• 반도체디스플레이기술학회지
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• 제14권1호
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• pp.19-25
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• 2015

Strengthened glass is widely used in the display industry for the smart phone and the tablet PC's, the market of which shows steady growth. The strengthened glass is prone to the fracture due to the machined surface defects such as crack and notch. The surface defects are caused mostly by the vibrations of the laser cutter. In this study, the vibrations of the laser cutter were investigated through the frequency response experiment and the computer simulation. The main reasons of the structural vibrations were analyzed, and further the design alterations were deduced and applied to the machine to check the effects of those alterations and to eventually improve the structural stability. The result shows that simple design modifications without major structural change can substantially suppress the vibrations, and improve the quality of the machined surface.

• 산업공학
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• 제15권2호
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• pp.152-158
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• 2002

The explosive growth of the internet traffic in the last few years has imposed tremendous stress on today's routers, particularly in the core network. Recently, ATM LSRs(Label Switching Router) are potentially capable of providing the highest forwarding capacity in the backbone Internet network. VC merging is a mechanism in an ATM LSR that allows many IP routes to be mapped to the same VC label, and provides a scalable mapping method that can support thousands of destinations. VC merging requires reassembly buffers so that cells belonging to different packets intended for the same destination do not interleave with each other. In this study, we propose an architecture of the ATM LSR which supports VC merging. We propose traffic control scheme called APD(Active Packet Discard) algorithm so that predicts and controls the congestion of the Internet traffic effectively. We study the performance of this algorithm using simulation.

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.295-303
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• 2009

Forging of square spline was investigated by using finite element methods in this study. Spline is widely used by torque transmitter in the fields of automobile, aircraft, and shipping etc. Friction on the surface of die is regarded as the most important factor to improve the dimensional accuracy for complete forming of spline teeth. Finite element simulation was carried out to improve the formability of the spline, especially remove unnecessary burrs which were extruded in gap between the die and the punch. To remove the burrs, various friction factors are considered on the surfaces of the die in the simulations and punch flat surface was designed. The simulated results were compared with experimental ones. As a results, it is possible to control the growth of burrs and improve formability of spline teeth by applying various friction factors and design of punch flat surface.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.370-373
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• 2000

In this work, an extractive membrane bioreactor containing coulture broth of Burkholderia cepacia G4 PR1 constitutively expressing the TCE-degrading enzyme, tolune-ortho-monooxygenase(TOM), was used for the degradation of TCE. The membrane bioreactor operates by seperating the TCE-containing waste gas from the aerated biomedium, by which the air-stripping of TCE without degradation was overcome that could occur in conventional aerobic biological treatments of TCE-contaminated waste gases. This was achieved by a silicone rubber membrane which was coiled around a perspex draft tube. TCE from the gas phase diffuses across the silicone rubber membrane into microbial culture broth that was continuously fed from a separate aerobic CSTR. Therefore, TCE degradation occured without the TCE being directly exposed to the aerating gas stream. Of the TCE supplied to the membrane bioreactor, 72.6% was biodegraded during the operation of this system. To construct a mathematical model for this system, parameters describing microbial growth kinetics on TCE were determined using a CSTR bioreactor. Else parameters used for numerical simulation were determined from either indepedent experiments or values reported in the literature. The model was compared with the experimental data, and there was a good agreement between the predicted and the measured TCE concentrations in the system. To achieve a higher treatment efficiency, various operating conditions were simulated as well.

• KSBB Journal
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• 제13권3호
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• pp.259-267
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• 1998

Optimal feeding strategies in bioreactor operation of Scutellaria baicalensis G. plant cell culture were investigated to maximize the production of flavone glycosides by using a structured kinetic model which can predict culture growth and flavone glycosides synthesis in a rigorous, quantitative manner. For the production of baicalin and wogonin-7-0-GA, the strategies for glucose feeding into Scutellaria baicalensis G. plant cell culture were proposed based on the model, which are a periodic fed-batch operation with maintenance of cell viability and of specific production rate respectively, and a perfusion operation with maintenance of specific production rate for baicalin and wogonin-7-0-GA. Simulation results showed that the highest volumetric concentration of flavone glycosides was obtained in a periodic fed-batch operation with maintenance of cell viability among all the suggested strategies. In the periodic fed-batch operations, the higher volumetric production of flavone glycosides was achieved compared with that in the perfusion operation. It can be concluded that a periodic fed-batch operation with maintenance of cell viability would be the optimal and practical operating strategy of Scutellaris baicalensis G. plant cell culture for the production of flavone glycosides.

• 대한기계학회논문집
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• 제16권7호
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• pp.1266-1277
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• 1992

본 연구에서는 공구의 형상과 절삭조건에 따른 공구의 결손형태를 예측하기 위하여 현재 가장 널리 쓰이고 있는 인볼류우트커터의 결손형태를 절삭날의 응력분포 값으로 예측하고 실험에 의하여 검증함과 동시에 기어 절삭실험을 통한 공구 결손의 성장거동을 고찰하였으며, 또한 마멸과 결손이 발생함에 따른 절삭력의 변화와 평형을 관찰하여 상호관련성을 비교함으로써 인볼류우트 기어커터의 초기 결손을 해석적으로 예측하였다.

