• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.197-206
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• 2000

A boundary integral equation method in the shape design sensitivity analysis is developed for the elasticity problems with axisymmetric non-homogeneous bodies. Functionals involving displacements and tractions at the zonal interface are considered. Sensitivity formula in terms of the interface shape variation is then derived by taking derivative of the boundary integral identity. Adjoint problem is defined such that displacement and traction discontinuity is imposed at the interface. Analytic example for a compound cylinder is taken to show the validity of the derived sensitivity formula. In the numerical implementation, solutions at the interface for the primal and adjoint system are used for the sensitivity. While the BEM is a natural tool for the solution, more generalization should be made since it should handle the jump conditions at the interface. Accuracy of the sensitivity is evaluated numerically by the same compound cylinder problem. The endosseous implant-bone interface problem is considered next as a practical application, in which the stress value is of great importance for successful osseointegration at the interface. As a preliminary step, a simple model with tapered cylinder is considered in this paper. Numerical accuracy is shown to be excellent which promises that the method can be used as an efficient and reliable tool in the optimization procedure for the implant design. Though only the axisymmetric problem is considered here, the method can be applied to general elasticity problems having interface.

• Current Optics and Photonics
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• v.6 no.3
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• pp.270-281
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• 2022

Based on the transfer-matrix method (TMM), we report the characteristics of the interface states in one-dimensional (1D) composite structures consisting of two photonic crystals (PCs) composed of binary dielectrics A and B, with unit-cell configurations ABA (PC I) and BAB (PC II). The dependence of the interface states on the number of unit cells N and the boundary factor x are displayed. It is verified that the interface states are independent of N when the PC has inversion symmetry (x = 0.5). Besides, the composite structures support the formation of interface states independent of the PC symmetry, except that the positions of the interface states will be varied within the photonic band gaps. Moreover, the robustness of the interface states against nonuniformities is investigated by adding Gaussian noise to the layer thickness. In the case of inversion symmetry (x = 0.5) the most robust interface states are achieved, while for the other cases (x ≠ 0.5) interface states decay linearly with position inside the band gap. This work could shed light on the development of robust photonic devices.

• Journal of applied mathematics & informatics
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• v.32 no.5_6
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• pp.761-781
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• 2014

An exponentially accurate nonconforming spectral element method for elasticity systems with discontinuities in the coefficients and the flux across the interface is proposed in this paper. The method is least-squares spectral element method. The jump in the flux across the interface is incorporated (in appropriate Sobolev norm) in the functional to be minimized. The interface is resolved exactly using blending elements. The solution is obtained by the preconditioned conjugate gradient method. The numerical solution for different examples with discontinuous coefficients and non-homogeneous jump in the flux across the interface are presented to show the efficiency of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.513-519
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• 1989

Modeling of the network interface for MAP and its performance analysis is investigated in this study. The parameters for the network interface are selected and a special interest is concentrated on the parameters related to the performance of the network interface itself. A queueing model of the network interface is proposed and simulation is performed to validate the proposed model of the network interface.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.513-518
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• 1998

In Half Precast Concrete Method, such as composite slab and composite wall, Interface between half PC plate and cast-in-place concrete is occurred. And this interface endure lastly in-plane shear which is occurred by external force. Therefore, test was executed to study in-plane shear strength of interface between half PC plate and cast-in-place concrete. In this test, Experimental parameters are finishing condition of the interface, cohesion of concrete, existence and nonexistence of re-bar truss, and angle and direction of lattice of re-bar truss. Comparing and analyzing experimental results, conclusions are obtained as follows. (1) In-plane shear strength of wide interface in composite plate is more affected by the roughness of interface than re-bar truss. And cohesion of concrete contribute to increasing in-plane shear strength. Therefore it seems that the interface should be roughen and kept clean to improve in-plane shear strength. (2) It seems that shear friction equation in ACI code can be sagely available for design of in-plane shear of composite plate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.6
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• pp.443-453
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• 2009

