• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.99-108
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• 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 Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.63-74
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• 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.

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

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

• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.177-183
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• 2008

The sub-salt imaging technique becomes more crucial to detect the hydro-carbonates in petroleum exploration as the target reservoirs get deeper. However, the weak reflections from the sub-salt structures prevent us from obtaining high fidelity sub-salt image. As an effort to overcome this difficulty, we applied the waveform inversion by implementing multi-grid technique to the sub-salt imaging. Through the comparison between the conventional waveform inversion using fixed grid and the multi-grid technique, we confirmed that the waveform inversion using multi-grid technique has advantages over the conventional fixed grid waveform inversion. We showed that the multi-grid technique can complement he velocity estimation result of the waveform inversion for imaging the sub-salt structures, of which velocity model cannot be obtained correctly by the conventional fixed grid waveform inversion.

• Journal of Korean Association for Spatial Structures
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• v.9 no.2
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• pp.83-90
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• 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 the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.166-191
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• 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 the Korean GEO-environmental Society
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• v.14 no.3
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• pp.5-11
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• 2013

The primary objective of this research is to evaluate the behavior of a bridge substructure subjected to scouring during flood. A finite element (FE) study was carried out on a substructure modeled using the standard section specified for highway bridges. The three-dimensional FE model consists of non-linear springs with tri-axial load capacities at the base in order to consider the loss of bearing capacity of the substructure by local scour phenomenon. Various time varying loading conditions and scouring patterns were considered in the analysis. The results indicate a change in the structural behavior of substructure depending on the eroded area and pattern. The outcome of this research will be useful to suggest basic design guidelines for ground sills of the bridge substructure.

• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.71-78
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• 2012

The dynamic behavior of spatial structures is different depending on the aspect ration of arch structure, as the rise-span ratio or open-angle, and these spatial structures show differently the character of seismic response in accordance with stiffness and connection of the lower support structures that are directly influenced by earthquake. Therefore, in this paper, dynamic analysis is conducted for seismic response of single layer arch structures by the influence of column's stiffness and connection, to reflect the different vertical and horizontal vibration mode of single layer arch structures. The vertical response of single layer arch structures is more influence by lower columns and the influence of column's connection rotational stiffness is not large, except to the hinged connections.

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