• 제목, 요약, 키워드: scheduling

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Work scheduling method by applying knowledge engineering supported by mathematical programming technique

  • Kurihara, Kenzo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.215-218
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    • 1996
  • In work scheduling problems, scheduling constraints are not absolutely rigid; they may be changed depending on the scheduling aspect effected. In order to cope with changes in scheduling constraints and assignment strategies and to optimize scheduling results quickly, this paper will propose a new scheduling method which combines knowledge engineering and mathematical programming techniques.

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조선 선행탑재 및 탑재 일정계획에서의 부하평준화를 위한 발견적 기법 (Heuristic Algorithms for Resource Leveling in Pre-Erection Scheduling and Erection Scheduling of Shipbuilding)

  • 우상복;류형곤;한형상
    • 산업공학
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    • v.16 no.3
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    • pp.332-343
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    • 2003
  • This paper deals with pre-erection scheduling and erection scheduling in shipbuilding. Among shipbuilding scheduling, the ship erection scheduling in a dock is one of the most important since the dock is the most critical resource in a shipyard. However, it is more reasonable to consider pre-erection scheduling and erection scheduling as unified because they compete with the common constrained resources such as labor, crane, space, and so on. It is very hard to consider two scheduling problems simultaneously, and hence, we approach them sequentially. At first, we propose space resource leveling heuristics in pre-erection scheduling given erection date. And then, considering the manpower resource determined by pre-erection scheduling, we also propose manpower resource leveling heuristics in erection scheduling. Various experimental results with real world data show that the proposed heuristics have good performance in terms of scheduling quality and time.

Locomotive Scheduling Using Constraint Satisfaction Problems Programming Technique

  • Hwang, Jong-Gyu;Lee, Jong-Woo;Park, Yong-Jin
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.4B no.1
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    • pp.29-35
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    • 2004
  • Locomotive scheduling in railway systems experiences many difficulties because of the complex interrelations among resources, knowledge and various constraints. Artificial intelligence technology has been applied to solve these scheduling problems. These technologies have proved to be efficient in representing knowledge and rules for complex scheduling problems. In this paper, we have applied the CSP (Constraints Satisfaction Problems) programming technique, one of the AI techniques, to solve the problems associated with locomotive scheduling. This method is more effective at solving complex scheduling problems than available mathematical programming techniques. The advanced locomotive scheduling system using the CSP programming technique is realized based on the actual timetable of the Saemaul type train on the Kyong-bu line. In this paper, an overview of the CSP programming technique is described, the modeling of domain and constraints is represented and the experimental results are compared with the real-world existing schedule. It is verified that the scheduling results by CSP programming are superior to existing scheduling performed by human experts. The executing time for locomotive scheduling is remarkably reduced to within several decade seconds, something requiring several days in the case of locomotive scheduling by human experts.

Efficient Channel State Feedback Scheme for Opportunistic Scheduling in OFDMA Systems by Scheduling Probability Prediction

  • Ko, Soomin;Lee, Jungsu;Lee, Byeong Gi;Park, Daeyoung
    • Journal of Communications and Networks
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    • v.15 no.6
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    • pp.589-600
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    • 2013
  • In this paper, we propose a new feedback scheme called mode selection-based feedback by scheduling probability prediction (SPP-MF) for channel state feedback in OFDMA downlink system. We design the scheme such that it determines the more desirable feedback mode among selective feedback by scheduling probability prediction (SPP-SF) mode and bitmap feedback by scheduling probability prediction (SPP-BF) mode, by calculating and comparing the throughputs of the two modes. In both feedback modes, each user first calculates the scheduling probability of each subchannel (i.e., the probability that a user wins the scheduling competition for a subchannel) and then forms a feedback message based on the scheduling probability. Specifically, in the SPP-SF mode, each user reports the modulation and coding scheme (MCS) levels and indices of its best S subchannels in terms of the scheduling probability. In the SPP-BF mode, each user determines its scheduling probability threshold. Then, it forms a bitmap for the subchannels according to the scheduling probability threshold and sends the bitmap along with the threshold. Numerical results reveal that the proposed SPP-MF scheme achieves significant performance gain over the existing feedback schemes.

