• 한국전산유체공학회:학술대회논문집
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• 1995.10a
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• pp.175-181
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• 1995

Three-Dimensional Euler equations are solved numerically for the analysis of contraction flows in wind or water tunnels. A second-order finite difference method is used for the spatial discretization on the nonstaggered grid system and the 4-stage Runge-Kutta scheme for the numerical integration in time. In order to speed up the convergence, the local time stepping and the implicit residual-averaging schemes are introduced. The pressure field is obtained by solving the pressure-Poisson equation with the Neumann boundary condition. For the evaluation of the present Euler solver, numerical computations are carried out for the various contraction geometries, one of which was adopted in the Large Cavitation Channel for the U.S. Navy. The comparison of the computational results with the available experimental data shows good agreements.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.8-12
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• 1997

The three-dimensional Euler equations are solved numerically for the analysis of contraction flows in wind or water tunnels. A second-order finite difference method is used for the spatial discretization on the nonstaggered grid system and the 4-stage Runge-Kutta scheme for the numerical integration in time. In order to speed up the convergence, the local time stepping and the implicit residual-averaging schemes are introduced. The pressure field is obtained by solving the pressure-Poisson equation with the Neumann boundary condition. For the evaluation of the present Euler solver, numerical computations are carried out for three contraction geometries, one of which was adopted in the Large Cavitation Channel for the U.S. Navy. The comparison of the computational results with the available experimental data shows good agreement.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.13-20
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• 1997

A fundamental study for the numerical scheme to simulate unsteady nonlinear waves by solving Euler equations is presented. First a conservation form and a non-conservation form of the Euler equations with a free surface fitted coordinate system are compared. Next, a time splitting fractional step method and an alternating direction implicit(ADI) method for the time integration are compared. For the comparative study, flow calculations around a bottom bump in a channel and a NACA 0012 hydrofoil in a flume are performed. The results show that the ADI method with a third order upwind differencing scheme is very efficient in reducing the computing time with keeping the accuracy, And, there is no distinct difference between two expression forms except that the non-conservative form shows faster wave propagating velocity than the conservation form. Some results are compared with experiments and show good agreement.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.82-93
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• 2004

The objective of this study is to lead balanced development of tourism industry by proving the nature of customer service which is one of the service characters as well as ultimate goal of tourism industry. This paper contains a few case studies of service industry customer service and proposed desirable development plan. This study tried differentiate customer service from management side in its role. Meanwhile, management and tourism industry integration, partly in the service channel, is a task to be studied continuously in terms of customer satisfaction. Customer service should utilize for social welfare and improving the firm's competitiveness in the tourism industry

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.387.1-387.1
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• 2014

A new class of temperature-sensing materials is demonstrated along with their integration into transparent and flexible field-effect transistor (FET) temperature sensors with high thermal responsivity, stability, and reproducibility. The novelty of this particular type of temperature sensor is the incorporation of an R-GO/P(VDF-TrFE) nanocomposite channel as a sensing layer that is highly responsive to temperature, and is optically transparent and mechanically flexible. Furthermore, the nanocomposite sensing layer is easily coated onto flexible substrates for the fabrication of transparent and flexible FETs using a simple spin-coating method. The transparent and flexible nanocomposite FETs are capable of detecting an extremely small temperature change as small as $0.1^{\circ}C$ and are highly responsive to human body temperature. Temperature responsivity and optical transmittance of transparent nanocomposite FETs were adjustable and tuneable by changing the thickness and R-GO concentration of the nanocomposite.

• Water for future
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• v.18 no.1
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• pp.67-73
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• 1985

Tidal propagation in the Keum River has been routinely handled by numerical integration of the long fravity wave equation by Dronkers. The dynamic equations include non-linear terms thereby reproducing the shallow water tides. The model was used to compute tidal distribution of the Kum River for aveage spring, mean, neap tidal conditions and further utilised to investigate the waterlevel response within tidal reaches by combined tide and flood discharge effects. The objective of this initial study is to investigate the tidal dynamics of the lower reaches of the Keum River under the condition of before-cross-channel barrage construction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.591-592
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• 2006

We studied about the manufacture of the drain-source contacts for OTFTs(organic thin-film transistors) by using screen printing method. The conductive fillers used Ag and carbon black. The conductive contacts with $100{\mu}m$ of channel length were screen printed on a silicon dioxide gate dielectric layer and, the pentacene semiconductor was deposited via vacuum deposition. As a result of studying various conductive pastes, we could obtain the OTFTs which exhibited field-effect behavior over arrange of drain-source and gate voltages, similar to devices employing deposited Au contacts. By using screen-printing with conductive paste, the contacts are processed at low temperature, thereby facilitating their integration with heat sensitive substrates.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.3
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• pp.70-77
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• 2009

We proposed the method of avionics integrated architecture using high-speed fiber optic bus. Typically, data bus of aircraft consists of electronic and optic data transmission method. Avionics systems are difficult to operate the electronic data transmission method for the high speed data processing, synchronization and interconnection between flight control system and flight management system efficiently. In this paper, it is known to look into the problem of data bus and the advanced trend in avionics systems, and propose the appropriate data bus of the advanced avionics systems.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.595-611
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• 2005

The objective of this study is to lead balanced development of tourism industry by proving the nature of customer service which is one of the service characters as well as ultimate goal of tourism industry. This paper contains a few case studies of service industry customer service and proposed desirable development plan. This study tried differentiate customer service from management side in its role. Meanwhile, management and tourism industry integration, partly in the service channel, is a task to be studied continuously in terms of customer satisfaction. Customer service should utilize for social welfare and improving the firm's competitiveness in the tourism industry.

• 한국IT서비스학회:학술대회논문집
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• 2003.05a
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• pp.117-123
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• 2003

인터넷 접속채널과 접속망이 다양해지고 채널활용이 다차원적으로 가능함에 따라 유무선의 다중 채널통합에 대한 관심이 고조되고 있다. 이는 유무선 인터넷 채널통합에 관한 방향이 필요하며, 유선과 무선인터넷의 채널통합 이슈에 대한 분석이 필요한 시점이라 할 수 있다. 본 연구에서는 유무선 인터넷 채널통합과 관련된 문제점 및 이슈를 분류하였으며, 유무선 채널통합을 크게 Interface 통합관점과Business Model 간의 통합관점으로 살펴보았다. 인터페이스 관점에서는 디스플레이, 입출력장치, 컨텐츠로 구분하여 채널통합 문제를 유형별로 분류하였다. 그리고 비즈니스 모델 관점에서는 무선인터넷 서비스 유형 및 특성을 분석하여 비즈니스의 채널통합 방향성을 제시하였다.