• Journal of the Korean Wood Science and Technology
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• v.21 no.2
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• pp.23-30
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• 1993

As the demand of wood furniture becomes diverse and large-sized, artificial intelligence technique is required to design the expert system which can promote the efficiency of the operations management in wood furniture industry. This study was carried out to develop the expert scheduler, which was applied to the scheduling in chair-manufacturing process to evaluate its validity. The expert scheduler could show the results of scheduling must faster than Gantt chart method with ease. Maximum tardiness in the current chair-manufacturing process could be reduced from 29 seconds to 5 seconds by the addition of a spindle sander, a 12 spindle universal boring machine, and a moulding sander to sanding, boring, and moulding process, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.75-87
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• 1994

The demand for automatic manufacturing systems is increasing. One of the crucial obstacles to the Flexible Manufacturing System(FMS) is the lack of excellent strategies for efficient operations. The aim of this research is constructing an automaton scheme in the low level of factories where various machineries are involved. An operating strategy is established for an automation unit named as a cell which resides between the upper level computers and manufacturing shop floor. The cell is defined to fit into the total manufacturing system. The defined cell has more functions than conventional cells. A scheduling scheme is adopted for the shop floor operations. A set of software has been developed and tested through simulations and shop floor experiments.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.75-78
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• 1998

In this paper, we propose a new cell discarding and scheduling scheme which reduce cell loss rate by measuring, in real time, the number of discarded cells in the queuing system with a different loss priority for each class of service such that each class of service meets its cell loss rate requirements and reduce average delay rate for the traffic that is sensitive in cell delay in output buffer of the ATM switch. Throughout the computer simulation, the existing scheduling scheme and proposed scheme are compared with respect to cell loss rate and average delay time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.27
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• pp.91-104
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• 1993

This paper is concerned with flow shop scheduling problems having the common due date. V-shape property is used for algorithms with early and tardy penalty cost. The objective of this paper is developing efficient heuristic scheduling algorithms for minimizing total penalty cost function and determining the optimal common due date. The between job delay and the work in process are considered for developing algorithms as penalty cost. Algorithms is simulated to analyze interrelated factors. A numerical example is given for illustrating the proposed algorithms.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1273-1275
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• 1999

This paper describes the optimal operation scheduling on cogeneration systems which have thermal loads of different pressure each other. The cogeneration systems has two units and operate connecting with various auxiliary devices as heat storage tanks, independent generators and auxiliary boilers. The optimal modeling and scheduling technique proposed in this paper will be applied to industrial cogeneration systems.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.2
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• pp.105-130
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• 1993

This study deals with finding a schedule for the movement of a material handling device (elevator) in a manufacturing plant. Two different algorithm (Traveling Salesman Technique and Greedy Algorithm) are used in the scheduling of the elevators using a simulation technique to determine the proper method of scheduling the elevator movement. Based on the simulation analysis, we have found that the Greedy algorithm serves better than the algorithm based on Traveling Salesman technique for scheduling the movement of a material handling device in the manufacturing plant.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.487-487
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• 2000

The scheduling of real-time tasks needs both correctness and timeliness. But it is not easy to schedule real-time tasks having different characteristics in a single system. In this paper we solve the problem through an approach using the performance evaluation of real-time tasks through fuzzy-random variables. Using the performance evaluation through fuzzy-random variable, we can achieve flexible and efficient scheduling for real-time systems.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.9
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• pp.1006-1016
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• 1990

A scheduler for a class of Factory Automation (FA) systems is suggested. The technique of Timed Petri Nets is used to model FA systems and, a new concept called Unit Timed Petri Nets is proposed to schedule the system. The scheduler consists of two parts, scheduling rules and input jobs. Since flexibility should be an indispensable ingredient of the scheduler for FA systems, the method using Timed Petri Nets is adopted to represent scheduling rules in a simple and systematic manner and the scheduler is implemented with the PROLOG language. The proposed scheduler is applied to the realistic problem of flow shop.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1375-1377
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• 2002

New graph coloring problems are discussed as models of a multihop network in this report. We consider a total scheduling problem, and prove that this problem is NP-hard. We propose new scheduling models of a multi-hop network for CDMA system, and show the complexity results of the scheduling problems.

• IE interfaces
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• v.12 no.1
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• pp.19-25
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• 1999

The time slot scheduling problem for a satellite cluster with an arbitrary number of satellite is considered, which is one of the most interesting problems in the satellite communication scheduling area. This problem is known to be NP-complete, and several heuristic algorithms have been proposed. In this paper, a new efficient algorithm is suggested, which has lower computational complexity and provides much better solution than other existing algorithms.