• 제목/요약/키워드: Multi-objective

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DBR 스케줄링에 있어 제약자원 선정에 관한 연구 (Selecting the Critical Resources Using DBR on Multi-parameters)

  • 서장훈;홍석묵;박명규
    • 대한안전경영과학회지
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    • 제4권1호
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    • pp.131-139
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    • 2002
  • Since introducing the "Theory of Constraints" by Goldratt, its effect was verified by lots of scholars, men of enterprise. These days it is also introducing and studying in this country with good results. The objective of this study is to show how to determine the constraint resources on DBR scheduling. Actually, previous studies based on the line which just think a load/capacity rate on doing scheduling. This study will show a scheduling method which reflects multi-parameters. It could be a standard to reflect real manufacturing surroundings. On calculating a priority of each resources, we classified factors with subjective and objective factors. And we propose a decision model to incorporate values assigned by a group of experts on different factors to select a critical resource. On deploying this model, SN ratio of Taguchi method for each of subjective and objective factors will be used. And we propose a procedure which is organized with 7 steps. To understand the logic, a numerical manufacturing simulation will be presented. This method is a incorporating decision model on determining the constraint on multi parameters with experts.h experts.

CSR 을 활용한 이중선각유조선 중앙단면의 최적구조설계 (Optimum Structural Design of Mid-ship Section of D/H Tankers Based on Common Structural Rules)

  • 나승수;전형근
    • 대한조선학회논문집
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    • 제45권2호
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    • pp.151-156
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    • 2008
  • It is necessary to perform the research works on the general structural designs and optimum structural designs of double hull tankers and bulk carriers due to the newly built Common Structural Rules(CSR). In this study, an optimum structural design of a mid-ship part of double hull oil tanker was carried out by using the CSR. An optimum structural design program was developed by using the Pareto optimal based multi-objective function method. The hull weight and fabrication cost obtained by the single and multi-objective function methods were compared with existing ship by the consideration of CSR and material cost which is recently increasing.

Multi-Objective Optimal Design of a Single Phase AC Solenoid Actuator Used for Maximum Holding Force and Minimum Eddy Current Loss

  • Yoon, Hee-Sung;Eum, Young-Hwan;Zhang, Yanli;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • 제3권2호
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    • pp.218-223
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    • 2008
  • A new Pareto-optimal design algorithm, requiring least computational work, is proposed for a single phase AC solenoid actuator with multi-design-objectives: maximizing holding force and minimizing eddy current loss simultaneously. In the algorithm, the design space is successively reduced by a suitable factor, as iteration repeats, with the center of pseudo-optimal point. At each iteration, the objective functions are approximated to a simple second-order response surface with the CCD sampling points generated within the reduced design space, and Pareto-optimal solutions are obtained by applying($1+{\lambda}$) evolution strategy with the fitness values of Pareto strength.

경량화에 대한 안전성을 고려한 로우컨트롤암의 다목적 최적설계 (Multi-objective Optimization of Lower Control Arm Considering the Stability for Weight Reduction)

  • 이동화;박영철;허선철
    • 한국자동차공학회논문집
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    • 제11권4호
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    • pp.94-101
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    • 2003
  • Recently, miniaturization and weight reduction is getting more attention due to various benefits in automotive components design. It is a trend that the design of experiment(DOE) and statical design method are frequently used for optimization. In this research, the safety of lower control arm is evaluated according to its material change form S45C to A16061 for the reduction of arm's weight. The variance analysis on the basis of structure analysis and DOE is applied to the lower control m. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering mass, stress and deflection.

직교배열표를 이용한 다목적 퍼지제어 알고리즘 및 능동자기베어링 시스템에의 응용 (Fuzzy Control Algorithm for Multi-Objective Problems using Orthogonal Array and its Application to an AMB System)

  • 김추호;이종원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.449-454
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    • 2000
  • A new fuzzy logic control design algorithm suitable for multi-objective control problems is proposed based on the orthogonal array which is widely used for design of experiments in statistics and industrial engineering. The essence of the algorithm is to introduce Nth-certainty factor defined from the F-value of the ANOVA(analysis of variance) table, in order to effectively exclude the less confident rules. The proposed algorithm with multi-objective decision table(MODT) is found to be capable of the detection of inconsistency and the rule classification, reduction and modification. It is also shown that the algorithm can be successfully applied to the fuzzy controller design of an active magnetic bearing system.

