• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.2003-2021
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• 2020

Today's computer systems are widely integrated with CPU and GPU to achieve considerable performance, but energy consumption of such system directly affects operational cost, maintainability and environmental problem, which has been aroused wide concern by researchers, computer architects, and developers. To cope with energy problem, we propose a task-scheduling framework to reduce energy under performance constraint by rationally allocating the tasks across the CPU and GPU. The framework first collects the estimated energy consumption of programs and performance information. Next, we use above information to formalize the scheduling problem as the 0-1 knapsack problem. Then, we elaborate our experiment on typical platform to verify proposed scheduling framework. The experimental results show that our proposed algorithm saves 14.97% energy compared with that of the time-oriented policy and yields 37.23% performance improvement than that of energy-oriented scheme on average.

• 제어로봇시스템학회논문지
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• 제8권6호
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• pp.506-513
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• 2002

Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

• Journal of Preventive Medicine and Public Health
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• 제19권1호
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• pp.56-64
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• 1986

This paper describes a GPSS-based, multi-server queueing model that was developed to simulate the patient flow, and to analyze the effectiveness of the patient scheduling system under various conditions. Unpredictable and unacceptably long waits to receive the service at the outpatient department of a general hospital necessitated the study. Arrival and service time distribution needed for the simulation model were generated from actual arrival and service patterns observed during the peak hours. The simulation results show that a change in patient scheduling system (i.e. time interval between appointments, starting time. and the number of physicians) from a current system would significantly reduce the patient wait time. This study provides the hospital administrator with an analysis of patient scheduling system under several conditions, and will be used to plan future scheduling system and staffing. Studies such as this can demonstrate the value of simulation in providing information for use in future planning.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.797-802
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• 2000

Flow shop scheduling problem involves processing several jobs on common facilities where a setup time Is incurred whenever there is a switch of jobs. Practical aspect of scheduling focuses on finding a near-optimum solution within a feasible time rather than striving for a global optimum. In this paper, a hybrid meta-heuristic method called tabu-genetic algorithm(TGA) is suggested, which combines the genetic algorithm(GA) with tabu list. The experiment shows that the proposed TGA can reach the optimum solution with higher probability than GA or SA(Simulated Annealing) in less time than TS(Tabu Search). It also shows that consideration of setup time becomes more important as the ratio of setup time to processing time increases.

• International Journal of Contents
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• 제8권4호
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• pp.7-11
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• 2012

Cloud Computing can be viewed as a dynamically-scalable pool of resources. Virtualization is one of the key technologies enabling Cloud Computing functionalities. Virtual machines (VMs) scheduling and allocation is essential in Cloud Computing environment. In this paper, two dynamic VMs scheduling and allocating schemes are presented and compared. One dynamically on-demand allocates VMs while the other deploys optimal threshold to control the scheduling and allocating of VMs. The aim is to dynamically allocate the virtual resources among the Cloud Computing applications based on their load changes to improve resource utilization and reduce the user usage cost. The schemes are implemented by using SimPy, and the simulation results show that the proposed adaptive scheme with one threshold can be effectively applied in a Cloud Computing environment both performance-wise and cost-wise.

• 한국콘텐츠학회논문지
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• 제6권2호
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• pp.9-16
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• 2006

본 논문은 광대역 무선 통신망의 물리계층 OFDMA시스템 구조에서 멀티미디어 패킷 서비스의 효율적인 처리를 위한 스케줄링 알고리즘을 제안한다. 스케줄링 알고리즘은 무선 채널 상태 정보 추정을 이용하고 클래스 및 우선권 정책 기반 전송 순위 결정과 이에 의한 전송률 할당을 한다. 그 결과로 제안된 스케줄링 알고리즘은 실시간 서비스에 대해선 최대 트래픽 처리량과 jitter의 최소화를 만족하고 비실시간 서비스에 대해 공평한 트래픽 처리를 수행한다. 제안 된 스케줄링 알고리즘은 기존의 라운드 로빈 스케줄링 방식과 시뮬레이션을 통한 비교를 통해서 보다 우수한 성능을 보인다.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.383-391
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• 2005

The paper is devoted to some flow shop scheduling problems, where job processing times are defined by functions dependent on their positions in the schedule. An example is constructed to show that the classical Johnson's rule is not the optimal solution for two different models of the two-machine flow shop scheduling to minimize makespan. In order to solve the makespan minimization problem in the two-machine flow shop scheduling, we suggest Johnson's rule as a heuristic algorithm, for which the worst-case bound is calculated. We find polynomial time solutions to some special cases of the considered problems for the following optimization criteria: the weighted sum of completion times and maximum lateness. Some furthermore extensions of the problems are also shown.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.303-305
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• 2012

This paper presents a system called a Cash-flow based Construction Scheduling Optimization (CfSO). The existing CPM is biased on schedule and cost management. For a profitable and successful project management, the cash-flow which occurred actually by contractual conditions should be considered in the project scheduling. Therefore, this study provides a method to estimate the amount of a cash-flow occurred periodically by integrating the terms of contract into scheduling. The proposed methodology is implemented as a system prototype in Microsoft Excel. CfSO helps a site manager as a decision-maker to establish a optimized project scheduling and decide profitable contractual conditions against a construction owner.

• 산업공학
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• 제14권4호
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• pp.394-402
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• 2001

In this study, we deal a spatial scheduling system for the block painting process in the shipbuilding industry. In general, the spatial scheduling for the block painting process is a very complicated task. Because spatial allocation of each block in blasting and painting cells is considered simultaneously. Thus the spatial scheduling for the block painting process is the problem of planning and control of operation, which arises in shipyard. This system is developed for blocks to meet the delivery date given by the shipyard production planning system, to maximize space utilization of blasting and painting cells and to balance workload among working teams. And it has been tested using actual scheduling data from a shipyard and successfully applied in a paint shop in a shipbuilding company.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1201-1210
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• 2000

In order to tolerate faults which may occur during the execution of distributed tasks in high-performance parallel computer systems, tasks are duplicated on different processors. In this paper, by utilizing the task duplication based scheduling algorithm, a new task scheduling algorithm which duplicates each task on more than two different processors with the minimum schedule length is presented, and the number of processors required for the duplication is analyzed with the ratio of communication cost to computation time and the workload of the system. A simulation with various task graphs reveals that the number of processors required for the full-duplex fault-tolerant task scheduling with the obtainable minimum schedule length increases about 30% to 75% when compared with that of the task duplication based scheduling algorithm.