• Title/Summary/Keyword: dynamic scheduling

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Modeling and Intelligent Scheduling for FMC (FMC의 모델링과 지능형 스케쥴링)

  • 서기성;이노성;안인석;우승규;이규호;우광방
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.3
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    • pp.31-40
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    • 1993
  • This paper deals with the modeling and scheduling for FMC(Flexible Manufacturing Cells). The FMC system composed of unit or multi cells is capable of improving productivity with flexibility for machine. However, the properties of multiple jobs and various alternatives results in tne dynamic states which make system management very complex. The extended Peti nets are used to represent for complex properties of FMC which performs short-term scheduling and dynamic operational scheduling. The hierarchical control structure and integlligent scheduling through expert module are adopted for efficiency of FMC operations. The computer simulation reveals that intelligent scheduling method is better than heuristics in various performance indices.

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Transporter Scheduling Based on a Network Flow Model for Dynamic Block Transportation Environment (동적 블록수송환경을 위한 네트워크 흐름모형 기반의 트랜스포터 일정계획)

  • Lee, Woon-Seek;Lim, Won-Il;Koo, Pyung-Hoi
    • IE interfaces
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    • v.22 no.1
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    • pp.63-72
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    • 2009
  • This paper considers a transporter scheduling problem under dynamic block transportation environment in shipbuilding. In dynamic situations, there exist the addition, cancellation or change of block transportation requirements, sudden breakdowns and maintenance of transporters. The transportation of the blocks in the shipyard has some distinct characteristics. Some blocks are available to be picked up at a specific time during the planning horizon while some other blocks need to be delivered before a specific time. These requirements cause two penalty times: 1) delay times incurred when a block is picked up after a required start time, and 2) tardy times incurred when a block shipment is completed after the required delivery time. The blocks are located at different areas in the shipyard and transported by transporters. The objective of this paper is to propose a heuristic algorithm based on a network flow model which minimize the weighted sum of empty transporter travel times, delay times, and tardy times. Also, a rolling-horizon scheduling method is proposed for dynamic block transportation environment. The performance of the proposed heuristic algorithms are evaluated through a simulation experiment.

Design and Implementation of a High Performance Web Crawler (고성능 웹크롤러의 설계 및 구현)

  • Kim Hie-Cheol;Chae Soo-Hoan
    • Journal of Digital Contents Society
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    • v.4 no.2
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    • pp.127-137
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    • 2003
  • A Web crawler is an important Internet software technology used in a variety of Internet application software which includes search engines. As Internet continues to grow, implementations of high performance web crawlers are urgently demanded. In this paper, we study how to support dynamic scheduling for a multiprocess-based web crawler. For high performance, web crawlers are usually based on multiprocess in their implementations. In these systems, crawl scheduling which manages the allocation of web pages to each process for loading is one of the important issues. In this paper, we identify issues which are important and challenging in the crawl scheduling. To address the issue, we propose a dynamic crawl scheduling framework and subsequently a system architecture for a web crawler with dynamic crawl scheduling support. This paper presents the design of the Web crawler with dynamic scheduling support.

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Design and Implementation of a High Performance Web Crawler (고성능 웹크롤러의 설계 및 구현)

  • 권성호;이영탁;김영준;이용두
    • Journal of Korea Society of Industrial Information Systems
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    • v.8 no.4
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    • pp.64-72
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    • 2003
  • A Web crawler is an important Internet software technology used in a variety of Internet application software which includes search engines. As Internet continues to grow, implementations of high performance web crawlers are urgently demanded. In this paper, we study how to support dynamic scheduling for a multiprocess-based web crawler. For high peformance, web crawlers are usually based on multiprocess in their implementations. In these systems, crawl scheduling which manages the allocation of web pages to each process for loading is one of the important issues. In this paper, we identify issues which are important and challenging in the crawl scheduling. To address the issue, we propose a dynamic crawl scheduling framework and subsequently a system architecture for a web crawler with dynamic crawl scheduling support. And we analysed the behaviors of Web crawler. Based on the analysis result, we suggest the direction for the design of high performance Web crawler.

