• 제목/요약/키워드: Evolutionary Process

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A Procedure for Robust Evolutionary Operations

  • Kim, Yongyun B.;Byun, Jai-Hyun;Lim, Sang-Gyu
    • International Journal of Quality Innovation
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    • 제1권1호
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    • pp.89-96
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    • 2000
  • Evolutionary operation (EVOP) is a continuous improvement system which explores a region of process operating conditions by deliberately creating some systematic changes to the process variable levels without jeopardizing the product. It is aimed at securing a satisfactory operating condition in full-scale manufacturing processes, which is generally different from that obtained in laboratory or pilot plant experiments. Information on how to improve the process is generated from a simple experimental design. Traditional EVOP procedures are established on the assumption that the variance of the response variable should be small and stable in the region of the process operation. However, it is often the case that process noises have an influence on the stability of the process. This process instability is due to many factors such as raw materials, ambient temperature, and equipment wear. Therefore, process variables should be optimized continuously not only to meet the target value but also to keep the variance of the response variables as low as possible. We propose a scheme to achieve robust process improvement. As a process performance measure, we adopted the mean square error (MSE) of the replicate response values on a specific operating condition, and used the Kruskal-Wallis test to identify significant differences between the process operating conditions.

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간호사의 감정노동 개념분석 (Concept Analysis of Nurses' Emotional Labor)

  • 안은경
    • 한국농촌간호학회지
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    • 제10권1호
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    • pp.5-15
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    • 2015
  • Purpose: This study was conducted to analyze the concept of nurses' emotional labor. Method: Rodgers's evolutionary concept analysis was used. Result: Nurses' emotional labor can be defined by two attributes: emotional distortion and self-regulation process. Antecedents of nurses' emotional labor include interactional, organizational and personal factors. The consequences of nurses' emotional labor are emotional dissonance and internalization of organizational display rules. Conclusion: Appropriate instrument to operationalize the concept need to be developed.

점진적최적화기법을 이용한 콘크리트 구조물의 위상최적화 (Topology Optimization of Concrete Structures using an Evolutionary Procedure)

  • 최창근;이태열
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.533-538
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    • 1997
  • Topology optimization of a concrete structure is discussed using an Evolutionary Structural Optimization(ESO) method introduced by Xie and Steven. During the evolution process low stressed materials are progressively removed from the structure. This paper discussed a proper rejection criterion(RC) to get a more reasonable topology of concrete structure. Some examples are presented to illustrate the optimum topology achieved by such a procedure.

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한국 신발산업의 진화 동태성과 쇠퇴 요인 (Evolutionary Perspectives on the Evolutionary Dynamics of the Footwear Industry in Korea)

  • 김성주;임정덕;이종호
    • 한국경제지리학회지
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    • 제11권4호
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    • pp.509-526
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    • 2008
  • 본 연구의 목적은 진화경제학적 관점으로 한국 신발산업의 진화적 발전경로를 분석하는 것이다. 산업의 변화를 연구함에 있어 진화론적 관점은 기업의 선택과 모방, 진입과 퇴출, 기술적 특성과 혁신과정 등 산업의 발전경로에 관한 복잡한 요인들이 어떻게 생성되고 지속되며 공진화하는지를 설명할 수 있는 장점을 가지고 있다. 한국 신발산업에 관한 기존의 연구들은 한국 신발산업의 쇠퇴 요인을 임금 상승과 노동집약적 산업의 환경 변화의 측면에서 찾고 있다. 이에 반해, 본 연구에서는 한국 신발산업의 쇠퇴 요인을 국내 기업의 전략적 선택과 모방의 경로, 지배적 기술 패러다임, 기업을 둘러싸고 있는 제도적 규제의 문제, 그리고 글로벌생산체제로 변화하는 메조 궤적의 진화적 발전경로의 측면에서 찾고자 하였다. 이러한 분석 결과를 토대로 한국의 신발산업은 스포츠화, 특히 혁제운동화의 제조기술에 대한 학습과정과 OEM 주문생산에 기초하여 성장했으며, 한국 신발산업의 사양화는 대내외 환경변화에 따른 경쟁조건과 시장선택체제에 적응하기 위한 기업의 진화적 선택과정에 따른 결과임을 강조한다.

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NUMBER OF CYCLES IN EVOLUTIONARY OPERATION

  • Lim, Yong-B.;Park, Sung-H.
    • Journal of the Korean Statistical Society
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    • 제36권2호
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    • pp.201-208
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    • 2007
  • Evolutionary operation (EVOP) proposed by Box (1957) is a method for continuous monitoring and improvement of a full-scale manufacturing process with the objective of moving the operating conditions toward the better ones. EVOP consists of systematically making small changes in the levels of the two or three process variables under consideration. Data are collected on the response variable at each point of two level factorial design with the center point and a cycle is said to have been completed. The cycles are replicated sequentially until the decision is made on whether further cycle of experiments is needed to conclude the significance of any of main effects or interaction effects or the curvature. In this paper, an improved flow chart of EVOP is proposed and how to determine the number of cycles is studied based on the size of type II error. In order to reject the alternative hypothesis of interests with more confidence and conclude that we believe in the null hypothesis of no effects, we propose a counter measure $p^*-value$ corresponding to the p-value. The relationship of $p^*-value$ to the probability of type II error ${\beta}$ under the alternative hypothesis of interests is analogous to that of p-value to the probability of type I error ${\alpha}$. Also the implementation of EVOP with a mixture experiment is discussed.

