• Title/Summary/Keyword: problem solving approach

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Facility Location Planning with Realistic Operation Times in Supply Chain (공급사슬에서 실제 시설물 운영시간을 고려한 시설배치계획에 관한 연구)

  • Lee Sang Heon;Kim Sook Han
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.2
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    • pp.143-156
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    • 2005
  • Facility location planning (FLP) problem is the strategic level planning in supply chain. The FLP is significantly affected by the operation time of each facility. In most of the FLP researches, operation time of facility has been treated as a fixed value. However, the operation time is not a static factor in real situations and the fixed operation time may lead unrealistic FLP. In this paper, a mixed integer programming (MIP) model is proposed for solving the 3-stage FLP problem and operation times are adjusted by the results from the simulation model and an iterative approach combining the analytic model and simulation model is proposed to obtain more realistic operation plans for FLP problems.

Environmental -Friendly Agricultural and Mechanization Trend in Japan -Prospects of Precision Farming in Japan (일본의 친환경 농업기계화기술 - 일본의 정밀농업 전망 -)

  • Shibuwasa, Sakae
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1999.06a
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    • pp.53-80
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    • 1999
  • Productivity and environmental conservation in nowadays trade-off and serious problem in agriculture. Precision farming is developing for solving the trade-off problem using systems approach and variable management. The systems approach is attributed to aiming at information-oriented agriculture, environmental-friendly sustainable agriculture, and complex system optimization . The variable management is composed of describing variability , variable-rate technology and decision support system. Three levels of technology development and three farming strategies are introduced for having a prospect. Describing the variability is the first step to promote it. Precision farming could be available for small scale farming as well as big scale farming. Paddy field precision farming will undergo in its distinctive way.

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The survey on the Approach to the problem of Security-Constrained Price-Based Unit Commitment in the Deregulated Power Market (전력시장에서 안전도와 가격을 고려한 발전기 기동정지계획문제에 대한 조사연구)

  • Jang, Se-Hwan;Kim, Jin-Ho
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.359-360
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    • 2006
  • This paper introduces a variable of methodology and models of solving Security-Constrained Price-Based Unit Commitment(SPUC) Problems in the Deregulated Power Market. The objective of SPUC is coordination between GENCOs and the ISO. GENCOs apply Price-Based Unit Commitment(PBUC) without security constraints and submit capacity bids to the ISO for maximizing their revenues. Using generation data and transmission data obtained from TRANSCOs, the ISO applies Security-Constrained Unit Commitment(SCUC), executes congestion management and contingency analysis for minimizing line flow violations and the risk supplying loads. Considering analysis data, the ISO should adjust GENCOS' bid. In this paper, we presents the result of survey and analyze on the approach of the SPUC problem.

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Evoluationary Design of a Fuzzy Logic Controller For Multi-Agent Robotic Systems

  • Jeong, ll-Kwon1;Lee, Ju-Jang
    • Transactions on Control, Automation and Systems Engineering
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    • v.1 no.2
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    • pp.147-152
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    • 1999
  • It is an interesting area in the field of artifical intelligence to find an analytic model of cooperative structure for multiagent system accomplishing a given task. Usually it is difficult to design controllers for multi-agent systems without a comprehensive knowledge about the system. One of the way to overcome this limitation is to implement an evolutionary approach to design the controllers. This paper introduces the use of a genetic algorithm to discover a fuzzy logic controller with rules that govern emergent agents solving a pursuit problem in a continuous world. Simulation results indicate that, given the complexity of the problem, an evolutionary approach to find the fuzzy logic controller seems to be promising.

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Partial Pole Assignment via Constant Gain Feedback in Two Classes of Frequency-domain Models

  • Wang, Guo-Sheng;Yang, Guo-Zhen;Duan, Guang-Ren
    • International Journal of Control, Automation, and Systems
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    • v.5 no.2
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    • pp.111-116
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    • 2007
  • The design problem of partial pole assignment (PPA) in two classes of frequency-domain MIMO models by constant gain feedback is investigated in this paper. Its aim is to design a constant gain feedback which changes only a subset of the open-loop eigenvalues, while the rest of them are kept unchanged in the closed-loop system. A near general parametric expression for the feedback gain matrix in term of a set of design parameter vectors and the set of the closed-loop poles, and a simple parametric approach for solving the proposed problem are presented. The set of poles do not need to be previously prescribed, and can be set undetermined and treated together with the set of parametric vectors as degrees of design freedom provided by the approach. An illustrative example shows that the proposed parametric method is simple and effective.

