• 제목/요약/키워드: on-line scheduling

검색결과 171건 처리시간 0.026초

세부공정으로 구성된 LCD 모듈 라인의 다중스테이지 메타휴리스틱 스케줄링 알고리즘 연구 (A Multistage Metaheuristic Scheduling Algorithm in LCD Module Lines Composed of Processes)

  • 서정대
    • 대한산업공학회지
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    • 제38권4호
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    • pp.262-275
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    • 2012
  • This paper develops a multistage scheduling algorithm for the module operation of the LCD(Liquid Crystal Display) production systems and tests the efficiency of the proposed algorithm. The module operation is a multistage form composed of multiple sub operations of processes, and each stage is consists of multiple lines with the same kinds of machines. This paper presents a mathematical modeling reflecting the constraints of the LCD module operation and develops a multistage scheduling algorithm based on tabu search metaheuristic approach. For this purpose, an production order is assigned to a line of the sub operations and a sequence of the assigned order is rearranged to draw an efficient schedule. Simulation experiments test performance measures and show the efficiency of the proposed algorithm.

조선 소조립 공정의 자동화를 위한 용접 로봇 스케줄링 (Scheduling of Welding Robots for Shipyard Sub-assembly Process)

  • 강장하;박성수;박경철;도기상
    • 대한산업공학회지
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    • 제25권1호
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    • pp.21-34
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    • 1999
  • We consider a scheduling problem arising in a shipyard subassembly welding process. There are four welding robots of gantry type, which perform the welding process for the subassemblies. Because the robots perform the welding operations at the same time, there is a possibility of collision between adjacent robots depending on the welding schedule. In this paper, we propose a heuristic method to find a welding schedule which does minimize the welding completion time while avoiding collision among the robots. The method consists of two phases: assignment and scheduling. In the assignment phase, we assign each welding line to a proper robot. In the scheduling phase, we determine the welding schedules for the robots so that collision is avoided. Computational experiences with the data which reflect the real situation are reported.

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건설기계 조립 라인 투입 순서를 고려한 제관 공정 생산 스케줄링에 관한 연구 (A Study on the Body Welding Operation Scheduling Considering the Assembly Line's Input Sequence in Construction Equipment Manufacturing)

  • 김기동;최호식
    • 산업기술연구
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    • 제27권A호
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    • pp.69-76
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    • 2007
  • The body of an excavator, one sort of the construction equipment, consists of mainframe part, track frame part, boom part and arm part. The all parts are manufactured in the body welding operation. The scheduling in the body welding operation of a construction equipment manufacturing is to take all the various constraints into consideration. The offset time, due date, daily capacity of operations, daily jig's capacity, precedence relation, outsourcing, alternative resource and all of the shop floor environment should be considered. An APS(Advanced Planning & Scheduling) system is a proper and efficient system in such circumstance. In this paper, we present an APS system, the optimal scheduling system for the construction equipment manufacturing specifically for the body welding operation, using ILOG Solver/Scheduler. ILOG Solver/Scheduler is a general purposed commercial software which supports to find a feasible or optimal solution using object oriented technique and constraints satisfaction programming, given constraints and objectives.

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Application Characteristic-based Divided Scheduling for Multicore Systems

  • Park, Jung Kyu;Kim, Jaeho
    • 한국컴퓨터정보학회논문지
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    • 제22권6호
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    • pp.9-16
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    • 2017
  • In this paper, we proposed a novel user-level scheduling scheme that monitors applications characteristics on-line using PMU and allocates applications into cpu cores. We utilize PMU (Performance Monitoring Unit) to analyze which shared resource has the strongest relation with the influence. Using the proposed scheduling method, it is possible to reduce the contention of shared resources. The key idea of this scheme is separating high-influential applications into different processors. The evaluation results have shown that the proposed scheduling scheme can enhance the performance up to 12% for a 8 core system and up to 25% for a 28 core system, respectively.

최대여유시간 제공 연성 비주기 실시간 태스크 스케줄링 알고리즘 (A Soft Aperiodic Real-Time Task Scheduling Algorithm Supporting Maximum Slack Time)

  • 임덕주;박성한
    • 전자공학회논문지CI
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    • 제37권4호
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    • pp.9-15
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    • 2000
  • 본 논문은 고정 우선순위 실시간 시스템에서 연성 비주기 실시간 태스크의 on-line 응답시간을 줄이기 위한 연산의 최소화에 목적이 있다. 제안하는 알고리즘은 온라인 시의 오버헤드를 줄이면서, 동시에 비주기 태스크에 할당할 수 있는 최대의 여유시간을 제공함으로써 목표를 만족시킨다. 제안하는 알고리즘은 고정우선 순위 비주기 실시간 태스크 스케줄링에서 off-line시 최적의 응답시간을 내는 알고리즘인 Slack Stealing에 비해 응답시간의 손실이 거의 없으면서 오버헤드 측면에서 7배 가량의 좋은 성능을 나타낸다.