The Limit of Gene-Culture Co-evolutionary Theory

  • Lee, Min-seop;Jang, Dayk
    • 인지과학
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    • 제28권3호
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    • pp.173-191
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    • 2017
  • The theories of cultural evolution hold subtly or clearly different stances about definition of culture, pattern of cultural evolution, biases that affect cultural evolution, and relationship between culture and organism. However, the cultural evolution theories have a common problem to solve: As the evolutionary theory of life tries to explain the early steps and the origin of life, the cultural evolution theories also must explain the early steps of the cultural evolution and the role of the human capability that makes cultural evolution possible. Therefore, explanations of the human's unique traits including the cultural ability are related to determine which one is the most plausible among many cultural evolution theories. Theories that tried to explain human uniqueness commonly depict the coevolution of gene (organism) and culture. We will explicitly call the niche construction theory and the dual inheritance theory the 'gene-culture co-evolutionary theory'. In these theories, the most important concept is the 'concept of positive feedback'. In this paper, we distinguish between core positive feedback and marginal positive feedback, according to whether the trait that the concept of positive feedback explains is the trait of human uniqueness. Both types of positive feedback effectively explain the generality of human uniqueness and the diversity of human traits driven by cultural groups. However, this positive feedback requires an end, in contrast to negative feedback which can be continued in order to maintain homeostasis. We argue that the co-evolutionary process in the gene-culture co-evolutionary theories include only the positive feedback, not covering the cultural evolution after the positive feedback. This thesis strives to define the coevolution concept more comprehensively by suggesting the potential relationships between gene and culture after the positive feedback.

Evolutionary Network Optimization: Hybrid Genetic Algorithms Approach

  • Gen, Mitsuo
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.195-204
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    • 2003
  • Network optimization is being increasingly important and fundamental issue in the fields such as engineering, computer science, operations research, transportation, telecommunication, decision support systems, manufacturing, and airline scheduling. Networks provide a useful way to modeling real world problems and are extensively used in practice. Many real world applications impose on more complex issues, such as, complex structure, complex constraints, and multiple objects to be handled simultaneously and make the problem intractable to the traditional approaches. Recent advances in evolutionary computation have made it possible to solve such practical network optimization problems. The invited talk introduces a thorough treatment of evolutionary approaches, i.e., hybrid genetic algorithms approach to network optimization problems, such as, fixed charge transportation problem, minimum cost and maximum flow problem, minimum spanning tree problem, multiple project scheduling problems, scheduling problem in FMS.

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Diversity, Evolution & Marketing Practice

  • Murray, John A.;Torres, Ann M.
    • 마케팅과학연구
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    • 제7권
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    • pp.71-103
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    • 2001
  • Marketing practice varies among firms. However, the prescriptive literature emphasises a universal view of practice, a 'one size fits all' view. This paper addresses the issue of explaining diversity in marketing practice in competitive space and in time. Diversity in competitive space reflects the existence of different routes to high performance. Diversity in time reflects some combination of change in the individual firm and change in a population of firms. In the former case, diversity is shaped by organisational change; in the latter by the disbandment and founding of firms in the population. In so far as diversity is the norm, the manner in which practice will be shaped by evolutionary processes is considered. Fnally, the role of the academy as one of the forces driving the evolutionary process is discussed. Miles and Snow's (1978, 1986) work is taken as a main point of departure in the search for explanation and ecological and evolutionary concepts are drawn on for support and to suggest an explanation for the nature of diversity over time.

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An Improved Element Removal Method for Evolutionary Structural Optimization

  • Han, Seog-Young
    • Journal of Mechanical Science and Technology
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    • 제14권9호
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    • pp.913-919
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    • 2000
  • The purpose of this study was to develop a new element removal method for ESO (Evolutionary Structural Optimization), which is one of the topology optimization methods. ESO starts with the maximum allowable design space and the optimal topology emerges by a process of removal of lowly stressed elements. The element removal ratio of ESO is fixed throughout topology optimization at 1 or 2%. BESO (bidirectional ESO) starts with either the least number of elements connecting the loads to the supports, or an initial design domain that fits within the maximum allowable domain, and the optimal topology evolves by adding or subtracting elements. But the convergence rate of BESO is also very slow. In this paper, a new element removal method for ESO was developed for improvement of the convergence rate. Then it was applied to the same problems as those in papers published previously. From the results, it was verified that the convergence rate was significantly improved compared with ESO as well as BESO.

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기계 구조의 합성적 자동생성을 위한 진화연산 (Evolutionary computation approach for automated synthesis design of mechanical structures)

  • 이인호;차주헌;김재정
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.643-646
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    • 2002
  • This paper proposes an evolutionary computation approach for automated design of mechanical structures especially in its early stage of design phases. Due to the known characteristics of the stage, the approach basically involves a synthetic design method with the composition of building blocks representing the elements of mechanical objects. In order for the building blocks to be more suitable for representation and evolution of mechanical structures, Elementary Cell Blocks (ECBs) are introduced as new building blocks. A new Darwinian evolution process for the new building blocks is also necessarily involved in the approach. We have demonstrated the implementation of the approach with the design of multi-step gear systems.

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