• Title, Summary, Keyword: scheduling

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A Blackboard-Based Scheduling Expert System (흑판모델을 이용한 일정계획 전문가 시스템)

  • Park, Ji-Hyeong;Gang, Mu-Jin;Lee, Gyo-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.1
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    • pp.14-23
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    • 1996
  • Scheduling jobs effectively under consideration of actual loads on machines is one of the most complicated tasks in production control. The complexity of the finite capacity scheduling often makes the conventional methods of industrial engineering fail. As an alternative, Knowledge-based approaches to job-shop scheduling have been evolved recently. This paper presents a blackboard- based scheduling expert system which combines knowledge-based scheduling with interactive scheduling. It is shown to be possible to generate the feasible schedule within a reasonable time. Flexible reaction management is also possible while keeping the changes in the generated schedule to the minimal and adjusting the schedule to tardy operations or working environmental changes. The system is equipped with a rule base with heuristics for handling conflicted event. A case study applying the implemented system is described.

Distributed opportunistic packet scheduling for wireless ad-hoc network (무선 에드혹 네트워크에서 분산화된 opportunistic 패킷스케줄링)

  • Park, Hyung-Kun;Yu, Yun-Seop
    • Proceedings of the IEEK Conference
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    • pp.204-206
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    • 2009
  • Opportunistic scheduling is one of the important techniques to maximize multiuser diversity gain. In this paper, we propose a distributed opportunistic scheduling scheme for ad-hoc network. In the proposed distributed scheduling scheme, each receiver estimates channel condition and calculates independently its own priority with probabilistic manner, which can reduce excessive probing overhead required to gather the channel conditions of all receivers. We evaluate the proposed scheduling using extensive simulation and simulation results show that proposed scheduling obtains higher network throughput than conventional scheduling schemes and has a flexibility to control the fairness and throughput by controlling the system parameter.

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LSB Algorithm for the Job Oriented Heuristic Scheduling (작업지향 탐색적 일정계획을 위한 LSB 기법)

  • Kim Hyun-joon;Park Changkyu
    • Korean Management Science Review
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    • v.21 no.2
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    • pp.79-91
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    • 2004
  • In industrial production settings, scheduling problems for detailed day-to-day operations are often ordeals to production practitioners. For those who have scheduling experiences with the Gantt Chart, the job oriented heuristic scheduling has illustrated its merits in solving practically large scale scheduling problems. It schedules all operations of a job within a finite capacity before considering the next job. In this paper, we Introduce the LSB (load smoothing backward) scheduling algorithm for the job oriented heuristic scheduling. Through a computer experiment in a hypothetical setting, we make a performance comparison of LSB scheduling algorithm with existing algorithms and also suggest a guideline for selecting the suitable algorithm for certain industrial settings.

A Hybrid Genetic Algorithm for Job Shop Scheduling (Job Shop 일정계획을 위한 혼합 유전 알고리즘)

  • 박병주;김현수
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.2
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    • pp.59-68
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    • 2001
  • The job shop scheduling problem is not only NP-hard, but is one of the well known hardest combinatorial optimization problems. The goal of this research is to develop an efficient scheduling method based on hybrid genetic algorithm to address job shop scheduling problem. In this scheduling method, generating method of initial population, new genetic operator, selection method are developed. The scheduling method based on genetic algorithm are tested on standard benchmark job shop scheduling problem. The results were compared with another genetic algorithm0-based scheduling method. Compared to traditional genetic, algorithm, the proposed approach yields significant improvement at a solution.

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The Scheduling Algorithm for Operating the Facility of Exhibition and Convention (전시.컨벤션 시설의 합리적 운영을 위한 스케줄링 개발)

  • Kim, Chang-Dae;Joo, Won-Sik
    • IE interfaces
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    • v.19 no.2
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    • pp.153-159
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    • 2006
  • The research of scheduling algorithms for operating the facility of exhibition and convention can be hardly found in published papers. This study is to find problems in the process of operating the facility of exhibition and convention and to develop the scheduling algorithm satisfying those problems. The scheduling algorithm of this paper is developed through constructing the mathematical model and analyzing the mathematical structure of variables and constraints in that model. The scheduling algorithm developed in this paper consists of the first stage of scheduling, the second stage of feasibility routine and the third stage of improving scheduling results. Some experimental results are given to verify the effectiveness of the scheduling algorithm developed in this paper.

