• 산업경영시스템학회지
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• 제21권48호
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• pp.213-222
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• 1998

The objective of this study is to develop a knowledge-based scheduler applying simulation and knowledge base. This study utilizes a machine induction to build knowledge base which enables knowledge acquisition without domain expert. In this study, the best job dispatching rule for each order is selected according to the specifications of the order information. And these results are built to the fact base and knowledge base using the attribute-oriented induction method and simulation. When a new order enters in the developed system, the scheduler retrieves the knowledge base in order to find a matching record. If there is a matching record, the scheduling will be carried out by using the job dispatching rule saved in the knowledge base. Otherwise the best rule will be added to the knowledge base as a new record after scheduling to all the rules. When all these above steps finished the system will furnish a learning function.

• 한국시뮬레이션학회논문지
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• 제27권2호
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• pp.71-81
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• 2018

조선소의 지게차는 작업 특성상 무거운 물건을 상/하차하거나 이송하는 작업이 빈번하다. 작업은 동적이며 시간대별로 생성 비율이 다르다. 특히 오전과 오후 업무시간 직후에 작업 발생 비율이 높은 경향을 보인다. 이러한 상/하차 작업과 이송작업의 무게는 매번 다르며, 활용되는 지게차 역시 작업 가능한 허용무게의 제약이 있다. 본 연구에서는 지게차의 원활한 운영을 위해 최소 비용할당을 사용한 최근린 배차 규칙 알고리즘을 제안한다. 제시된 알고리즘은 다양한 종류의 지게차와 다수의 작업을 동시에 고려하여 배차를 결정하며, 지게차 종류에 따른 작업 불가능을 고려하기 위해 가상 지게차와 가상 작업을 생성하는 방법을 제안한다. 그리고 차량의 상태를 고려하여 체계적으로 지게차를 선택하는 방법도 함께 제시한다. 성능지표는 평균 공차이동거리와 평균 작업대기시간으로 한다. 성능비교를 위해 조선소의 지게차 운영방식을 모델링한 우선순위 규칙을 비교 대상으로 한다. 시뮬레이션을 통해 제시한 알고리즘의 우수성을 확인한다.

• 한국경영과학회지
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• 제27권2호
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• pp.97-109
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• 2002

Manufacturing environments in the real world are subject to many sources of change and uncertainty, such as new job releases, job cancellations, a chance in the processing time or start time of some operation. Thus, the realistic scheduling method should Properly reflect these dynamic environment. Based on the release times of jobs, JSSP (Job Shoe Scheduling Problem) can be classified as static and dynamic scheduling problem. In this research, we mainly consider the dynamic JSSP with continually arriving jobs. The goal of this research is to develop an efficient scheduling method based on GA (Genetic Algorithm) to address dynamic JSSP. we designed scheduling method based on SGA (Sing1e Genetic Algorithm) and PGA (Parallel Genetic Algorithm) The scheduling method based on GA is extended to address dynamic JSSP. Then, This algorithms are tested for scheduling and rescheduling in dynamic JSSP. The results is compared with dispatching rule. In comparison to dispatching rule, the GA approach produces better scheduling performance.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3232-3238
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• 2010

유연생산시스템은 고자동화 생산시스템일 뿐만 아니라, 사용자와 시장의 요구를 만족시키기 위해 유연한 생산시스템이 요구됨에 따라 작업배정규칙 할당에 있어서 시스템과 작업환경에 많은 제약을 받게 된다. 본 논문에서는 온톨로지 지식 기반의 작업환경을 고려한 유연생산시스템의 작업배경규칙 할당방법을 제시한다. 에이전트를 이용하여 작업장 환경과 작업내용을 모니터링하고, 이에 적합한 작업배정규칙을 온톨로지 지식으로부터 추론하여 시스템에 적용한다. 본 시스템 개발을 위해 멀티에이전트를 지원하는 $JADE^{TM}$ 플랫폼을 이용하였으며, 온톨로지는 Protege를 이용하여 개발되었다.

