• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.170-180
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• 1995

A parallel crack in bonded dissimilar orthotropic planes under out-of-plane loading is analyzed. The problem is formulated by Fourier integral transforms, and reduced to a pair of dual integral equations. By solving the integral equations, the asymptotic stress and displacement fields near the crack tip are determined in closed form, from which the stress intensity factor and energy release rate are obtained. Discontinuity in the stress intensity factor as the distance ratio h/a of the parallel crack approaches zero is found, while the energy releas rate is shown to be continuous at h/a = 0. This information can immediately be used to generate the stress intensity factor for the parallel crack near the interface. By employing "the maximum energy release rate criterion", it could be shown in the case of no existing crack initially that the parallel crack is formed far from the interface for the more compliant material, while it is formed close to the interface for the stiffer material. material.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.70-77
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• 2008

A pre-processing program based on the OOP(object-oriented programming) concept has been developed. The program consists of the input of a 2D or 3D flow problem to a CFD program by means of an user-friendly interface and the subsequent transformation of this input into a form suitable for the solver(PowerCFD) using unstructured cell-centered method. User-friendly GUI(graphic user interface) has been built on the base of MFC(Microsoft Foundation Class). The program is organized as modules by classes based on VTK(Visualization ToolKit)-library, and these classes are made to function through inheritance and cooperation which is an important and valuable concept of object-oriented programming. The major functions of this program are introduced and demonstrated, which include mesh generation, boundary settings, solver settings, generation of grid connectivity and geometric data etc.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.23-29
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• 2008

Two high resolution compressive schemes, CICSAM(Ubbink, 1997) and HRIC(Muzaferija & Peric, 1999), in interface capturing method are reviewed briefly with respect to the extended forms suitable for unstructured meshes. And then those are applied to three typical test cases of translation test, shearing flow test and collapsing water problem with an obstacle. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method, which is based on the finite-volume technique and fully conservative. The calculated results show that CICSAM is better than HRIC with respect to accuracy and robustness, although either scheme can be used as a good choice for free surface or two-phase flow simulation.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.98-103
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• 2003

Recently, to solve the urban transportation problem, the introduction of Light Rail Transit system has been proceeded positively. therefore, development of the Korean standard LRT system in which safety, efficiency and cost effectiveness are emphasized. The Korea Railroad Research institute study on Rubber Tired AGT system of Light Rail Transit to obtain the essential technology and engineering know-how, which leads lower LRT construction cost. In the development procedure, SE(system Engineering) is needed for combination of subsystem and optimum operation effect. This study is focused on the interface of LRT subsystem(Development of the rubber tired LRT, Power supply system, signalling and train control system, Elevated track structure for the rubber tired LRT), a important part of SE, to develop of the driverless LRT system and establish the test and evaluation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.44.1-44
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• 2001

This paper discusses the interacting mobile robots for tele-operation system using the world wide web. In multi-agent and web-based teleoperation environment the problem of communication delay must be solved for the efficient and robust control of the system. The standard graphic user interface(GUI)is implemented using Java Programing language. The web browser is used to integrate the virtual environment and the standard GUI(Java applet) in a single user interface. Users can access a dedicated WWWserver and download the user interface. Reinforcement learning is applied to indirect control in order to autonomously operate without the need of human intervention. Java application has been developed to communicate and control multi robots using WWW. The effectiveness of our multi robots system is verified by simulation and experiments ...

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.106-113
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• 2002

In this study, a numerical analysis method for soil-pile interaction in frequency domain problem is presented. The total soil-pile interaction system is divided into two parts so called near field and far field. In the near field, beam elements are used for a pile and plain strain finite elements for soil. In the far field, dynamic fundamental solution for multi-layered half planes based on boundary element formulation is adopted for soil. These two fields are coupled using FE-BE coupling technique In order to verify the proposed soil-pile interaction analysis, the dynamic responses of pile on multi-layered half planes are simulated and the results are compared with the experimental results. Also, the dynamic response analyses of interface spring elements are performed. As a result, less spring stiffness makes the natural frequency decrease and the resonant amplitude increase.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.745-750
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• 2000

Steel plate bonding technique is most widely used in strengthening of existing concrete structures, but it has inherently a problem of the premature failure such as interface separation and rip off. So far, many studies have been arid out in the manner of laboratory tests for the reinforced concrete beams to find out he mechanism of the premature failure. However, in order to verify the characteristics of the premature failure, more reasonable local investigations are needed rather than such relatively global experimental works. In this study, therefore, the double lap test which simulate the pure shear loadings and the half beam tests which consider combined flexure-shear force have been done. There are, however, difficulties in getting the normal stress caused to premature failure, so that finite element analysis was performed, too. In numerical study, material nonlinearity was considered, and the interface element was applied to model the interface between steel plate and adhesive. From the results of experimental and numerical studies, a realistic failure criterion on the separation of steel plates has been derived.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1239-1244
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• 2001

The Virtual Interface Architecture (VIA) is usually suggested as a new standard high-performance communication of the cluster systems. However the VIA specification aims for platform independence, the current Intel VI Provider Library (VIPL) design favors systems with Intel architecture processors running the Windows operating system (OS). This paper aims for clarifying the guesstion problem of VIA and VIPL in the newtrul time of CPU Architecture and OS further more, It suggests the solution aiming the communication in the other CPU or OS

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.416-421
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• 2005

In order to use component for various domain, it need to add tangling code. Component reuse suffers from it. AOP was resolved this problem. We present in this paper a component model, called fractal, that added aspect interface using mixin class named joinController interface. Mixin class are used to combine controller object and interceptor object. we design the dynamic weaver that use the decorator pattern, for increase the reuse of aspect.

• Journal of Korea Multimedia Society
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• v.4 no.6
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• pp.579-587
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• 2001

In this paper, we design and implement a parallel programming environment using graphicial user interface. Parallel program must be written according to the characters of various hardwares or programs. So it is difficult to write the parallel program. In this paper, we design and implement a parallel programming environment which solved this problem. The traditional parallel compiler provides the parallel information in the text environment. But this paper provides the parallel information using graphicial user interface so that the user may use it more easily. This parallel environment provide functions such as, data dependence analysis, CFG, HTF, and loop transformation.