• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.251-255
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• 2012

Structural intensity has been mainly utilized to identify vibration energy flow in a vessel. In this paper, the structural intensity of a shuttle tanker subjected to H-moment of the main engine was calculated using a finite element model. From the analysis, it was found that the top-bracing elements, which support the main engine onto the hull structure to prevent the excessive transverse vibration of the main engine, play the role of the dominant path and sink for vibration energy flow from the main engine. Therefore, the structural intensity was controlled by the modification of stiffness and damping characteristics of the top-bracing elements. As a result, it is observed that the transverse vibration level at the center of navigation bridge deck decreased after the control of structural intensity.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.40-52
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• 1998

A good grasp of the failure mechanisms of resistance spot weld, widely used in joining the auto-panels, in essential to the structural/crashworthy analyses and integrity assessment of the whole auto-body. In this study, We provide an estimative model describing the failure behavior of resistance spotf weld, and apply the model to the finite element analysis of crashworthiness. First, in "Part 1-Failure Criteria", to be used for the finite element analysis of spot-welded structural panels of an auto-body, (i) a methodology for quantifying the spot weld failure and the accompanying failure criteria are presented, and (ii) the coefficients of the failure equation are determined by a munimum number of appropriate experimental tests. To achieve these, we derive the functional form of the failure envelop by limit analysis, and correlate it with the form in PAM-$CRASH^{TM}$ code, and also investigate the effect of the failure coefficients on the failure envelop form. An estimative model obtained in this Part1, as spot weld failure criteria is applied to the Macroscopic finite element analysis of autobody structural panels using PAM-$CRASH^{TM}$ code in Part 2.

• 복합신소재구조학회 논문집
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• 제2권2호
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• pp.1-6
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• 2011

본 연구는 하이브리드 FRP로 보강된 철근 콘크리트 보의 구조거동 예측을 목표로 구조해석을 수행하여 기존에 발표된 실험 연구 데이터와 비교하였다. 보다 정확한 구조해석을 위하여 현존하는 다양한 부착강도 모델을 검토한 후, 이 중 콘크리트 피복분리를 예측하는 Teng and Yao model과 FRP 탈락 현상을 예측할 수 있는 Smith and Teng model을 유한요소 해석 모델에 포함시켰다. 비선형 재료 및 형상 역시 구조해석 모델에 포함되었으며 이렇게 해석된 결과는 실험결과와 비교하여 유사한 경향을 나타냈다. 그러나 다양한 하이브리드 FRP로 보강한 철근 콘크리트 보의 파괴모드를 보다 정확하게 예측하기 위하여 현존하는 수치식의 수정 및 도입이 필요하다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.284-291
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• 2002

New information technology developments continue to have a significant impact on civil engineering fields. The objective of this study is to develop STEP-based database which will be able to store and manipulate the information of steel bridges over the life cycle. In this study, there are three steps to fulfil the objective to build database and develop the application module for that data model practically and effectively To begin with, STEP methodology for a development of data model has been used for modelling data structure. And then the data model for a steel bridge's shape and structural analysis information has been made up by using AP203 (configuration controlled design) and AP203 (composite and metallic structural analysis and related design) which are the international standard in STEP Lastly, the application module for an access to information of steel bridges has been developed by means of already made database. This study show efficiently the prototype of developing information system with the existing standard technology in civil engineering fields.

• 디지털융복합연구
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• 제14권6호
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• pp.167-175
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• 2016

본 연구는 인과관계 분석에서 주로 활용되는 SPSS statistic(회귀분석)과 구조방정식모델을 구현하는 프로그램 중 하나인 AMOS 프로그램을 각각 활용하여 동일한 데이터에 대하여 실증분석을 실시하였다. 실증분석 결과, 회귀계수 및 유의확률에서 서로 다른 결과값이 나왔으며, 특히 매개효과 검정에서 귀무가설 기각역 근처의 유의확률값(즉, t값 및 C.R.값의 절대값이 1.96 근처)을 보이는 상황에서 SPSS statistic(회귀분석)에서는 매개효과가 있는 반면, AMOS 프로그램(구조방정식)에서는 매개효과가 없는 것으로 나타났다. 결국, 동일한 데이터임에도 불구하고 어떤 통계프로그램을 활용하느냐에 따라 다른 결과값(특히, 측정오차가 클수록 결과값이 크게 달라짐)이 나올 수 있음을 알 수 있다.

