• Journal of Korean Association for Spatial Structures
• /
• v.7 no.2 s.24
• /
• pp.63-74
• /
• 2007

Large spatial structures consist of roof structure and its supporting structure. Authors simply call the supporting structure "lower parts" and roof structure "upper parts". To study the influence of an lower part on the seismic response of the upper part of a structure as a first step, authors substitute the upper part and the lower part of the structure to a single degree of freedom system individually, and set up a new 2 DOF structural model connected by them. It is clarified that the mass ratio and the period ratio of an upper part to a lower part are important parameters to find the amplification or reduction of the seismic response of an upper part.

• Journal of Korea Spatial Information System Society
• /
• v.1 no.1 s.1
• /
• pp.99-108
• /
• 1999

이제 GIS 표준은 국제적으로 공인된 과정을 거쳐 제정되고 있다. 이러한 과정과 표준자체의 중요성은 물론이며 표준 개발을 의한 GIS 표준 하부구조 즉 범 세계적 공간 정보 하부 구조 (the Global Spatial Data Infrastructure: GSDI) 의 개발도 아주 중요한 것이다. 기술이란 항상 변하고 있는 것이기에 GSDI등 표준 하부구조가 구축되면 새로운 GIS 표준은 이러한 하부 구조에 의해 쉽게 개발 되게 된다. 본 논문에서는 지금까지 구축된 공간 정보 표준 하부 구조는 어떠한 것이 있고 또 앞으로의 GIS 표준 개발 방향은 어떻게 나아가야 할 것인지 살피고자 한다.

• Journal of Technologic Dentistry
• /
• v.2 no.1
• /
• pp.51-53
• /
• 1980

앞에서 말씀드린 기술은 가철식 국부의치 하부구조(removable partial denture frame work)를 구강 내에 맞추기 전에 master cast에 맞추는 것을 기술한 것이다. 이 과정에서는 본 하부구조(frame work)의 외형을 유지하며 적합성을 높이는 것에 중점을 두어야 한다. 또한 제거된 금속의 양은 모형(cast)이 긁히지 않게 하기 위한 것이며, master cast 위에 주조체를 안착시키기에 필요한 양 만큼이어야 한다. 주조체의 치아 접촉면의 적합이 끝나면 가벼운 압박을 주며 광택을 낸다. 이러한 과정이 기공소에서 주의깊게 완수되면 치과의사는 하부구조를 최소한 짧은 시간에 구강 내에 맞출 수 있게 된다(그림 7).

• Magazine of the Korea Concrete Institute
• /
• v.13 no.2
• /
• pp.38-43
• /
• 2001

교량 하부구조 특히 교각 및 기초의 경우는 지반 또는 수중에 묻혀 있기 때문에 손상을 발견하기도 어렵고 또한 손상의 보수 및 보강이 곤란한 경우가 많다. 하부구조의 손상은 지반의 마모, 침하, 측방유동토압, 하상세굴, 홍수류, 선박 및 유하물에 의한 충격, 지진 등의 여러 원인에 의하여 발생된다. 이러한 손상은 지표수 및 지하수 배제공, 성토공, 지반개량공, 단면보수공, 세굴방지공, 내진보강공 등에 의하여 보수 및 보강이 행하여 진다. 본 고에서는 이러한 하부구조의 보수.보강공법 중 수중부에 실시되는 방법에 대하여 소개하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.639-642
• /
• 2011

이 연구에서는 완전 조립식 교량 하부구조의 비선형해석을 위한 전산플랫폼을 개발하였다. 완전 조립식 교량 하부구조의 비선형거동을 정확하게 파악하고 합리적이면서 경제적인 설계기준의 개발을 위한 자료를 제공하는데 그 목적이 있다. 재료적 비선형성에 대해서는 균열콘크리트에 대한 인장, 압축, 전단모델과 콘크리트 속에 있는 철근모델을 조합하여 고려하였다. 사용된 부착 또는 비부착 텐던요소는 유한요소법에 근거하며 프리스트레스트 콘크리트 부재의 콘크리트와 텐던의 상호작용을 구현할 수 있다. 그리고 접합면요소는 세그먼트 접합부의 비탄성거동을 예측할 수 있다. 제안된 해석기법은 수치예제에 대하여 비선형거동을 비교적 정확하게 예측하였다.

