• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1432-1435
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• 1996

This paper obtains maximum allowable delay bounds for stability of network-based control systems and presents a network scheduling method which makes the network-induced delay be less than the maximum allowable delay bound. The maximum allowable delay bounds are obtained using the Lyapunov theorem. Using the network scheduling method, the bandwidth of a network can be allocated to each node and the sampling period of each sensor and controller can be determined. The presented method can handle three kinds of data (periodic, real-time asynchronous, and non real-time asynchronous data) and guarantee real-time transmissions of real-time synchronous data and periodic data, and possible transmissions of non real-time asynchronous data. The proposed method is shown to be useful by examples in two types of network protocols such as the token control and the central control.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.2
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• pp.83-87
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• 2011

Clock selection has a significant impact on the performance and quality of designs in high-level synthesis. Almost systems require that the clock length is required prior to scheduling, the best value of the clock can be found only after evaluating different schedules. In this study, we presents a scheduling method that works simultaneously with synthesis by selecting a clock from a chainable operation set. Our scheduling algorithm is based on list scheduling and executes chaining considering bit level delays based on selected clock period. Experimental results show that our method improves the performance by 18 percent.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.297-305
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• 2006

High-rate wireless personal area network (HR-WPAN) has been standardized by the IEEE 802.15.3 task group (TG). To support multimedia services, the IEEE 802.15.3 TG adopts a time-slotted medium access control (MAC) protocol controlled by a central device. In the time division multiple access (TDMA)-based wireless packet networks, the packet scheduling algorithm plays a key role in quality of service (QoS) provisioning for multimedia services. In this paper, we propose an adaptive cross-layer packet scheduling method for the TDMA-based HR-WPAN. Physical channel conditions, MAC protocol, link layer status, random traffic arrival, and QoS requirement are taken into consideration by the proposed packet scheduling method. Performance evaluations are carried out through extensive simulations and significant performance enhancements are observed. Furthermore, the performance of the proposed scheme remains stable regardless of the variable system parameters such as the number of devices (DEVs) and delay bound.

• IE interfaces
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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.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.297-300
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• 2001

This paper proposes a sound multicast packet-switching method which can less affect QoS degradation. The method includes a switch fabric with extra switching paths dedicated for multicast packets. Presented also are both a buffering structure and a scheduling algorithm for the proposed method. Simulation analysis for the method shows that the switching delay of unicast packets is decreased even though arrival rate of multicast packets is increased.

• Korean Management Science Review
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• v.12 no.3
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• pp.177-185
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• 1995

This paper presents a Tabu Search method to minimize a number of tardy jobs in the nonidentical parallel machine scheduling. The Tabu Search method employs a restricted neighborhood for the reduction of computation time. In this paper, we use two different types of method for a single machine scheduling. One is Moore's algorithm and the other is insertion method. We discuss computational experiments on more than 1000 test problems.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.488-492
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• 1991

This paper deals with modeling and scheduling for flexible manufacturing systems(FMS). In modeling extended Petri nets are used to describe various and complex properties. To resolve multiple conflict without predefined properties, such as part selection, machine selection, rule-based scheduling method is introduced. This structure have a capability of on-line scheduling with systematic modeling description.

• IE interfaces
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• v.14 no.3
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• pp.218-226
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• 2001

Scheduling for shipbuilding processes has many alternative solutions since it has long time horizon and handles many jobs. This requests the scheduling system to generate and search feasible alternative solutions in short period of time. Among shipbuilding schedules, the ship erection schedule in a dock is the most important since the dock is the most critical resource in shipyard. In this research, we model the erection scheduling problem for shipbuilding and develop a new problem solving method using CST(Constraint Satisfaction Technique) and ILOG Scheduler. Experimental results show that the proposed scheduling method outperforms the existing manual scheduling methods in terms of schedule performance and required time.

• Journal of Multimedia Information System
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• v.3 no.4
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• pp.149-154
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• 2016

Wireless mesh networks (WMNs) are used for metropolitan area network that requires high network throughput for handling many users. TDMA-based access is a common solution for this problem and several scheduling methods have been proposed. However, existing heuristic methods have room for improvement at network throughput although they are low complexity. In this paper, we propose a novel divided scheduling method based on structural characteristics in order to improve network throughput in WMNs. It separately schedules neighbor links of gateways and that of the other links by different scheduling algorithms. Simulation-based evaluations show that our proposal improves up to 14% of network throughput compared with conventional scheduling algorithm script.

• Journal of Korean Institute of Industrial Engineers
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• v.18 no.1
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• pp.91-104
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• 1992

Flowshop scheduling problem is known to be NP-complete. Since the optimization apporach like branch-and-bound is limited by exponentially growing computation time, many heuristic methods have been developed. Total tardiness is one of the criteria that the researchers have recently considered in flowshop scheduling. There, however, are few literatures which studied the general (m machine)-flowshop scheduling under the total tardiness criterion. In this paper, a heuristic scheduling method to minimize total tardiness at the (m machine, n job)-flowshop is presented. A heuristic value function is proposed to be used as a dispatching criterion in initial schedule generation. And the schedule improving procedure, by pairwise interchange of tardy job with the job right ahead of it, is introduced. Illustrative examles and simulated results are presented.