• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.4
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• pp.163-170
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• 2023

In the fluid-structure interaction analysis, the finite element formulation is performed for the wave equation for dynamic fluid pressure, and the dynamic pressure is defined as a degree of freedom at the fluid nodes. Therefore, to connect the fluid to the structure, it is necessary to connect the degree of freedom of fluid dynamic pressure and the degree of freedom of structure displacement through an interface element derived from the relationship between dynamic pressure and displacement. The previously proposed fluid-structure interface elements use conformal finite element meshes in which the fluid and structure match. However, it is challenging to construct conformal meshes when complex models, such as water purification plants and wastewater treatment facilities, are models. Therefore, to increase modeling convenience, a method is required to model the fluid and structure domains by independent finite element meshes and then connect them. In this study, two fluid-structure interface elements, one based on constraints and the other based on the integration of nonsmooth functions, are proposed in nonconformal finite element meshes for structures and fluids, and their accuracy is verified.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.9-20
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• 2002

The purpose of this research is to develop computational procedures for studying nonlinear soil-structure interaction Problems. In orders to study soil-structure interaction behavior, the finite element analysis for the strip footing subjected to both vortical and lateral loads, and foundation layer reinforced with sheet pile are considered, interface elements are used between the footing and the soil to model the interaction behavior The main analyzed results are as follows; 1. For the prediction of settlement and lateral displacement, the result due to interface element was evaluated larger then without interface element. 2. For the determination of ultimate bearing capacity, the value using interface element appeared smaller by 12%, which was safe. 3. The horizontal and vertical displacement of strip footing affected by the presence of interface element.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.128.1-128.1
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• 2016

Nitrided-metal gates on the high-${\kappa}$ dielectric material are widely studied because of their use for sub-20nm semiconductor devices and the academic interest for the evanescent states at the Si/insulator interface. Issues in these systems with the Si substrate are the electron mobility degradation and the reliability problems caused from N defects that permeates between the Si and the $SiO_2$ buffer layer interface from the nitrided-gate during the gate deposition process. Previous studies proposed the N defect structures with the gap states at the Si band gap region. However, recent experimental data shows the possibility of the most stable structure without any N defect state between the bulk Si valence band maximum (VBM) and conduction band minimum (CBM). In this talk, we present a new type of the N defect structure and the electronic structure of the proposed structure by using the first-principles calculation. We find that the pair structure of N atoms at the $Si/SiO_2$ interface has the lowest energy among the structures considered. In the electronic structure, the N pair changes the eigenvalue of the silicon-induced gap state (SIGS) that is spatially localized at the interface and energetically located just above the bulk VBM. With increase of the number of N defects, the SIGS gradually disappears in the bulk Si gap region, as a result, the system gap is increased by the N defect. We find that the SIGS shift with the N defect mainly originates from the change of the kinetic energy part of the eigenstate by the reduction of the SIGS modulation for the incorporated N defect.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.289-296
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• 2000

This paper summarizes the results of a study which has quantified the evolution of the structure of sands adjacent to geomembranes of varying roughness at different stages of shearing. The results show that the structure evolution, and hence shear mechanisms for rounded uniform sands adjacent to geomembranes, are directly influenced by the surface roughness of the geomembranes. For smooth geomembranes, the shear mechanism predominantly involves sliding of sand particles and only affects the sand structure within two particle diameters of the geomembrane. For slightly textured geomembranes, the effects of interlocking and dilation of sand particles extends the zone of evolution to four particles diameters from the interface. For moderately/heavily textured geomembranes, the interlocking and dilation of sand particles is fully developed and results in large dilation in the interfacial zone, which extends up to six particle diameters from the interface. By understanding how the structure of the sand adjacent to geomembranes of different roughness changes during shearing, it may be possible to identify alternative geomembrane roughening procedures and patterns that can lead to more efficient interface designs.

