• Title/Summary/Keyword: Evolution strategy

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Intelligent 3-D Obstacle Avoidance Algorithm for Autonomous Control of Underwater Flight Vehicle (수중비행체의 자율제어를 위한 지능형 3-D 장애물회피 알고리즘)

  • Kim, Hyun-Sik;Jin, Tae-Seok;Sur, Joo-No
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.323-328
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    • 2011
  • In real system application, the 3-D obstacle avoidance system for the autonomous control of the underwater flight vehicle (UFV) operates with the following problems: the sonar offers the range/bearing information of obstacles in a local detection area, it requires the system that has reduced acoustic noise and power consumption in terms of the autonomous underwater vehicle (AUV), it has the UFV operation constraints such as maximum pitch and depth, and it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an intelligent 3-D obstacle avoidance algorithm using the evolution strategy (ES) and the fuzzy logic controller (FLC), is proposed. To verify the performance of the proposed algorithm, the 3-D obstacle avoidance of UFV is performed. Simulation results show that the proposed algorithm effectively solves the problems in the real system application.

Intelligent Obstacle Avoidance Algorithm for Autonomous Control of Underwater Flight Vehicle (수중비행체의 자율제어를 위한 지능형 장애물회피 알고리즘)

  • Kim, Hyun-Sik;Jin, Tae-Seok
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.635-640
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    • 2009
  • In real system application, the obstacle avoidance system for the autonomous control of the underwater flight vehicle (UFV) operates with the following problems: it has local information because the sonar can only offer the obstacle information in a local detection area, it requires a continuous control input because the system that has reduced acoustic noise and power consumption is necessary, and further, it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an intelligent obstacle avoidance algorithm using the evolution strategy (ES) and the fuzzy logic controller (FLC), is proposed. To verify the performance of the proposed algorithm, the obstacle avoidance of UFV is performed. Simulation results show that the proposed algorithm effectively solves the problems in the real system application.

A study on minimum weight design of vertical corrugated bulkheads for chemical tankers

  • Shin, Sang-Hoon;Ko, Dae-Eun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.2
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    • pp.180-187
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    • 2018
  • Corrugated bulkhead has been adopted for cargo tank bulkheads of commercial vessels such as bulk carriers, product oil carriers and chemical tankers. It is considered that corrugated bulkhead is a preferred structural solution, compared to the flat stiffened bulkhead, due to several advantages such as lower mass, easier maintenance and smaller corrosion problems. Many researches to find the optimum shape of corrugated bulkhead have been mostly carried out for bulk carriers. Compared to corrugated bulkheads of bulk carriers, ones of chemical tankers are more complicated since they are composed of transverse and longitudinal bulkheads, and they are made of higher priced materials. The purpose of this study is the development of minimum weight design method for corrugated bulkhead of chemical tankers. Evolution strategy is applied as an optimization technique. It has been verified from many researches that evolution strategy searches global optimum point prominently by using multi-individual searching technique. Multi-individual searching methods need excessive time if they connect to 3-D finite element model for repetitive structural analyses. In order to resolve this issue, 2-D beam element connected to deck and lower stool is substituted for a corrugated structure in this study. To verify the reliability of the structural responses by idealized 2-D beam model, they have been compared with ones by 3-D finite element model. In this study, optimum design for corrugated bulkhead of 30 K chemical tanker has been carried out, and the results by developed optimum design program have been compared with design data of existing ship. It is found out that optimum design is about 9% lighter than one of existing ship.

A Study on the Components and Systems Archytypes of the Resilience for the New Regional Development Strategy (새로운 지역개발전략으로서의 회복탄력성의 요소와 인과순환적 원형구조에 관한 연구)

  • Choi, Nam-Hee
    • Korean System Dynamics Review
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    • v.16 no.4
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    • pp.155-178
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    • 2015
  • This study aims to explore the new paradigm of regional development strategy with the theory of Resilience. Resilience can be defined in terms of a set of interacted capacities to absorb and adapted to different kinds of shocks and disturbance at the regional level. This study focuses particularly on the interaction of component of resilience with the context of regional development strategy. As a result of the Systems thinking approach about dynamic interactions between resilience components and regional problems, this study find that there are many feedback structures which is need for a better understanding of the complex regional resilient development system. This study suggests that the Archytypes of resilience-focused strategy of regional development, which could help achieve an evolution for regional community and people to adapt and bounce back from crisis.

