• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1158-1168
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• 1994

For BEM analyses of the impact problems of dissimilar materials, the connected multi-region method using perfect bonded conditions on the interface boundaries was added to two-dimensional Laplace transformed-domain BEM program for a single region analysis. It was confirmed that the BEM results of impact problems of a single-region and multi-regions for a homogeneous isotropic material are agreed well. The two-dimensional Laplace transformed-domain BEM program combined with connected multi-region method was applied to analyse several impact problems of dissimilar materials. Also the feasibility of BEM impact analyses was investigated for dissimilar materials by the analysis of the BEM results for impact problems of dissimilar materials in terms of physical aspects. As for an application, the two-dimensional Laplace transformed BEM concerning impact problems of cracks at the interface of dissimilar materials and the determinating process of the dynamic stress intensity factors by extrapolation method are presented in this paper.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.528-533
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• 2002

The mechanical and metallurgical properties of friction welded joints type 5052 Al alloy/A36 steel have been studied in this paper. The joint strength increased with increasing upset pressure and friction time till it reached the critical value. The joint strength was fixed at low strength compare to that of base metal in the case of increasing friction time. Microstructure of 5052 Al alloy was greatly deformed near the weld interface. The very fine and equaxied grain structure was observed at the near interface. The elongated grain was formed outside dynamic recrystallizatoin region at the peripheral part, while the A36 steel' side was not deformed. The hardness of the near interface was slightly softer than that of 5052 Al alloy base metal. The maximum softening width was about 8mm from the interface. In the present work, the friction welding condition, t$_1$=0.5sec, P$_2$=137.5MPa, showed a maximum joint strength (202MPa) when friction pressure, upset time and rotation speed were fixed at 75MPa, 5sec, 2000rev/min and these were the optimum friction welding condition of 5052Al/A36 steel joints.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.105-111
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• 2008

Various visualizing methods have been proposed according to the input and output types. To show complex and large-scale raw data and information. LOD and special region scale method have been used for them. In this paper, I propose level scale interface for dynamic and interactive controlling large scale data such as bio-data. The method has not only advantage of LOD and special region scale but also dynamic and real-time processing. In addition, the method supports elaborate control from large scale to small one for visualization on a region in detail. Proposed method was adopted for genome relationship visualization tool and showed reasonable control method.

• Electrical & Electronic Materials
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• v.11 no.10
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• pp.24-31
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• 1998

Interfacial effect in polymetric composites have been studied extensively. This report deals mainly with the effects of interfacial space charge and interface structure. A model for the dynamic process of interfacial space charge accumulation is proposed. The new model might interpret some interface phenomena which is difficult to be explained in terms of traditional Maxwell-Wagner theory. An interface structure is also presented, by which the importance of surface treatment of glass Fiber for improving the properties of FRP could be well understood.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.21-29
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• 1995

The automotive transmission is the principal component of the power transmission system which converts the engine power into the adjustable power for the vehicle driving system. To the unskilled driver the automization of transmission is required for the safety and fuel economy. In this study, the dynamic model of the automotive power transmission system was presented and simulation program and interface board which interface IBM-PC with ECU was devloped. Through the traveling simulation by interfacing ECU with simulation program, the shifting transients are investigated. For verification of simulation experiment was carried out, the results of simulation was agreed well with those of simulation.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.56.1-56.1
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• 2005

• The Journal of Advanced Prosthodontics
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• v.3 no.3
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• pp.140-144
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• 2011

PURPOSE. Finite element study on the effect of abutment length and material on implant bone interface against dynamic loading. MATERIALS AND METHODS. Two dimensional finite element models of cylinderical implant, abutments and bone made by titanium or polyoxymethylene were simulated with the aid of Marc/Mentat software. Each model represented bone, implant and titanium or polyoxymethylene abutment. Model 1: Implant with 3 mm titanium abutment, Model 2: Implant with 2 mm polyoxymethylene resilient material abutment, Model 3: Implant with 3 mm polyoxymethylene resilient material abutment and Model 4: Implant with 4 mm polyoxymethylene resilient material abutment. A vertical load of 11 N was applied with a frequency of 2 cycles/sec. The stress distribution pattern and displacement at the junction of cortical bone and implant was recorded. RESULTS. When Model 2, 3 and 4 are compared with Model 1, they showed narrowing of stress distribution pattern in the cortical bone as the height of the polyoxymethylene resilient material abutment increases. Model 2, 3 and 4 showed slightly less but similar displacement when compared to Model 1. CONCLUSION. Within the limitation of this study, we conclude that introduction of different height resilient material abutment with different heights i.e. 2 mm, 3 mm and 4 mm polyoxymethylene, does not bring about significant change in stress distribution pattern and displacement as compared to 3 mm Ti abutment. Clinically, with the application of resilient material abutment there is no significant change in stress distribution around implant-bone interface.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.488-493
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• 2002

MPEG-4 movies are composed of several media objects, organized in a hierarchical fashion. Those media objects are served to the clients as elementary streams. To play the movie, client players compose the elementary streams according to the meta- information called the scene graph. The meta-information streams are delivered as BIFS and OD elementary stream. Using dynamically generated BIFS and OD streams, we can provide a service something differs from traditional file services. For example, we can insert weather or stock information into the bottom of the screen while an existing movie was played in the screen. In this paper, we propose a dynamic service framework and dynamic server. Dynamic service framework is an object-oriented framework dynamically generating BIFS and OD streams based on the external DB information. Dynamic server provides a GUI for the server management and interface for registering dynamic services. In this framework, the dynamic service has the same interface as a file service. So, a dynamic service is considered as a file service by clients and other services.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.34-41
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• 2005

An experimental study of molecular motions on a liquid-vapor interface is limited due to micro-scale characteristics of a system with an angstrom or a nanometer size Therefore, in recent, many studies for micro-scale systems have been conducted by a computer simulation because it is free from experimental limitations. In this study, through the molecular dynamic (MD) method. molecular behavior was clarified on a liquid-vapor interface and a criterion to distinguish between liquid and vapor was suggested by a potential energy and the number of neighboring molecules. At an interface. the potential energy of a molecule was increased but the number of neighboring molecules was decreased when the molecule moved into a vapor region from a liquid region, and vice versa.

• Smart Structures and Systems
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• v.20 no.2
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• pp.181-195
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• 2017

In this study, the severity of damage in tendon anchorage caused by the loss of tendon forces is quantitatively identified by using the PZT interface-based impedance monitoring technique. Firstly, a 2-DOF impedance model is newly designed to represent coupled dynamic responses of PZT interface-host structure. Secondly, the 2-DOF impedance model is adopted for the tendon anchorage system. A prototype of PZT interface is designed for the impedance monitoring. Then impedance signatures are experimentally measured from a laboratory-scale tendon anchorage structure with various tendon forces. Finally, damage severities of the tendon anchorage induced by the variation of tendon forces are quantitatively identified from the phase-by-phase model updating process, from which the change in impedance signatures is correlated to the change in structural properties.