• Title/Summary/Keyword: Exploration and Exploitation

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Proposal on the Creation of a New Space Organization for the Moon and Celestial Bodies' Exploitation (달과 천체 개발을 위한 새로운 우주기구의 창설에 관한 제안)

  • Kim, Doo-Hwan
    • The Korean Journal of Air & Space Law and Policy
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    • v.29 no.1
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    • pp.161-198
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    • 2014
  • The idea of creating an International Space Exploitation Agency (tentative title: hereinafter referred to ISEA) is only my academic and theoretical opinion. It is necessary for us to establish ISEA as an international organization for the efficient and rapid exploitation of natural resources in the moon and other celestial bodies. The creation of ISEA as a new international organization is based on the Article 11, 5 and Article 18 of the 1979 Moon Agreement. In order to create it as a preliminary procedure, it needs to make the Draft for the Convention on the Establishment an ISEA among the space-faring countries. The main contents of this paper is composed of (1) introduction, (2) joint exploitation of the natural resources (Heliumn-3, etc.) in the moon and ISEA, (3) activities for the exploitation of moon and other celestial bodies by the space-faring powers, (4) legal problems and Solution for the exploitation and mining rights of the natural resources in the moon, mars and celestial bodies, (5) procedure of creating an ISEA, (6) the principal points that need to be included in the draft for the ISEA convention, (7) conclusion. The creation of an ISEA would lead to a strengthening of the cooperation among the States deemed essential by the global community towards joint undertakings in space and would act as a catalyst for the efforts on the exploitation of the natural resources moon, mars, Venus, Mercury and other celestial bodies and allow resources, technology, manpower and finances to be centrally managed in an independent fashion to the benefit of the space-faring countries. It is desirable and necessary for us to create ISEA in order to promote cooperation in the field of space policy, law, science technology and industry etc. among the space-faring countries. The creation of the ISEA will be promoted the international cooperation among the space-faring countries in exploration and exploitations of the natural resources in the moon, Mars, Venus, Mercury and other celestial bodies. Finally, it should be noted that the political drive will be necessary not only to set up the organization ISEA, but also study a subsequent measures. It is also necessary for us to create the ISEA in order to develop the space industry, to strengthen friendly relations and to promote research cooperation among the space-faring countries based on the new ideology and creative ideas. If the heads (president or prime minister) of the space super-powers including the UNCOPUOS will be agreed to establish ISEA at a summit conference, 1 believe that it is possible to establish an ISEA in the near future.

Observer-Teacher-Learner-Based Optimization: An enhanced meta-heuristic for structural sizing design

  • Shahrouzi, Mohsen;Aghabaglou, Mahdi;Rafiee, Fataneh
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.537-550
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    • 2017
  • Structural sizing is a rewarding task due to its non-convex constrained nature in the design space. In order to provide both global exploration and proper search refinement, a hybrid method is developed here based on outstanding features of Evolutionary Computing and Teaching-Learning-Based Optimization. The new method introduces an observer phase for memory exploitation in addition to vector-sum movements in the original teacher and learner phases. Proper integer coding is suited and applied for structural size optimization together with a fly-to-boundary technique and an elitism strategy. Performance of the proposed method is further evaluated treating a number of truss examples compared with teaching-learning-based optimization. The results show enhanced capability of the method in efficient and stable convergence toward the optimum and effective capturing of high quality solutions in discrete structural sizing problems.

Nonlinear identification of Bouc-Wen hysteretic parameters using improved experience-based learning algorithm

  • Luo, Weili;Zheng, Tongyi;Tong, Huawei;Zhou, Yun;Lu, Zhongrong
    • Structural Engineering and Mechanics
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    • v.76 no.1
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    • pp.101-114
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    • 2020
  • In this paper, an improved experience-based learning algorithm (EBL), termed as IEBL, is proposed to solve the nonlinear hysteretic parameter identification problem with Bouc-Wen model. A quasi-opposition-based learning mechanism and new updating equations are introduced to improve both the exploration and exploitation abilities of the algorithm. Numerical studies on a single-degree-of-freedom system without/with viscous damping are conducted to investigate the efficiency and robustness of the proposed algorithm. A laboratory test of seven lead-filled steel tube dampers is presented and their hysteretic parameters are also successfully identified with normalized mean square error values less than 2.97%. Both numerical and laboratory results confirm that, in comparison with EBL, CMFOA, SSA, and Jaya, the IEBL is superior in nonlinear hysteretic parameter identification in terms of convergence and accuracy even under measurement noise.

Effects of Knowledge-based Resource and Ambidextrous Capability on Export Performance in SMEs (중소기업의 지식기반자원과 양면성 역량이 수출성과에 미치는 영향)

  • Dong-Woo Ryu
    • Korea Trade Review
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    • v.45 no.2
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    • pp.31-49
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    • 2020
  • The purpose of this study is to investigate the effects of knowledge-based resource and ambidextrous capability on their export performance of small and medium-sized enterprises (SMEs). Drawing on an extensive review of the literature on Knowledge-based resource and ambidextrous capability, hypotheses are developed and tested using a sample of 284 SMEs in South Korea. Structural equation modeling was applied. As a result of analysis, first, international entrepreneurship has a significant effect on ambidextrous capability. Second, human capital has significant influence on ambidextrous capability. Third, ambidextrous capability has a significant effect on export performance. The results indicate that their knowledge-based resources ware significant driver of their ambidextrous capability. and that their ambidextrous capability was significant driver of their export performance. In the final conclusion section, implications and limitations of research results and suggestions for future research are discussed.

