• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.800-807
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• 2003

Decomposition of tasks in the ordinary manufacturing systems is usually based on the predefined goal of the system. To achieve the high-level-goals (e.g., factory goal or company goal), several sub-goals should be achieved in advance. However, goals can change along with the current status of the system and the external environmental situations. Thus, a manufacturing system should support the goal-formations which can be bearable these changes for efficient and effective operations. Therefore, it IS necessary to develop a systematic methodology for the goal-formations in a manufacturing system. Especially, the formation and/or change of goals in real-time should be possible for distributed and dynamic systems including the fractal manufacturing system (FrMS). In this paper, a threefold methodology is proposed for the goal-formation process (GFP) in the FrMS; 1) a goal­generating process (GGP) to make and propagate fuzzy goals, 2) a goal-harmonizing process (GHP) to eliminate or reduce conflicts and interferences of goals by using a mobile agent- based negotiation scheme, and 3) a goal-balancing process (GBP) to make a compromise between goals by using quantifiable indicators of the manufacturing system.

• International Journal of Quality Innovation
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• v.6 no.2
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• pp.59-89
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• 2005

Manufacturing Resources Planning (MRPII) is one kind of manufacturing information system that can help manufacturing companies gain competitive advantages. It is estimated that more than one hundred MRPII systems are available in the market, many of them are mature enough to solve most operational issues in accordance with users' requirements. More often than not, many of these systems provide more functions than a company expects. Manufacturing companies worldwide have attempted to implement these MRPII systems, however, many companies experienced failure (Turbide, 1996) due to managerial rather than technical issues. The authors propose an approach utilising a roadmap to integrate BPR and the MRPII implementation in order to overcome this difficulty. A detail road map is developed to guide this implementation, which is designed using a hierarchical analysis technique known as Integrated DEFinition Method (IDEF). IDEF is a systematic manufacturing management and integration-modeling tool. The proposed approach is implemented and illustrated using a reference company and the results indicated that 66% reduction in errors for maintaining the bills of materials system; 99% reduction in time to carry out material requirement planning; and 70% reduction in time previously taken for non-productive discussions.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.287-295
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• 2014

Smart manufacturing (SM) considered as a new trend of modern manufacturing helps to meet objectives associated with the productivity, quality, cost and competiveness. It is characterized by decentralized, distributed, networked compositions of autonomous systems. The model of SM is inherited from the organization of the living systems in biology and nature such as ant colony, school of fish, bee's foraging behaviors, and so on. In which, the resources of the manufacturing system are considered as biological organisms, which are autonomous entities so that the manufacturing system has the advanced characteristics inspired from biology such as self-adaptation, self-diagnosis, and self-healing. To prove this concept, a cloud machining system is considered as research object in which internet of things and cloud computing are used to integrate, organize and allocate the machining resources. Artificial life tools are used for cooperation among autonomous elements in the cloud machining system.

• IE interfaces
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• v.15 no.4
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• pp.356-363
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• 2002

Virtual Manufacturing is a technology to facilitate effective product development and agile production by computer models representing the physical and logical schema and the behavior of real manufacturing systems including manufacturing resources, environments and products. For the successful application of this technology, a virtual factory as a well-designed and integrated environment is essential. In this research, we constructed a sophisticated virtual factory model of an automotive company's paint shop, and performed precise simulations of unit cells, lines and whole plant operations for collision check and off-line programming. It is expected that this virtual paint shop is useful for achieving time and cost savings in many manufacturing preparation and planning activities of new car development processes.

• Journal of Information Technology Services
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• v.8 no.4
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• pp.165-174
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• 2009

This paper outlines opportunities and challenges in the implementation of BPEL based WFMS(WorkFlow Management System) for the MES(Manufacturing Execution Systems) in semiconductor manufacturing. At present, the most MESs in semiconductor wafer fabrication shop have the problems in terms of application software integration, reactivity, and adaptability. When a plant has to produce new product mix, remodel the manufacturing execution process, or replace obsolete equipments, the principal road blocks for responding to new manufacturing environment are the difficulties in porting existing application software to new configurations. In this paper, the issues about WFMS technologies including BPEL standard applied for MES are presented. And then, we introduce the integrated development framework named nanoFlow which is optimized for developing the BPEL based WFMS application for automated manufacturing system. And we describe a WFMS implemented with using nanoFlow framework, review and evaluate the system.

• 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.

• Korean Journal of Computational Design and Engineering
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• v.14 no.3
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• pp.176-185
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• 2009

Modern manufacturing systems consist of highly automated manufacturing devices, and they are controlled by complicated PLC programs. To make sure the achievement of the control objectives of a manufacturing system, it is very important to monitor the dynamic system behaviors of the manufacturing system. In this paper, we propose a monitoring methodology of a PLC program based on the Software In the Loop Simulation(SILS), which makes use of the time gap information between PLC signals. The errors relevant with PLC signals can be found using the proposed methodology, comparing a normal PLC signal trajectory with a target PLC signal trajectory. The proposed methodology has been implemented and tested with simple examples.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.194-198
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• 2014

In recent years, RGM(roller gear mechanism) systems, wherein one of the gears of a meshing gear pair is replaced with pins or rollers, have been reintroduced, which is a consequence of, and therefore a reflection of, the rapid advances made in manufacturing technology. Three RTG(roller track gear) systems for arbitrary path transportation (e.g., L-, O-, U-, and S-shaped tracks) were constructed using two out of three RGM systems, namely, the CRP(cam rack pinion), CRG(cam ring gear), and RPG(roller pinion gear) systems, and are introduced in this paper. We also present three ways to prevent the intersection and non-contact phenomena at the teeth in the vicinity of the conversion point between two joined RGM systems.

• Current Optics and Photonics
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• v.1 no.6
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• pp.587-597
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• 2017

The extraction of the valid measurement region from the interference fringe pattern is a significant step when measuring gear tooth flank form deviation with grazing incidence interferometry, which will affect the measurement accuracy. In order to overcome the drawback of the conventionally used method in which the object image pattern must be captured, an improved segmentation approach is proposed in this paper. The interference fringe patterns feature, which is smoothed by the nonlinear diffusion, would be extracted by the structure tensor first. And then they are incorporated into the vector-valued Chan-Vese model to extract the valid measurement region. This method is verified in a variety of interference fringe patterns, and the segmentation results show its feasibility and accuracy.

• IE interfaces
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• v.22 no.1
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• pp.10-16
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• 2009

In this paper, we propose an efficient search algorithm for finding an optimal schedule to minimize makespan, while avoiding deadlock situation in Flexible Manufacturing Systems (FMS) with finite capacity, in which each job needs to be processed in several job stages for completion. The proposed algorithm uses a modeling and control method based on Petri-net. Especially, we improve the efficiency of the search algorithm by using a priority rule and an efficient bounding function during the search procedure. The performance of the proposed algorithm is evaluated through a numerical experiment, showing that it holds considerable promise for providing an optimal solution efficiently comparing to past work.