• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.37-42
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• 2009

The performance of an OLED(organic luminescent emitting device) fabrication system strongly depends on the design of the evaporation cell-source. Trends in display sizes have hauled the enlargement of mother glass substrates. The enlargement of substrates requires the improvement and the enlargement of the effusion cell-source for OLED evaporation process. The deposited layers should be as uniform as possible, and therefore it is important to know the effusion profile of the molecules emitted from the cell-source. Conventional 2D DSMC algorithm cannot be used for simulating the new concept cell-source design, such as a linear source. This work concerns the development of 3D DSMC (direct simulation Monte Carlo) analysis for simulating the behavior of the evaporation cell-sources. In this paper, the 3D DSMC algorithm was developed and the film thickness profiles were obtained by the numerical analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.197-199
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• 2006

The Proton Exchange Membrane Fuel Cells (PEMFCs) are being used in a variety of applications including portable power generation, transportation and back-up power systems. In this paper presents a novel circuit model for a PEMFC that can be used to design and analyze fuel-cell power system. The Pspice-based model uses BJTs, L and C elements available in the Pspice library with some modification. The model includes the phenomena like activation polarization, ohmic polarization and mass transport effect present in a PEM fuel cell. Simulated characteristics of the fuel cell were compared with the experimental results obtained on a commercial fuel cell.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.85-94
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• 1999

Reconfiguration, expansion, or new establishment of FMS requires the availability of a shop floor control (SFC) system relevant to the FMS since it is closely related with the hardware component of FMS. Due to the expensive cost of its development, significant research efforts have been made to develop an SFC system that is reusable. This paper presents Abstract Machine Tool (AMT) approach applied to develop an SFC sytem that is reusable without additional programming. The AMT model enables us to design the SFC system independently of the hardware-dependent attributes of euqipment; an AMT models a workstation by abstraction and presents an equipment-independent interface to machining cell controller. Specifically, we describe how we formalize the interfaces among equipment in order to build an AMT and how we design the machining cell control software based on AMT models. We also present MACHINIST the machining cell control system for IAE-FMS plant as an implementation example.

• 한국산학기술학회논문지
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• 제6권5호
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• pp.396-400
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• 2005

소규모 독립형 태양광발전시스템의 안정적인 설계를 위해서는 태양전지와 배터리 용량이 매우 중요한 요소이다. 태양전지 및 배터리의 용량산정이 잘못되면 시스템의 동작이 불안정해지고 잦은 고장의 원인이 된다. 따라서 본 논문에서는 안정적인 태양광발전시스템의 설계를 위해 부하특성을 고려한 태양전지와 배터리 용량산정 방안을 제시하였다.

• 한국강구조학회 논문집
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• 제9권2호통권31호
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• pp.249-257
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• 1997

본 연구에서는 호안의 안벽 및 방파제의 조성에 있어 기존의 타공법에 비해 경제성, 공사기간 및 시공장비 측면에서 유리한 거치식 강판셀 공법의 설계 기법 및 구조적 건전성 확보를 위해 실시한 실험 연구 결과를 제시하였다. 강판셀 구조는 다수의 보강재와 셀-아크 연결부 등이 존재하는 얇은 쉘 구조로서 그 거동이 복잡할 뿐만 아니라 설계 기준에서 셀 및 아크 내부의 속채움 토압의 크기가 다소 모호하게 규정되어 있다. 이러한 문제의 해결을 위해 실규모의 원통형 단면벽 강판셀 구조$(D11.0^m{\times}H14.0^m{\times}12t)$를 설계 제작하여 해상에 거치하고 속채움을 한 후 현장 응력계측을 수행하였으며, 그 결과를 상세 구조해석 결과와 비교 분석함으로써 당 공법의 설계 기술을 구축하고자 하였다.

