• 제목/요약/키워드: Structural equation

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

  • 임오강;이병우
    • 전산구조공학
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    • 제7권2호
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    • pp.131-138
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    • 1994
  • 실제 시스템에는 재료의 물성과 기하학적 매개변수, 외부 하중등에 불확정 요인들을 내포하고 있다. 그러므로 제작시나 수학적으로 모델링할 때 이 요인들을 설계에 반영해 주어야 한다. 기울기에 근거를 둔 최적설계 수행시에 변동량을 고려하여 제한식으로 설정하고, 설계 민감도를 구할 수 있는 방법을 제시하였다.

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선형 구조계의 동특성 추정법 (Identification of Linear Structural Systems)

  • 윤정방
    • 전산구조공학
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    • 제2권4호
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    • pp.111-116
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    • 1989
  • 구조설계에 작용되는 하중과 이로 인한 동적거동의 측정기록을 바탕으로 하여 구조계의 미지계수 행렬을 추정하는 방법에 대하여 연구하였다. 이를 위하여 통상 미분방정식으로 주어지는 운동방정식을 ARMAX 모형식으로 변환시켜 ARMAX 식의 계수행렬을 추정한 후, 이로부터 운동방정식의 계수행렬을 구하였다. ARMAX 계수의 추정은 최소자승법, Instrumental Variable방법, Maximum Likelihood방법 및 Limited Information Maximum Likelihood방법을 사용하여 수행하였으며, 지진 하중을 받는 3층 건물 모형을 예제로 하여 각 방법의 효율성을 비교분석하였다.

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

  • 강종헌;고범석
    • 한국생활과학회지
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    • 제16권5호
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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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    • 제38권5호
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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.

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

  • 박희석;전영호;신정태
    • 산업공학
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    • 제12권2호
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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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간호사의 재직의도 구조모형 (Structural Equation Modeling of Retention Intention in Nurses)

  • 조헌하;강정미;이경은
    • 동서간호학연구지
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    • 제27권2호
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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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    • 제23권1호
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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
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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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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2차 모우드 섭동법에 의한 구조물의 손상도 추정 (Damage Estimation of Structures by Second Order Modal Perturbation)

  • 홍규선;윤정방;류정선
    • 전산구조공학
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    • 제5권3호
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    • pp.119-126
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    • 1992
  • 교량, 발전소, 해양구조물과 같은 토목구조물은 사용기간중에 지진, 바람, 파랑하중등에 의해 구조적 손상을 받기 쉽다. 장기간에 걸쳐 구조물에 손상이 누적되면 구조물 전체의 파괴를 초래할 수도 있다. 따라서 현존하는 구조물의 안전성을 분석하기 위한 구조물의 손상도를 추정하는 방법이 필요하다. 본 논문에서는 Inverse Modal Perturbation기법을 이용하여 구조물의 손상도를 추정하는 방법에 대하여 연구하였다. Perturbation식은 구조물의 강성 및 질량행렬의 변화량과 구조물의 고유진동수와 모우드형상의 변화량의 식으로 구성된다. 또한 구조물의 손상은 강성행렬의 변화량으로 표현하였다. 본 연구에서는 구조물의 손상도추정의 효율성을 증대시키기 위하여 2차-Perturbation식을 구성하고, 이것을 반복적인 절차를 거쳐 해를 구하는 방법에 대하여 연구하였다. 제안된 방법의 효율성은 일련의 예제해석을 통하여 검증하였으며, 추정된 결과로 부터 본 방법이 구조물의 손상을 적절히 산정함을 알 수 있었다.

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Prediction of the dynamic flow stress

  • Alves, Marcilio
    • Structural Engineering and Mechanics
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    • 제20권5호
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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.