Evolution of Manufacturing Strategy Model: A Quality Perspective (생산전략모형의 진화: 품질의 관점)

  • Heetak Kim
    • Journal of Korean Society for Quality Management
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    • v.29 no.1
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    • pp.85-100
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    • 2001
  • There is a significant discrepancy between manufacturing strategy and quality management. This paper attempts to review the literature of manufacturing strategy model in quality perspective The objective of the paper is to clarify the quality aspect of manufacturing strategy models for a better understanding of the subject and to lay a foundation to integrate manufacturing strategy with quality management. The paper is organized as follows. First, the literature review on the issue is presented. The trade-off model, lean production model, cumulative model, sand cone model, quality staircase model are critically reviewed. Next, the discussion on the review model is brought. Finally, conclusions are presented.

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THE FIT BETWEEN NEW PRODUCT STRATEGY AND VALUE CHAIN STRATEGY : A SYSTEM DYNAMICS PERSPECTIVE

  • Heungshik Oh;Kim, Bowon
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.37-43
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    • 2001
  • New product development has been a key element fur organizational evolution. The bulk of research about new product strategy has focused solely on new product development function itself. This paper investigates cross-functional elements in new product development. More specifically, we suggest that there must exist a fit between new product strategy and value chain strategy. It means that, in order to support new product development activity, there must exist a relevant value chain strategy. We consider three types of integration - internal integration, customer integration, and supplier integration - as strategic elements of value chain strategy. For the case of new product strategy, we consider market newness and product technology unfamiliarity as strategic elements. We also consider two types of learning characteristic, i.e., \\\"fast-adaptive learning\\\" and \\\"slow-adaptive leaning\\\" as control factor. Learning characteristic represents firms organizational capability related with organizational learning. For example, fur fast-adaptive learning case, the effect of integration appears early in time. System dynamics simulation is employed to verify our research framework. The results exhibit that there must exist cross-functional relationships between value chain strategy and new product strategy in order to shorten total development time.al development time.

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Structural health monitoring through meta-heuristics - comparative performance study

  • Pholdee, Nantiwat;Bureerat, Sujin
    • Advances in Computational Design
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    • v.1 no.4
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    • pp.315-327
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    • 2016
  • Damage detection and localisation in structures is essential since it can be a means for preventive maintenance of those structures under service conditions. The use of structural modal data for detecting the damage is one of the most efficient methods. This paper presents comparative performance of various state-of-the-art meta-heuristics for use in structural damage detection based on changes in modal data. The metaheuristics include differential evolution (DE), artificial bee colony algorithm (ABC), real-code ant colony optimisation (ACOR), charged system search (ChSS), league championship algorithm (LCA), simulated annealing (SA), particle swarm optimisation (PSO), evolution strategies (ES), teaching-learning-based optimisation (TLBO), adaptive differential evolution (JADE), evolution strategy with covariance matrix adaptation (CMAES), success-history based adaptive differential evolution (SHADE) and SHADE with linear population size reduction (L-SHADE). Three truss structures are used to pose several test problems for structural damage detection. The meta-heuristics are then used to solve the test problems treated as optimisation problems. Comparative performance is carried out where the statistically best algorithms are identified.

Fuzzy Controller of Three-Inertia Resonance System designed by Differential Evolution

  • Ikeda, Hidehiro;Hanamoto, Tsuyoshi
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.184-189
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    • 2014
  • In this paper, a new design method of vibration suppression controller for multi-inertia (especially, 3-ineritia) resonance systems is proposed. The controller consists of a digital fuzzy controller for speed loop and a digital PI controller for current minor loop. The three scaling factor of the fuzzy controller and two PI controller gains are determined by Differential Evolution (DE). The DE is one of optimization techniques and a kind of evolutionary computation technique. In this paper, we have applied the DE/rand/1/bin strategy to design the optimal controller parameters. Comparing with the conventional design algorithm, the proposed method is able to shorten the time of the controller design to a large extent and to obtain accurate results. Finally, we confirmed the effectiveness of the proposal method by the computer simulations.

Design Evolution and Spatial Composition of Schindler's Demolished Cabin for Mr. and Mrs. Popenoe of 1922 at Coachella, California

  • Park, Jin-Ho;Lee, Hong-Kyu;Joo, Yong-Sun;Cho, Young-Ho
    • Architectural research
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    • v.9 no.2
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    • pp.11-18
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    • 2007
  • A cabin for Mr. and Mrs. Popenoe of 1922 was designed by the eminent Los Angeles architect, Rudolph M. Schindler. It stands out as an early exemplar of Schindler's most notable work in its unique employment of compositional strategy. Unfortunately, the cabin was demolished before an in-depth research was executed. In addition, there remains no documentary record with regard to the construction process, structural details and the use of materials of the built cabin. However, a set of drawings of the house are housed in the Schindler Archive. Reworking drawings and fabricating a scale model based on the materials obtained from the Archive, this article first depicts the evolution of the design, and then, attempts to investigate underlying principles governing the spatial composition of the cabin.