• 제목/요약/키워드: Machine Scheduling

검색결과 383건 처리시간 0.027초

On-line Scheduling Analysis for Job-Shop Type FMS

  • Lee, Jeong Hwan
    • 산업경영시스템학회지
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    • 제24권64호
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    • pp.63-76
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    • 2001
  • This paper presents a job-shop type flexible manufacturing system(FMS) scheduling problem and examines the effects of scheduling rules on the performance of FMS. Several machine and AGV scheduling rules are tested against the mean flow-time criterion. In this paper, I compare the rules under various experimental conditions by using an FMS simulation model. One of the objectives of this study is to discuss how the simulation-based scheduling problem can be operated. The other is to measure sensitivity of the rules to changes at inter arrival time, queue capacity, breakdown rates for machines and AGV, and AGV speed. Therefore, the results of simulation experiments were considered on FMS design and operating stages. A comprehensive bibliograph? is also presented in the paper.

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Effect of Representation Methods on Time Complexity of Genetic Algorithm based Task Scheduling for Heterogeneous Network Systems

  • Kim, Hwa-Sung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제1권1호
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    • pp.35-53
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    • 1997
  • This paper analyzes the time complexity of Genetic Algorithm based Task Scheduling (GATS) which is designed for the scheduling of parallel programs with diverse embedded parallelism types in a heterogeneous network systems. The analysis of time complexity is performed based on two representation methods (REIA, REIS) which are proposed in this paper to encode the scheduling information. And the heterogeneous network systems consist of a set of loosely coupled parallel and vector machines connected via a high-speed network. The objective of heterogeneous network computing is to solve computationally intensive problems that have several types of parallelism, on a suite of high performance and parallel machines in a manner that best utilizes the capabilities of each machine. Therefore, when scheduling in heterogeneous network systems, the matching of the parallelism characteristics between tasks and parallel machines should be carefully handled in order to obtain more speedup. This paper shows how the parallelism type matching affects the time complexity of GATS.

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선각 내업 가공작업의 공정계획과 일정계획의 통합화 방안 연구 (Integrated Process Planning and Scheduling for Machining Operation in Shipbuilding)

  • 조규갑;오정수;김영구
    • 한국정밀공학회지
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    • 제14권10호
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    • pp.75-84
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    • 1997
  • This paper describes the development of an integrating method for process planning and scheduling activities for block assembly in shipbuilding. A block is composed of several steel plates and steel sections with the predetermined shapes according to the ship design. The parts which constitute the block are manufac- tured by cutting and/or bending operations, which are termed as machining operation in this paper. The machining operation is the first process for block assembly which influences the remaining block assembly processes. Thus process planning and scheduling for machining operation to manufacture parts for block are very important to meet the assembly schedule in the shipyard. An integrating method for process plan- ning and scheduling is developed by introducing the concept of distributed process planning and scheduling composed of initial planning, alternative planning and final planning stages. In initial planning stage, nesting parts information and machining emthods are generated for each steel plate. In alternative plan- ning stage, machine groups are selected and workcenter dispatching information is generated. In final planning stage, cutting sequences are determined. The integrated system is tested by case study. The result shows that the integrated system is more efficient than existing manual planning system.

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유전 알고리즘을 이용한 클라우드 환경의 인공지능 워크로드 스케줄링 (Scheduling of Artificial Intelligence Workloads in Could Environments Using Genetic Algorithms)

  • 권석민;반효경
    • 한국인터넷방송통신학회논문지
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    • 제24권3호
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    • pp.63-67
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    • 2024
  • 최근 스마트 물류, 핀테크, 엔터테인먼트 등 다양한 산업 분야의 인공지능 워크로드들이 클라우드 상에서 실행되고 있다. 본 논문은 이기종 GPU 클러스터로 구성된 다중 테넌트 클라우드 시스템에서 다양한 인공지능 워크로드가 실행될 때 발생하는 스케줄링 문제를 다룬다. 전통적인 스케줄링은 이러한 환경에서 GPU 이용률을 크게 저하시켜 시스템의 성능을 떨어뜨린다. 이러한 문제를 해결하기 위해, 본 논문에서는 유전 알고리즘 기반의 최적화 기법을 사용하는 새로운 스케줄링 접근 방식을 제안하고, 이를 프로세스 기반 이벤트 시뮬레이션 프레임워크에 구현하였다. 알리바바의 MLaaS 클러스터에서 수집한 광범위한 인공지능 작업들의 트레이스를 재현하는 실험을 통해 제안하는 스케줄링이 기존 스케줄링에 비해 GPU 이용률을 크게 개선함을 확인하였다.

Proposition and Evaluation of Parallelism-Independent Scheduling Algorithms for DAGs of Tasks with Non-Uniform Execution Time

  • Kirilka Nikolova;Atusi Maeda;Sowa, Masa-Hiro
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.289-293
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    • 2000
  • We propose two new algorithms for parallelism-independent scheduling. The machine code generated from the compiler using these algorithms in its scheduling phase is parallelism-independent code, executable in minimum time regardless of the number of the processors in the parallel computer. Our new algorithms have the following phases: finding the minimum number of processors on which the program can be executed in minimal time, scheduling by an heuristic algorithm for this predefined number of processors, and serialization of the parallel schedule according to the earliest start time of the tasks. At run time tasks are taken from the serialized schedule and assigned to the processor which allows the earliest start time of the task. The order of the tasks decided at compile time is not changed at run time regardless of the number of the available processors which means there is no out-of-order issue and execution. The scheduling is done predominantly at compile time and dynamic scheduling is minimized and diminished to allocation of the tasks to the processors. We evaluate the proposed algorithms by comparing them in terms of schedule length to the CP/MISF algorithm. For performance evaluation we use both randomly generated DAGs (directed acyclic graphs) and DACs representing real applications. From practical point of view, the algorithms we propose can be successfully used for scheduling programs for in-order superscalar processors and shared memory multiprocessor systems. Superscalar processors with any number of functional units can execute the parallelism-independent code in minimum time without necessity for dynamic scheduling and out-of-order issue hardware. This means that the use of our algorithms will lead to reducing the complexity of the hardware of the processors and the run-time overhead related to the dynamic scheduling.

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의미패턴에 기반한 대화체 한영 기계 번역 (Machine Translation of Korean-to-English spoken language Based on Semantic Patterns)

  • 정천영;서영훈
    • 한국정보처리학회논문지
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    • 제5권9호
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    • pp.2361-2368
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    • 1998
  • 본 논문에서는 한국어대화체를 분석하고 의미패턴에 기반한 대화체 한영 기계번역 시스템에 대하여 기술한다. 한영 기계번역에서 구문정보를 이용한 한국어 모호성은 의미패턴을 이용하여 해결할 수 있다. 따라서 대화체 번역을 위하여 한국어 스케쥴링 도메인으로부터 추출된 의미패턴에 기반한 시스템을 구성한다. 번역의 강건함을 위하여 한국어 문장 분석시 음절을 건너뛰어 분석할 수 있도록 하였으며, 패턴수를 줄이기 위하여 의미패턴에 옵션을 부가하였다. 실험을 위하여 사용된 데이터는 스케쥴링 도메인으로 실험결과 88%의 번역율을 보인다.

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