• Title/Summary/Keyword: near-optimal

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IP를 이용한 패트리어트 미사일 최적배치모형

  • Lee, Jae-Yeong;Jeong, Chi-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.10a
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    • pp.38-50
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    • 2005
  • The current Air defense missile, Nike, will be replaced by the Patriot missile in the near future. In this paper, we developed an optimal allocation model for the Patriot missile. In order to formulate the model, we applied a set covering and If model. This model considers not only weapon's characteristics and performances but also the threat of enemy aircrafts and SCUD missiles. When we apply this model, we can find the optimal location of Patriot batteries which maximizes the kill probability of enemy aircrafts and SCUD missiles attacking vital area of our forces. This model can directly be used to the decision making for the optimal military facility allocation.

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An Efficient Algorithm for a Block Angular Linear Program with the Same Blocks (부분문제가 같은 블록대각형 선형계획문제의 효율적인 방볍)

  • 양병학;박순달
    • Journal of the Korean Operations Research and Management Science Society
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    • v.12 no.2
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    • pp.42-50
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    • 1987
  • This objective of this paper is to develop an efficient method with small memory requirement for a feed-mixing problem on a micro computer. First this method uses the decomposition principle to reduce the memory requirement. Next, the decomposition principle is modified to fit the problem. Further four different variations in solving subproblems are designed in order to improve efficiency of the principle. According to the test with respect to the processing time, the best variation is such that the dual simplex method is used, and the optimal basis of a previous subproblem is used as an initial basis, and the master problem is (M +1) dimensional. In general, the convergence of solution becomes slower near the optimal value. This paper introduces a termination criterion for a sufficiently good solution. According to the test, 5%-tolerence is acceptable with respect to the relation between the processing time and optimal value.

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A Heuristic Algorithm for Designing Near-Optimal Mobile Agent Itineraries

  • Gavalas Damianos
    • Journal of Communications and Networks
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    • v.8 no.1
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    • pp.123-131
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    • 2006
  • Several distributed architectures, incorporating mobile agent technology, have been recently proposed to answer the scalability limitations of their centralized counterparts. However, these architectures fail to address scalability problems, when distributed tasks requiring the employment of itinerant agents is considered. This is because they lack mechanisms that guarantee optimization of agents' itineraries so as to minimize the total migration cost in terms of the round-trip latency and the incurred traffic. This is of particular importance when MAs itineraries span multiple subnets. The work presented herein aspires to address these issues. To that end, we have designed and implemented an algorithm that adapts methods usually applied for addressing network design problems in the specific area of mobile agent itinerary planning. The algorithm not only suggests the optimal number of mobile agents that minimize the overall cost but also constructs optimal itineraries for each of them. The algorithm implementation has been integrated into our mobile agent framework research prototype and tested in real network environments, demonstrating significant cost savings.

Chaotic Search Algorithm for Network Reconfiguration in Distribution Systems (배전계통 최적구성을 위한 카오스 탐색법 응용)

  • 이상봉;유석구
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.6
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    • pp.325-332
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    • 2003
  • The loss minimization is one of the most important problems to save the operational cost in distribution systems. This paper presents an efficient method for optimal feeder reconfiguration of distribution systems. Chaos search algorithm (CSA) is used to reconfigure distribution systems so that active power losses are globally minimized with turning on/off sectionalizing switches. In optimization problem, the CSA searches the global optimal solution on the basis of regularity in chaotic motions and easily escapes from local or near optimal solution. The CSA is tested on 15 buses and 32 buses distribution systems, and the results indicate that it is able to determine appropriate switching options for global optimum reconfiguration.

Capacitor Placement in Radial Distribution Systems Using Chaotic Search Algorithm (방사상 배전계통의 커패시터 설치를 위한 카오스 탐색알고리즘)

  • Rhee, Sang-Bong;Kim, Kyu-Ho;You, Seok-Ku
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.124-126
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    • 2002
  • The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, the method employing the chaos search algorithm is proposed to solve optimal capacitor placement problem with reducing computational effort and enhancing optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

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Development of a Tool to Automate One-Dimensional Finite Element Analysis of Machine Tool Spindles

  • Choi, Jin-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.2
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    • pp.172-176
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    • 2015
  • In this research, a tool was developed to automate one-dimensional finite element analysis (1D FEA) for design of a machine tool spindle. Based on object-oriented programing, this tool employs the objects of a CAD system to construct a geometric model and then to convert it into the FE model of 1D beams at the workbenches of the CAD system with minimum data to define the spindle such as bearing positions and cross-sections of the shaft. Graphic user interfaces were developed for users to interact with the tool. This tool is helpful in identifying a near optimal design of the spindle with the automation of the FEA process with numerous design changes in minimum time and efforts. It is also expected to allow even design engineers to perform the FEA in search of an optimal design of the machine tool spindle.

