• International Journal of Railway
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• 제6권1호
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• pp.7-12
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• 2013

This paper provides an overview of Pakistan Railways scheduling and rescheduling. First of all, Pakistan Railways is introduced with its brief history and importance in this country. Assets of this network with passengers and freight using this are given. Current hope less situation is leading to privatization of this system as well as promoting short distance traveler to use road and Government efforts to retain is also presented. Train scheduling in Pakistan is being done manually, based on manual time distance graph preparation and resolution of conflicts based on manager's experience and ability. In Real-time management of this traffic Lahore head office is connected with six control stations in the Pakistan, decision for resolution of any disturbance is coordinated among them. It is recommended that computer aided tools must be developed for this system to help traffic managers and it is needed to invest on the segments to increase their speed limits which might attract passengers to use this mode of transportation with high priority.

• 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.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.99-107
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• 2008

This paper is concerned with scheduling in Flexible Manufacturing Systems (FMS) using a Fuzzy Logic (FL) approach. Four fuzzy input variables: machine allocated processing time, machine priority, machine available time and transportation priority are defined. The job priority is the output fuzzy variable, showing the priority status of a job to be selected for the next operation on a machine. The model will first select the machines and then assign operations based on a multi-criteria scheduling scheme. System/machine utilization, minimizing mean flow time and balancing machine usage will be covered. Experimental and comparative tests indicate the superiority of this fuzzy based scheduling model over the existing approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.59-61
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• 2004

Researches about scheduling distributed real-time systems have some weak points, not scheduling both sporadic and periodic tasks and messages or being unable to guaranteeing the end-to-end constraints due to omitting precedence relations between sporadic tasks. This paper describes the application model of sporadic tasks with precedence constraints in a distributed real-time system. It is shown that existing scheduling methods such as Rate Monotonic scheduling are not proper to be applied to the system having sporadic tasks with precedence constraints. So this paper proposes an end-to-end laxity-based priority assignment algorithm which considers the practical laxity of a task and allocates a proper priority to a task.

• 대한간호학회지
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• 제26권2호
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• pp.399-412
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• 1996

Even though Korean medical law stipulates that number of patients attended by a nurse is 2.5 for hospitalization and 30 for ambulatory care, the number of patients cared by a nurse per day is much greater than the standard prescribed by the medical law. Current nursing productivity of nurses is not desirable unless the quality of care considered. Moreover. nursing manpower staffing based on neither current nurses' productivity nor standard of medical law cannot respond properly to dynamic situation of the medical services. As for the nurse scheduling, the critical problem of it in the hospital is determining the day-to-day shift assignments for each nurse for the specified period in a way that satisfies the given requirements of the hospital. Nurse scheduling, however, involves many factors and requirements, manual scheduling requires much time and effort to produce an adequate schedule. Under these backgrounds, the necessity of more efficient management of nursing manpower occupying 1/3 of total hospital workers has been recognized by many nursing administrators. This study was performed to develop a system computerizing nurse staffing and scheduling based on the patient classification. As a preliminary step for the system development, nursing workload in a secondary hospital was measured from Sep. to Oct. 1994. On the grounds of this result, computerization of nurse staffing and scheduling was proceeded with three options. First one is based on the current medical law. Second one is based on the assigned number of nursing staff. And the last is based on the request by patient classification. Computer languages used in this study were MS Visual Basic 3.0 for the staffing and Access 2.0 for the scheduling, respectively. Prospective users may operate this system easily because icons and mouse are used for easier graphic user interface and reducing the need for typing efforts. This system can help nurse administrators manage nursing manpower efficiently and nurses develop quick and easy schedule generation and allow more time for the patient care.

• 정보과학회지
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• 제5권1호
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• pp.04-10
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• 1987

本 論文은 단일 processor를 가진 computer time sharing system의 運用 에 關한 것이다. 서로 다른 K 종류의 task들이 各各 獨立的이고 time-homojeneous한 Poisson分布를 따라 System에 들어 오고 있다. 또한, task 가 配當된 quantum동안 process를 받고 난후 이미 주어진 確率에 의해, 써어비스 를 完了받고 System을 離脫하기도 하고, 未完結된 경우 다른 種類의 task로 바뀌 어져 다시 process를 받기 爲해 待期한다고 한다. 이러한 여러종류의 task를 相對 로 한 time sharing model에서는 各種類의 完結에 必要한 process time의 길이에 의해 各種類의 順位(priority)가 一方的으로 決定된 것이 通例이었다. 本 硏究에서 는 各 種類의 順位를 결정하는데 있어서, 좀더 現實的인 諸條件을 반영키 위해, 各種類의 完決에 要하는 process time의 길이 뿐만 아니라, 그들의 重要度 그리고 또 緊急度까지도 고려한 새로운 Schedulign rule을 개발하였다. 또한 이 새로운 Scheduling rule에 의해 順位를 決定하는 Algorithm도 수록하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.61-66
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• 2004

In this paper an effort is made to develop an innovative spatial arrangement concept pertaining to ship building industry. The spatial scheduling is the problem that concentrates on effective planning of available space and arrangements of blocks and in a priority manner. In order to create an effective spatial scheduling. a database providing the priority has to be available to make the erection sequence. Such a system works hand in hand with erection sequence generator program The erection sequence program works on the conventional network analysis method which uses a typical parent-children idea for the calculation of the ENT(possible earliest network start time) and LNT(possible latest network start time). This program works in a cyclic manner taking turns by calculating the ENT in upward trace and LNT on the return trace thereby generating the entire erection sequence diagram for the requisite problem The generated database serves as an input data for spatial scheduling problem. When the system works it takes into consideration the entire system based on heuristic concepts as mentioned. There system uses the spatial aspects such as the available area of the P. E area and plan area of the corresponding blocks and its priority of erection from the erection sequence generator program develops the spatial scheduling arrangement. In this paper using all these concepts an innovative spatial schedule development system developed.

• 인터넷정보학회논문지
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• 제9권3호
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• pp.59-67
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• 2008

본 연구에서는 의료서비스의 복잡한 스케줄링문제 해결을 위한 새로운 시스템을 제안하였다. 기존 FCFS 시스템은 병원의 입장만 고려하였으나 제안 시스템은 병원의 사정과 환자들의 선호시간을 자동협상으로 반영하였다. 본 시스템은 개인의 서비스이용 희망시간을 우선도로 표현하였고 개인이 선택한 협상전략에 따라 변화되는 우선도를 기준으로 스케줄을 조정할 수 있도록 설계하였고 병원의 정책에 따라 스케줄을 확정 할 수도 있게 하였다. 따라서 제안시스템은 장비의 유휴시간만을 고려하는 기존시스템과 달리 장비의 효율성뿐만 아니라 환자의 대기시간까지 고려할 수 있도록 하여 의료서비스의 고객만족경영을 지원할 수 있을 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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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.

• 산업경영시스템학회지
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• 제23권59호
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• pp.11-20
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• 2000

The Job Shop Scheduling Problem(JSSP) is one of the most general and difficult of all traditional scheduling problems. The goal of this research is to develop an efficient scheduling method based on single genetic algorithm(SGA) and parallel genetic algorithm (PGA) to address JSSP. In this scheduling method, new genetic operator, generating method of initial population are developed and island model PGA are proposed. The scheduling method based on PGA are tested on standard benchmark JSSP. The results were compared with SGA and another GA-based scheduling method. The PGA search the better solution or improves average of solution in benchmark JSSP. Compared to traditional GA, the proposed approach yields significant improvement at a solution.