• 한국전산구조공학회논문집
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• 제22권1호
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• pp.81-88
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• 2009

본 논문은 부재 단위의 강성 재설계를 통해 전역 자유도 변위의 정량적 조절이 가능한 변위조절 기법의 개발을 목적으로 하고 있다. 이를 위해 부분적 강성변경이 발생했을 때 전체 구조물을 재해석하지 않고 관심 있는 특정 위치의 변위와 부재력만을 실시간 응답수준에서 재계산할 수 있는 부분재해석 기법을 적용하였다. 부분재해석 기법은 복잡한 미분계산이나 반복적인 구조해석을 수행하지 않아도 되는 단순한 기본개념의 기법으로서 계산이 효율적이고 강성변경 후의 변위를 바탕으로 변위에 대한 민감도를 계산하기에 수렴 속도가 빠른 장점을 가진다. 부분재해석 기법을 통해 전역 자유도에 대한 강성 변경 부재의 변위기여도를 계산하고 변위기여도에 따라 해당 부재의 강성을 변경시킴으로써 반복적 구조해석이나 민감도 해석 없이 특정 변위를 최소의 물량만으로 정량적으로 제어하는 변위조절 설계법을 제시하였다. 예제를 통한 검증결과, 부분재해석 기법이 고층건물의 횡변위제어에 효과적으로 활용될 수 있음을 확인하였다.

• 한국강구조학회 논문집
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• 제12권1호통권44호
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• pp.45-54
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• 2000

본 연구는 반복되는 중간단계의 구조설계과정에 연동되는 근사 재해석 모델을 비교 평가하고, 특히 설계변수가 크게 변화할 때도 일정한 정확도를 유지하여 전체 설계과정에 효율성과 신뢰성을 함께 줄 수 있는 안정된 모델을 찾는다. 이를 위해 대형 프레임구조를 대상으로 설계변수 그룹의 갯수와 변화량을 달리하면서 최대 변위값을 정해와 비교하여 정확도 및 신뢰성을 검토하고, CPU 연산시간 비교를 통해 효율성을 시험한다. 예제를 통하여 부분근사화는 가장 간편하고 빠르기는 하나 설계의 면화가 극히 적은 특정한 경우에만 유용한 반면 전역근사화는 기저벡터를 효과적으로 취할 경우 설계 변화량이 클 때에도 비교적 높은 정확도를 유지하나 효율성이 떨어지는 취약점을 갖고 있다. 이들에 비해 전역-부분근사화는 어느 경우에나 높은 정확성과 효율성을 아울러 갖추고 있음을 보여준다. 이 방법들을 구조 재설계 과정에 연계할 때 설계정보에 따라 혼용하므로써 효율성을 증대시킬 수 있다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.191-196
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• 2004

This study proposed the analysis of mass position detection and modified stiffness due to the change of the mass and stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the mass. The predicted detection of mass positions and magnitudes are in good agrement with these from the structural reanalysis using the modified mass.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.50-55
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• 2003

This study proposed the analysis of damage detection due to the change of the stiffness of structure by using the original and modified dynamic characteristics. The present approach allows the use of composite data which consist of eigenvalues and eigenvectors. The suggested method is applied to examples of a cantilever and 3 degree of freedom system by modifying the stiffness. The predicted damage detections are in good agreement with these from the structural reanalysis using the modified stiffness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.760-763
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• 2003

This study proposed the analysis of damage defection due to the change of the stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the stiffness. The predicted damage detections are in good agreement with these from the structural reanalysis using the modified stiffness.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.120-126
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• 2004

This study proposed the analysis of mass position detection due to the change of the mass and strifeless of structure by using the original and modified dynamic characteristics. The method is applied to examples of the cantilevers beam and the 3 degrees of freedom system by modifying the mass. The predicted detection of the mass positions and magnitudes are in good agrement with the present study from the structural reanalysis using the modified mass.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.209-213
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• 2002

This study proposed the analysis of mass position detection due to the change of the mass and stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the mass. The predicted detection of mass positions and magnitudes are in good agreement with these from the structural reanalysis using the modified mass.

• 한국영어학회지:영어학
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• 제1권2호
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• pp.211-225
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• 2001

The prepositional object (PO) of an active sentence in English can sometimes be passivized, becoming the subject of the corresponding passive sentence. In particular, the verb (V) and preposition (P) in the English prepositional passive (P-Passive) are assumed to be reanalyzed to form a single structural unit, giving the status of a verbal object to the PO to be passivized. However, not every V+P sequence can undergo reanalysis, permitting the passivization of POs. Thus, we have to explain what licenses the reanalysis of V and p. resulting in an acceptable P-Passive sentence. In this paper, I will identify the factors which determine the passivization possibilities of POs and explain how they interact with one another. The results of this study will illustrate how formal and functional factors work together to form a major syntactic construction and to determine its grammaticality and acceptability.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.421-424
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• 2004

Model updating is a very active research field, in which significant efforts has been invested in recent years. Model updating methodologies are invariably successful when used on noise-free simulated data, but tend to be unpredictable when presented with real experimental data that are-unavoidably-corrupted with uncorrelated noise content. In this paper, Reanalysis using frequency response functions for correlating and updating dynamic systems is presented. A transformation matrix is obtained from the relationship between the complex and the normal frequency response functions of a structure. The transformation matrix is employed to calculate the modified damping matrix of the system. The modified mass and stiffness matrices are identified from the normal frequency response functions by using the least squares method. Full scale pseudo dynamic pier test is employed to illustrate the applicability of the proposed method. The result indicate that the damping matrix of correlated finite element model can be identified accurately by the proposed method. In addition, the robustness of the new approach uniformly distributed measurement noise is also addressed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.599-604
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• 2002

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.