• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.251-262
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• 1999

In the automated manufacturing systems, the problem regarding how to make production activities flexible is even more important and critical than that regarding how to product large quantities, and the more flexible, if possible, the manufacturing system is, the more competitiveness and profitable factors it gets. This research, therefore, concentrated on establishing the flexibility and evaluating performance on the manufacturing system, operational flexibility is considered because of enabling the manufacturing system to get both the improvement of production rate and the adaptive ability of environment changes. For it, we used the analytical tool, GSPNs, which is a kind of timed Petri-Nets. GSPNs is competent enough to consider practical situations just like operation priorities, machine failure, randomness, concurrency and so on. Through the GSPNs analysis, it is confirmed that in the manufacturing system with operational flexibility is compatible with the traditional performances such as production rate or mean waiting time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.297-309
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• 1997

Exceptional Elements(E.E) are generally eliminated by a machine duplication or a subcontract in cellular manufacturing system. One of the advantages in FMS consists of machines capable of multi-processing. This paper presents a method that eliminates E.Es by tool duplication. First, we develop the exceptional operation similarity(EOS) by machine cell-operation incidence matrix and part-operation incidence matrix. The EOS indicates a similarity of unperformable operations in each part when two exceptional parts are assigned to a machine cell. Secondly, a mathematical model to minimize tool duplication is developed by the EOS. Finally, a heuristic algorithm is developed to reflect dynamic situation in process of elimination of exceptional elements by the EOS and the mathematical model. A numerical example is provided to illustrate the algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.17-29
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• 1999

The manufacturing systems have to cope with the circumstance that the requirements of customers are changed abruptly and the life cycle of product becomes short. In this paper, to develop the efficient control and operation of autonomous, distributed machining systems the concept of Holonic Manufacturing System is adopted and methods for the control and operation of the system are proposed including an evaluation function for the negotiation between holons. And it is applied to scheduling and selection of operations to be worked with consideration of quality. It is expected that the proposed methods may be applied to operate autonomous, distributed machining systems.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.274-279
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• 2001

This paper presented a virtual manufacturing simulation system by using Virtual Reality Modeling Language (VRML) and Finite Element Method(FEM). The system is to simulate forging operation. Stress distributions and deformation profiles as well as the operation of forging machine can be simulated and visualized in the web. Since the forging machine, user interface, and specimen were modeled by using Java and VRML, the forging machine and analysis results were browsed and integrated on the web that is interfaced to users through EAI to show the whole forging simulation. The developed system realized the working environment virtually so that education and experiment of forging process could be performed effectively even on the PC.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.1
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• pp.19-25
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• 2009

We suggest and evaluate a dynamic scheduling rule of machines and material handling systems for on-line operation in job shop type Flexible Manufacturing System. Alternating status should be able to take operation scheduling procedures and without delay in dynamic industrial environments effectively. The interaction(SPT-NS, SPT-QSNS, SPT-NUJ, EDD-NS, EDD-QSNS, EDD-NUJ, CR-NS, CR-QSNS, CR-NUJ) between machine operation scheduling and AGV dispatching rule were also studied in this research. The performance evaluation which was obtained from DSS compares the performance of Flow time, and Empty to loaded travel ratio. It is Compared with the best rules & two system.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.799-810
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• 2022

Welding work is a production work method widely used throughout the industry, and various types of welding technologies exist. In addition, many methods are being studied to automate these welding operations using robots, but in the ship manufacturing field, welding such as painting, cutting, and grinding is also the most common operation, but the manual operation ratio is higher than in other industries. Such a high manual labor ratio in the field of ship manufacturing not only causes quality problems and production delays according to the skill of workers, but also causes problems in the supply and demand of manpower. Therefore, this paper analyzed the reason why the automation rate is low in welding work at ship manufacturing sites compared to other industries, and analyzed the production process and field environment for small and medium-sized ship manufacturing companies that repeatedly manufactured with a small quantity production method. Based on the analysis results, it is intended to propose a robot system that can easily move between workplaces and secure uniform welding quality and productivity by collaborating simple welding tasks with humans. Finally, the simulation environment is constructed and analyzed to secure the suitability of robot system application to current production site environment, work process, and productivity, rather than to develop and apply the proposed robot system. Through such pre-simulation and robot system suitability analysis, it is expected to reduce trial and error that may occur in actual field installation and operation, and to improve the possibility of robot application and positive perception of robot system at ship manufacturing sites.

• International Journal of Quality Innovation
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• v.6 no.3
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• pp.70-94
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• 2005

The IC packaging industry heavily relies on shop floor information, necessitating the development of a model to flexibly define shop floor information and timely handle manufacturing data. This study presents a novel data model of product manufacturing flow to define shop floor information to effectively respond to accelerated developments in IC package industry. The proposed data model consists of four modules: operation template setup, general process setup, enhanced bill of manufacture (EBOMfr) setup, and work-order process setup. The data model can flexibly define the required shop floor information and decision rules for shop floor product manufacturing flow, allowing one to easily adopt changes of the product and on the shop floor. However, to handle floor dynamics of the IC packaging industry, this work also proposes a WIP (i.e. work-in-process) system for monitoring and controlling the product manufacturing flow on the shop floor. The WIP system integrates the data model with a WIP execution module. Furthermore, an illustrative example, the MIRL WIP System, developed by Mechanical Industrial Research Laboratories of Industrial Technology Research Institute, demonstrates the effectiveness of the proposed model.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.161-166
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• 1999

Virtual Manufacturing System(VMS) is a computer model that represents the precise and whole structure of manufacturing systems and simulates their physical and logical behavior in operation. In this paper, a real time simulation for the virtual factory is proposed to integrate a process planning with scheduling under distributed environments. In order to communicate the information under distributed environments, we use a server/client concept using socket program and internet.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.15-20
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• 2014

The manufacturing equipment on most shop floors consists of numerical control machines, and the condition of each piece of equipment is monitored and controlled by an internal sensor or programmable logic controller (PLC). To control and monitor production lines that consist of an equipment or production module, a separate control and monitoring system such as a manufacturing execution system should be introduced. However, there is no standardized system, and it is costly and difficult to build a system for small or medium-sized plants. In this paper, a PLC-based supervisory system for operation control of a group of production machines is proposed, and the developed PLC-based system is evaluated by applying it to a computer numerical control machine.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.391-391
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• 2000

Manufacturing process generally exhibits major or minor variations due to deviation of raw materials, equipment degradation, controller malfunction, and so on. Extensive research based on multivariate statistical process control has been done to monitor the unstable states and indicate a corrective action. A prototype of intelligent operation support system ("ISYS-MSPC") has been developed as a tool that supports the enhanced operation to guarantee the high productivity and a uniform high quality product. This system has been applied to the industrial batch and continuous processes and its performance has been validated .