• 한국작물학회지
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• 제27권4호
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• pp.314-339
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• 1982

Fluctuating climate is still most important environmental constrain, although improved modem agricultural technology has succeeded to increase crop production in the world. To stabilize the food production under fluctuating weather conditions, it is very needed to obain the quantitative information of interactions between crops and climate. The main purpose of this paper is three hold. Using the JIBP-data, the dry matter accumulation of rice crops is studied in relation to weather indexes (\SigmaTa and \SigmaSt). Temperature dependence of the yield index of rice is analyzed as to air temperature and water temperature. \SigmaT$_{10}$ -fluctuations are studied using meteorological data at various stations. The possible shift of \SigmaT$_{10}$ -isopleths due to climate fluctuation is evaluated. The second interest is in the plant climate of rice crops. Using results of canopy photosynthesis, it is pointed that the canopy structure has most important implication in plant climate. Leaf-air, stomatal, and mesophyll resistances of rice crops are described in relation to weather conditions. The change in light condition and aerodynamical property of rice crops with the growth is illustrated. The energy partition is also studied at different growing stages. Third point is to show in more detail effective countermeasures against cold irrigation water and cool summer. Heat balance of warming pond and polyethylene tube as a heat exchanger is studied to make nomo-grams for evaluating the necessary area and necessary length. Effects of windbreak net on rice crops are illustrated by using experimental and simulation results.lts.

• 한국멀티미디어학회논문지
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• 제9권8호
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• pp.1086-1094
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• 2006

CT는 문화콘텐츠를 만들어내는데 직 간접적으로 활용되는 모든 관련 지식과 기술이다. 최근 문화콘텐츠 산업의 폭발적인 성장과 기술의 첨단화 추세에 따라 CT에 대한 수요가 급증하고 있다. 본 연구는 CT의 R & D 성과와 기술 확산 촉진을 위하여 개발 및 거래대상 기술의 가치평가 방법을 제시하고 시뮬레이션을 통해 그 가치를 추정하기 위한 것이다. 이를 위하여 CT의 분류와 특성을 기술하고, 학계 및 실무에서 개발한 기술 가치평가 방법을 고찰하여 CT기술 가치평가모델을 연구하였다.

• 정보처리학회논문지C
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• 제8C권1호
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• pp.41-50
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• 2001

최근에 인터넷은 시간이 가면 갈수록 실시간 멀티미디어 서비스를 망을 통해서 제공받기 원하고 있다. 이러한 실시간 서비스를 IPOA 환경에서 지원하기 위해 ATM 망에서 RSVP를 이용하고 IP계층에서는 이를 멀티캐스트 서비스로 제공하기 위해 기존의 MARS가 지원 예약 메시지를 처리하도록 그 기능을 확장하도록 함으로써 이질적인 수신자의 QoS를 보장하는 방식을 제안하였다. 또한 이를 직접 구현한, 간단한 시뮬레이션을 통해 확장된 MARS 서버의 성능을 분석하였다. 시뮬레이션 결과 이질적인 수신자들에게 IP 멀티캐스트 서비스를 제공하기 위하여 RSVP를 적용할 때에는 수신자의 규모와 QoS 변경 요청의 발생 빈도 등을 예측하였다. 이를 통해 망 자원의 불필요한 낭비와 서버의 처리 지연을 줄임으로써 서버의 효율적인 관리 및 이질적인 수산자들의 서비스 품질을 보장할 수 있음을 확인할 수 있었다.

• 한국게임학회 논문지
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• 제4권4호
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• pp.25-30
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• 2004

현재, 웹 기반 기술 및 네트워크 기술의 발달로 인해 실질적이고 다양한 서비스를 원하는 이용자들이 늘어나고 있다. 그중에서 게임을 포함하는 웹 및 모바일 컨텐츠 분야에 대한 관심은 급격히 증가하고 있다. 대부분의 컨텐츠들은 컨텐츠의 이용에 대한 결과로 포인트나 E-Money로 제공하고 있다. 하지만, 포인트 시스템은 포인트를 활용할 수 있는 컨텐츠나 관련 서비스가 부족한 실정이어서 유명무실하게 되었다. 이러한 문제를 해결하기 위하여, 본 논문에서 여러 컨텐츠에서 제공하고 있는 포인트 시스템을 통합하고 이러한 포인트를 이용하여 게임에 접목할 수 있는 시스템을 설계하였다. 설계한 시스템을 시뮬레이션하기 위하여 웹상에서 간단한 게임 및 기타 부가적인 컨텐츠 시스템을 제작하였다. 또한, 모바일 기기로 웹상에서 발생하는 결과를 전송받는 시스템도 구현하였다.