• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.78-86
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• 2002

In this paper, LMI (Linear Matrix Inequality) based on H$\_$$\infty$/ controller for a lire of sight (LOS) stabilization system. It shows that the proposed controller has more excellent stabilization performance than that of the conventional PI-Lead controller. An H$\_$$\infty$/ control has been also applied to the system for reducing modeling errors and the settling time of the system. The LMI-based H$\_$$\infty$/ controller design is more practical in view of reducing a run-time than Riccati-based H$\_$$\infty$/ controller. This H$\_$$\infty$/ controller is available not only to decrease the gain in PI-Lead control, but also to compensate the identifications for the various uncertain parameters. Therefore, this paper, shows that the proposed LMI-based H$\_$$\infty$/ controller had good disturbance attenuation and reference input tracking performance compared with the control performance of the conventional controller under any real disturbances.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.124-131
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• 2000

Rapid Prototyping(RP) models are no longer used only for design verification. Currently, parts built utilizing layer manufacturing technology can be employed as functional prototypes and as patterns or tools for different manufacturing processes such as vacuum casting, investment casting, injection molding, precise casting and sand casting. This trend of Rapid Prototyping application meets the requirement of concurrent engineering and its range covers a more spreaded area. The aim of this paper is saving the manufacturing lead time and cost of plastic parts having hollow space shapes used by prototype-car. Using rapid prototype patterns, made by the Selective Laser Sintering(SLS) technique, a new approach of manufacturing resin-based blow mold is discussed. It has a great potential fur making prototype-car parts with the batch size of under 200 parts, in case of rapid modification due to a subsequent design changes in developing stage. So, the process proposed in this research shows reduction of process time and manufacturing cost when compared with the conventional process such as a Zinc Alloy fur Stamping(ZAS) mold.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.157-163
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• 2002

Automated manufacturing systems are applied to shop floors as a tool for the increase of productivity and quality and the decrease of manufacturing lead times and industry accidents. One of the most important issue of the present day is the application of Internet. The development of Internet technologies makes manufacturing enterprises break spacial barriers between users and shop floors, and collect various field data in remote sites. In this research, an Internet-based remote control system for a small-sized automated storage and retrieval system is developed for the purpose of real-time monitoring and control of automatic production equipment. The developed system has a client-server architecture and transmits real-time images of the automated storage and retrieval system to a client by ar CCD camera connected to a server. Based on the transmitted images, the client sends commands to PLC of the server, and part storage and retrieval tasks are executed.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.83-91
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• 1999

Dynamic characteristic of manufacturing stage is understood and the utilization of each machine is maximized by developing on-line dynamic CAPP system to consider the overloads in the aircraft part manufacturing line. In this paper, a scheme of production planning and scheduling system was proposed through inspection about some predeveloped CAPP system. Developed production planning and scheduling system included process planning module. After precise inspection of some FMS line schema at domestic heavy industry, optimized FMS line was applied to aircraft part manufacturing and repairing factory. By virtue of considering overloads of factory and machine through on-line dynamic CAPP system, the utilization of resources is maximized and manufacturing lead time is minimized.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.133-141
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• 2020

Up to date cosmetic OEM/ODM (original equipment manufacturing/original development manufacturing) industry receives attention as a future growth engine due to steady growth. However, because of limited research and development capability, many companies have employed commercial management platforms specialized for large-sized companies; thus, overall system effectiveness and efficiency is low. Especially, MRP (material requirement planning) system introduced originally in 1970s is employed to calculate the requirement of the parts. However, dynamic nature of production lead time usually results in incorrect requirements. In addition, its algorithm does not consider the capability of the production resources. Also, because the commercial MRP system calculates all subcomponent for fixed period, the more goods have subcomponent, the slower calculation is. Therefore, conventional MRP system cannot respond complicated situation in time. In this study, we will suggest a new method that can respond to complicated situations resulting from short lead time and urgent production order in Korean cosmetic market. In particular, a distributed MRP system is proposed, that consists of multi-functional and operational modules, based on the characteristic of the BOM (bill of material). The distributed MRP system divides components (i.e. products and parts) into several fields and decrease the problem size; thus, we can respond to dynamically changed data any time. Through this solution, we can order components quickly, adjust schedules and planned quantity, and manage stocks reasonably. In addition, a prototype of the distributed MRP system is presented in this paper, in which ERP (enterprise resource planning) sever data is associated with an excel spreadsheet via MSsql. System user interface is implemented by a VBA (visual basic for applications) tool. According to a case study, response rate for delivery and planning achievement rate were enhanced about 20%, and inventory turnover was also decreased. Consequently, the proposed system improves overall profit.