GRID시스템을 위한 온라인 스케줄링 알고리즘 (An On-line Scheduling Algorithm for a GRID System)

  • 김학두;김진석;박형우
    • 한국정보과학회논문지:시스템및이론
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    • v.31 no.1_2
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    • pp.95-101
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    • 2004
  • 이질적인 계산자원들로 구성된 분산 컴퓨팅 환경에서 의존성이 존재하지 않는 독립적인 작업들을 자원들에 배치하기 위한 방법은 NP-Complete 문제로 알려져 있다[1]. 이질적인 자원으로 구성된 시스템의 대표적인 예가 GRID[2]이다. 현재까지 그리드 시스템에서 스케줄링 문제를 풀기 위한 다양한 휴리스틱 스케줄링 방법이 연구되어 왔다[1,3,4,5]. 스케줄링 방법은 정적인 방법과 동적인 방법으로 나뉘어진다. 동적 스케줄링 방법은 작업의 선후 관계를 예측할 수 없는 상황에서 사용되며 동적 스케줄링 방법은 스케줄링 시기에 따라 온라인방식과 배치방식으로 나뉘어진다[1,6]. 본 논문에서는 새로운 온라인 휴리스틱 스케줄링 알고리즘을 제안하였으며 제안된 스케줄링 알고리즘의 성능이 기존의 스케줄링 알고리즘의 성능보다 뛰어남을 시뮬레이션을 통하여 보였다.

글로벌 공급사슬에서 경쟁협력 스케줄링을 위한 에이전트 기반 플랫폼 구축 (Development of Agent-based Platform for Coordinated Scheduling in Global Supply Chain)

  • 이정승;최성우
    • 지능정보연구
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    • v.17 no.4
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    • pp.213-226
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    • 2011
  • 글로벌 공급사슬 환경에서 글로벌하게 분산 조달, 생산, 유통하게 됨에 따라 전체 공급사슬의 스케줄을 최적화하기 위해서 공급사슬상의 개별 기업 혹은 공장의 스케줄링 최적화뿐만 아니라 각 개별 기업 혹은 공장의 스케줄을 긴밀하게 연계하는 것이 필요하게 되었다. 이는 경쟁과 협력을 동시에 하는 개별 기업 혹은 공장을 개별 에이전트로 보고 각 에이전트간 커뮤니케이션을 통해 개별 에이전트가 관할하는 스케줄러의 스케줄을 조정함으로써 가능해진다. 하지만 전통적인 스케줄링 연구는 개별 스케줄러의 최적화에 집중되어 있고, 에이전트 연구는 스케줄링 도메인에 적용한 예가 제한적이며 이 예도 개별 스케줄러 내의 최적화에 적용하거나 실제 현장 문제가 아닌 실험실 문제 수준에 그치고 있다. 따라서 본 연구에서는 전체 글로벌 공급사슬 스케줄의 최적화를 위해 개별 기업 혹은 공장 스케줄러의 스케줄링을 연계하는 경쟁협력 스케줄링을 위한 에이전트 기반 플랫폼을 구축하였다. 글로벌 공급사슬에서 경쟁협력 스케줄링을 위한 에이전트 기반 플랫폼을 구축하기 위해 첫째, 경쟁협력 스케줄링 분류 체계를 확립하고, 둘째, 경쟁협력 스케줄링을 위한 에이전트를 설계하고, 셋째, 경쟁협력 스케줄링을 위한 지식기반 의사결정 모델을 개발한 후, 넷째 조선산업에 적용 가능한 프로토타입 시스템을 개발했다. 이를 통해 글로벌 공급사슬상의 전체 스케줄의 품질과 에이전트간 커뮤니케이션의 노력에 대한 균형점을 찾을 수 있다. 이를 통해 공급사슬내 개별 기업 혹은 공장의 부분 최적화를 극복할 수 있는 대안을 제시할 것으로 기대한다.