Unsteady Temperature Distributions in a Semi-infinite Hollow Circular Cylinder of Functionally Graded Materials

  • Kim, Kui-Seob;NODA, Naotake
    • International Journal of Aeronautical and Space Sciences
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    • v.2 no.2
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    • pp.46-55
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    • 2001
  • A Green's function approach based on the laminate theory is adopted to obtain the unsteady temperature distributions in a semi-infinite hollow circular cylinder made of functionally graded materials (FGMs). The transient heat conduction equation based on the laminate theory is formulated into an eigenvalue problem for each layer by using the eigenfunction expansion theory and the separation of variables. The eigenvalues and the corresponding eigenfunctions obtained by solving an eigenvalue problem for each layer constitute the Green's function solution for analyzing the unsteady temperature distributions. Numerical calculations are carried out for the semi-infinite hollow circular FGM cylinder subjected to partially heated loads, and the numerical results are shown in figures.

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Application of Candidate Order Approach for Solving Job Sequencing Problem with Finish Date Constraint (완료 시간 제약이 있는 작업 순서 결정 문제 풀이를 위한 후보 순위 접근법 응용)

  • Kim, Jun Woo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.421-422
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    • 2018
  • 작업 순서 결정 문제의 목표는 다양한 작업들에 대한 최적의 처리 순서를 결정하여 총 처리시간이나 납기 지연과 관련된 지표들을 최소화하는 것이다. 나아가, 실제 생산 현장에서는 작업 처리 순서를 결정할 때, 긴급도나 고객과의 관계 등과 같은 요인을 고려하여 일부 작업들을 특정 시간 내에 완료해야 할 수 있으며, 이 같은 제약 조건을 완료 시간 제약이라 한다. 본 논문에서는 완료 시간 제약을 갖는 작업 순서 결정 문제의 개념과 특성에 대해 살펴보고, 이러한 문제를 풀이하기 위한 알고리즘 개발에 후보 순위 접근법을 적용할 것을 제안한다.

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Production/Distribution Scheduling for Integrated Supply Chain Management (통합 공급체인관리를 위한 생산/배송 스케줄링)

  • Park, Yang-Byung
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.4
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    • pp.443-453
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    • 2002
  • Many firms are trying to optimize their production and distribution systems separately, but possible profit increase by this approach is limited. Nowadays, it is more important to analyze these two systems simultaneously for the integrated supply chain management. This paper is a computational study to investigate the effectiveness of integrating production and distribution scheduling. We are interested in a multi-plant, multi-retailer, multi-product and multi-period industrial problem where the objective in solving production and distribution scheduling problem is to maximize the total net profit. Computational results on test problems of various sizes using the heuristic we developed show a substantial advantage of the integrated scheduling approach over the decoupled scheduling process. Sensitivity analysis on the parameter values indicates that, under the right conditions, the effectiveness of integrating production and distribution functions can be extremely high.

A Mathematical Approach to Time-Varying Obstacle Avoidance of Robot manipulators (로보트의 시변 장애물 회피를 위한 수학적 접근 방법)

  • 고낙용;이범희;고명삼
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.7
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    • pp.809-822
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    • 1992
  • A mathematical approach to solving the time-varying obstacle avoidance problem is pursued. The mathematical formulation of the problem is given in robot joint space(JS). View-time concept is used to deal with time-varying obstacles. The view-time is the period in which a time-varying obstacles. The view-time is the period in which a time-varying obstacle is viewed and approximated by an equivalent stationary obstacle. The equivalent stationary obstacle is the volume swept by the time-varying obstacle for the view-time. The swept volume is transformed into the JS obstacle that is the set of JS robot configurations causing the collision between the robot and the swept volume. In JS, the path avoiding the JS obstacle is planned, and a trajectory satisfying the constraints on robot motion planning is planned along the path. This method is applied to the collision-free motion planning of two SCARA robots, and the simulation results are given.

Guide-Path Design for Automated Guided Vehicles (AGV 유도경로 설계에 관한 연구)

  • Choe, H.;Jung, M.
    • Journal of Korean Institute of Industrial Engineers
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    • v.18 no.1
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    • pp.121-139
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    • 1992
  • AGVS(Automated Guided Vehicle Systems) in material handling have been used widely since late 1970s. Implementation of an AGVS generally requires substantial study to optimize the design and performance of guide-paths. Traditional mathematical approaches have been used with limited success to analyze AGVS. These approaches, however, do not provide a practical tool for guide-path designers. This paper presents a new approach based on rules in designing and assessing AGV guide-paths to improve the design of a closed-loop layout. A framework for the integrated approach is proposed, problem solving procedures are explained, and a case study is reported to demonstrate the framework. Deletion of seldom used guide-paths, and addition of bypasses to solve the congestion problem, are conducted interactively and iteratively through simulation experiments. To visualize the results, a graphic control program is developed and integrated with the AutoMod/AutoGram simulation package.

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