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Implicit Scheduling Algorithm for Dynamic Slot Assignment in Wireless ATM Networks (무선 ATM 네트워크에서의 동적 대역 할당을 위한 묵시적 스케쥴링 알고리즘)

  • 황민재;강충구;김용진
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.7B
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    • pp.1229-1238
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    • 1999
  • To maximize the statistical multiplexing gain in wireless ATM MAC, a centralized scheduling function must be provided for the dynamic slot assignment in the wireless ATM access point. Exploiting the dynamic parameters received in the wireless ATM access point, the centralized scheduler will execute a dynamic slot assignment to determine bandwidth required for individual wireless terminal. In this paper, we propose a new scheduling algorithm, which can effectively reduce a burden of the explicit signaling requirement of transmitting the dynamic parameters in a timely manner. We have demonstrated that the proposed approach outperforms the existing schemes in terms of the timeliness of transmitting the dynamic parameters, which is a critical factor to the performance of delay-sensitive service classes, and works as an effective means of dynamic slot assignment without heavily relying on the dynamic parameters in the wireless ATM networks.

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Deep Learning-Based Dynamic Scheduling with Multi-Agents Supporting Scalability in Edge Computing Environments (멀티 에이전트 에지 컴퓨팅 환경에서 확장성을 지원하는 딥러닝 기반 동적 스케줄링)

  • JongBeom Lim
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.9
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    • pp.399-406
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    • 2023
  • Cloud computing has been evolved to support edge computing architecture that combines fog management layer with edge servers. The main reason why it is received much attention is low communication latency for real-time IoT applications. At the same time, various cloud task scheduling techniques based on artificial intelligence have been proposed. Artificial intelligence-based cloud task scheduling techniques show better performance in comparison to existing methods, but it has relatively high scheduling time. In this paper, we propose a deep learning-based dynamic scheduling with multi-agents supporting scalability in edge computing environments. The proposed method shows low scheduling time than previous artificial intelligence-based scheduling techniques. To show the effectiveness of the proposed method, we compare the performance between previous and proposed methods in a scalable experimental environment. The results show that our method supports real-time IoT applications with low scheduling time, and shows better performance in terms of the number of completed cloud tasks in a scalable experimental environment.

Minimization of Cell-based Handoff Delays to Balance the Load in Fiber Optic Micro-cellular Systems (광마이크로셀 이동통신 시스템의 균등부하를 위한 셀단위 핸드오프 순서결정)

  • 이채영;장세헌
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.2
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    • pp.1-11
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    • 2001
  • This paper considers the scheduling of cell-based handoffs to balance the traffic in a fiber-optic microcelluar system. In the system depending on the order of cell based handoff, periodical balancing of the traffic among microcells can be achieved. The cell based handoff problem is formulated as a dynamic programming and the computational complexity is analyzed. Since the scheduling problem requires real time solution, heuristic algorithms are proposed and the computational results are discussed.

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An Efficient Scheduling Method based on Dynamic Voltage Scaling for Multiprocessor System (멀티프로세서 시스템을 위한 동적 전압 조절 기반의 효율적인 스케줄링 기법)

  • Noh, Kyung-Woo;Park, Chang-Woo;Kim, Seok-Yoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.3
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    • pp.421-428
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    • 2008
  • The DVS(Dynamic Voltage Scaling) technique is the method to reduce the dynamic energy consumption. As using slack times, it extends the execution time of the big load operations by changing the frequency and the voltage of variable voltage processors. Researches, that controlling the energy consumption of the processors and the data transmission among processors by controlling the bandwidth to reduce the energy consumption of the entire system, have been going on. Since operations in multiprocessor systems have the data dependency between processors, however, the DVS techniques devised for single processors are not suitable to improve the energy efficiency of multiprocessor systems. We propose the new scheduling algorithm based on DVS for increasing energy efficiency of multiprocessor systems. The proposed DVS algorithm can improve the energy efficiency of the entire system because it controls frequency and voltages having the data dependency among processors.

Rescheduling algorithms considering unit failure on the batch process management (회분공정의 장치 고장을 고려한 동적생산계획 기법)

  • Ko, Dae-Ho;Moon, Il
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1028-1031
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    • 1996
  • Dynamic scheduling is very important in constructing CIM and improving productivity of chemical processing systems. Computation at the scheduling level requires mostly a long time to generate an optimal schedule, so it is difficult to immediately respond to actual process events in real-time. To solve these problems, we developed dynamic scheduling algorithms such as DSMM(Dynamic Shift Modification Method), PUOM(Parallel Unit Operation Method) and UVVM(Unit Validity Verification Method). Their main functions are to minimize the effects of unexpected disturbances such as process time variations and unit failure, to predict a makespan of the updated dynamic schedule and to modify schedule desirably in real-time responding to process time variations. As a result, the algorithms generate a new pertinent schedule in real-time which is close to the original schedule but provides an efficient way of responding to the variation of process environment. Examples in a shampoo production batch process illustrate the efficiency of the algorithms.

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