• Journal of Industrial Technology
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• v.35
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• pp.3-8
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• 2015

A study has been made on defects which are formed in manufacturing processes of engine bearing and also on fatigue crack growth behavior in each step of bearing metal manufacturing. After the first step(sinter brass powder on steel plate ; Series A) many voids are made on brass surface and its size is decreased by the second step(rolling process of sintered plate ; Series B). After the third step(re-sintering step of brass powder and rolling ; Series C) the number of voids is decreased and its type shows line. The time of fatigue crack initiation and the growth rate of fatigue crack are in order of Series A, Series B, Series C. These reasons are that void fosters the crack initiation and growth, and residual stress made by rolling process effects on the crack growth rate in Series B, C. In forming and machining processes by use of final bearing metal, crack was observed at internal corner of flange and peeling off was observed at junction between steel and brass. Owing to the above crack and peeling off, it is considered that there is a possibility of fatigue fracture during the application time.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.45-51
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• 2011

A study has been made on defects which are formed in manufacturing processes of engine bearing and also on fatigue crack growth behavior in each step of bearing metal manufacturing. After the first step (sinter brass powder on steel plate ; Series A) many voids are made on brass surface and its size is decreased at the second step (rolling process of sintered plate ; Series B). After the third step (re-sintering step of brass powder and rolling ; Series C) the number of voids is decreased and its type shows line. The time of fatigue crack initiation and the growth rate of fatigue crack are in order of Series A, Series B, Series C. These reasons are that void fosters the crack initiation and growth, and residual stress made by rolling process affects on the crack growth rate in Series B, C. In forming and machining processes by use of final bearing metal, crack was observed at internal corner of flange and peeling off was observed at interface between steel and brass. Owing to the above crack and peeling off, it is considered that there is a possibility of fatigue fracture during the application time.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.264-264
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• 2007

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.3
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• pp.441-461
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• 1995

This research proposes an Integrated Product Information Model (IPIM) using STEP (Standard for the Exchange of product model data) for Computer Integrated Manufacturing (CIM) of Concurrent Engineering (CE). IPIM is based on Geometry and Topology (STEP Part 42), Form Feature (STEP Part 48), and Tolerance (STEP Part 48) for representing the integrated information of mechanical parts. For the IPIM, 1) new entities are developed for integration of existing entities, and 2) the existing entities are restructured and modified for a special application protocol. In CIM or CE, the advantages of using IPIM having integrated form of geometry, feature and tolerance are 1) integration of product design, process design and manufacturing sequentially or concurrently. 2) keep the product data consistency, modified by different domain, and 3) automatic data exchange between different application software and different hardware. The prototype system is composed of CAD, Data Probe, DBMS and SDAI (Standard Data Access Interface), and the generated STEP data is stored in a step file of DBMS for other applications.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.257-264
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• 2004

분산 제조 시스템간의 협업을 가능케 하는 e-Manufacturing paradigm 의 성공을 위해서는 CAD-CAM-CNC chain 의 제조 분야뿐만 아니라 SCM, ERP, CRM 등의 상위 시스템과의 제품 및 가공 정보의 원활한 흐름이 필수적이다. STEP 과 STEP-NC 는 이를 해결할 표준으로 자리매김 할 것으로 기대되고 있다. 본 논문은 STEP-NC 의 국내 promotion 차원에서 참고문헌 [1]의 밀링용 파트프로그래밍 소개에 이어: 1) 선반용 데이터 모델, 2) 선반용 파트 프로그램의 작성 방법, 3) XML 을 이용한 파트 프로그램의 표현 방법들을 소개하고, 4) STEP-NC 기반의 생산 환경 구축을 위한 방안을 기술하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.525-526
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• 2007

Over-polishing is required to completely remove the material of top surface across whole wafer, in spite of a local dishing problem. This paper introduces the two-step CMP process using protective layer and high selectivity slurry, to reduce dishing amount and variation. The 30nm thick protective oxide layer was deposited on the pattern, and then polished with low selectivity slurry to partially remove the projected area while suppressing the removal rate of the recessed area. After the first step CMP process, high selectivity slurry was used to minimize the dishing amount and variation in pattern structure. Experimental result shows that two-step CMP process can be successfully applicable to reduce the dishing defect generated in over-polishing.

• Journal of the East Asian Society of Dietary Life
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• v.2 no.1
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• pp.133-138
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• 1992

The research on the manufacturing procedure of Hosanchun jun in the classical literature(17 kinds) showed that the most usually brewed rice wine in it is the 3rd step rice wine, which is brewed by adding rice wine base to it at the intervals used quantity are as follows. Nonglutinous rice(88.2%), flour(82.3%), and nu-ruk(100%) are used in the 1st step of brewing, and nonglutinous rice(82.3%), glutinous rice(17.6%), flour(23.5%), and nu-ruk(11.3%) are used in the 2nd sep, and glutinous rice, flour, and 3rd step of brewing. The grains are used in the form of -paste(88.2%) in the 1st, and in the form of paste(64.7%) and steamed water-soaked rice(sul-bab)(29.4%) in the second step, and sul-bab(64.7%) in the 3rd step of brewing. Nu-ruk is used in small quantity in the 3rd step but it is used I somewhat larger quantity in the 2nd step of brewing.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.38-46
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• 1994

The role of CIMS(Computer Integrated Manufacturing Systems) is to integrate various applications throughout a product's life cycle. STEP is an international effort to standardize information models and interfaces so that independently developed applications can be easily integrated. A prototype for the Ship CIMS is built using STEP. In this prototype, the information model defined by EXPRESS is translated into database schemas. In this paper, we explain the operation of this prototype using the examples from two application programs, i.e., the Block Division System and the Erection System which are used for the process planning of ship manufacturing. As an example. Real data stored in a relational database system(Oracle) is presented in this paper.

• Journal of the Korean institute of surface engineering
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• v.43 no.1
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• pp.17-24
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• 2010

In this study, surface characteristics of dental implant fixture with various manufacturing process have been researched using electrochemical methods. The dental implant fixture was selected with 5 steps by cleaning, surface treatment and sterilization with same size and screw structure; the 1st step-machined surface, 2nd step-cleaned by thinner and prosol solution, 3th step-surface treated by RBM (resorbable blasting media) method, 4th step-cleaned and dried, 5th step-sterilized by gamma-ray. The electrochemical behavior of dental implant fixture has been evaluated by using potentiostat (EG&G Co, 2273A) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The corrosion surface was observed using field-emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDS). The step 5 sample showed the cleaner and rougher surface than step 3 sample. The step 5 sample of implant fixture treated by RBM and gamma sterilization showed the low corrosion current density compared to others. Especially, the step 3 sample of implant fixture treated by RBM was presented the lowest value of corrosion resistance and the highest value of corrosion current density. The step 3 sample showed the low value of polarization resistance compared to other samples. In conclusion, the implant fixture treated with RBM and gamma sterilization has the higher corrosion resistance, and corrosion resistance depends on the step of manufacturing process.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.157-163
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• 2006

There are big differences in six sigma applications between manufacturing processes and transactional processes. This paper analyzes the differences between two areas by examining 18 six sigma case studies in Korean companies. To characterize six sigma cases, a step-by-step checklist is developed based on 12-step DMAIC methodology proposed by US six sigma academy. On the basis of those characterized data, the differences between two areas are analyzed. The most significant differences is that statistical tools are widely used in manufacturing processes, but qualitative tools are used in transactional processes during improvement phase.