• Journal of the Economic Geographical Society of Korea
• /
• v.15 no.2
• /
• pp.166-191
• /
• 2012

This paper investigates how the agent specificity of economic infrastructure-related public company proceeds in overseas investments. At first this paper examines general features focused on investment region, project type, starting year, and then analyzes overseas investments based on specific cases with three classifications which are composed of special consulting type that do not accompany capital investment, FDI type, and type of overseas energy resources development that go with capital investment and business risk. Finally nationality issues that is generated by agent characteristics of infrastructure public company are interpreted in perspective of duality which is financial pressure and dependency of host county's position, and relationship with private capital of home country.

• Journal of Korean Association for Spatial Structures
• /
• v.9 no.2
• /
• pp.83-90
• /
• 2009

The previous studies for dynamic behavior of spatial structure have been zoomed in on roof structure by numerical analytic method. But the roof structure of real spatial structures is supported by lower structure as column and wall. So, when earthquake is occurred, it is predicted that dynamic behavior of roof structure is affected by lower structure. Therefore, on this study, natural period characteristics of arch structures are analyzed according to section, length and the modulus of elasticity of brass column and polycarbonate column and additional mass of roof structure by the scale-down model of arch structure as the most simple structure of spatial structures. The changes of natural periods are generally alike. But, when Polycarbonate column is connected to roof structure, the change of natural period for change of section is relatively large. That means that change of section and section and length of column and additional mass of roof structure have less influence on change of stiffness because the modulus of elasticity of brass is relatively large.

• Journal of Science and Technology Studies
• /
• v.6 no.2 s.12
• /
• pp.185-205
• /
• 2006

This article analyzes statistical indicators on the infrastructure of S&T culture in Korea. In the case of visible infrastructure, science museums, S&T programs in TV, and S&T books are not sufficiently secured except for internet. The utilization of visible infrastructure tends to be increased but in rudimentary stage. In relation to invisible infrastructure, public interest and understanding of &T is underdeveloped, social status of S&T personnel is low compared to social importance, and participation in S&T policy of S&T personnel and citizens organization is limited. For the development of statistical indicators in S&T culture, personal, institutional, and social contexts should be much considered, surveys on the particular social groups are systematically pursued, and a white paper on the S&T culture in Korea needs to be published.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.3
• /
• pp.283-288
• /
• 2011

For the earthquake resistance design designer should provide that structural yielding process is principally designed with the ductile failure mechanism. In order to get the ductile failure mechanism for typical bridges, pier columns yielding should occur before that of connections. However domestic bridge design with unnecessary stiff substructure leads to unnecessary seismic loads and makes it difficult to get the ductile failure mechanism. Such a problem arises from the situation that earthquake resistant design is not carried out in the preliminary design step. In this study a typical bridge is selected as an analysis bridge and design strengths for connections and pier columns are determined in the preliminary design step by carrying out earthquake resistant design. It is shown through this procedure that it is possible to get the ductile failure mechanism with structural members determined by other design.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.15 no.2
• /
• pp.11-22
• /
• 2011

The design comparison and nonlinear analysis of totally prefabricated bridge substructure systems are performed. The prefabricated bridge substructures are designed by the methods of present design and load and resistance factor design (LRFD). For the design, the current Korea Highway Bridge Code (KHBD), with DB-24 and DL-24 live loads, is used. This study evaluates the present design method of KHBD (2005) and AASHTO-LRFD (2007) for totally prefabricated bridge substructure systems. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures, was used.