Optimal Scheduling of Multi-product Batch Process for Common Intermediate Storage Policy; A Model for Batch Process Automation (다품종용 회분식 공정에서의 중간 저장 탱크 공유를 위한 최적 생산계획 ; 회분식 조업의 자동화 모델)

  • 정재학;이인범;양대륙;장근수
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.303-308
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    • 1992
  • In this study, we propose a shared storage system which is more efficient policy than MIS(Mixed Intermediate Storage) policy for relatively rare storage system and can be called CIS(Common Intermediate Storage) policy. Using this strategy, we develop a new completion time algorithm and apply it to two kinds of optimal or near optimal scheduling method; combinatorial search and simulated annealing method. We also extend this strategy to other storage policy, for example MIS policy, with PLC(Programmable Logic Controller) logic and on/off action of electronic valves. It thus can be accepted as a basic form of FMS(Flexible Manufacturing System) for operating various storage policies. Finally we suggest the interlocking block to compansate for the shortcoming of CIS policy, i.e, complication of operation and safety, resulting in a basic batch process automation mode.

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A Global Optimization Technique for the Capacitor Placement in Distribution Systems (배전계통 커패시터 설치를 위한 전역적 최적화 기법)

  • Rhee, Sang-Bong;Kim, Kyu-Ho;Lee, Sang-Keun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.748-754
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    • 2008
  • The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, a global optimization technique, which employing the chaos search algorithm, is applied to solve optimal capacitor placement problem with reducing computational effort and enhancing global optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

WWW-based Vehicle Routing Problem using Mixed Genetic Algorithm (혼합형 유전자 알고리즘을 이용한 웹 기반의 차량 경로 문제)

  • 김기섭;양병학
    • Journal of the military operations research society of Korea
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    • v.24 no.2
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    • pp.117-129
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    • 1998
  • This study is concerned with developing a heuristic for a web-based vehicle routing problem using mixed genetic algorithm(VRPMGA) which determines each vehicle route in order to minimize the transportation costs, subject to meeting the demands of all delivery points. VRP is known to be NP-hard, and it needs a lot of computing time to get the optimal solution, so that heuristics are more frequently developed than optimal algorithms. This study aims to develop a mixed genetic algorithm by partitioned strategy which can give a good solution in comparatively brief time. The good features of the VRPMGA are, fristly, the ability of early convergence and, secondly, the capability of producing multiple, alternative, and near-optimal solutions. The VRPMGA is a useful algorithm that can be appliable to VRP and TSP. Finally, the computational test were performed using the benchmark problems and the proposed heuristic is compared with the other existing algorithms (COSA). The result of computational tests shows that proposed heuristic gives good solutions, in much shorter time, which are same as the best known solutions in the pervious research.

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Efficient Elitist Genetic Algorithm for Resource-Constrained Project Scheduling

  • Kim, Jin-Lee
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.6
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    • pp.235-245
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    • 2007
  • This research study presents the development and application of an Elitist Genetic Algorithm (Elitist GA) for solving the resource-constrained project scheduling problem, which is one of the most challenging problems in construction engineering. Main features of the developed algorithm are that the elitist roulette selection operator is developed to preserve the best individual solution for the next generation so as to obtain the improved solution, and that parallel schedule generation scheme is used to generate a feasible solution to the problem. The experimental results on standard problem sets indicate that the proposed algorithm not only produces reasonably good solutions to the problems over the heuristic method and other GA, but also can find the optimal and/or near optimal solutions for the large-sized problems with multiple resources within a reasonable amount of time that will be applicable to the construction industry. This paper will help researchers and/or practitioners in the construction project scheduling software area with alternative means to find the optimal schedules by utilizing the advantages of the Elitist GA.