• Geomechanics and Engineering
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• 제37권1호
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• pp.21-29
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• 2024

The effective management of damage in tunnels is crucial for ensuring their safety, longevity, and operational efficiency. In this paper, we propose an educational management model tailored specifically for addressing damage in tunnels, utilizing numerical solution techniques. By leveraging advanced computational methods, we aim to develop a comprehensive understanding of the factors contributing to tunnel damage and to establish proactive measures for mitigation and repair. The proposed model integrates principles of tunnel engineering, structural mechanics, and numerical analysis to facilitate a systematic approach to damage assessment, diagnosis, and management. Through the application of numerical solution techniques, such as finite element analysis, we demonstrate the efficacy of the proposed model in simulating various damage scenarios and predicting their impact on tunnel performance. Additionally, the educational component of the model provides valuable insights and training opportunities for tunnel management personnel, empowering them to make informed decisions and implement effective strategies for ensuring the structural integrity and safety of tunnel infrastructure. Overall, the proposed educational management model represents a significant advancement in tunnel management practices, offering a proactive and knowledge-driven approach to addressing damage and enhancing the resilience of tunnel systems.

• 대한산업공학회지
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• 제24권4호
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• pp.475-483
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• 1998

Structural changes in an economy system bring about serious problems in establishing economic policies. The boom of middle-east export, the oil shock, and the recent dollar crisis in Korean economy are such examples. Hence, it is necessary to identify and estimate those structural changes. This study focuses on an output and price and analyzes structural changes in aggregate demand and supply. The aggregate demand and supply structures are described by conventional dynamic simultaneous equations model, where each structural change is represented by dummy variables and estimated by the proposed Bayesian method. By applying this model to Korean output and price, structural changes in the aggregate demand and supply are analyzed.

• Smart Structures and Systems
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• 제20권6호
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• pp.669-682
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• 2017

The normalised version of bispectrum, the so-called bicoherence, has often proved a reliable method of damage detection on engineering applications. Indeed, higher-order spectral analysis (HOSA) has the advantage of being able to detect non-linearity in the structural dynamic response while being insensitive to ambient vibrations. Skewness in the response may be easily spotted and related to damage conditions, as the majority of common faults and cracks shows bilinear effects. The present study tries to extend the application of HOSA to damage localisation, resorting to a neural network based classification algorithm. In order to validate the approach, a non-linear finite element model of a 4-meters-long cantilever beam has been built. This model could be seen as a first generic concept of more complex structural systems, such as aircraft wings, wind turbine blades, etc. The main aim of the study is to train a Neural Network (NN) able to classify different damage locations, when fed with bispectra. These are computed using the dynamic response of the FE nonlinear model to random noise excitation.

• Structural Engineering and Mechanics
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• 제86권1호
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• pp.49-68
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• 2023

This study investigates the static and dynamic structural analysis of symmetrical and asymmetrical coupled shear walls using the continuous and modified transfer matrix methods by idealizing the coupled shear wall as a three-field CTB-type replacement beam. The coupled shear wall is modeled as a continuous structure consisting of the parallel coupling of a Timoshenko beam in tension (with axial extensibility in the shear walls) and a shear beam (replacing the beam coupling effect between the shear walls). The variational method using the Hamilton principle is used to obtain the coupled differential equations and the boundary conditions associated with the model. Using the continuous method, closed-form analytical solutions to the differential equation for the coupled shear wall with uniform properties along the height are derived and a numerical solution using the modified transfer matrix is proposed to overcome the difficulty of coupled shear walls with non-uniform properties along height. The computational advantage of the modified transfer matrix method compared to the classical method is shown. The results of the numerical examples and the parametric analysis show that the proposed analytical and numerical model and method is accurate, reliable and involves reduced processing time for generalized static and dynamic structural analysis of coupled shear walls at a preliminary stage and can used as a verification method in the final stage of the project.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.97-102
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• 2003

A real train load fluctuates along the track because of complicated movements(Bouncing, Rolling, Pitching and Yawing) and rail conditions. This research has for its object in development of a numerical real train load model including fluctuation characteristics of lateral forces. It is based on Klingel movement theory of a wheelset on straight track it presents a propriety of application by comparison between a 3D-Numerical analysis result using this train load model and a measured data. And this paper presents further study subject to improve a method about the train load modeling.