• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2313-2320
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• 2011

The management of a panel block shop in a shipyard is a complex process that entails the largest amount of work and in which many decisions are involved. Shipbuilders have considered the process as a bottleneck since every panel for every ship and offshore hull structure must be processed through the shop. In order to maximize process productivity, simulation-based ship production execution system(SPEXS) is proposed for panel block operations utilising discrete-event simulation and simulated annealing. An application of panel block assembly shop, called SPEX-Panel supports production planners by general dispatching rules and metaheuristics to make better scheduling decisions on the shop floor. In addition, the system will help increase productivity in the yard with continuous improvement.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.149-159
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• 2006

This research is a development of useful S/W program for real industry about optimal product scheduling in real plant for manufacturing polymer products. For this, we used a fine model with total amount of losses in weight(ton) as an objective for optimal scheduling and a genetic algorithm for optimization in this factory they manufacture three different products. Major products are A and B but the product which can be process in the period of products change over. They also sells them as a chap product in market. The major products have several types of packing process-bulk, pack for domestic market, pack for export. The demands of product with each packing type are increased, and frequently they failed keep the deadline for sail. Based on realistic production situation, we composed a fine modeling for optimal scheduling. And we also develop a S/W program for optimal scheduling which can be used by non-specialist in scheduling problem. We used a modified genetic algorithm and it gave us a better solution in process. We can have a result of reducing the total amount of losses in weight by half compared with the losses when existing production schedule.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.107-117
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• 2019

Because shipbuilding is single-product production with limited resources, production management technology is essential to manage the resources effectively and maximize the productivity of ship-process. Therefore, many shipbuilding companies are conducting research on ship production plan and process considering various constraints in the field by applying modeling and simulation. However, it is difficult to provide accurate production plan on sudden schedule and process changes, and to understand the interconnectivity between the processes that produce blocks in existing research. In addition, there are many differences between the production planning and field planning because detailed processes and quantity of blocks can not be considered. In this research, we propose the integrated process-based modeling method considering process-operation sequences, BOM(Bill of materials) and resource constraints of all the scheduled blocks in the indoor system. Through the integrated process-based model, it is easy for the user to grasp the assembly relationship, workspace and preliminary relationship of assembly process between the blocks in indoor system. Also, it is possible to obtain the overall production plan that maximizes resource efficiency without the separate simulation and resource modeling procedures because resource balancing that considers the amount of resource quantity shared in the indoor system is carried out.

• The Journal of Society for e-Business Studies
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• v.25 no.2
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• pp.15-27
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• 2020

This study starts with the idea that the process of creating a Gantt Chart for schedule planning is similar to Tetris game with only a straight line. In Tetris games, the X axis is M machines and the Y axis is time. It is assumed that all types of orders can be worked without separation in all machines, but if the types of orders are different, setup cost will be incurred without delay. In this study, the game described above was named Gantris and the game environment was implemented. The AI-scheduling table through in-depth reinforcement learning compares the real-time scheduling table with the human-made game schedule. In the comparative study, the learning environment was studied in single order list learning environment and random order list learning environment. The two systems to be compared in this study are four machines (Machine)-two types of system (4M2T) and ten machines-six types of system (10M6T). As a performance indicator of the generated schedule, a weighted sum of setup cost, makespan and idle time in processing 100 orders were scheduled. As a result of the comparative study, in 4M2T system, regardless of the learning environment, the learned system generated schedule plan with better performance index than the experimenter. In the case of 10M6T system, the AI system generated a schedule of better performance indicators than the experimenter in a single learning environment, but showed a bad performance index than the experimenter in random learning environment. However, in comparing the number of job changes, the learning system showed better results than those of the 4M2T and 10M6T, showing excellent scheduling performance.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.73-82
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• 1988