• 품질경영학회지
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• 제47권4호
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• pp.823-835
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• 2019

Purpose: This study deals with a production planning and scheduling problem to minimize the total weighted tardiness on hybrid flow shop with sets of non-identical parallel machines on stages, where parallel machines in the set are dedicated to perform specific subsets of jobs and sequence-dependent setup times are also considered. Methods: A two-stage approach, that applies MILP model in the 1st stage and dispatching rules in the 2nd stage, is proposed in this paper. The MILP model is used to assign jobs to a specific machine in order to equalize the workload of the machines at each stage, while new dispatching rules are proposed and applied to sequence jobs in the queue at each stage. Results: The proposed two-stage approach was implemented by using a commercial MILP solver and a commercial simulation software and a case study was developed based on the spark plug manufacturing process, which is an automotive component, and verified using the company's actual production history. The computational experiment shows that it can reduce the tardiness when used in conjunction with the dispatching rule. Conclusion: This proposed two-stage approach can be used for HFS systems with dedicated machines, which can be evaluated in terms of tardiness and makespan. The method is expected to be used for the aggregated production planning or shop floor-level production scheduling.

• 산업경영시스템학회지
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• 제29권1호
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• pp.26-33
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• 2006

The potential needs as well as visible needs of customer should be considered in order to research and analyze of the customer data. The methods to analyze customer data is classified into customer segmentation, clustering analysis model, forecasting customer response probability model, analysis of the customer break rate model and new customer analysis model by the purpose. In this study, we developed the CW-CLV (Correlation Weight Customer Lifetime Value)method that used AHP(Analytic Hierarchy Process)rule for enhance the reliability of customer data and quantitative analysis of the customer segmentation, based on CLV(Customer Lifetime Value). We suggest to new variables and methodology from determined CW-CLV coefficients, because all of companies respect to the diversified customers classification and complexity of consumers needs. Finally, we unfolded any company's scheduling added new methodology using simulation and leaded conclusion about the new methodology.

• 대한산업공학회지
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• 제20권4호
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• pp.37-50
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• 1994

The efficiency of production system is mainly considered in the viewpoints of reducing the average flow time of products and increasing the throughput rate. The performance in these viewpoints is very depending on job dispatching of each machine in real time operation, in the case jobs are released dynamically. In this research, a heuristic dynamic dispatching method is suggested for a flow shop case where new jobs with random process times are released by an interarrival time distribution and the number of waiting jobs between each pair of machines are limited. The proposed method has been compared with some priority rule-based dispatching methods by simulation and found to be superior to them.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.517-522
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• 2005

This paper addresses scheduling heuristics for an assembly job-shop that includes at least an assembly process throughout its processes. The assembly job shop has certain characteristics not only considering the precedence relationship between the processes but also considering the processing progress between the parts. In addition, it probably presents a different processing time for the same product according to the order of processes and the point of workable time, due to the difference in the availability of equipments. The paper proposes several priority-based dispatching rules that consider these characteristics of the assembly job-shop, aiming to minimize the total tardiness of products in the shop floor. Computational tests showed that job due date based priority rules significantly outperform existing priority rules in terms of total tardiness.

• 산업경영시스템학회지
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• 제22권52호
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• pp.191-201
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• 1999

There have been a huge volume of researches concerning dispatching rules in job shop environments. Strangely, studies all but one pay no attention to multiple identical jobs due to the existence of production orders each of which calls for a fixed quantity, called an order size, of a specific part. Jobs arrive in the form of production orders in most, if not all, job shop type flexible manufacturing systems. This paper presents simple processing-time-based dispatching rules, and shows experimentally based on simulation that the rules with order-size considerations perform consistently well for tardiness and utilization measures. Several alternative strategies for rule specifications are examined.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1111-1116
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• 1993

In this study, we discuss the design of the expert system for the scheduling of the FMC(Flexible Manufacturing Cell) consisting of the several versatile machines. Due to the NP property, the scheduling problem of several machine FMC is very complex task. Thus we proposed the two heuritstic shceduling algorithms for solving the problem and constituted the algorithm based of solving the problem and constituted the algorithm base of ISS(Intelligent Scheduling System) using them. By the rules in the rule base, the best alternative among various algorithms in algorithm base is selected and applied in controlling the FMC. To show the efficiency of ISS, the scheduling output of ISS and the existent dynamic dispatching rule were tested and compared. The results indicate that the ISS is superior to the existent dynamic dispatching rules in various performance indexes.