• 대한전기학회논문지
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• 제41권8호
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• pp.831-840
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• 1992

This paper presents an efficient short-term generation scheduling method using a rule-based expert/consulting system approach to assist electric energy system operators and planners. The expert system approach is applied to improve the Dynamic Programming(DP) based generation scheduling algorithm. In the selection procedure of the feasible combinations of generating units at each stage, automatic consulting on the manipulation of several constraints such as the minimum up time, the minimum down time and the maximum running time constraints of generating units will be performed by the expert/consulting system. In order to maximize the solution feasibility, the aforementioned constraints are controlled by a rule-based expert system, that is, instead of imposing penalty cost to those constraint violated combinations, which sometimes may become the very reason of no existing solution, several constraints will be manipulated within their flexibilities using the rules and facts that are established by domain experts. In this paper, for the purpose of implementing the consulting of several constraints during the dynamic process of generation scheduling, an expert system named STGSCS is developed. As a building tool of the expert system, C Language Integrated Production System(CLIPS) is used. The effectiveness of the proposed algorithm has been demonstrated by applying it to a model electric energy system.

• 제어로봇시스템학회논문지
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• 제4권5호
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• pp.651-657
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• 1998

In this study, an intelligent scheduling with hybrid architecture, which integrates expert system and neural network, is proposed. Neural network is trained with the data acquired from simulation model of FMC to obtain the knowledge about the relationship between the state of the FMC and its best dispatching rule. Expert system controls the scheduling of FMC by integrating the output of neural network, the states of FMS, and user input. By applying the hybrid system to a scheduling problem, the human knowledge on scheduling and the generation of non-logical knowledge by machine teaming, can be processed in one scheduler. The computer simulation shows that comparing with MST(Minimum Slack Time), there is a little increment in tardness, 5% growth in flow time. And at breakdown, tardness is not increased by expert system comparing with EDD(Earliest Due Date).

• 산업융합연구
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• 제1권2호
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• pp.69-79
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• 2003

In order to solve scheduling, many techniques including optimization and heuristics methods have been proposed. However, these conventional approaches are usually inadequate to obtain a satisfactory solution because of a NP-Complete which requires extensive computation effort. The aim of this paper is to develop an expert system for job shop scheduling using an AI technique. Through this system, the user can choose one of several performances. If one performance is chosen, then the system solves a scheduling in order to satisfy that performance. Then, this system decides urgent job. This system can utilize production resources efficiently and minimize work-in-process inventories and tardy jobs.

• 대한산업공학회지
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• 제17권2호
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• pp.63-74
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• 1991

An expert scheduling system on real time basis for computer-aided manufacturing systems has been developed. In developing expert scheduling system, the most time-consuming job is to obtain rules from expert schedulers. An efficient process of obtaining rules directly form the schedules produced by expert schedulers is proposed. By the process, a set of complete and minimal set of rules is obtained. During a real time scheduling, when given information on possible values of elements, the rules produce possible values of decision elements, where logical explanations of the result may be offered in terms of chaining rules. The learning and scheduling processes have been simulated with an automated manufacturing line engaged in the production of circuit boards.

• 대한산업공학회지
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• 제23권4호
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• pp.621-633
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• 1997

This paper is concerned with the multiobjective vehicle scheduling problem with time and area-dependent travel speeds(MVSPTD), in which two conflicting objectives are explicitly treated and the travel speed between two locations depends on the passing area and time of day. The two objectives are the minimization of total vehicle travel time and the minimization of total weighted tardiness. First, I construct a mixed integer linear programming formulation of the MVSPTD, and present o heuristic algorithm that builds the vehicle schedules based on the savings computed. The results of computational experiments showed that the heuristic performs very well. Finally, I propose an expert system for vehicle scheduling in the MVSPTD. Its whole process is executed under VP-Expert expert system environment.

• 산업경영시스템학회지
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• 제15권26호
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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.

• Journal of the Korean Wood Science and Technology
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• 제21권2호
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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.

• 지능정보연구
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• 제1권2호
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• pp.123-137
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• 1995

Most of solution methods in scheduling attempt to generate good solutions by either developing algorithms or heuristic rules. However, scheduling problems in the real world require considering more factors such as multiple objectives, different combinations of heuristic rules due to problem characteristics. In this respect, the traditional mathematical a, pp.oach showed limited performance so that new a, pp.oaches need to be developed. Expert system is one of them. When an expert system is developed for scheduling one of the most difficult processes faced could be knowledge acquisition on scheduling heuristics. In this paper we propose a method for the acquisition of knowledge on the selection of scheduling heuristics using Dempster-Shafer Theory(DST). We also show the examples in the multi-objectives environment.

• 지능정보연구
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• 제2권1호
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• pp.75-91
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• 1996

제철소에서의 원료 운송 작업은, 선박에 선적된 원료를 하역하여 야드에 적치한 후, 제반 원료 소요공장까지의 벨트 컨베이어를 통한 원료 수송 작업을 의미한다. 본 연구에서는 원료 운송과 관련한 선박 접안, 원료 하역 및 벨트 컨베이어 수송 일정 계획을 효과적으로 수립하기 위하여 이단계 계획적 구조를 이용한 일정계획 휴리스틱을 개발하고 이를 구현하기 위한 전문가 시스템을 개발하였다. 이단계 계층적 구조는 상위 단계의 Scheduler 와 하위 단계의 복수개의 Dispatcher 로 구성되어 있다. 하위 단계의 Dispatcher는 주어진 제약조건하에서 단위 문제를 해결하고 이를 상위 단계의 Scheduler에게 보고하게 된다. 상위 단계의 Scheduler 는 전체적인 문제 해결의 우선 순위 결정 및 Dispatcher 간의 상층을 해결하는 역할을 맡게 된다. 이러한 계층적 구조를 이용한 분산처리를 통해 문제의 복잡성을 줄이고, 시스템 설계의 모듈화 및 유연성있는 시스템 구축이 가능하게 되었다. 본 시스템은 실시간 전문가 시스템 도구인 G2를 이용하여 SUN Workstation에서 개발되었다.

• 대한기계학회논문집A
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• 제20권1호
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• pp.14-23
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• 1996

Scheduling jobs effectively under consideration of actual loads on machines is one of the most complicated tasks in production control. The complexity of the finite capacity scheduling often makes the conventional methods of industrial engineering fail. As an alternative, Knowledge-based approaches to job-shop scheduling have been evolved recently. This paper presents a blackboard- based scheduling expert system which combines knowledge-based scheduling with interactive scheduling. It is shown to be possible to generate the feasible schedule within a reasonable time. Flexible reaction management is also possible while keeping the changes in the generated schedule to the minimal and adjusting the schedule to tardy operations or working environmental changes. The system is equipped with a rule base with heuristics for handling conflicted event. A case study applying the implemented system is described.