading in many countries. CECMPA is also applied to a COVID-19 dataset. The experimental results and statistical analysis demonstrate that CECMPA is superior to other compared methods in the literature in terms of several evaluation metrics. The proposed method has strong competitive abilities and promising prospects.

Automated Generation of Optimal Security Defense Strategy using Simulation-based Evolutionary Techniques (시뮬레이션 기반 진화기법을 이용한 최적 보안 대응전략 자동생성)

  • Lee, Jang-Se;Hwang, Hun-Gyu;Yun, Jin-Sik;Park, Geun-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.11
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    • pp.2514-2520
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    • 2010
  • The objective of this paper is to propose the methodology for automated generation of the optimal security defense strategies using evolutionary techniques. As damages by penetration exploiting vulnerability in computer systems and networks are increasing, security techniques have been researched actively. However it is difficult to generate optimal defense strategies because it needs to consider various situations on network environment according to countermeasures. Thus we have adopted a genetic algorithm in order to generate an optimal defense strategy as combination of countermeasures. We have represented gene information with countermeasures. And by using simulation technique, we have evaluated fitness through evaluating the vulnerability of system having applied various countermeasures. Finally, we have examined the feasibility by experiments on the system implemented by proposed method.

Application of Soft Computing Based Response Surface Techniques in Sizing of A-Pillar Trim with Rib Structures (승용차 A-Pillar Trim의 치수설계를 위한 소프트컴퓨팅기반 반응표면기법의 응용)

  • Kim, Seung-Jin;Kim, Hyeong-Gon;Lee, Jong-Su;Gang, Sin-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.537-547
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    • 2001
  • The paper proposes the fuzzy logic global approximate optimization strategies in optimal sizing of automotive A-pillar trim with rib structures for occupant head protection. Two different strategies referred to as evolutionary fuzzy modeling (EFM) and neuro-fuzzy modeling (NFM) are implemented in the context of global approximate optimization. EFM and NFM are based on soft computing paradigms utilizing fuzzy systems, neural networks and evolutionary computing techniques. Such approximation methods may have their promising characteristics in a case where the inherent nonlinearity in analysis model should be accommodated over the entire design space and the training data is not sufficiently provided. The objective of structural design is to determine the dimensions of rib in A-pillar, minimizing the equivalent head injury criterion HIC(d). The paper describes the head-form modeling and head impact simulation using LS-DYNA3D, and the approximation procedures including fuzzy rule generation, membership function selection and inference process for EFM and NFM, and subsequently presents their generalization capabilities in terms of number of fuzzy rules and training data.

A Study for searching optimized combination of Spent light water reactor fuel to reuse as heavy water reactor fuel by using evolutionary algorithm (진화 알고리즘을 이용한 경수로 폐연료의 중수로 재사용을 위한 최적 조합 탐색에 관한 연구)

  • 안종일;정경숙;정태충
    • Journal of Intelligence and Information Systems
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    • v.3 no.2
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    • pp.1-9
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    • 1997
  • These papers propose an evolutionary algorithm for re-using output of waste fuel of light water reactor system in nuclear power plants. Evolutionary algorithm is useful for optimization of the large space problem. The wastes contain several re-useable elements, and they should be carefully selected and blended to satisfy requirements as input material to the heavy water nuclear reactor system. This problem belongs to a NP-hard like the 0/1 Knapsack problem. Two evolutionary strategies are used as a, pp.oximation algorithms in the highly constrained combinatorial optimization problem. One is the traditional strategy, using random operator with evaluation function, and the other is heuristic based search that uses the vector operator reducing between goal and current status. We also show the method, which performs the feasible teat and solution evaluation by using the vectorized data in problem. Finally, We compare the simulation results of using random operator and vector operator for such combinatorial optimization problems.

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A Co-Evolutionary Approach for Learning and Structure Search of Neural Networks (공진화에 의한 신경회로망의 구조탐색 및 학습)

  • 이동욱;전효병;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.111-114
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    • 1997
  • Usually, Evolutionary Algorithms are considered more efficient for optimal system design, However, the performance of the system is determined by fitness function and system environment. In this paper, in order to overcome the limitation of the performance by this factor, we propose a co-evolutionary method that two populations constantly interact and coevolve. In this paper, we apply coevolution to neural network's evolving. So, one population is composed of the structure of neural networks and other population is composed of training patterns. The structure of neural networks evolve to optimal structure and, at the same time, training patterns coevolve to feature patterns. This method prevent the system from the limitation of the performance by random design of neural network structure and inadequate selection of training patterns. In this time neural networks are trained by evolution strategies that are able to apply to the unsupervised learning. And in the coding of neural networks, we propose the method to maintain nonredundancy and character preservingness that are essential factor of genetic coding. We show the validity and the effectiveness of the proposed scheme by applying it to the visual servoing of RV-M2 robot manipulators.

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A Multiobjective Process Planning of Flexible Assembly Systems with Evolutionary Algorithms (진화알고리듬을 이용한 유연조립시스템의 다목적 공정계획)

  • Shin, Kyoung Seok;Kim, Yeo Keun
    • Journal of Korean Institute of Industrial Engineers
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    • v.31 no.3
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    • pp.180-193
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    • 2005
  • This paper deals with a multiobjective process planning problem of flexible assembly systems(FASs). The FAS planning problem addressed in this paper is an integrated one of the assignment of assembly tasks to stations and the determination of assembly routing, while satisfying precedence relations among the tasks and flexibility capacity for each station. In this research, we consider two objectives: minimizing transfer time of the products among stations and absolute deviation of workstation workload(ADWW). We place emphasis on finding a set of diverse near Pareto or true Pareto optimal solutions. To achieve this, we present a new multiobjective coevolutionary algorithm for the integrated problem here, named a multiobjective symbiotic evolutionary algorithm(MOSEA). The structure of the algorithm and the strategies of evolution are devised in this paper to enhance the search ability. Extensive computational experiments are carried out to demonstrate the performance of the proposed algorithm. The experimental results show that the proposed algorithm is a promising method for the integrated and multiobjective problem.