The Rayleigh-Taylor instability, the bubble rising in both partially and fully filled containers and the droplet splash are simulated by an in-house solution code(PowerCFD), which are typical benchmark problems among multiphase flows with material interface due to density difference. The present method(code) employs an unstructured cell-centered method based on a conservative pressure-based finite-volume method with interface capturing method(CICSAM) in a volume of fluid(VOF) scheme for phase interface capturing. The present results are compared with other numerical solutions found in the literature. It is found that the present method simulates efficiently and accurately complex free surface flows such as multiphase flows with material interface due to both density difference and instability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1991.10a
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• pp.83-89
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• 1991

The partial discharge properties of interface layer in Mica-Epoxy composite, which has been mainly used for the coil insulating material of high voltage machinery, are different from those of resins due to the abnormal interface layer to be presented between inorganic material and resin. Accordingly, the study on discharge of interface in composite insulting system is strongly requsted for not only an increasing of insulating strength, but also the basical information of diagnosis system for high voltage equipment. As a result, it has been confirmed that the interface is an abnormal resin layer and the contact states at interface is depended upon the density of silane aqueous solution. Pulse frequency at abnormal interface shows a linear increasing with enlargement of discharge quantity. Whereas, in case of normal interface, pulse frequency property represents exponential increasing at the point of saturating. A life model can be diagramed from results of time dependance of skewness, and a survival life time can be quantified from the life model suggested.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.2
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• pp.113-122
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• 2014

The objective of the paper is to clarify a methodology based on the use of the existing component mode synthesis methods for the case of two damped substructures which are coupled through a linking viscoelastic flexible substructure and for which the structural modes with free geometrical interface are used for each main substructure. The proposed methodology corresponds to a convenient alternative to the direct use either of the Craig-Bampton method applied to the three substructures (using the fixed geometric interface modes) or of the flexibility residual approaches initiated by MacNeal (using the free geometric interface modes). In opposite to a geometrical interface which is a topological interface on which there is a direct linkage between the degrees of freedom of substructures, we consider a physical flexible interface which exists in certain present technologies and for which the general framework linear viscoelasticity is used and yields a frequency-dependent damping and stiffness matrices of the physical flexible interface.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.11-23
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• 2011

In this study, a finite element(FE) analysis on electro-mechanical impedance response of cable-anchor connection interface under various anchor force is presented. In order to achieve the objective, the following approaches are implemented. Firstly, an interface washer coupled with piezoelectric(PZT) material is designed for monitoring cable-force loss. The interface washer is a small aluminum plate on which a PZT patch is surface-bonded. Cable-force loss could be monitored by installing the interface washer between the anchor plate and the anchorage of cable-anchor connection and examining the changes of impedance of the interface washer. Secondly, a FE model for cable-anchor connection is established to examine the effect of cable-force on impedance response of interface washer. Also, the effects of geometrical and material properties of the interface washer on impedance responses under various cable-forces are investigated. Finally, validation of the FE analysis is experimentally evaluated by a lab-scale cable-anchor connection.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1037-1040
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• 1999

In this paper, we designed the extended ATA(AT Attachment interface with extension) interface that combines with goods price and ability and intellectual behavior of SCSI, for make progress the ability and structure of ordinary interface for connect with device of using PC. ATA is establish a standard of IDE(Intelligent Drive Electronics) public in small form factor. SCSI bus is device behaving intellectual and have stable hardware structure, calssified instructions structure. But it is device that difficult to buy, because of price of more than two times. The other side, ATA device is worse than SCSI bus in part of ability, but it came to SCSI in part of speed after improve and it's price is less expensive. another improvement of ATA is a standard of ARAP(AT Attachment Packet Interface) and use method of packet transmission and behaves as if SCSI use a method. Finally, improvement of ATAPI behave from interface of only HDD to ability of ordinary interface. This paper propose the structure of extended interface that satisfied the price and ability.