• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.331-336
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• 2001

경제규모의 증대와 사용부지의 제한으로 인하여 용접구조물들은 복합화, 대형화 추세에 있고, 이러한 경향에 따라 구조물에서 용접부가 차지하는 비중 역시 증가하고 있다. 용접과정을 통해 다양한 금속학적, 역학적 변화를 경험하게 되는 용접부는 대형 강 용접 구조물/설비의 건전성을 확보하기 위해서 가장 주의를 기울여야 하는 평가 대상 부위임에 분명하다.(중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.491-496
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• 2002

중력식 댐과 같은 대형구조체의 콘크리트에만 적용되는 것으로 인식되어 왔던 매스콘크리트의 개념적용은 최근 콘크리트 구조물이 대형화, 특수화되어 유동성이 충분히 확보된 콘크리트의 대량 급속 시공이 증가하고 있어 그 특별한 범주를 규정하기 힘든 실정이다. 이러한 현실 뿐만아니라 과거보다는 상대적으로 고강도화된 콘크리트가 요구되고 있기 때문에 빈번히 관찰되고 있는 매스콘크리트 구조물의 균열발생원인 및 발생시기의 예측이 어려워지고 있다.(중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.445-452
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• 2002

토목 및 건축구조물에 대한 합리적이고 정확한 설계, 시공은 물론 구조물 시공후의 안전 점검, 보수ㆍ보강 등을 위한 계측은 구조물의 사용성을 항상 최적의 상태로 유지하고 구조물의 공용수명을 연장시키는데 있어 매우 중요하다. 일반적으로 사용단계의 구조물은 시간이 경과함에 따라 초기의 설계, 시공상 오류에 의한 초기결함, 반복하중 그리고 취약한 환경 등 외부 조건에 노출될 경우에는 구조물 본연의 성능을 점차 상실하게 되어 심지어는 인명과 재산권을 위협하는 대형 붕괴사고를 일으키기도 한다. (중략)

• Journal of the KSME
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• v.22 no.6
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• pp.447-451
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• 1982

NASTRAN은 모든 구조물 특히 대형 구조물의 정적 해석(static analysis)뿐 아니라 동적 해석, 구조물과 주변 유체 유동과의 관계, seismic analysis, acoustic analysis등 광범위하게 사용되어 질 수 있는 전산 프로그램이다. KAIST에서는 NASTRAN을 보다 효과적으로 활용하기 위하여 pre-processor, postprocess의 개발에 노력하고 있으며 특히 NASTRAN 해석의 결과를 가시화 하기 위하여 computer graphics를 위한 전산 프로그램인 MOVIE-BYU를 NASTRAN과 연결 시켜 사용하려 시도하고 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.11-19
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• 2004

Such social structures as bridges,, buildings, dams and towers have been transformed by their own load or fundamental ground. They have been behaved by other external causes. These regular or irregular behaviors threaten to do their users safety. Therefore, to monitor the load of the structures or reaction shown by them could help to verify their behaviors. RTK GPS allows the use of a static base station and remote rover unit to allow f3r data collection within several seconds and in real time. It is useful for monitoring the behaviors of massive structures like bridges. In this Study, Among GPS methods, we used RTK GPS to analyze the precision of monitoring and then on the basis of it, we developed a monitoring system using RTK GPS when measured the behavior of main tower of a suspension bridge by using RTK GPS. Comparing a deviation between observation values, X axis was Imm, Y axis was 1mm and Z axis 2.2mm. It turned out that it was possible to monitor and measure structures by RTK GPS.

• Computational Structural Engineering
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• v.10 no.3
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• pp.157-165
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• 1997

This research aims to develop an algorithm of optimal transducer placement for health monitoring of large structural system. The structural vibration response-based health monitoring is considered one of the best for the system which requires a long-term, continuous monitoring. In its experimental modal testing, however, it is difficult to decide on the measurement locations and their number, especially for complex structures, which have a major influence on the quality of the results. In order to minimize the number of sensing operations and optimize the transducer location while maximizing the accuracy of results, this paper discusses about an optimum transducer placement criterion suitable for the identification of structural damage for continuous health monitoring. As a criterion algorithm, it proposes the Kinetic Energy Optimization Technique (EOT), and then addresses the numerical issues which are subsequently applicable to actual experiment where a bridge model is used. By using the experimental data, it compares the EOT with the EIM(Effective Indefence Method) which is generally used to optimize the transducer placement for the damage identification and control purposes. The comparison conclusively shows that the EOT algorithm proposed in this paper is preferable when a structure is to be instrumented with fewer sensors for monitoring purpose.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.12
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• pp.1035-1044
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• 2013

Because of the high specific stiffness and strength inherent in the sandwich structure composed of facesheet that resists in-plane loads and a core that resists out-of-plane loads, it is often used for large and light-weighted structures. However, inevitably the increased flexibility allows greater deformation-based disturbances in the structures. Thus, it is necessary to analyze the structural safety. To obtain more accurate analytical results, the input disturbances must more closely simulate real load conditions; to improve accuracy, non-linear elements such as gust effects were considered. In addition, the structural safety was analyzed for the iso-grid sandwich panel structure using fluid-structure interactions. For a more realistic simulation, flow velocity fields, which consider the effects of irregular gust fluctuation, were generated and the coupled field was analyzed by mapping the pressure and displacement.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.2
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• pp.96-106
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• 2000

Though the recent years, large scale structures have been built on offshore for utilization of coastal ocean space as offshore airport and marine terminals. Sometimes, those big scale structures, however, happened to act as significant barriers against waves and severe beach erosion would take place on the coast. The present study deals nearshore topography changes affected by construction of an offshore structure with different distance from the shore. The series of three dimensional movable bed experiments have been examined in detail. Moreover, in order to make clear the relation of nearshore currents and local erosions behind offshore structure, the nearshore currents are calculated by Boussinesq equation model and compared with the same scale condition of the physical model experiments.

• Computational Structural Engineering
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• v.1 no.2
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• pp.34-36
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• 1988

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.189-197
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• 2013

With the trend of technological advances in electronic communications and the advent of ubiquitous environments, the density of existing electronic equipment in the surroundings is increasing significantly. It is hence great importance to study the numerically efficient and fast algorithm for complex and large environments to identify their electromagnetic compatibility and interference characteristics of equipments installed in those structure. This paper introduces a statistical-based power balance method(PWB) for the analysis of these problems and considers its practical utility. The 2-dimensional lossy rectangular cavity was numerically revisited to clarify its relationship with the classical deterministic analysis solutions based on the Maxwell's equation. It can be shown that the statistical assumptions and analysis results from the power balance method correspond to the volume average over the realistic deterministic domain. This statistical power balance approach should be a sufficiently practical alternative to the electromagnetic problem of complex and large environment since it is apparent that the full-wave analysis methods have some severe limits of its computational burdens under the situation of complex and large environment.