Survey of Evolutionary Algorithms in Advanced Planning and Scheduling

  • Gen, Mitsuo;Zhang, Wenqiang;Lin, Lin
    • Journal of Korean Institute of Industrial Engineers
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    • v.35 no.1
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    • pp.15-39
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    • 2009
  • Advanced planning and scheduling (APS) refers to a manufacturing management process by which raw materials and production capacity are optimally allocated to meet demand. APS is especially well-suited to environments where simpler planning methods cannot adequately address complex trade-offs between competing priorities. However, most scheduling problems of APS in the real world face both inevitable constraints such as due date, capability, transportation cost, set up cost and available resources. In this survey paper, we address three crucial issues in APS, including basic scheduling model, job-shop scheduling (JSP), assembly line balancing (ALB) model, and integrated scheduling models for manufacturing and logistics. Several evolutionary algorithms which adapt to the problems are surveyed and proposed; some test instances based on the practical problems demonstrate the effectiveness and efficiency of evolutionary approaches.

Development of an Extended EDS Algorithm for CAN-based Real-Time System (CAN기반 실시간 시스템을 위한 확장된 EDS 알고리즘 개발)

  • Lee, Byong-Hoon;Kim, Dae-Won;Kim, Hong-Ryeol
    • Proceedings of the KIEE Conference
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    • pp.2369-2373
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    • 2001
  • Usually the static scheduling algorithms such as DMS (Deadline Monotonic Scheduling) or RMS(Rate Monotonic Scheduling) are used for CAN scheduling due to its ease with implementation. However, due to their inherently low utilization of network media, some dynamic scheduling approaches have been studied to enhance the utilization. In case of dynamic scheduling algorithms, two considerations are needed. The one is a priority inversion due to rough deadline encoding into stricted arbitration fields of CAN. The other is an arbitration delay due to the non-preemptive feature of CAN. In this paper, an extended algorithm is proposed from an existing EDS(Earliest Deadline Scheduling) approach of CAN scheduling algorithm haying a solution to the priority inversion. In the proposed algorithm, the available bandwidth of network media can be checked dynamically by all nodes. Through the algorithm, arbitration delay causing the miss of their deadline can be avoided in advance. Also non real-time messages can be processed with their bandwidth allocation. The proposed algorithm can achieve full network utilization and enhance aperiodic responsiveness, still guaranteeing the transmission of periodic messages.

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Service Prediction-Based Job Scheduling Model for Computational Grid (계산 그리드를 위한 서비스 예측 기반의 작업 스케쥴링 모델)

  • Jang Sung-Ho;Lee Jong-Sik
    • Proceedings of the Korea Society for Simulation Conference
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    • pp.29-33
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    • 2005
  • Grid computing is widely applicable to various fields of industry including process control and manufacturing, military command and control, transportation management, and so on. In a viewpoint of application area, grid computing can be classified to three aspects that are computational grid, data grid and access grid. This paper focuses on computational grid which handles complex and large-scale computing problems. Computational grid is characterized by system dynamics which handles a variety of processors and jobs on continuous time. To solve problems of system complexity and reliability due to complex system dynamics, computational grid needs scheduling policies that allocate various jobs to proper processors and decide processing orders of allocated jobs. This paper proposes the service prediction-based job scheduling model and present its algorithm that is applicable for computational grid. The service prediction-based job scheduling model can minimize overall system execution time since the model predicts a processing time of each processing component and distributes a job to processing component with minimum processing time. This paper implements the job scheduling model on the DEVSJAVA modeling and simulation environment and simulates with a case study to evaluate its efficiency and reliability Empirical results, which are compared to the conventional scheduling policies such as the random scheduling and the round-robin scheduling, show the usefulness of service prediction-based job scheduling.

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Development of a Scheduling Assistant Program for Usability Improvement of Construction Scheduling Solutions (건설 공정관리 솔루션의 활용성 증대를 위한 공정표 작성 지원 프로그램 개발)

  • Park, Sung Hwan;Lee, Si Wook;Woo, Sungkwon;Shin, Do Hyoung
    • Journal of The Korean Society of Civil Engineers
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    • v.30 no.4D
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    • pp.413-421
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    • 2010
  • Scheduling management is one of the most important factors for the efficient performance of construction projects. Various computer-aided solutions for schedule management have been developed, but they are not commonly used in practice. This study conducted surveys on scheduling management methods and the related solutions to identify their status and problems in practice. Based on the results of the surveys, this study also developed a scheduling assistant program to improve the usability of scheduling management solutions. Through the developed program, the usability of scheduling management solutions will be improved in practice, thus enabling efficient scheduling management.

Application of the hierarchical scheduling policy to FMC (FMC에 계층적 스케쥴링 전략의 적용)

  • Yeo, Yong-Kee;Lyou, Joon
    • 제어로봇시스템학회:학술대회논문집
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    • pp.482-487
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    • 1991
  • The scheduling algorithm based on the hierarchical scheduling policy is presented for the Job Shop type FMC control, and the simulation results using this hierarchical scheduling policy are with the results which are based on the heuristic scheduling policy. The results show that the hierarchical ling policy is more efficient than the heuristic scheduling policy in either case that there exist machine failures in the FMC or not.

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