• Explosives and Blasting
• /
• v.15 no.1
• /
• pp.44-60
• /
• 1997

The design of underground cavern is basically governed by the mechanical properties of ground mass distributed around excavation. It is seldom possible to consider all the factors of ground mass properties in the evaluation of ground mass behavior as well as to classify those factors to a simple category. Until computer sciences have developed to calculate complex and laborious mechanical simulation of underground openings, ground behavior was quantitatively and qualitatively evaluated using empirical classification system. In this paper, analysis methods of ground behavior for underground cavern using the prediction of loosening zone, empirical method derived from rock mass classification and element stress analysis are described with chronological sequence.

• The Journal of Engineering Geology
• /
• v.1 no.1
• /
• pp.38-53
• /
• 1991

The design of underground cavern is basically governed by the mechanical properties of ground mass distributed around excavation. It is seldom possible to consider all the factors of ground mass properties in the evaluation of ground mass behavior as well as to classify those factors to a simple category. Until computer sciences have developed to calculate complex and laborious mechanical simulation of underground openings, ground behavior was quantitatively and qualitatively evaluated using empirical classification system. In this paper, analysis methods of ground behavior for underground cavern using the prediction of loosening zone, empirical method derived from rock mass classification and element stress analysis are described with chronological sequence.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.10 no.2
• /
• pp.193-205
• /
• 2008

The construction of underground structures such as oil and food storage caverns are recently increasing in our country. The stability of those underground caverns are greatly influenced by their shape and size. In this study therefore, the effect that the shape of an underground cavern have on its stability were analyzed in terms of safety factor. To this end, caverns with 5 different shapes were investigated and sensitivity analyses were performed based on rock class, overburden, and lateral earth pressure coefficient. The proper amount of shotcrete and rockbolt as supports of a cavern was also assumed based on the shape and site of the cavern and rock conditions. This study is expected to be helpful in designing and evaluating the stability of caverns in future.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.931-946
• /
• 2018

In line with the increased usability of utility pipe conduits in urban areas, construction and R&D activities of utility tunnel, incorporated with the shield TBM method, are actively under way. The utility tunnels are installed through underground excavation, and thus are relatively weak in terms of construction safety. However, hazards associated with the utility tunnel construction have not been properly identified, despite the introduction of a policy to the 'Design for Safety' for the purpose of reducing accident rates in the construction industry. Therefore, in this study, following the derivation of hazards associated with utility tunnel, these hazards were then used as the basis to uncover key safety hazards requiring extensive management in a field, which were then used to conduct a risk assessment having applied the matrix method so that the results can be utilized in risk assessment during the stages of utility tunnel planning, design, and construction, while also serving as a data reference.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.4
• /
• pp.535-541
• /
• 1998

A 2 stage 6-pole bandpass filter(BPF) is designed and implemented by using triple-mode cavity for satellite payload system. The BPF has an 100 MHz bandwidth at the center frequency of 14.5 GHz, Ku-band. The cavity filter uses two orthogonal $TE_{113}$ modes and one $TM_{012}$ mode. The intercavity coupling between the adjacent cavities results in a Chebyshev response and is accomplished by H-field component of TE modes. The size and location of intercavity slot are determined by the coupling equation from H-field of TE resonant modes in circular cavity. The measured filter response agrees well with the theoretical data.

• Tunnel and Underground Space
• /
• v.18 no.4
• /
• pp.243-251
• /
• 2008

Recently, the mining methods are changing from surface mining to underground mining because of the increment of the environmental issues and legal regulations. Therefore, the stability of underground openings is a major concern for the safety and productivity of mining operations. In this paper, a survey of structural geology and discontinuities were carried out at a limestone mine. The relevant mechanical properties of rocks were determined by the laboratory tests and rock mass classifications (RMR and Q-system) for the mine design and input data for the stability analysis. The dimensions of unsupported span for underground openings and pillar were decided based on the RMR values of rock mass classifications. The stability analysis for the suggested mine design was examined through the empirical methods (stability graph method and critical span curve) and 3-D numerical analysis (Visual-FEA).

• Ingenium
• /
• v.10 no.4
• /
• pp.62-68
• /
• 2003

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.05a
• /
• pp.1087-1090
• /
• 2005

최근에 웹 기반의 공동 작업에 대한 연구가 활발히 진행되고 있으며, 웹 표준 언어인 XML 데이터에 대한 접근 제어 및 관리에 대한 필요성이 점차 중요시되고 있다. 이에 접근 제어 표준인 XACML이 제안되었지만, 공동 작업에 대한 정의가 없는 문제가 있다. 본 논문은 이러한 문제를 해결하기 위하여 공동 작업에 관한 기능을 기존의 XACML 스키마에 추가하여 확장하였으며, 이를 통해 기존의 공동 작업을 위한 XML 데이터에서 원하지 않는 권한 모두를 위임하는 경우를 방지하고, 권한의 오 남용을 줄 일 수 있게 되었다. 또한 본 논문에서는 이러한 공동 작업을 관리하기 위한 접근 권한 메커니즘을 설계하고 구현한다.

• Proceedings of the CALSEC Conference
• /
• 1998.10b
• /
• pp.355-364
• /
• 1998

인터넷을 사용한 부품 정보 공유 서비스. 부품정보 중개 - 다수 공급자의 참여에 의한 부품 정보 데이터베이스의 구축 - 제품개발자의 요구사항에 따른 부품 검색 및 공급자 선정. 3차원 공동 작업 - 제품설계자의 현재 설계 정보와 선정된 공급자의 부품 정보를 가상 조립, 공동 수정, 평가할 수 있는 기능을 제공 - 가상 조립 결과의 형성 - 조립 결과의 비동기적 전송 및 재현(중략)

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.758-763
• /
• 2001

웹 기반 프로젝트학습은 학생들 스스로 웹에서 자신들의 제작물을 만들면서 자신의 기능과 지식을 실제로 적용하는 과정과 학습경험을 모두 의미한다. 그러므로 학습자들의 다양하고 폭넓은 학습활동이 기대된다. 본 연구에서 설계한 프로젝트 학습 시스템은 수시로 교사와 전문가의 도움도 받고 다른 팀의 동료 학생들로부터 평가를 받으면서 아동의 관심과 흥미, 주제 중심, 활동 중심, 문제 중심의 프로젝트 활동을 할 수 있도록 한다. 그리고 이들 웹 상에서 구현함으로써 학습자 중심의 공동 프로젝트 학습이 되도록 한다.