• Title/Summary/Keyword: Structural equation

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Design Sensitivity Analysis of the Eigenproblems for Random Structural System (불확정 구조계 고유치에 관한 민감도 해석)

  • 임오강;이병우
    • Computational Structural Engineering
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    • v.7 no.2
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    • pp.131-138
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    • 1994
  • Derivatives of eigenvalues and eigenvectors for statistical properties is presented. Dynamic response of random system including uncertainties for the design variable is calculated with the first order perturbation method to original governing equation. In optimal design methods, there is fundamental requirement for design gradients. A method for calculating the sensitivity coefficients is developed using the governing equation and first order perturbed equation.

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Identification of Linear Structural Systems (선형 구조계의 동특성 추정법)

  • 윤정방
    • Computational Structural Engineering
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    • v.2 no.4
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    • pp.111-116
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    • 1989
  • Methods for the estimation of the coefficient matrices in the equation of motion for a linear multi-degree-of-freedom structure are studied. For this purpose, the equation of motion is transformed into an auto-regressive and moving average with auxiliary input(ARMAX) model. The ARMAX parameters are evaluated using several methods of parameter estimation : such as the least squares, the instrumental variable, the maximum likelihood and the limited information maximum likelihood methods. Then the parameters of the equation of motion are recovered therefrom. Numerical example is given for a 3-story building model subjected to an earthquake exitation.

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Assessing the Causal Relationships of Attitude toward Fish Eating, Health Involvement, Convenience, Fish Consumption and Age (생선 섭취태도, 건강몰입, 편의성, 생선 소비와 연령의 인과관계 평가)

  • Kang, Jong-Heon;Ko, Beam-Seok
    • Korean Journal of Human Ecology
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    • v.16 no.5
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    • pp.1031-1040
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    • 2007
  • The purpose of this study was to assess the causal relationships of attitude toward fish eating, health involvement, convenience, fish consumption and age. A total of 235 questionnaires were completed. Structural equation model was used to assess the causal relationships among constructs. Results of the study demonstrated that the structural equation analysis result for the data also indicated excellent model fit. The influences of age on health involvement and convenience were statistically significant. The influences of health involvement on attitude toward fish eating and fish consumption behavior were statistically significant. The influence of convenience on fish consumption behavior were statistically significant. Moreover, the age had a significant indirect effect on attitude toward fish eating through health involvement. The age also had a significant indirect effect on fish consumption behavior through convenience.

Analytic solution for the interaction between a viscoelastic Bernoulli-Navier beam and a winkler medium

  • Floris, Claudio;Lamacchia, Francesco Paolo
    • Structural Engineering and Mechanics
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    • v.38 no.5
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    • pp.593-618
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    • 2011
  • This paper deals with the problem of the determination of the response of a viscoelastic Bernoulli-Navier beam, which is resting on an elastic medium. Assuming uniaxial bending, the displacement of the beam axis is governed by an integro-differential equation. The compatibility of the displacements between the beam and the elastic medium is imposed through an integral equation. In general and in particular in the case of a Boussinesq medium, the solution has to be pursued numerically. On the contrary, in the case of a Winkler's medium the compatibility equation becomes a linear finite relationship, which allows finding an original analytical solution of the problem for both hereditary and aging behavior of the beam. Some numerical examples complete the paper, in which a comparison is made between the hereditary and the aging model for the creep of the beam.

A Study on Evaluation of Sensibility Vocabularies Using Structural Equation Model (구조방정식 모델을 응용한 감성어휘 평가에 관한 연구)

  • Park, Hee-Sok;Chun, Young-Ho;Shin, Jung-Tae
    • IE interfaces
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    • v.12 no.2
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    • pp.247-253
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    • 1999
  • The main objective of this study is to quantify the appropriateness of the sensibility vocabularies used in sensibility ergonomic evaluation scheme by applying structural equation model. In the conventional sensibility ergonomic evaluation scheme, factor analysis is employed to classify various vocabularies into some common factors. However, since the vocabularies were chosen quite subjectively, it is difficult to ascertain that they represent the product attributes properly. It was shown in a case study that the structural equation model provides the quantitative results to verify whether the selected vocabularies are eligible for further steps of sensibility ergonomic evaluation.

