• Journal of Korean Tunnelling and Underground Space Association
• /
• v.8 no.2
• /
• pp.87-100
• /
• 2006

A kinematically constrained microplane constitutive model is developed for intact granite. The model is verified by fitting the experimented data of Westerly granite and Bonnet granite. Using the model with the standard finite element method, the behavior of the intact granite subjected blasting impact is studied. What is studied includes the attenuation of the blasting waves, the size of the fractured zone and the effect of the charge condition to avoid overbreak of the rock mass. The model developed captures the energy loss due to the inelastic behavior and the microcracking of granite during blasting very well. The attenuation of the blasting waves calculated based on the model is much more than that based on the linear-elastic constitutive law. The size of damaged (or fractured) zone is calculated directly from the principal strain as blasting impact is spreading, not like in the case with the linear elasticity model.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.2
• /
• pp.41-53
• /
• 2006

The brittle materials like rocks show complicated strain-softening behavior after the peak which is hard to model using the classical constitutive models based on the relation between strain and stress tensors. A kinematically constrained three-dimensional microplane constitutive model is developed for granite. The model is verified by fitting the experimented data of Westerly granite and Bonnet granite. The triaxial behavior of granite is well reproduced by the model as well as the uniaxial behavior. We studied the development of the fracture zone in granite during blasting impact using the model with the standard finite element method. All the results obtained from the microplane model developed are compared to those from the linear elasticity model which is commonly used in many researches and practices. It is found that the nonlinearity of rocks sigificantly affects the results of analysis.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.2529-2530
• /
• 2001

0.24인치 크기의 액정표시소자를 이용하여 10인치 이상의 가상화면을 구현할 수 있는 마이크로 디스플레이를 개발하였다. 본 연구를 통하여 개발된 마이크로디스플레이는 한 쪽 눈으로 화면을 볼 수 있는 형태를 지녔다. 한 개의 비구면렌즈를 설계 및 제작하였고, 페이저 형태 및 head set 형태의 두 가지 모델을 제작하였다.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.32-33
• /
• 2006

현재 변전소 자동화의 국제 표준으로 대두되고 있는 IEC61850은 스테이션 버스뿐만 아니라 프로세서 버스까지도 표준화된 통신기술을 채용하였고 자동화에 필요한 모델을 제시하였다. 본 연구에서는 프로세서 버스의 대표적인 장비인 Merging Unit의 특성과 구현에 필요한 기술을 고찰하였다. 특히 정밀한 시간동기에 필요한 GPS(Global Positioning System)를 이용한 동기화 기술에 대하여 고찰하였다. 이와 더불어 IEC61850-9-2 SV(Sampled Value) 서비스를 분석하고 실제로 마이크로프로세서를 이용하여 Merging Unit에 대한 설계를 수행하였다. 제안된 Merging Unit의 성능을 검증하기 위해서 전송된 SV 데이터를 시간 정보를 기준으로 재구성할 수 있는 오실로그래피(Oscillography)를 위한 플레이백(Playback) 프로그램을 제작하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.6
• /
• pp.1237-1242
• /
• 2006

Microsoft's ActiveX corresponding to the advanced type of COM based distributed application model is made available for the use of component communication[1]. ActiveX supports reuse of code and object linking, so developers can integrate many objects into application and improve the efficiency of development. Also, Integration of seperated application makes easy to develop customized program[2]. ActiveX, formerly used to develope communication application in Visual C++ or Visual Basic, has the efficiency of programming and is widely used in the M&C(Monitoring and Control) of instruments. In this paper, we will implement M&C application capable of remote operating, and besides, develop web browser and media player in the form of ActiveX control in order to control and monitor program remotely.