• Archives of design research
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• v.19 no.2 s.64
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• pp.251-260
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• 2006

Rapid development of electronic technology has made it possible to perform various function. But this technology made it increase it's complexity. Therefore, It was important to identify usability problem in interface design. The quality of interface to promote the efficient interaction should be evaluated with regard to users' cognitive characteristics. So, in this paper, washing machine, that is one of the most useful electronic home application was studied menu structure on interface and it's operational states transition. At first, an cognitive menu structure is identified with users' conceptual similarity of the main function of washing machine. Then three washing machines was selected to compare with the cognitive menu structure. And, we were analyzed how operational state of the washing machine was transfered. As a result, we can be revealed that menu operational method based on the cognitive structure was consistent with the user's preferred operational method during the experimental tasks and the users and designers had a different knowledge of an it's function structure. These results will be useful to design the washing machine interface.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.287-318
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• 2012

We apply a partitioned-solution (iterative-staggered) coupling method based on a fixed Eulerian mesh with the level set function to a large-deformation fluid-structure interaction (FSI) problem where a large-deformable thin structure moves in a high-speed flow field, as an airbag does during deployment. This method combines advanced fluid and structure solvers-specifically, the constrained interpolation profile finite element method (CIP-FEM) for fluid Eulerian mesh and large-deformable structural elements for Lagrangian structural mesh. We express the large-deformable interface as a zero isosurface by the level set function, and introduce virtual nodes with level sets and structural normal velocities to generate the level set function according to the large-deformable interfacial geometry and enforce the kinematic condition at the interface. The virtual nodes are located in the direction normal to the structural mesh. It is confirmed that application of the method to unfolded airbag deployment simulation shows the adequacy of the method.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.34-40
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• 2012

This paper presents an experimental modal analysis of a caisson-type breakwater to produce basic information for the structural health assessment of a caisson structure. To achieve the objective, the following approaches are implemented. First, modal analysis methods are selected to examine the modal characteristics of a caisson structure. Second, experimental modal analyses are performed using finite element analyses and lab-scale model tests. Third, damage scenarios that include several damage levels in a foundation-structure interface are designed. Finally, the effects of damage on the modal characteristics are analyzed for the purpose of utilizing them for damage identification.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.235-238
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• 2006

Interface formation between $12CaO{\cdot}7Al_2O_3(C12A7:e^-)$ and Alq3 was investigated using in-situ ultra-violet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). The work function and vacuum level shift of $C12A7:e^-$ were change by different surface treatment from 2.6eV to 4.2eV. Also vacuum level shift $(\Delta)$ at the interface were from +0.3eV to -0.3eV.

• Journal of Korean Society of Steel Construction
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• v.15 no.5 s.66
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• pp.509-518
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• 2003

In this study, we carried out nonlinear analysis according to various interface nonlinear models by interaction magnitude, and analyzed interface behavior such as distribution of tangential traction and relative slip in steel-concrete composite structure. As a result of this study, tangential traction and relative slip of interface is rapidly increased at the steel plate-concrete interface, especially at the neutral region, rather than tensile, as opposed to the T beam-concrete interface. In transverse direction, it has gradually reduced to go outside from loading position. In longitudinal direction, it was minimum at the central region near the loading point, maximum at 0.6-0.7L from support and gradually reduced as it nears support. Moreover, as the load is increased, the failure of interface gradually expands from the maximum tangential traction position to the entire region. It is expected to provide fundamentality for interface behavior and load-carrying mechanism, and for the design of bending and shear connection of steel-concrete composite structure.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.163-170
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• 2017

As the usage of smart phones continues to increase, the control UI, which users have to continue to use, sometimes finds a heavy burden on users. Therefore, in this study, we have studied the control user interface structure along with the theoretical background of the control user interface, and we have studied the role and usage of the control component based on it. Typical commonly used controls are button controls for transmission, selection controls for various selections, link controls for navigation, text controls for inputting characters, indicator controls for feedback on progress, A message control that displays information about warnings and errors, and a window control such as a dialog box. The structure of the control should be designed according to the use of the separated control to help the user efficiently use the control user interface. Based on the analysis of the theoretical usage of representative components belonging to the separated controls, we presented a new and correct way to use the control to improve the user experience. The use of improved control components will help to design the control structure efficiently and to improve the user experience.