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반도체 FAB공정의 사이클타임 단축을 위한 병목일정계획 (Bottleneck Scheduling for Cycletime Reduction in Semiconductor Fabrication Line)

  • 이영훈;김태헌
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2001년도 추계학술대회 논문집
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    • pp.298-301
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    • 2001
  • In semiconductor manufacturing, wafer fabrication is the most complicated and important process, which is composed of several hundreds of process steps and several hundreds of machines involved. The productivity of the manufacturing mainly depends on how well they control balance of WIP flow to achieve maximal throughput under short manufacturing cycle time. In this paper mathematical formulation is suggested for the stepper scheduling, in which cycle time reduction and maximal production is achieved.

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Modularized Gain Scheduled Fuzzy Logic Control with Application to Nonlinear Magnetic Bearings

  • Hong, Sung-Kyung
    • 한국지능시스템학회논문지
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    • 제9권4호
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    • pp.384-388
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    • 1999
  • This paper describes an approach for synthesizing a modularized gain scheduled PD type fuzzy logic controller(FLC) of nonlinear magnetic bearing system where the gains of FLC are on-line adapted according to the operating point. Specifically the systematic procedure via root locus technique is carried out for the selection of the gains of FLC. Simulation results demonstrate that the proposed gain scheduled fuzzy logic controller yields not only maximization of stability boundary but also better control performance than a single operating point (without gain scheduling)fuzzy controller.

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선로사고 및 선로용량을 고려한 전력계통 최적운영에 관한 연구 (Study on the Calculation of the Optimal Power System Operation Considering Line Contingencies and Line Capacities)

  • 박영문;백영식;서보혁;신중린
    • 대한전기학회논문지
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    • 제36권9호
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    • pp.609-615
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    • 1987
  • The optimal operation of power system is developed by alternately using real power dispatch and reactive power dispatch problem. The real power system scheduling process is formulated as an optimization problem with linear inequality constraints. A.C. loadflow method is used for the problem solution and line losses are considered. The constraints under consideration are generator power limits, load scehdling limits and line capacity limits. In solving the objective function the Dual Relaxation method is adopted. Tests indicate that the method is practical for real time application. The reactive power control problem uses the Dual Simplex Relaxation method as in the real scheduling case. Insted of minimizing the cost of power system, the objective is selected as to determine the highest possible voltage schedule. The constraints under consideration are the voltage limits at each node and the possibilities of supply or absobtion of reactive energy by generator units and the compensation facilities. Tests indicate that the method is practical for real time applications. The overall optimization methods developed in this paper proved to obtained fine results in minimizing object function compared with the method without using voltage control. And the overall voltage profiles were also improved.

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부정확 타스크의 최대가중치 오류를 최소화시키는 온라인 스케쥴링 알고리즘 (On-line Scheduling Algorithms for Reducing the Largest Weighted Error Incurred by Imprecise Tasks)

  • 이춘희;류원;송기현;최경희;정기현;박승규
    • 한국통신학회논문지
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    • 제24권6B호
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    • pp.1032-1041
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    • 1999
  • 본 논문은 단일프로세서 환경에서 부정확 타스크들을 선점형태로 스케쥴할 때 발생하는 오류의 최대치를 최소화하는 온라인 스케쥴링 알고리즘을 제시한다. 알고리즘은 상위수준 및 하위수준 알고리즘으로 나눈다. 상위수준 알고리즘에서는 매번 타스크가 도착할 때마다 스케쥴링을 수행하며, 대상 타스크들의 전체 오류 및 최대오류가 동시에 최소가 되도록 각 타스크들의 수행시간을 구한다. 하위수준 알고리즘에서는 배당된 타스크들의 할당 시간을 실제 프로세서가 어떤 순서대로 수행할지를 정한다. 상위수준 알고리즘은 주어진 조건을 LP 문제로 정형화하여 복잡도가 상당히 개선된 알고리즘을 제시하였고, 하위수준 알고리즘은 Shih and Liu[4] 의 온라인 알고리즘을 확장하였다. 시뮬레이션을 통하여 다수 경우의 상황을 실험한 결과 전의 연구방법 보다 상당히 개선된 효과, 최대오류를 더 최소화시키는 것을 관찰하였다.

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상정사고를 고려한 전력계통 최적운용에 관한 연구 (Study on the Calculation of the Optimal Power Operation Considering Line Contingencies)

  • 박영문;백영식
    • 대한전기학회논문지
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    • 제33권6호
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    • pp.241-246
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    • 1984
  • The power system scheduling process is formulated as an optimization problem with linear inequality constraints. AC Loadflow method is used for the problem solution and line losses are considered. The constraints under consiceration are generator power limits, load schedding limits and line capacity limits. In solving the objective function the Dual Relaxation method is adopted. Tests indicate that the method is practical for real time applications.

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