• Journal of Korean Institute of Industrial Engineers
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• v.31 no.2
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• pp.135-142
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• 2005

This study addresses the problem of flexible technology acquisition in a multi-product market when demands are uncertain. We confine the concept of flexibility to the ability of manufacturing system to produce a number of different types of products, called a product-mix flexibility type. And an analytical model in which the economies of scope are incorporated explicitly as a feature of flexible technology is presented to find the optimal investment decision to acquire flexible technology and optimal production planning. The characteristics of optimal investment strategy related to capacity and production planning are discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.74-81
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• 2007

절삭가공에서 가공조건은 가공비용의 감소와 제품 품질의 향상에 영향을 주는 주요 요인 중의 하나이다. 본 논문에서는 밀링작업을 대상으로 가공조건을 보다 효율적으로 수정하고 이를 지속적으로 향상시킬 수 있는 방법론과 이를 기반으로 개발된 작업설계시스템을 소개한다. 개발된 시스템은 (1) 표준 가공조건을 세부 공정별 요구 사항이 만족되도록 수정하고, (2) 퍼지아트맵 신경회로망 모델을 이용하여, 생성된 가공조건을 온라인(incremental) 학습한 후, (3) 보다 효율적인 새로운 가공조건이 생성되었을 때 이를 교체알고리즘이라 불리는 제안된 알고리즘을 이용하여 기존의 가공조건을 대체하는 3가지 핵심 기능으로 구성된다. 우선 새로운 방법론이 적용된 작업설계시스템의 전반적인 내용을 소개한 후, 다음으로 다양한 시뮬레이션을 통하여 제안된 방법론의 성능을 예시한다. 마지막으로 실제부품에 적용한 실행 결과를 기술하고 토의한다.

• International Journal of Reliability and Applications
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• v.2 no.4
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• pp.241-251
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• 2001

In this paper, optimal bum-in time to minimize the total mean cost, which is the sum of manufacturing cost with burn-in and cumulative warranty-related cost, is obtained. When the products with cumulative pro-rata warranty have high failure rate in the early period (infant mortality period), a burn-in procedure is adopted to eliminate early product failures. After burn-in, the posterior product life distribution and the warranty-related cost are dependent on burn-in time; long burn-in period may reduce the warranty-related cost, but it increases the manufacturing cost. The paper provides a methodology to obtain total mean cost under burn-in and cumulative pro-rata warranty. Property of the optimal burn-in time is analyzed, and numerical examples and sensitivity analysis are studied.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.4
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• pp.334-344
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• 2003

A mixture experiment is a special type of response surface experiment in which factors are the ingredients or components of a mixture, and the response is a function of the proportions of each ingredient. Evolutionary operation is useful to improve on-line full-scale manufacturing process by systematically changing the levels of the process variables without jeopardizing the product. This paper presents an evolutionary operation procedure with mixture variables for large-scale mixture production process which can be beneficial to practitioners who should improve on-line mixture quality while maintaining the production amount of the mixture product.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.156-162
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• 2013

Social manufacturing architecture is based on information delivery through social media and SNS, PLM and social platform, crowd source and knowledge base on whole phase of product life cycle. Although advanced social manufacturing issues are rising globally, its technology emerging into domestic industry is likely to be slow. We focused to review technological changes and R&D trend, patent issues, and then suggest assignments and advices to be practiced for social manufacturing modeling.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.26-29
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• 2007

In Korean Electric Motor Unit(EMU) industry, the government should lead and drive the development of the product-oriented fundamental technologies(for example, Life Cycle Assessment, Environmental Labelling, Ecodesign, Eco-efficiency etc.) for the EMU. International Railway Union(UIC) establish UIC code 345: Environmental specification and it is based on using the product-oriented fundamental technologies. And also many foreign railway related companies already shown their environmental performance using the product-oriented fundamental technologies So, in Korean situation, it is important that let the EMU industrial player understand the importance of the product-oriented fundamental technology for the EMU and clarify who drive the development of the product-oriented fundamental technology for the EMU and what the type of driving forces.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.11-18
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• 2004

CAD systems have been developed with network technology and it is needed to exchange product data among them. STEP becomes world-wide international standard to exchange CAD data among various heterogeneous CAD systems in manufacturing industrial fields. We report results to test errors that can happen when exchanging STEP files of product model through the STEP translator of different commercial CAD systems. Also the tests of Korean Character, Hangul, have been carried out. And also we report the STEP rallies held twice in Korea and several rounds abroad, and their testing results are shown as tables and graphs. The tested results can be used for exchanging product models to the next domestic STEP Rally and extended to Northeastem Asian STEP rally by steadily contacting with the organizations for Asian STEP centers such as JSTEP(Japan) and CSTEP(China). Finally we expect that the result can be used to specify STEP standardization in the field of managing product data.

• Journal of Applied Reliability
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• v.9 no.4
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• pp.343-349
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• 2009

One of the recent hot issues in the manufacturing business is how to incorporate environmental attributes into product and process design. Design for environment considers the potential environmental impact of a product throughout its life-cycle. In the case of something breaks, it can become waste immediately, hence reliability and durability is the essential part of product design. This paper presents reliability technology for sustainable product design to improve the product longevity that extends performance life, serviceability and durability. The presented method will help to develop a sound design and avoid weak links to minimize the waste.

• IE interfaces
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• v.12 no.1
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• pp.150-157
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• 1999

Mini-Mill process has been recently in operation at Pohang steel company, which enables more flexible steel coil production on customer demands. The effects of process parameters in Mini-Mill process need to be analyzed not only to make the process stable but also to improve product quality. This work aims to develop a regression model of Mini-Mill process using accumulated product data such that the process parameter effects on product tensile strength may be analyzed. The analysis shows that tensile strength is influenced mainly by the amount of components such as carbon, manganese, silicon, and sulfur. The effect of temperature is shown to be small. It is concluded that control of the components is much more responsible for both meeting the target and reducing the variation of the product tensile strength. Heat treatment is more useful in compensating tensile strength variations due to thickness differences and improving workability and other quality characteristics. More work is necessary for establishing regression expressions of the process that is reliable and accurate enough to dispense with the off-line inspection of the product tensile strength.

• IE interfaces
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• v.19 no.3
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• pp.181-189
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• 2006

This study introduces an overall framework for RFID applications in product lifecycle management(PLM). PLM is a new strategic approach to manage product related information efficiently over the whole product lifecycle. Recently, with emerging technologies such as radio frequency identification(RFID), global positioning system(GPS), and wireless communication, PLM provides a new environment that enables us to gather and analyze product lifecycle information, and make decisions on several issues without spatial and temporal constrains. However, a PLM system just provides us with new opportunities to gain the PLM system, first and foremost, it is necessary to look into its overall framework in the viewpoint of hardware, software, and business model. For this purpose, in this study, first, we introduce the technical framework of the new PLM environment with the concept of extended RFID system, called product embedded information device(PEID). Then, for each lifecycle phase such as beginning of life(BOL), middle of life(MOL), and end of life(EOL), we explore several research problems that become highlighted under the new PLM environment.