• 전력전자학회논문지
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• 제17권6호
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• pp.553-561
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• 2012

Existing energy sources convert chemical energy into mechanical energy, while fuel cell directly generates electricity through an electrochemical reaction between hydrogen and oxygen. Therefore, it has a lot of strong points such as high efficiency, zero emission, and etc. In addition, with the development of hydrogen preservation technique, some companies have been researching and releasing portable fuel cell power packs for specific applications like military equipment, automobile, and so on. However, there are some drawbacks to the fuel cell, high cost and slow dynamic response. In order to compensate these weak points, auxiliary energy storages could be applied to the fuel cell system. In this paper, the optimum structure for a 150W portable fuel cell power pack with a battery pack is selected considering the specification of the system, and the design process of main parts is described in detail. Here, main objectives are compact size, simple control, high efficiency, and low cost. Then, an automatic mode change algorithm, which converts the operating mode depending on the states of fuel cell stack, battery pack, and load, is introduced. Finally, performance of the designed prototype using the automatic mode change control is verified through experiments.

• 한국수소및신에너지학회논문집
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• 제14권1호
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• pp.35-45
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• 2003

Polymer electrolyte fuel cells(PEFC) have been considered to be a suitable candidate for residential, portable and mobile applications, due to their high efficiency and power density, even at low operating temperature. KIER developed a 5kW class PEFC system for residential application and operated the system for over 1,000 hours. To develop a 5kW PEFC system, performance of a cell was improved through successive tests of single cell of small and large area. Fabrication of three 2,5 kW class stacks, design and fabrication of natural gas reformer, design of auxiliary equipments such as DC/DC converter, DC/AC inverter and humidifying units were carried out along with integration of components, operation and evaluation of total system. During the development period from 1999 to 2001, MEA(membrane electrode assembly) fabrication technologies, design and fabrication technologies for separators, stacking technologies and so on were developed, thereby providing basis for developing stacks of higher efficiency and power density in the future. Experience of development of natural gas reformer opened possibilities to use various kinds of fuels. Main results obtained from the development of a 5kW class PEFC system for residential application are summarized.

• ETRI Journal
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• 제42권1호
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• pp.129-137
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• 2020

All-solid-state batteries are promising energy storage devices in which high-energy-density and superior safety can be obtained by efficient cell design and the use of nonflammable solid electrolytes, respectively. This paper presents a systematic study of experimental factors that affect the electrochemical performance of all-solid-state batteries. The morphological changes in composite electrodes fabricated using different mixing speeds are carefully observed, and the corresponding electrochemical performances are evaluated in symmetric cell and half-cell configurations. We also investigate the effect of the composite electrode thickness at different charge/discharge rates for the realization of all-solid-state batteries with high-energy-density. The results of this investigation confirm a consistent relationship between the cell capacity and the ionic resistance within the composite electrodes. Finally, a concentration-gradient composite electrode design is presented for enhanced power density in thick composite electrodes; it provides a promising route to improving the cell performance simply by composite electrode design.

• 대한전자공학회논문지SD
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• 제43권11호
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• pp.69-76
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• 2006

본 논문에서는 생명체의 구조를 모방하여, 다중고장에 대한 효율적인 자가치유시스템 구조를 제안한다. 기존의 자가치유시스템은 인공 셀의 데이터의 패스가 좌우상하로만 가능하여 열 단위 치유만이 가능했다. 또한, 인공 셀의 게놈블록의 설계에 있어서, gene정보 저장방식을 이용함으로써 하드웨어 오버헤드가 큰 문제점이 있다. 본 논문에서는 인공 셀의 데이터의 패스를 대각선으로도 가능하게 설계하여, 열 단위가 아닌 셀 단위로 고장 셀의 용이한 대체가 가능하고 다중고장에 대해서도 효율적으로 자가치유가 가능하다. 또한, 게놈블록은 로직기반 생성방식을 이용하여 설계함으로써 저면적 설계가 가능하다. 2진 up/down 카운터를 예제로 하여 설계한 결과 하드웨어 오버 헤드를 약 40.3% 개선했다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.357-362
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• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. In this thesis, dynamic characteristics of the steel can labeling machine on the automatic cell assembly line are studied. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed for each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Therefore, Virtual Engineering of the steel can labeling machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.