• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.598-601
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• 2011

동적응답과 하중을 정확히 산정하기 위해서는 구조물의 동적특성을 정확히 평가하는 것이 중요하기 때문에, 현재 대부분의 경우 FE 모델을 이용한 Modal 해석을 dldydg하여 동특성을 평가하고 있다. 그러나 실제 건물의 계측결과와 동적특성의 해석결과가 많은 차이를 나타내고 있으므로 해석결과의 신뢰성을 향상하기 위해서는 FE 모델에 대한 Calibration이 수행될 필요성이 있다. 이 논문에서는 초고층, 아파트, 대공간 구조물에 대한 계측을 수행하고 이 결과를 바탕으로 동특성을 정확히 예측하기 위한 FE 모델의Calibration 과정을 제시하였다. 이 결과를 바탕으로 동적특성의 정확성이 풍동실험결과의 신뢰성에 미치는 영향을 분석하였다.

• Computational Structural Engineering
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• v.7 no.3
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• pp.153-166
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• 1994

A methodology to assess damage prediction accuracy as a function of model uncertainty in structures is presented. In the first part, a theory of approach is outlined. First, a damage detection algorithm to locate and size damage in structures using few modal responses of the structures is summarized. Next, methods to quantify model uncertainty and the damage detection accuracy are formulated. In the second part, a methodology to assess the effect of model uncertainty on the damage detection accuracy of real structures is designed. In the last part, the feasibility of the assessment methodology is demonstrated by using a plate-girder bridge for which only information on a single mode is available.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.396-399
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• 2010

본 논문에서는 실제 건설중인 초고층건물을 대상으로 상시 풍하중을 이용한 풍진동 모니터링을 통해 고유주기와 감쇠비를 예측하고 이를 설계단계에서의 구조해석 및 가정에 의한 고유주기 및 감쇠비와 비교하였다. 이를 위해 시공중 풍진동계측을 실시하여 고유주기와 감쇠비를 측정하고, 시공단계를 고려한 구조해석모델을 통해 고유주기와 감쇠비가 유사하도록 모델을 수정한 후 이를 바탕으로 완공단계에서의 구조해석모델을 재구성하였다. 이 완공단계에서의 구조해석모델을 바탕으로 완공후의 고유주기 및 감쇠비를 예측하고 이를 설계단계에서의 값과 비교하였다. 향후 이러한 실계측 및 분석을 충분히 축적된다면 초고층설계시의 보수적인 가정사항들을 개선시키고, 풍동실험에 의한 풍진동 산정시의 정확성을 크게 향상시킬 것으로 기대된다.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.56-65
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• 2001

The structural model of midship section is within the scope of STEP AP218. It supports to represent the ship structure, but most of shipyards and classification societies exchange the information using 2D drawings at the present. To translate the 2D information into the ship structure model of STEP AP218, we analyze the 2D midship section information of KR-TRAS of Korean Register of shipping, and include the transverse members information with the 3D model. We also define the mapping table and the mapping relationships between two data structures. With this mapping table we develop the translator for the midship section, and visualize the translated ship structure model using a STEP viewer. The ship structure model can be used to exchange information between design departments, and through the lifecycle of design, analysis, and maintenance.

• Journal of the Korea Computer Graphics Society
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• v.21 no.5
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• pp.37-44
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• 2015

This paper presents a novel 3D model representation, called hybrid model representation, to overcome existing 3D volume-based indoor scene reconstruction mechanism. In indoor 3D scene reconstruction, volume-based model representation can reconstruct detailed 3D model for the narrow scene. However it cannot reconstruct large-scale indoor scene due to its memory consumption. This paper presents a memory efficient plane-hash model representation to enlarge the scalability of the indoor scene reconstruction. Also, the proposed method uses plane-hash model representation to reconstruct large, structural planar objects, and at the same time it uses volume-based model representation to recover small detailed region. Proposed method can be implemented in GPU to accelerate the computation and reconstruct the indoor scene in real-time.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.35-42
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• 2021

This paper presents an on-line finite element model updating method for in-service structures using measured data. Conventional updating methods, which are based on numerical optimization, are not efficient for on-line updating because they generally require repeated eigenvalue analyses until convergence criteria are met. The proposed method enables fully automated on-line finite element model updating, almost simultaneously with vibration measurement, without any user intervention or off-line procedures. The automated covariance-driven stochastic subspace identification (Cov-SSI) method is utilized to identify modal frequencies and vectors, and the identified modal data is fed to the neural network of the inverse eigenvalue function to produce the updated finite element model parameters. Numerical examples for a wind excited 20-story building structure shows that the proposed method can update the series of finite element model parameters automatically. It is also shown that sudden changes in the structural parameters can be detected and traced successfully.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.147-152
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• 2016

One of major issues in machine learning that extracts and acquires knowledge implicit in data is to find an appropriate way of representing it. Knowledge can be represented by a number of structures such as networks, trees, lists, and rules. The differences among these exist not only in their structures but also in effectiveness of the models for their problem solving capability. In this paper, we propose partition utility as a criterion function for clustering that can lead to simplification of the model and thus avoid overfitting problem. In addition, a heuristic is proposed as a way to construct balanced hierarchical models.

• Computational Structural Engineering
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• v.8 no.1
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• pp.95-106
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• 1995

Noise and vibration induced by subway operation are one of the major factor that annoy residents living near the subway tracks. In general, lateral vibration is the major concern when we are considering vibration of a building. However, the vertical vibration is the major concern in considering the vibration induced by the subway operation. Analysis model for the vertical vibration of the structure should consider the effect of beam vibration. Thus, the same model used for the lateral vibration analysis can not be used for an analysis of vertical vibration of the structure. Appropriate analysis model which can consider the inertia force of the beam is necessary when analyzing a structure for the vertical vibration. Modeling technique for the vertical vibration analysis of structures has been studied on this paper. It is recommended to use one or more elements for columns and to use two or more elements for beams when analyzing structures for vertical vibration induced by subway operation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.370-373
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• 2006

본 논문에서는 복잡하고 비선형적인 시스템에 대하여 구체적이고 체계적인 방법에 의한 퍼지 모델을 설계하기 위해 유전자알고리즘을 이용하여 전반부 및 후반부의 구조와 파라미터 동정한다. 정보 입자 기반 퍼지 모델의 구조를 동정하기 위하여 유전자 알고리즘을 이용하여 입력 변수의 수, 선택될 입력 변수, 멤버쉽함수의 수, 그리고 후반부 형태를 결정하고, 파라미터를 동정하기 위하여 전반부 멤버쉽 파라미터를 동조하여 최적의 퍼지 모델을 설계한다. 또한 구조 동정 및 파라미터 동정에 있어서 개선된 연속적 동조 방법으로 접근하여 정보 입자 기반 퍼지 모델의 최적 동정을 도모한다. 마지막으로 제안된 퍼지 모델은 표준 모델로서 널리 사용되는 수치적인 예를 통하여 평가한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.231-231
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• 2004

공학해석기반의 설계/제조 시스템에서의 설계는 설계평가와 설계 trade-offs로 구성되어 진다. 설계평가는 설계의 유용성을 평가하거나 CAD모델을 공학해석 모델로 변환하여 구조해석을 통하여 평가하기 위해 사용되며 이러한 평가결과를 근거로 성능치를 정의하고 CAD모델에서의 치수가 trade-offs 해석을 위한 설계변수로 정의되어 진다. 설길 trade-offs는 개선된 설계를 얻기 위한 목적으로 수행되는 데 설계변경은 CAD와 공학해석 모델로 피드백하게 된다.(중략)