• Transactions of Materials Processing
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• v.21 no.8
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• pp.499-505
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• 2012

The fuel cell is a very promising power generation system combining the benefits of extremely low emissions, high efficiency, ease of maintenance and durability. In order to promote the commercialization of fuel cells, a flexible forming process, in which a hyper-elastic rubber is adopted as a medium to transmit forming pressure, is suggested as an efficient and cost effective manufacturing method for fuel cell bipolar plates. In this study, the ability of this flexible forming process to produce the micro channel arrays on metallic bipolar plates was first demonstrated experimentally. Then, a finite element (FE) model was built and validated through comparisons between simulated and experimental results. The effects of key process parameters on the forming performance such as applied load and punch velocity were investigated. As a result, appropriate process parameter values allowing high dimensional accuracy without failure were suggested.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.23-23
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• 1993

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.273-274
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• 2010

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.315-318
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• 1996

The machine-part cell formation means the grouping of similar parts and similar machines into families in order to minimize bottleneck machines, bottleneck parts, and inter-cell part movements in cellular manufacturing systems and flexible manufacturing systems. The cell formation problem is knows as a kind of NP complete problems. This paper briefly introduces the cell-formation problem and proposes a cell formation method based on the Kohonen's self-organizing feature map which is a neural network model. It also shows some experiment results using the proposed method. The proposed method can be easily applied to the cell formation problem compared to other meta-heuristic based methods. In addition, it can be used to solve large-scale cell formation problems.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.84-89
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• 2004

The machine cell formation problem is the problem to group machines into machine families and parts into part families so as to minimize bottleneck machines, exceptional parts, and inter-cell part movements in cellular manufacturing systems and flexible manufacturing systems. This paper proposes a new machine cell formation method based on the adaptive Hamming net which is a kind of neural network model. To show the applicability of the proposed method, it presents some experiment results and compares the method with other cell formation methods. From the experiments, we observed that the proposed method could produce good cells for the machine cell formation problem.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.20-31
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• 1994

FMS(Flesible Manufacturing System), FMX(Flexible Manufacturing Cell)와 같은 유연 생산시스템 뿐만 아니고 공장자동화(FA)의 최하위 단위인 절삭가공 공작기계에 대한 무인화의 실현은 머지않은 장래에 완성될 IMS(Intelligent Manufacturing System)시스템이 구축에 있어서 최대의 걸림돌이 되고 있다. 전통적인 생산시스템에서는 경험을 가진 작업자에 의해 절삭공정이 감시되어지며, 만약 이상이 발생했을 때에는 그 상태에 따른 적절한 조치를 즉시 취할 수 있었다. 그러나 급속도로 연구가 진행되는 무인생산 시스템에서는 이러한 작업자의 역할이 컴퓨터에 의한 자동적인 감시 및 제어 시스템으로 대체되어야 한다. 이러한감시활동 중에서도 공구마모 및 파단의 검출은 효율적인 공구교환정책, 가공물의 품위유지 및 공구와 공작기계의 보호를 위해서 가장 중요한 부분으로 취급되고 있다.

• 연구논문집
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• s.26
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• pp.57-68
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• 1996

Recently, a lot of researches on material handling system are actively studied for realization of FA(Factory Automation), FMS(Flexible Manufacturing System) and CIM(Computer Integrated Manufacturing). Management and application of material handling system are precondition technologies playing an important part in integration of production system including manufacturing. assemhly, and inspection cell. In this paper, the general situation of automation technology is investigated and technology level is analyzed in comparision with an advanced country. And the operation trend and part of material handling system including AS/RS, AGV, and Conveyor, are studied. And also technologies related to material handling system in the inside and outside of the country are studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.506-511
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• 1996

The performance evaluation of flexible manufacturing systems or cells at the stages of design and planning is one of important issues in manufacturing. For that reason, Guo has presented an approachbased on moment generating function and generalized stochastic PetriNets for performance analysis. In this paper, Buo's approach is extended tothe cases of flexible manufacturing cell including one machining center with a local buffer, AS/RS(Automatic Storage and Retrieval System), set-up station and AGV(Automated Guided Vehicle). Then the performance measures from this approach is compared with simulation. The major advantage ofthis method over existing performance evaluation methods is the ability to compute analytic solutions for performance measures.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.39-42
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• 1995

A new methodology for representing the interaction between machines and the interlock signals required in FMCs has been developed. Object-Oriented Philosophies (OOPs) lend themselves to the development of such a scheme. A methodology developed here regards the tasks to be performed by the cell or any of its constituent machines for being primal. Sensory signals indicating the changes of state pf machines are used to trigger or initiate tasks. A task may be simple and require a relatively short time to execute, or may be complex and lengthy. This methodology may be depicated by a set of diagrams called Task Initiation Diagram (TID) and their accompanying rules.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.03a
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• pp.74-77
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• 1998

This paper presents a real design and implementation of an intelligent client-server equipment controller in computer-integrated manufacturing systems. An automated manufacturing process is commonly controlled by a number of PLC (Programmable Logic Controllers), which are attached to various equipments. A manufacturing cell consists of a set of equipments or workstation, which are also controlled by equipment or cell controller. We propose an intelligent equipment controller which has two function: one is to request (collect) an important information from each equipment and the other is to send the collected equipment information to the upper level controller (shop floor controller). Two-phase approaches are considered for the development of equipment client-server controller. The first events are generated virtually using computer simulation. Using the virtually generated activities, operating software of equipment server is developed. The second phase is to embed the virtually developed software (controller) into a real manufacturing system. The proposed methodology might be a novel design and implementation of a virtual simulator, which could be used for developing an intelligent equipment server.