• 한국CDE학회논문집
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• 제13권4호
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• pp.243-254
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• 2008

As modular production becoming increasingly widespread in globalized manufacturing industries, sub modules or parts of the final product are being provided by many suppliers. Some part suppliers design their own products for themselves. In some cases, part suppliers provide the same type of product to multiple OEM companies. Because all part suppliers and OEM companies typically cannot use the same CAD system, engineering change in the CAD model of one company cannot be directly propagated to related CAD models of other companies. Even if two companies use the same CAD system, it may be difficult to share their CAD model owing to corporate security policy. In this paper, a neutral reference model that consists of a neutral skeleton model and an external reference data model is proposed as a new medium for the sharing and propagation of engineering change information among collaborating companies.

• 산업공학
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• 제15권3호
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• pp.218-229
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• 2002

This paper proposes how to develop the EC(Electronic Commerce) for industrial-related items, which has not been tried yet in EC areas. Usually industrial design derives an idea and concept for a new product from the needs of end-users and manufacturers. Then this product is developed through the design process such as idea-sketch, rendering, and design modeling mock-up. The purpose of this paper is to vitalize the trade for some items which are necessary for the design process and are intermediate products. That is, the idea and concept from the needs and seeds can be dealt with as one item. Furthermore, the idea-sketch and rendering materializing from the idea can be an item also. By doing so, excellent design items which could be thrown away in the middle of the process can be made into valuable commodities. Then we can specify the role of Designer, Manufacturer, and End-User as a buyer or a seller.

• 소성∙가공
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• 제10권6호
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• pp.456-464
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• 2001

Deep drawing and ironing are tile major process today in manufacturing of aluminum alloy battery case used in cellular phone. Most of these process require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of these processes are relatively less known. Thus, it is expected that process analysis using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product. A commercially available finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• 한국CDE학회논문집
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• 제1권2호
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• pp.87-96
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• 1996

IGES is a file format which has gained widespread use but has certain limitations such as limited information coverage and ambiguous definitions. In order to overcome the limitations of existing neutral file formats, STEP has been developed as a more comprehensive mechanism for product data exchange by ISO. This paper describes a file translation system between IGES and STEP. In this system, three EXPRESS schemata are defined for IGES, STEP and the translation relationship between IGES and STEP. Object codes are generated from the schemata and linked with file access libraries to IGES and STEP files. The translation was verified by visualization and reverse translation. The system developed in this study can easily applied to translate other file formats because the file structure and translation relationship are defined in EXPRESS - a high level information modeling language.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.155-158
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• 2004

In resin transfer molding, the preform similar to product shape is placed into a mold cavity. Rapid flow front without void formation is important for the composites processing. Multi-layered preform of sandwich is selected. Experiments is carried out using redial flow. An analytical modeling is performed and compared with experimental results. Accurate prediction of flow advance in the preform is of use for reducing the time consumption in the process and enhancing product properties of the final part.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1793-1799
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• 2006

생산자 폐기 책임 규제 강화로 인하여, 제조업 영역이 제품 제조(BOL) 뿐만 아니라 사용, 보수(MOL)와 폐기(EOL)까지 확장 수명주기로 확대 되고 있다. 또한 EOL상에서 개별 제품에 대한 제품 복원 관리 시스템 (PRMS: Product Recovery Management System)에 관한 연구가 활발히 진행 되고 있다. 그러나 BOL, MOL과 EOL간의 정보 단절 문제, MOL상의 정보를 저장하고 사용할 수 없었던 문제는 EOL관리의 자동화를 저해한 큰 요인이다. 최근 유비쿼터스 기술의 발달로 개별 제품 추적이 가능해 졌지만, EOC 등의 식별부호(ID)만으로는 PRMS에 필요한 제품 정보를 얻을 수 없다. 본 논문에서는 제품 ID로부터 MOL상의 정보를 연결하고, 국제표준 기반 정보모델을 이용하는 PRMS를 개발한다. 이를 위해: (1) PRMS에 필요한 정보를 국제표준(ISO10303-239 등)을 기반으로 모델링하고, (2) 제품 ID를 통해 MOL상의 정보를 수집하여 제품 복원에 대한 의사결정을 수행할 수 있는 PRMS를 설계하고, (3) 시제품 구현을 통해 제안된 데이터 모델 및 시스템의 유효성을 검증한다.

• 한국정밀공학회지
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• 제12권11호
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• pp.118-124
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• 1995

In the paper, we have proposed a new technique to determine the initial billet for the forged products using a function approximation in neural network. A three-layer neural network is used and a back propagation algorithm is employed to train the network. An optimal billet which satisfied the forming limitation, minimum of incomplete filling in the die cavity, load and energy as well as more uniform distribution of effective strain, is determined by applying the ability of function approximation of the neural network. The amount of incomplete filling in the die, load and forming energy as well as effective strain are measured by the rigid-plastic finite element method. This new technique is applied to find the optimal billet size for the axisymmetric rib-web product in hot forging. This would reduce the number of finite element simulation for determining the optimal billet of forging products, further it is usefully adopted to physical modeling for the forging design

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.146-151
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• 1992

A two-compartment four-cell model is developed for the adiabatic autoclave slim type reactor for free radical polymerization of low density polyethylene(LDPE). The mass and energy balances give rise to a set of ordinary differential equations, and by analyzing the system it is possible to predict properly not only the reactor performance but also the properties of polymer product. The steady state multiplicity is found to exist and examined by constructing the bifurcation diagram. The effects of various operation parameters on the reactor performance and polymer properties are investigated systematically to show that the temperature distribution plays the central role for the properties of polymer product. Therefore, it is essential to establish a good control strategy for the temperature in each compartment. In this study it is shown that the reactor system can be adoptively controlled by pole-placement algorithm with conventional PID controller. To accomplish a satisfactory control, the estimator and controller are initialized during the period of start-up.

• 소성∙가공
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• 제23권4호
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• pp.206-210
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• 2014

The metal lead frame, a semiconductor component, has product tolerances in micro units as compared to products made with a larger size mold. Therefore, small deflections of the mold and of the press as well as the press molding process itself have a strong influence on accuracy of the product. Hence, it is necessary for the process design to consider the structural response of the mold and the press during deformation. In the current study, the mold deflection and pressure on the punch is examined using the finite element modeling (FEM) program ABAQUS. The results from the simulation were verified with the dynamic deformation measurement equipment using digital image correlation (DIC).

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 제34차 추계 국제 학술대회
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• pp.407-411
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• 2004

Ohmic heating occurs when an electric current is passes through food, resulting in a temperature rise in the product due to the conversion of the electric energy into heat. The time spent in the thawing is critical for product sterility and quality. The objective of this study is to conduct numerical modelling between the effect of ohmic thawing intensity on PTT(phase transition time) at constant concentration and the effect of matrix concentrations on PTT at constant voltage condition. the stronger ohmic thawing intensity resulted in decreasing the PTT. High ohmic intensity causes short PTT. And the higher gelatin concentration, the faster increment of PTT. A numerical modeling was executed to predict the PTT influenced by the power intensity using exponential regression and the PTT influenced by gelatin concentration using logarithmic regression. Therefore, from this numerical model of gelatin matrix, it is possible to estimate exact values extensively.