• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.183-186
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• 2007

The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. Therefore, in order to control temperature of the molds actively and improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

• Wind and Structures
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• v.4 no.5
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• pp.367-382
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• 2001

Wind tunnel tests were conducted on a model of deck section from the Ting Kau cable stayed bridge. The purpose of the tests was to determine the set of aerodynamic derivatives conventionally used to describe the motion-induced forces arising from the wind flow, and to investigate the stability of the deck under different conditions of turbulence and angle of attack. The study shows that except for large negative angles of attack the deck section itself is stable up to a high wind speed, and that when instability does occur it is essentially a single degree of freedom (torsional) flutter.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2301-2304
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• 2002

IT 산업의 발달로 조직의 자동화된 업무 흐름인 워크플로우에 대한 관심과 연구가 활발해지고 있다. 본 논문에서는 워크플로우 설계시 자주 사용되는 기본 구조를 개념적 설계와 수학적 해석이 가능한 EMFG(Extended Mark Flow Graph)로 표현하고 이를 이용하여 워크플로우를 모델링한다. 모델링된 EMFG로 도달가능트리를 구현하여 워크플로우의 수행완료 가능성과 논리적 오류의 존재 여부를 검증한다. 또한 논리적 오류가 발생할 경우에 이를 제거하는 방법을 제안하고 이를 통해 워크플로우의 정형적 설계와 동적 분석을 가능하게 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2219-2222
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• 2002

웹사이트의 활용가치가 높아지고 사용자의 요구가 다양해짐으로 인해 웹사이트의 규모가 방대해지고 구조가 복잡해져서 웹사이트 설계에 많은 어려움이 있다. 이에 개념적이고 직관적인 설계가 가능한 EMFG(Extended Mark Flow Graph)를 이용하여 웹사이트를 표현하였다. 웹사이트의 EMFG 표현을 통해서 웹사이트의 전체적인 흐름과 페이지간의 세부적인 연결 관계를 파악할 수 있게 한다.

• Transactions of Materials Processing
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• v.17 no.5
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• pp.337-342
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• 2008

The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. In order to actively control temperature of the molds and effectively improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.266-269
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• 2008

Urban is more intelligent continuously with the help of the convergence with IT technology. And it requires an integrated control system, which can manage urban facilities or monitor large-scale events based on GIS data, to provide its citizen with various ubiquitous services such as u-Health, u-Traffic, context-awareness etc. In order to realize the intelligent city geo-sensors that have the functionalities of generic sensing as well as location awareness will be established everywhere in the near future. Our system we presented have a rule engine to handle a atomic event as well as complex events that contain control flow or branch among them. And it can allow for visualization and monitoring the results through KML (Keyhole Mark-up Language) in the Google Maps. This paper describes au-GIS event processing system that can deal effectively with u-GIS events coming from various geo-sensor data in ubiquitous computing environments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.221-221
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• 2004

플라스틱의 사출성형중 용용 수지에 가스를 주입하는 가스사출성형(Gas Assisted Injection Molding GAIM)에 의해 성형품을 만드는 생산방법은 약 30년 전부터 유럽지역을 중심으로 시작되었다 GAIN의 개발 배경은 발포성형을 대체하기 위한 공법으로 개발되었다. 발포성형은 싱크마크(sink mark) 제거, 치수안정성, 강도보강의 목적으로 사용하는 공법이지만, 가스기포가 표면으로 빠져나오고 표면에 가스 기포가 발생하여 외관부품에 부적당하며, 두께가 5-6mm이하의 성형품에는 적용할 수 없고, 성형시간이 긴 문제점을 가지고 있어 이러한 문제를 보강한 공법을 연구할 결과로 GAIM이 탄생하게 되었다.(중략)

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.40-43
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• 2015

A hybrid mesh based finite volume compressible flow code (PolySim) has been developed recently. Instead of the simple average method for the gradients of variables at each face, the volume average is applied for the calculation of the viscous flux. What is more, an improved Green Gauss method for the calculation of the gradient is also presented. These two techniques will improve both the accuracy and robustness of the code. The aerodynamic performance of this in-house cell centered code is examined by several widely-used bench-mark test cases. These cases include flows over flat plate and RAE 2822 etc. The comparisons on results between calculation and experiment are conducted. They show that the code can produce good numerical results which agree well with the corresponding experiment data.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.31 no.10
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• pp.109-115
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• 1982

Reactor dynamics were studied by reactor noise at TRIGA MARK Il reactor whose rated power is 250KW thermal. The power spectral densities(PSD) of the noise were measured by stochastic method with high resolution digital filters and Fast Fourier Transformers. The transfer function of the reactor at zero power was identical to the theoretical characteristics. When the power was increasec above 1KW, reactor showed its poswer resonances at 3Hz and 10 Hz. It was analyzed that 3Hz peak was generated by heat transfer and coolant flow effects and 10Hz peak by nuclear reaction effects.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1725-1728
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• 2003

인터넷의 보급 확산과 정보통신기술 및 웹 기술의 발달로 쇼핑몰 사이트가 등장하게 되었다. 현재 쇼핑몰 사이트는 그 종류가 다양해지고, 규모가 대형화되고 있으며, 매출규모 또한 증가하고 있는 추세이다. 이러한 많은 쇼핑몰 사이트들은 매출경쟁에서 자사의 수익창출을 위해 끈임없이 노력하고 있고 특히, 고객이 편리하게 쇼핑을 할 수 있도록 원활한 페이지 이동을 지원하고 있다. 고객의 쇼핑과정에 영향을 미치는 페이지 이동을 기존의 웹사이트 설계기법인 플로우차트, 스토리보드, 사이트 맵으로 표현하기에는 미흡한 점이 있다. 따라서 본 논문에서는 개념적이고 직관적인 설계가 가능한 EMFG(Extended Mark Flow Graph)[6]를 이용하여 쇼핑몰 사이트에서 웹 페이지간의 이동흐름을 나타내는 링크구조를 표현하고 분석 한다.