Design of a Coordinating Mechanism for Multi-Level Scheduling Systems in Supply Chain

  • Lee, Jung-Seung;Kim, Soo
    • Journal of Information Technology Applications and Management
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    • v.19 no.1
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    • pp.37-46
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    • 2012
  • The scheduling problem of large products like ships, airplanes, space shuttles, assembled constructions, and automobiles is very complex in nature. To reduce inherent computational complexity, we often design scheduling systems that the original problem is decomposed into small sub-problems, which are scheduled independently and integrated into the original one. Moreover, the steep growth of communication technology and logistics makes it possible to produce a lot of multi-nation corporation by which products are produced across more than one plant. Therefore vertical and lateral coordination among decomposed scheduling systems is necessary. In this research, we suggest an agent-based coordinating mechanism for multi-level scheduling systems in supply chain. For design of a general coordination mechanism, at first, we propose a grammar to define individual scheduling agents which are responsible to their own plants, and a meta-level coordination agent which is engaged to supervise individual scheduling agents. Second, we suggest scheduling agent communication protocols for each scheduling agent topology which is classified according to the system architecture, existence of coordinator, and direction of coordination. We also suggest a scheduling agent communication language which consists of three layers : Agent Communication Layer, Scheduling Coordination Layer, Industry-specific Layer. Finally, in order to improve the efficiency of communication among scheduling agents we suggest a rough capacity coordination model which supports to monitor participating agents and analyze the status of them. With this coordination mechanism, we can easily model coordination processes of multiple scheduling systems. In the future, we will apply this mechanism to shipbuilding domain and develop a prototype system which consists of a dock-scheduling agent, four assembly-plant-scheduling agents, and a meta-level coordination agent. A series of experiment using the real-world data will be performed to examine this mechanism.

전문가 스케쥴링 프로그램의 개발에 관한 연구 (A Study on the Development of Expert Scheduling Program)

  • 신용진;박노국;송문익
    • 산업경영시스템학회지
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    • v.15 no.26
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    • pp.21-31
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    • 1992
  • Today, manpower is used as a major factor in the production of service industry that is on the increasing trend. So the research on manpower structure have been regarded as a important field. The research on personnel scheduling, however, have got de-emphasizeed as compared wi th the field of manufacturing scheduling. As the increasing trend of service industry, an appropriate personnel scheduling for each type of service industry is needed urgently. This paper deals with nurse scheduling problem in the field of personnel scheduling. We aim at developing prototype of the expert nurse scheduling program which is easy to use when scheduling without help of expert, and satisfies the various request of hospital scheduling policy and nurse scheduling.

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유전 알고리즘을 이용한 선각 가공 작업일정계획 시스템의 개발에 관한 연구 (Operation Scheduling System for Hull Block Fabrication in Shipbuilding using Genetic Algorithm)

  • 조규갑;김영구;류광렬;황준하;최형림
    • 산업공학
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    • v.11 no.3
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    • pp.115-128
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    • 1998
  • This paper presents a development of operation scheduling and reactive operation scheduling system for hull fabrication. The methodology for implementing operation scheduling system is HHGA(Hierarchical Hybrid Genetic Algorithm) which exploits both the global perspective of the genetic algorithm and the rapid convergence of the heuristic search for operation scheduling. The methodology for the reactive operation scheduling is the revised HHGA which consists of manual schedule editor for occurrence of exceptional events and the revised scheduling method used in operation scheduling. As the results of experiment, it has been confirmed that HHGA is able to search good operation scheduling within reasonable time, and the revised HHGA is able to search load-balanced reactive operation scheduling with minimum changes of initial operation schedule within short period of time.

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동적 Job Shop 일정계획을 위한 유전 알고리즘 (A Genetic Algorithm for Dynamic Job Shop Scheduling)

  • 박병주;최형림;김현수;이상완
    • 한국경영과학회지
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    • v.27 no.2
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    • pp.97-109
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    • 2002
  • Manufacturing environments in the real world are subject to many sources of change and uncertainty, such as new job releases, job cancellations, a chance in the processing time or start time of some operation. Thus, the realistic scheduling method should Properly reflect these dynamic environment. Based on the release times of jobs, JSSP (Job Shoe Scheduling Problem) can be classified as static and dynamic scheduling problem. In this research, we mainly consider the dynamic JSSP with continually arriving jobs. The goal of this research is to develop an efficient scheduling method based on GA (Genetic Algorithm) to address dynamic JSSP. we designed scheduling method based on SGA (Sing1e Genetic Algorithm) and PGA (Parallel Genetic Algorithm) The scheduling method based on GA is extended to address dynamic JSSP. Then, This algorithms are tested for scheduling and rescheduling in dynamic JSSP. The results is compared with dispatching rule. In comparison to dispatching rule, the GA approach produces better scheduling performance.