• Structural Engineering and Mechanics
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• v.35 no.2
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• pp.175-190
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• 2010

One of the intractable problems in multiresolution structural analysis is the decoupling computation between scales, which can be realized by the operator-orthogonal wavelets based on the lifting scheme. The multiresolution finite element space is described and the formulation of multiresolution finite element models for structural problems is discussed. Various operator-orthogonal wavelets are constructed by the lifting scheme according to the operators of multiresolution finite element models. A dynamic multiresolution algorithm using operator-orthogonal wavelets is proposed to solve structural problems. Numerical examples demonstrate that the lifting scheme is a flexible and efficient tool to construct operator-orthogonal wavelets for multiresolution structural analysis with high convergence rate.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.3
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• pp.55-61
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• 2006

The purpose of this study is to propose guidelines for Introducing the JIT(Just-In-Time) purchasing to enhance the competitiveness of Korean manufacturing companies. This study employed an extensive survey on the use of the JIT purchasing systems among different Korean manufacturing companies to understand the current status of the JIT purchasing in use and to identify the benefits from implementing JIT purchasing. The survey has covered 163 manufacturing companies of different sizes from various sectors of Korean industries including electronics, automobiles, machineries, and textiles. The research results support that the JIT purchasing would contribute to increase the purchasing performances of Korean manufacturing companies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.35-45
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• 1998

Scheduling problem in Flexible Manufacturing Systems(FMS) is complex because of various situation of Manufacturing Systems. Especially, in case of short-term scheduling demanding high efficiency, low cost at short-period, efficient scheduling is a serious problem. To solve this problem, many dispatching rules are developed. But, it leave much to be desired, because real situation in shop floor is complex and real-time scheduling is needed in real manufacturing shop floor. In this paper, search algorithm that allocate different dispatching rules to each machine is presented to complement lack of dispatching rule and develop practical real-time scheduling system. The search algorithm is described in detail. First, algorithm detect machine breakdown, evaluate each dispatching rule. dispatching rules for each machine meeting performance criteria are ranked. The algorithm selects new dispatching nile for bottleneck machine. The effectivenes and efficiency of the mixed dispatching rule and search algorithm is demonstrated.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.2
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• pp.51-56
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• 2006

Manufacturing having formed spinal structure of the nation's industry is on the verge of collapse due to various kinds of reasons. We should seek and realize another sustainable engines of growth but can hardly find them except manufacturing as for now. It can be said, accordingly, that we are well advised to find the path leading to our ultimate goal just in the systems engineering approach, which can differentiate us from the neighbouring hunted and hunting countries with their inherent competitiveness. In this paper, the desirable way needed is reviewed with the direction for us to take being suggested.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.2
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• pp.117-128
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• 1987

A major problem in the adoption of advanced manufacturing systems such as F.M.S. (Flexible Manufacturing Systems) is the prerequisite economic justification process because of high investment needed for the acquisition and installation of F.M.S. While some of the benefits expected are readily quantifiable, others are very difficult or even impossible, using conventional method. Thus the investment in F.M.S. should be considered as a strategic decision rather than a tactical decision which concerns with only financial implications. In this paper we review papers on major justification techniques developed during thelast decade and identify the benefits of F.M.S. and describe the considerations in the justification of F.M.S. Also, we deal with the current and future research directions in justifying F.M.S.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1020-1023
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• 1996

Fieldbus provides real-time data communication among field devices in the process control and manufacturing automation systems. This paper presents an implementation method of Profibus in the experimental model of manufacturing automation system. The manufacturing automation system considered in this paper consists of robots, NC machines, sensors, conveyers and PCs. The application task programs are developed on the basis of FMS/FMA7 communication services which are provided by Profibus application layer. The communication and application programs are developed in the real-time environment.

• IE interfaces
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• v.4 no.2
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• pp.73-79
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• 1991

This paper concerns the issues involved in development and use of manufacturing simulation software using the Object Oriented Programming System(OOPS) in a computer integrated manufacturing environment, with particular emphasis on large scale integrated circuit fabrication. We introduce OOPS and compare it with existing simulation packages as well as general purpose languages. Our implementation of OOPS shows numerous advantages over the other programming systems. Based on our experience, guidelines for devloping manufacturing simulation systems in OOPS are discussed.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.3
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• pp.305-310
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• 1997

In this paper, a fuzzy set based machine-cell formation algorithm for cellular manufacturing is presented. The fuzzy logic is emoloyed to express the degree of appropriateness when alternative machines are specified to process a part shape. For machine grouping, the similarity coefficient based approach is used. The algorithm produces efficient machine cells and part families which maximize the similarity values.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1155-1164
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• 2008

Supervisory control theory, which was first proposed by Ramadge and Wonahm, is a well-suited control theory for the control of complex systems such as semiconductor manufacturing systems, automobile manufacturing systems, and chemical processes because these are better modeled by discrete event models than by differential or difference equation models at higher levels of abstraction. Moreover, decentralized supervisory control is an efficient method for large complex systems according to the divide-and-conquer principle. Decentralized supervisors cannot observe the events those of which occur only within the other supervisors. Therefore decentralized supervisors can be designed according to supervisory control theory under partial observation. This paper presents a solution and a design procedure of supervisory control problem (SCP) for the case of decentralized control and SCP under partial observation (SCPPO). We apply the proposed design procedure to an experimental CIM Testbed. And we compare and analyze the designed decentralized supervisors and partially observed supervisors.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.270-276
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• 2009

This paper outlines opportunities and challenges in the Implementation of BPEL based WFMS(Work Flow Management System) for the MES(Manufacturing Execution Systems) level in semiconductor manufacturing. At present, the most MES that are composed of several hundreds of applications in semiconductor wafer fabrication shop have the same problems as others about flexibility 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 inflexible communication infrastructure among the manufacturing process components and the difficulty in porting existing application software to new configurations. In this paper, the issues about BPEL standard, used for the flexibility of Workflow Management System, are presented. We introduce the integrated development framework named nanoFlow which is optimized for developing the BPEL based WFMS application for automated manufacturing system. We describe a WFMS implemented with using nanoFlow framework, review and evaluate the system in terms of flexibility and adaptability.