• Journal of the Korea Safety Management & Science
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• v.5 no.1
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• pp.83-92
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• 2003

Scheduling plays an important role in shop floor planning. A scheduling shows the planned time when processing of a specific job will start on each machine that the job requires. It also indicates when the job will be completed on every process. Thus, it is a timetable for both jobs and machines. There is only one server available and arriving work require services from this server. Job are processed by the machine one at a time. The most common objective is to sequence jobs on the severs so as to minimize the penalty for being late, commonly called tardiness penalty. Based on other objectives, many criteria may serve as s basis for developing job schedules. The process also comprises all strategic planning, capital investments, management decisions, and tasks necessary to create a new product. manufacturing processes must be created so that the product can be produced in the product facility. Purchasing new equipment and training workers may be required if new technology is to be used. Tools, fixtures, and the sequence of steps in the manufacturing processes must all be developed to allow rapid, high-quality, cost effective production. Also, it may be needed to be rearrange the production facility to adapt to the new manufacturing processes. Therefore, this study tries to proposed that Scheduling by customer needs group for minimizing the problem and reducing inventory, product development time, cycle time, and order lead time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.101-104
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• 2002

Leading companies have embraced the new economy with new and innovative BTO models. Instead of conventional company-oriented manufacturing scheduling, customer-oriented scheduling method attracts more and more attention. To evaluate the delivery of customer order in advance, the real production capacity as well as procurement lead time should be taken into account. This paper describes a quasi-real-time order delivery estimation system using TOC(Theory of Constraints) based scheduling method.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.2
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• pp.85-90
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• 2009

The Toyota production system (TPS) developed by Toyota corporation is a management principle and production model to improve values added through elimination of waste. Since the oil shock in 1970s, the TPS has drawn the worldwide attentions as a main factor of competitiveness of Japanese manufacturing system and has been studied and implemented in many countries regardless of size and types of industry. For the correspondence to various customer's requirement, it is required to establish on time delivery procedure and to shorten lead time. Therefore it intended to establish TPS which is adopted to 7 losses reduction and JIT(Just in Time). In this paper, the automatic production line for color TV manufacturing by TPS was developed and proved to push up two times of productivity, to reduce the 25 workers at a time, and to widen the flexibility of manufacturing from 14" to 25" TV.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.224-230
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• 2006

As business competition gets together, there is much pressure on product development service organizations and manufacturing to become more productive and efficient. Product developers need to create innovative products in less time, even though the products may be very complex. To get this purpose, Six sigma methodology can be used. Six sigma is a strategic approach that works across all processes, all products, and all industries. The purpose of this paper is to develop the innovation strategy for shortening the lead time of the new product using six sigma method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.13-18
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• 2011

This study deals with the effect of the honing in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by honing. Therein, the honing techniques are welcomed especially as one of the physical surface improvement methods. As a result, gear honing reduces vibration and noise, and will increase the life of gear. And gear honing also changes the surface of gear tooth in a short time and price, so it is a very important method in manufacturing industry. But nowadays, it is hard to find the detail information of gear honing. The test gear is a planetary gear which is used in the automotive industry. It is manufactured by the hobbing, shaving, carburizing and honing. This study investigates the effect of honing in surface shape of SCM420H planetary gears, including fatigue strength test and characteristics of honing of SCM420H planetary gears.