A Study on Ambidextrous Innovation's Proceeding Elements (양면성 혁신의 선행요인에 대한 연구)

  • Seong, Gi-Uk;Kim, Bong-Seon
    • Proceedings of the Safety Management and Science Conference
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    • 2012.11a
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    • pp.253-268
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    • 2012
  • Recently, creative innovation has become a major topic in management innovation and due to this, various researches on its need and methodologies are being performed. According to previous studies on ambidexterity, explorative innovation is closer to divergent and right-sided brain, while exploitative innovation is closer to convergent and left-sided brain. Topic was to identify preceding element which affects Ambidextrous Innovation. For this topic, 129 Six Sigma projects from 19 different companies were collected. Ambidextrous index from preceding studies was used. This index represents the degree of ambidextrous activation and can be calculated by multiplying cumulative usage of exploitative tools with that of explorative tools. In the project characteristics, simple linear regression result showed leadership degree, team's vitalization degree and leader capability degree have effect in positive direction.

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The Impact of Internal and External Sources of Knowledge on Innovation Performance in Independent Firms and Business Group Affiliates (기업의 내·외부 지식원천이 혁신성과에 미치는 영향과 기업집단 효과)

  • Kim, Ji-Hee;Lee, Ji-Hwan
    • Knowledge Management Research
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    • v.16 no.1
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    • pp.171-191
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    • 2015
  • This paper investigates how internal knowledge dependency and its interaction with external knowledge adoption affect innovation performance in Korean companies. We categorize innovation performance into exploratory innovation and exploitative innovation. Especially, we examine business group effects as group headquarters and sister subsidiaries holistically form the boundary of the firm. Our empirical results first suggest that the degree of internal knowledge dependency is positively associated with exploitative innovation, but negatively with exploratory innovation. Second, internal knowledge dependency is more negatively related to exploratory innovation in independent firms than in business group affiliates. Third, independent firms' adoption of external knowledge tends to strengthen the positive relationship between internal knowledge dependency and exploitative innovation. Finally, exploitative external knowledge search appears to strengthen the negative relationship between internal knowledge dependency and exploratory innovation in both types of firms.

Sexual Reproduction Genetic Algorithms: The Effects of Multi-Selection & Diploidy on Search Performances (유성생식 유전알고리즘 : 다중선택과 이배성이 탐색성능에 미치는 영향)

  • Ryu, K.B.;Choi, Y.J.;Kim, C.E.;Lee, H.S.;Jung, C.K.
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.1006-1010
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    • 1995
  • This paper describes Sexual Reproduction Genetic Algorithm(SRGA) for function optimization. In SRGA, each individual utilize a diploid chromosome structure. Sex cells(gametes) are produced through artificial meiosis in which crossover and mutation occur. The proposed method has two selection operators, one, individual selection which selects the individual to fertilize, and the other, gamete selection which makes zygote for offspring production. We consider the effects of multi-selection and diploidy on search performance. SRGA improves local and global search(exploitation and exploration) and show optimum tracking performance in nonstationary environments. Gray coding is incorporated to transforming the search space and Genic uniform distribution method is proposed to alleviate the problem of premature convergence.

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Multi-Objective Optimization Using Kriging Model and Data Mining

  • Jeong, Shin-Kyu;Obayashi, Shigeru
    • International Journal of Aeronautical and Space Sciences
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    • v.7 no.1
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    • pp.1-12
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    • 2006
  • In this study, a surrogate model is applied to multi-objective aerodynamic optimization design. For the balanced exploration and exploitation, each objective function is converted into the Expected Improvement (EI) and this value is used as fitness value in the multi-objective optimization instead of the objective function itself. Among the non-dominated solutions about EIs, additional sample points for the update of the Kriging model are selected. The present method was applied to a transonic airfoil design. Design results showed the validity of the present method. In order to obtain the information about design space, two data mining techniques are applied to design results: Analysis of Variance (ANOVA) and the Self-Organizing Map (SOM).

Derivative Evaluation and Conditional Random Selection for Accelerating Genetic Algorithms

  • Jung, Sung-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.1
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    • pp.21-28
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    • 2005
  • This paper proposes a new method for accelerating the search speed of genetic algorithms by taking derivative evaluation and conditional random selection into account in their evolution process. Derivative evaluation makes genetic algorithms focus on the individuals whose fitness is rapidly increased. This accelerates the search speed of genetic algorithms by enhancing exploitation like steepest descent methods but also increases the possibility of a premature convergence that means most individuals after a few generations approach to local optima. On the other hand, derivative evaluation under a premature convergence helps genetic algorithms escape the local optima by enhancing exploration. If GAs fall into a premature convergence, random selection is used in order to help escaping local optimum, but its effects are not large. We experimented our method with one combinatorial problem and five complex function optimization problems. Experimental results showed that our method was superior to the simple genetic algorithm especially when the search space is large.

An Ant System Extrapolated Genetic Algorithm (개미 알고리즘을 융합한 적응형 유전알고리즘)

  • Kim Joong Hang;Lee Se-Young;Chang Hyeong Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.8
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    • pp.399-410
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    • 2005
  • This paper Proposes a novel adaptive genetic algorithm (GA) extrapolated by an ant colony optimization. We first prove that the algorithm converges to the unique global optimal solution with probability arbitrarily close to one and then, by experimental studies, show that the algorithm converges faster to the optimal solution than GA with elitism and the population average fitness value also converges to the optimal fitness value. We further discuss controlling the tradeoff of exploration and exploitation by a parameter associated with the proposed algorithm.