• Title/Summary/Keyword: heuristic algorithms

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Developing Meta heuristics for the minimum latency problem (대기시간 최소화 문제를 위한 메타 휴리스틱 해법의 개발)

  • Yang, Byoung-Hak
    • Journal of the Korea Safety Management & Science
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    • v.11 no.4
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    • pp.213-220
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    • 2009
  • The minimum latency problem, also known as the traveling repairman problem and the deliveryman problem is to minimize the overall waiting times of customers, not to minimize their routing times. In this research, a genetic algorithm, a clonal selection algorithm and a population management genetic algorithm are introduced. The computational experiment shows the objective value of the clonal selection algorithm is the best among the three algorithms and the calculating time of the population management genetic algorithm is the best among the three algorithms.

A Mathematical Decision Making Model for Real-Time Scheduling of an FMS (FMS 의 실시간 일정계획을 위한 수리적 의사결정에 관한 연구)

  • Kim, Jong-Han;Park, Jong-Hun;Park, Jin-Woo;Chung, Sung-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.16 no.2
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    • pp.119-127
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    • 1990
  • This paper deals with the production scheduling problems of a dedicated Flexible Manufacturing System. In this work, a new mathematical formulation is proposed and two heuristic algorithms which can generate real-time schedules are suggested. Example problems to demonstrate the good performance and the validity of these two proposed algorithms are also included.

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Efficient Maximal Flow Algorithms in a Large Time-Expanded Network (대규모 시간전개형 네트워크에서의 효율적 최대유량 해법)

  • 이달상
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.37
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    • pp.211-220
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    • 1996
  • We consider the problem of scheduling a maximal amount of additional, low priority transport through a large multiperiod network, given that we may not interfere with an existing schedule for high priority transport. The problem is transformed into the Time-Expanded network(TENET) without traverse time using TENET Generator (TENETGEN). We describe two specialized heuristic algorithms that guarantee the optimal solutions and show the effectiveness of them by comparing quite favorably with Dinic.

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Design of a Time Optimaized Technology Mapping System (타이밍 최적화 기술 매핑 시스템의 설계)

  • 이상우;황선영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.4
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    • pp.106-115
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    • 1994
  • This paper presents the design of a technology mapping system for optimizing delays of combinational and synchronous sequential logic circuits. The proposed system performs delay optimization for combinational logic circuits by remapping, buffering, and gate merging methods through the correct delay calculation in which the loading values are considered. To get time optimized synchronous sequential circuits, heuristic algorithms are proposed. The proposed algorithms reallocate registers by considering the critical path characteristics. Experimental results show that the proposed system produces a more optimized technology mapping for MCNC benchmarks compared with mis-II.

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A Multi-Resource Leveling Algorithm for Project Networks

  • Lee, Chung-Ung
    • Journal of the military operations research society of Korea
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    • v.3 no.1
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    • pp.123-136
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    • 1977
  • This thesis presents a modification and extension to the Burgess and Killebrew heuristic resource leveling procedure for project networks. In contrast to previous algorithms appearing in the literature, the objective function of this algorithm. is the minimization of the sum of the squared errors in each time period (deviations around the mean usage) of all resources over the duration of the project. This objective function continues the search for an improved schedule beyond that of previous algorithms with their associated objective functions. One important feature is that the algorithm tends to reduce the number of periods that a resource is idle during its duration on the project.

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Routing in Computer Networks: A Survey of Algorithms (컴퓨터 네트웍에서의 경로선정 :알고리즘의 개관)

  • 차동완;정남기;장석권
    • Journal of the Korean Operations Research and Management Science Society
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    • v.9 no.2
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    • pp.46-55
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    • 1984
  • The purpose of this parer is to provide a survey of the state of the art of routing methods in store-and-forward computer networks. The survey is carried out in line with a new taxonomy: heuristic methods, user-optimization methods, and system-optimization methods. This taxonomy on routing algorithms is based on two viewpoints: the level of optimization and the relative difficulty for the implementation in real computer networks. Some actual methods implemented in real computer networks are surveyed as well as the theoretical studies in the literature. This paper concludes with some points in need of further researches.

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Time Slot Scheduling Algorithm for SS/TDMA Networks with Intersatellite Links (위성간 링크를 가진 SS/TDMA 망에 대한 타임슬롯 스케줄링 알고리즘)

  • Chang, Kun-Nyeong
    • IE interfaces
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    • v.12 no.1
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    • pp.19-25
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    • 1999
  • The time slot scheduling problem for a satellite cluster with an arbitrary number of satellite is considered, which is one of the most interesting problems in the satellite communication scheduling area. This problem is known to be NP-complete, and several heuristic algorithms have been proposed. In this paper, a new efficient algorithm is suggested, which has lower computational complexity and provides much better solution than other existing algorithms.

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Development of Scheduling Software for Flexible Manufacturing System (FMS운용을 위한 일정계획용 소프트웨어)

  • 윤덕균;황의철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.14 no.24
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    • pp.53-69
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    • 1991
  • This paper is concerned with software developments for scheduling and sequencing of FMS. The scheduling algorithms are developed for 3 types of FMS:single machine type FMS, flowshop type FMS. assembly line type FMS. For the single machine type FMS. full enumeration algorithm is used. For the flowshop type FMS heuristic algorithms are developed. For the assembly type FMS the exsisting PERT/CPM algorithm is applied. Numerical examples are presented for illustration of each algorithm. Each soft ware program list are attached as appendices.

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A Distributed Nearest Neighbor Heuristic with Bounding Function (분기 함수를 적용한 분산 최근접 휴리스틱)

  • Kim, Jung-Sook
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.7
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    • pp.377-383
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    • 2002
  • The TSP(Traveling Salesman Problem) has been known as NP-complete, there have been various studies to find the near optimal solution. The nearest neighbor heuristic is more simple than the other algorithms which are to find the optimal solution. This paper designs and implements a new distributed nearest neighbor heuristic with bounding function for the TSP using the master/slave model of PVM(Parallel Virtual Machine). Distributed genetic algorithm obtains a near optimal solution and distributed nearest neighbor heuristic finds an optimal solution for the TSP using the near optimal value obtained by distributed genetic algorithm as the initial bounding value. Especially, we get more speedup using a new genetic operator in the genetic algorithm.

Branch and Bound Algorithm for Two-Machine Reentrant Flowshop with the Objective of Minimizing Total Flowtime (재투입이 존재하는 2단계 흐름공정에서 총 작업 흐름시간을 최소화하는 분지한계방법)

  • Choi, Seong-Woo;Shim, Sang-Oh
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.4
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    • pp.1-9
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    • 2010
  • In this paper, we consider a two-machine re-entrant permutation flowshop scheduling problem with the objective of minimizing total flowtime, and suggest branch and bound algorithms for the scheduling problem. In this scheduling problem, each job must be processed twice on each machine, that is, each job should be processed on the two machines in the order of machine 1, machine 2 and then machine 1 and machine 2. In this research, based on the results of existing researches for re-entrant permutation flowshop scheduling problems, various dominance properties, lower bound and heuristic algorithm are suggested for the problem, and those are used to develop branch and bound algorithms. In the computational experiments for evaluation of the performance of the algorithms, the suggested branch and bound algorithms are tested on randomly generated test problems and results are reported.