• Advances in aircraft and spacecraft science
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• v.4 no.6
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• pp.639-650
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• 2017

The objective of this paper is to obtain three-dimensional (3D) effective properties for layered composites with imperfect interfaces using mechanics of structure genome. The imperfect interface is modeled using linear traction-displacement model that allows small infinitesimal displacement jump across the interface. The predictions obtained from the current analysis are compared with the 3D finite element analysis (FEA). In this study, it is found that the present model shows excellent agreement with the results obtained using 3D FEA by employing periodic boundary conditions. The prediction also reveals that in-plane longitudinal and shear moduli, and all Poisson's ratios are observed to be not affected by the interfacial stiffness while the predictions of transverse longitudinal and shear moduli are significantly influenced by interfacial stiffness.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.72-76
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• 2003

This paper deals with the stress singularity developed in a polymer layer that is coated to a concrete surface, due to temperature change. The boundary element method is employed to investigate the behavior of interface stresses. The polymeric layer is assumed to be a linear viscoelastic material, and is thermorheologically simple. The order of the singularity is obtained, numerically, for a given viscoelastic model. Numerical results exhibit the relaxation of interface stresses, and large gradients are observed in the vicinity of the free surface. Results show that the stress singularity factor is relaxed with time, while the order of the singularity increases with time for the viscoelastic model.

• Interaction and multiscale mechanics
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• v.1 no.1
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• pp.53-81
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• 2008

The theory of microlocal analysis of hyperbolic partial differential equations shows that the energy density associated to their high-frequency solutions satisfies transport equations, or radiative transfer equations for randomly heterogeneous materials with correlation lengths comparable to the (small) wavelength. The main limitation to the existing developments is the consideration of boundary or interface conditions for the energy and power flow densities. This paper deals with the high-frequency transport regime in coupled heterogeneous structures. An analytical model for the derivation of high-frequency power flow reflection/transmission coefficients at a beam or a plate junction is proposed. These results may be used in subsequent computations to solve numerically the transport equations for coupled systems, including interface conditions. Applications of this research concern the prediction of the transient response of slender structures impacted by acoustic or mechanical shocks.

• Journal of Korea Multimedia Society
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• v.6 no.4
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• pp.650-657
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• 2003

We describe a scheme for developing character-based interface within the context of an agent-based tutoring system in the Web environment. The ideas in this paper stem from original work representing aspects of human emotion in tutoring computer models, where may provide mote natural ways for students to communicate with digital learning materials. The proposed system model is a set of software services that enable developers to incorporate interactive animated characters into their Web pages designed for on-line lectures. The prototypical application is developed and shown for validating the applicability and the effectiveness of this model in real tutoring settings.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.87-92
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• 2000

The real situation of an underground reinforced concrete(RC) structure with the surrounding soil medium subjected to seismic load is quite difficult to be simulated through an expensive work and, even if it is possible to arrange such an experiment, it will be too expensive. So development of analytical method can be applied usefully to seismic design and seismic retrofit through an analysis of seismic behavior and seismic performance evaluation. A path-dependent constitutive model for soil that can estimate the response of soil layer is indispensible for dealing with kinematic interaction of RC/soil entire system under seismic loads. And interface model which deals with the dynamic interaction of RC/soil entire system is also necessary. In this study, finite element analysis program that can consider path-dependent behavior of RC and soil, and interfacial behavior between RC and soil is developed for rational seismic analysis of RC/soil entire system. Using this program, nonlinear behavior of interface between RC and soil is analyzed, and the effect of interfacial behavior to entire system is investigated.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.7 no.1
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• pp.147-169
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• 1994

The study is to assist system developers or designers who are participated in the design of the user-computer interface on online services such as Online Public Access Catalogue and Online Search-ins. To design the optimal user interface, system developers and designers should try to complete the following process orderly: 1) they should know and understand the active and potential user's information seeking behaviors concerning online services in details as possible. 2) they should design the conceptional user model on basis of that knowledge. 3）They should design the logical and hierachical computer model adaptable to the current environment. 4) they should design the display of the computer terminal which is ease to learn and use by the users. 5) finally, they should design the optimal and practical user inter-face on basis of the above 2, 3, and 4.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.15-18
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• 2004

A numerical method for simulating two-phase flows including surface force is presented. The method is based on fractional step method of finite volume formulation and the interface is tracked with PLIC VOF method. In the CSF model, as color function, f, representing the location of interface varies steeply in the interface region, we need to use smoothed function f to get accurate unit normal and the curvature. Peskin kernel is used to get smoothed function f. A spherical drop in static equilibrium and three-dimensional merging of gas bubble are tested, resulting in the validation of this method

• Structural Engineering and Mechanics
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• v.34 no.6
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• pp.667-683
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• 2010

A mathematical model and its analytic solution for the analysis of stress-strain state of a linear elastic two-layer beam is presented. The model considers both slip and uplift at the interface. The solution is employed in assessing the effects of transverse and shear contact stiffnesses and the thickness of the interface layer on behaviour of nailed, two-layer timber beams. The analysis shows that the transverse contact stiffness and the thickness of the interface layer have only a minor influence on the stress-strain state in the beam and can safely be neglected in a serviceability limit state design.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.103-111
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• 2006

To optimize the ventilation and smoke control systems in subway equipped with platform screen door, the technology to analyze the unsteady tunnel flow caused by running of train should be developed. The development of model experiment and numerical analysis technique with relation to unsteady flow of subway were presented. The pressure and air velocity changes in 1/20-scaling experiment unit were measured and results were comparied to those of 3-D unsteady numerical analysis applied with sharp interface method. The experimental and numerical results were quantitatively similar and it would be reasonable to apply sharp interface method to analyze the unsteady flow in subway equipped with platform screen door.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.952-953
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• 2007

In the present study, we propose MC simulation that takes interface phenomena between liquid crystal and substrate into consideration. We use rigid model molecules of liquid crystal and substrate. Interface is generated using potential field that induces decomposition of molecules.