This research is concerned with production scheduling for FMS (Flexible Manufacturing System) which consists of machine centers served by cycle conveyor. The objective of the research is to develop and evaluate scheduling procedures to minimize the mean flow time. An optimal algorithm called SCTF (Shortest Circle Time First) is proposed when the conveyor runs at minimum possible speed (CS=1) and a heuristic algorithm called SCTJMF (Shortest Cycle Time and Job Matching Algorithm) is suggested when the conveyor runs at double speed (CS=2). The evaluation of the heuristic algorithm was implemented by comparison with the optimal algorithm for 112 experimentations for CS=1 and random schedule. The results showed that the proposed heuristic algorithm provides better solution that can be regarded noticeable when compared with SCTF algorithm and random scheduling.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.166-169
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• 2003

일정한 시간이 지나면 제품으로서의 가치가 사라지게 되는 단일기간 재고품목들은 생산된 직후 전량 각 고객들에게 주어진 납기에 맞추어 효율적인 분배가 요구된다. 본 연구에서는 고객들은 다수 종류의 제품을 주문할 수 있으며 제품종류별 분리배송을 허용하는 상황에서 생산비, 수송비, 납기위반비, 차량고정비를 최소화하기 위한 생산순서 및 차량경로를 수립함을 목적으로 한다. 이에 대한 해법으로써 진화개미해법을 개발하였다. 개발된 해법의 성능평가를 위해 각 고객의 위치, 주문 제품 종류, 주문량들을 다르게 하여 구축한 실험문제에 대하여 유전알고리듬해법과 비교실험을 수행하였다.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.287-291
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• 2000

고객의 요구는 더욱더 개성화, 다양화되고 있고, 글로벌 시장은 다양한 가치관, 문화, 전통을 바탕으로 지역적인 개성을 추구한다. 전 세계에 그물처럼 엮어진 인터넷망은 시간과 거리의 제약을 완전히 없앴다. 기업은 국가와 대륙을 초월한 세계 무대에서 치열한 경쟁을 전개하고 있다. 이러한 상황에서 고객의 요구를 파악하여 이에 부합되는 제품의 생산 및 판매가 기업 경영에 있어서 주요 이슈로 등장하고 있으며, 이러한 추세는 제품 개발 기술의 보편화로 고객에 대한 서비스의 차별화로 집중되고 있다. 이런 수요를 충족시키기 해서는 CRM(Customer Relationship Management) 개념이 도입되어야 하고, 제조공정을 개선하며 경쟁력을 강화하기 위해서는 모든 기업이 고객의 가치를 최대화 할 수 있는 동기화 생산이 필수적이라고 하겠다. 본 연구에서는 CRM의 고객정보분류 방법 중 하나인 FART(F;Frequency, R;Recency, A;Amount, T;Type of merchandise/service)를 이용하여 주요고객을 분류하고, 이 정보를 Drum-Buffer-Rope 스케줄링 방법에 반영하여 기업의 생산능력과 우수고객 주문을 고려한 일정계획 방법을 제시한다. 이 결과로 우수고객에 대한 서비스 수준을 향상시키고 궁극적으로는 기업의 이윤을 최대화하는데 기여하고자 한다.

• Journal of Korean Society for Quality Management
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• v.20 no.1
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• pp.136-146
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• 1992

Most of scheduling papers on FMS have been considered that the fabrication process, the machining process and the assembly process etc. are independent and the releasing, routing, dependent, batching, loading problem are treated separetely. In this paper, we discuss that the integrated scheduling problem which can be solved for efficient use. We combine two systems that each process system which in order to produce a product is treated dependently, the releasing and the routing problem are combined one system and we present the efficient flexible manufacturing system as including the alternate process.

• Journal of the Korea Society for Simulation
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• v.5 no.2
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• pp.1-12
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• 1996

Utilizing the simulation approaches, the dynamic production scheduling system FOLS(Flexible flowshop On-Line Simulation) is developed under the flexible flowshop environment. When an interruption such as machine failure/recovery is occurred at the shop floor, the FOLS system performs evaluations for job selection rule oriented alternatives, and generates a dynamic production schedule based on the collected current shop floor data. For the case study, the FOLS system is applied to the printed circuit card assembly(PCCA) line and simulation results are reported.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.657-658
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• 2006