• Title/Summary/Keyword: engineering problem

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A Sequencing Problem with Fuzzy Preference Relation and its Genetic Algorithm-based Solution (퍼지선호관계 순서화 문제와 유전자 알고리즘 기반 해법)

  • Lee, Keon-Myung;Sohn, Bong-Ki
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.1
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    • pp.69-74
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    • 2004
  • A sequencing problem is to find an ordered sequence of some entities which maximizes (or minimize) the domain specific objective function. As some typical examples of sequencing problems, there are traveling salesman problem, job shop scheduling, flow shop scheduling, and so on. This paper introduces a new type of sequencing problems, named a sequencing problem with fuzzy preference relation, where a fuzzy preference relation is provided for the evaluation of the quality of sequences. It presents how such a problem can be formulated in terms of objective function. It also proposes a genetic algorithm applicable to such a sequencing problem.

The Impact of Engineering Design Based STEM Research Experience on Gifted Students' Creative Engineering Problem Solving Propensity and Attitudes Toward Engineering (영재 학생들의 공학 설계 기반 통합적 STEM 연구 활동이 창의적 공학문제해결 성향 및 공학에 대한 태도에 미치는 영향)

  • Kang, Ju-Won;Nam, Younkyeong
    • Journal of The Korean Association For Science Education
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    • v.37 no.4
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    • pp.719-730
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    • 2017
  • The purpose of this study is to investigate how engineering design-based STEM research experience affects gifted students' creative engineering problem-solving propensity and attitude toward engineering. The students' creative engineering problem-solving propensity and attitude toward engineering were measured before and after the STEM research experience. The pre-/post-tests results were analyzed by paired t-test with the significance level of p <.05. The conclusions of the study are as follows: First, the engineering design based STEM research experience had a positive effect on the students' creative engineering problem-solving propensity. Over all, the average score of the creative engineering problem-solving propensity increased significantly (p <.05) after the STEM research experience. Second, the average score of gifted-students' attitude toward engineering had increased significantly after the integrated STEM research activities (p <.05). In addition, we analyzed the difference between pre-post results of both instruments based on the gifted students' desired career paths (natural science and engineering) and gender. The result shows that the students' career paths or gender did not affect the results in most of the sub-categories in both instruments. However, the STEM research experience had more positive effect on the female students than male students in term of their 'engineering design ability', which is one of the sub-categories of the creative engineering problem-solving propensity instrument.

Generalized $H^{\infty}$ Control Theory

  • Liu, Kang-Zhi;Mita, Tsutomu
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1539-1544
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    • 1991
  • In this paper we formulate and solve a generalized $H^{\infty}$ control problem. The conventional formulation of $H^{\infty}$ problem has some constraints in application, e.g. it can not deal with the servo problem. This is due to the superfluous requirement of internal stability of the augmented system. In this paper, we alleviate the stability of the augmented system to admit pole-zero cancellation on the imaginary aids outside the feedback loop of G22 and K. After such generalization, the servo problem is naturally incorporated into the $H^{\infty}$ synthesis.is.

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An Application of Heuristic Algorithms for the Large Scale Traveling Salesman Problem in Printed Circuit Board Production (회로기판 생산에서의 대형 외판원문제를 위한 경험적 해법의 응용)

  • 백시현;김내헌
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.41
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    • pp.177-188
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    • 1997
  • This study describes the important information for establishing Human Computer Interface System for solving the large scale Traveling Saleman Problem in Printed Circuit Board production. Appropriate types and sizes of partitioning of large scale problems are discussed. Optimal tours for the special patterns appeared in PCB's are given. The comparision of optimal solutions of non-Euclidean problems and Euclidean problems shows the possibilities of using human interface in solving the Chebyshev TSP. Algorithm for the large scale problem using described information and coputational result of the practical problem are given.

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공정계획 전문가시스템의 개발-조선 블럭분할에의 응용

  • 박병태;이재원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.04b
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    • pp.370-374
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    • 1993
  • This paper describes a study on the expert system based process planning of the block division process in shipbuilding. The prototype system developed deterines the block division line of the midship of crude-oil tanker. Case-based reasoning (CBR) approach relying on previous similar cases to solve the problem is applied instead of rule-based reasoning (RBR). Similar cases are retrieved from case base according to the similarity metrics between input problem and cases. The retrieved case with the highest priority is then adapted to fit to the input problem buy adaptation rules. The adapted solution is proposed as the division line for the input problem.

A Heuristic Approach for Material Collection System by Multiple Mobile Robot Agents (휴리스틱 접근법에 의한 다수 이동 로봇 에이전트를 이용한 물질 수집 시스템)

  • Lee, Young-Dae;Kim, Sik
    • Proceedings of the Korea Multimedia Society Conference
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    • 2001.11a
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    • pp.890-895
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    • 2001
  • In this paper, we address on the problem of automatic scheduling and motion generation of multiple mobile robots fur collecting material parts. We propose a model and so]union algorithm for the system. The formulated problem is divided into two kinds of problems; assignment problem and planning problem of robot motion. In this paper, several approaches to solution methods are presented and compared through computer simulation.

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Application of tree search to a control problem

  • Miyashita, Mitsutaka;Inooka, Hikaru
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.896-900
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    • 1988
  • Tree search can be applied to a control problem if the system is a discrete-time one and if the control input takes only discrete values. This paper considers the application of heuristic tree search to a simple control problem. The results of simulation studies show the good possibility of this approach to a control problem.

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Machine-Part Grouping Algorithm for the Bottleneck Machine Problem (애로기계가 존재하는 기계-부품 그룹형성 문제에 대한 해법)

  • 박수관;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.37
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    • pp.1-7
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    • 1996
  • The grouping of parts into families and machines into cells poses an important problem for the improvement of productivity and quality in the design and planning of the flexible manufacturing system(FMS). This paper proposes a new algorithm of forming machine-part groups in case of the bottleneck machine problem and shows the numerical example. This algorithm could be applied to the large scale machine-part grouping problem.

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Multicast Routing Algorithm under Cell Replication Limits of Switches in ATM Networks (ATM 망에서 교환기의 셀 복제 능력을 고려한 멀티캐스트 라우팅 알고리듬)

  • 주종혁
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.23 no.61
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    • pp.33-39
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    • 2000
  • In this paper, we present an algorithm for the multicast routing problem when there exit the cell replication limits of ATM switching nodes. This problem can be formulated as a Degree Constrained Minimum Steiner Tree Problem(DCSP). The proposed algorithm is a modification of the shortest path heuristic originally devised for minimum Steiner tree problem. From the experimental results, it can be seen that our algorithm is efficient to obtain a near optimal solution with comparatively low computational time.

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Optimization in Reliability Design with Lognormally Stress and Lognormally Strength (부하와 강도가 대수정규분포를 하는 신뢰성 설계에서 최적화에 관한 연구(II))

  • 김복만;황의철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.13 no.22
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    • pp.25-34
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    • 1990
  • This paper is to maximize the reliability subject to certain constraints on amounts of resources available for control of the parameters. The lagrange multiplier method is used to optimize t-th lognormal stress-lognormal strength problem. This optimization problem can be reduced to a search problem in one variable. A numerical example is presented to illustrate the optimization problem.

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