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초기투자비와 1차 에너지소비량을 고려한 에너지시스템의 다중최적 설계 방법론 (A Multi-objective Optimization Method for Energy System Design Considering Initial Cost and Primary Energy Consumption)

  • 공동석;장용성;허정호
    • 설비공학논문집
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    • 제26권8호
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    • pp.357-365
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    • 2014
  • This paper proposed a multi-objective optimization method for building energy system design using primary energy consumption and initial cost. The designing of building energy systems is a complex task, because life cycle cost and efficiency of building are determined by decisions of engineer during the early stage of design. Therefore, methods such as pareto analysis that can generate various alternatives for decision making are necessary. In this study, the optimization is performed using the NSGAII and case study was carried out for feasibility of the proposed method. As a result, alternative solutions can be obtained for the optimal building energy system design.

Multiobjective Decision-Making applied to Ship Optimal Design

  • Wang, Li-Zheng;Xi, Rong-Fei;Bao, Cong-Xi
    • Journal of Ship and Ocean Technology
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    • 제5권1호
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    • pp.30-37
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    • 2001
  • Ship optimal design is a multi-objective decision-making process and its optimal solution does not exit in general. It is a problem in which the decision-maker is very interested that an effective solution is how to be found which has good characteristic and is substituted for optimal solution in a sense. In the previous methods of multi-objective decision-making, the weighting coefficients are decided from the point of view of individuals which have a bit sub-jective an unilateral behavior. in order to fairly and objectively decide the weighting coeffi-cients, which are considered to be optimal in all system of multi-objective decision-making and satisfactory solution to the decision-maker, the pater presents a method of applying the Technology of the Biggest Entropy. It is proved that the method described in the paper is very feasible and effective be means of a practical example of ship optimal design.

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MOGA-Based Structural Design Method for Diagrid Structural Control System Subjected to Wind and Earthquake Loads

  • Kim, Hyun-Su;Kang, Joo-Won
    • 국제강구조저널
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    • 제18권5호
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    • pp.1598-1606
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    • 2018
  • An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.

반응표면법을 이용한 Al5052 판재의 점진성형 최적화 연구 (Optimization of Incremental Sheet Forming Al5052 Using Response Surface Method)

  • 오세현;샤오샤오;김영석
    • 소성∙가공
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    • 제30권1호
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    • pp.27-34
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    • 2021
  • In this study, response surface method (RSM) was used in modeling and multi-objective optimization of the parameters of AA5052-H32 in incremental sheet forming (ISF). The goals of optimization were the maximum forming angle, minimum thickness reduction, and minimum surface roughness, with varying values in response to changes in production process parameters, such as tool diameter, tool spindle speed, step depth, and tool feed rate. A Box-Behnken experimental design (BBD) was used to develop an RSM model for modeling the variations in the forming angle, thickness reduction, and surface roughness in response to variations in process parameters. Subsequently, the RSM model was used as the fitness function for multi-objective optimization of the ISF process based on experimental design. The results showed that RSM can be effectively used to control the forming angle, thickness reduction, and surface roughness.

Knee-driven many-objective sine-cosine algorithm

  • Hongxia, Zhao;Yongjie, Wang;Maolin, Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권2호
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    • pp.335-352
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    • 2023
  • When solving multi-objective optimization problems, the blindness of the evolution direction of the population gradually emerges with the increase in the number of objectives, and there are also problems of convergence and diversity that are difficult to balance. The many- objective optimization problem makes some classic multi-objective optimization algorithms face challenges due to the huge objective space. The sine cosine algorithm is a new type of natural simulation optimization algorithm, which uses the sine and cosine mathematical model to solve the optimization problem. In this paper, a knee-driven many-objective sine-cosine algorithm (MaSCA-KD) is proposed. First, the Latin hypercube population initialization strategy is used to generate the initial population, in order to ensure that the population is evenly distributed in the decision space. Secondly, special points in the population, such as nadir point and knee points, are adopted to increase selection pressure and guide population evolution. In the process of environmental selection, the diversity of the population is promoted through diversity criteria. Through the above strategies, the balance of population convergence and diversity is achieved. Experimental research on the WFG series of benchmark problems shows that the MaSCA-KD algorithm has a certain degree of competitiveness compared with the existing algorithms. The algorithm has good performance and can be used as an alternative tool for many-objective optimization problems.