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Structural Equation Modeling of Retention Intention in Nurses (간호사의 재직의도 구조모형)

  • Cho, Hun Ha;Kang, Jung-Mi;Lee, Kyoung-Eun
    • Journal of East-West Nursing Research
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    • v.27 no.2
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    • pp.95-103
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    • 2021
  • Purpose: This study was conducted to investigate the structural equation modeling of retention intention in nurses. Methods: A total of 210 nurses from three hospitals in B city, South Korea participated in this study. A structural equation model was constructed to verify the fitness of this model. Data were analyzed using SPSS 20.0 and AMOS 21.0 programs. Results: The hypothetical model appeared to fit the data. Three of the selected six hypotheses for the hypothetical model were statistically significant. The retention intention model showed significant direct effects for job crafting and job demands and indirect effects for relation oriented culture, which explained 28% of the variation in nurses' retention intention. Conclusion: We found that nurses' job crafting behavior and job demands had significant influences on retention intention and relation oriented culture which affected by the factors job crafting.

Analysis of PMIS Users Satisfaction and Loyalty Using Structural Equation Model

  • Kim, Min-Cheol;Lee, Hyung-Il;Cho, Sang-Ho;Kim, Ju-Hyung
    • Architectural research
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    • v.23 no.1
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    • pp.1-10
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    • 2021
  • Project management information systems (PMIS) have been implemented to support cooperation among the participants of construction projects. Unlike other information systems used by members from an organization with similar culture and business environment, the PMIS are members from one-off fragmented project organization with diverse professional background. Successful operation is significantly affected by the tendencies of client's side and individual awareness of participants. In this regard, it is imperative to evaluate the success of the system based on the individual characteristics of PMIS users. Thus, this study proposes a method for determining the system success by analyzing the extent of the effects of system factors such as System Quality, Information Quality, and Service Quality and individual factors such as a user's IT application ability, Extrinsic Motivation to achieve User Satisfaction, and loyalty. Accordingly, a structural equation model (SEM), an effective tool to examine of the comprehensive structure of a causal relationship, is applied for analysis because the internal awareness of individuals is established as a variable.

HOUSING PRICE MODEL USING GIS IN SEOUL (APPLICATIONS OF STRUCTURAL EQUATION MODELING)

  • Kyong-Hoon Kim;Jae-Jun Kim;Bong-Sik Kim
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.366-375
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    • 2007
  • Our nation has a problem with discrimination of income distribution and inefficient of resources distribution caused by real estate price rising from a sudden economy growth and industrialization. Specially, in recent years, there is a great disparity of condominium price between the north and south of the Han river. Because the housing price is deciede by the immanent value of a house and neighborhood effects of the regional where the house is situated, the housing price is occurred difference. In this study, I analyzed the differences of housing price determinants about condominium developments in the old and new residential areas, and found the important factors that affect the condominium price using Structural Equation Modeling(SEM) The purpose of study is to analyze the influence of various factors of housing price. Also, this study tried to predict real estate market and to establish previous effective real estate policy.

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Damage Estimation of Structures by Second Order Modal Perturbation (2차 모우드 섭동법에 의한 구조물의 손상도 추정)

  • 홍규선;윤정방;류정선
    • Computational Structural Engineering
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    • v.5 no.3
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    • pp.119-126
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    • 1992
  • Most civil engineering structures such as bridges, power plants, and offshore platforms are apt to suffer structural damages over their service lives caused by adverse loadings, such as earthquakes, wind and wave forces. Accumulation of structural damages over a long period of time might cause catastrophic structural failure. Therefore, a methodology for monitoring the structural integrity is essential for assuring the safety of the existing structures. A method for the damage assessment of structures by the second order inverse modal perturbation technique is presented in this paper. Perturbation equation consists of a matrix equation involving matrices of structural changes(stiffness and mass matrix changes) and matrices of modal property changes(natural frequency and mode shape changes). The damages of a structure are represented as changes in the stiffness matrix. In this study, a second order perturbation equation is formulated for the damage assessment of structures, and solved by an iterative procedure. The effectiveness of the proposed method has been investigated through a series of example analysis. The estimated results for the structural damage indicated that the present method yields resonable estimates for the structural changes.

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Prediction of the dynamic flow stress

  • Alves, Marcilio
    • Structural Engineering and Mechanics
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    • v.20 no.5
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    • pp.495-504
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    • 2005
  • This article explores a constitutive equation that is able to correlate stress, strain and strain rate. In order to show the advantages of the constitutive equation here proposed and how its material parameters are obtained, data extracted from the literature, for materials as different as polymers and metallic alloys, are used. Finite element simulation of the impact behaviour of a beam is presented to highlight the care one needs to exercise when using the more traditional Cowper-Symonds equation. The present constitutive equation has shown to be accurate for a wide range of strains, stresses and strain rates.