• 대한기계학회논문집
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• 제19권1호
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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.

• 대한기계학회논문집B
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• 제32권1호
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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.

• 대한기계학회논문집B
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• 제32권1호
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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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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• 제어로봇시스템학회 2001년도 ICCAS
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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 ...

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 추계 학술발표회 논문집
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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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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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.

• 한국컴퓨터산업학회논문지
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• 제2권9호
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• pp.1239-1244
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• 2001

클러스터시스템의 표준 고속통신구조로서 Virtual Interface Architecture (VIA)가 일반적으로 제안되어진다. 그러나 현재 VIA 및 Virtual Interface Provider Library (VIPL)의 사양은 POSIX의 정해진 Fork 나 시그널 기능에 응답하는 규정이 없거나, 디스크립터가 잘못 규정되어지는 등, Windows OS와 Intel 아키텍처의 CPU에만 적합하도록 되어 있는 부분이 있다. 본 논문에서는 OS와 CPU 아키텍처의 중립적인 시각에서 VIA 및 VIPL의 문제점을 명확화하고, 다른 OS나 CPU에의 상용화를 목적으로 하는 해결 방식을 제안한다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
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• pp.416-421
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• 2005

컴포넌트를 다양한 영역에 사용하기 위해 코드를 추가적으로 요구할 경우, 추가되는 코드가 뒤엉켜져서 컴포넌트 재사용을 방해하게 된다. AOP는 이러한 컴포넌트의 다양성 문제를 해결하기 위해 나온 방법이다. 본 논문에서는 Fractal 컴포넌트 모델에 제어 객체와 인터셉터 객체를 합성하기위해 혼합클래스(mixin class)를 사용하여 joinpoint controller interface를 생성하였으며, 이러한 인터페이스에 합성된 aspect을 적용하였다. 그리고, Aspect의 재사용성을 높이기 위하여, Decorator 디자인 패턴을 사용하여 동적으로 위빙하는 위버를 설계하였다.

• 한국멀티미디어학회논문지
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• 제4권6호
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• pp.579-587
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• 2001

본 논문은 그래픽 사용자 인터페이스를 이용하여 병렬 프로그래밍 환경을 설계하고 구현하였다. 병렬 프로그램은 다양한 하드웨어의 특성에 따라 또는 프로그램의 특성에 따라 사용자가 병렬 프로그램을 작성하여야 하기 때문에 사용자가 병렬 프로그램을 작성하는 것은 매우 어렵다. 본 논문에서는 이런 문제를 도와주기 위하여 기존의 병렬 컴파일러에서 제공되고 있는 텍스트 위주의 병렬화 정보 대신에 그래픽 사용자 인터페이스를 이용하여 편안하고 쉽게 병렬화 정보를 제공하는 병렬 프로그래밍 환경을 제안하고, 구현하였다. 본 논문의 병렬 프로그래밍 환경은 종속성 분석, CFG, HTG, 루프 병렬화 등의 기능을 제공한다.