• Title/Summary/Keyword: Structural Equation Analysis

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

  • 임오강;이병우
    • Computational Structural Engineering
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    • v.7 no.3
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    • pp.115-122
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    • 1994
  • Design sensitivity analysis of the second order perturbed eigenproblems for random structural system is presented. Dynamic response of random system including uncertainties for the design variable is calculated with the first order and second 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 direct differentiation method for the governing equation and first order and second order perturbed equation.

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Vibration Analysis of the Beam Structure with a Moving Mass (이동물체에 의한 보 구조물의 진동 해석)

  • 이우식;임강민
    • Computational Structural Engineering
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    • v.8 no.4
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    • pp.57-64
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    • 1995
  • This paper introduced a simple numerical analysis algorithm for the calculation of the dynamic responses of the beam structure with a moving mass. The dynamic equation of motion of the Bernoulli-Euler beam is derived by considering the moving mass as a moving particle, and the dynamic equation of motion is transformed into an integro-differential equation by use of the structural influence function. The numerical solutions of the integro-differential equation are obtained by the modal analysis approach, and compared with those cited from well-known references. The proves that the numerical analysis algorithm proposed herein provide very reliable results, and thus it can be utilized in the design analysis of the beamlike structures exited by a mass which is traveling on it.

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Dynamic Analysis of Concrete Rigid Barriers by Computer Simulation (컴퓨터 시뮬레이션에 의한 콘크리트 교량난간의 동적거동 분석)

  • 김재일;안재석;박진환;우광성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.217-224
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    • 2004
  • This paper proposed a new impact equation by analyzing the form of the proposal section 1 and section 2 proposed by Korea Highway Corporation, F-type, NJ-type and SS-type with HVOSM program Because the impact equation proposed by Ministry Construction & Transportation(1992) considered an only impact velocity, the values of impact loads calculated by HVOSM program are 21.5∼44 times as large as those using equation of MCT. The values of HVOSM program are 1.4 times as large as those of Olson's model because Olson's equation consider impact vehicle, impact velocity and impact angle. But, it does not consider geometric characters, while HVOSM program considers characters. Considering the shapes of sections and the conditions of colliding, HVOSM program can calculate imuact load. As Multiple Regression Analysis is conducted with the calculated values, the R² values of the proposed equations are 0.984 in SB1∼SB3 and 0.958 in SB4∼SB6. After all, the equation proposed in this study have better results than Olson's equation.

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Customer satisfaction and competitiveness in Global Company: Structural Equation Modeling(SEM) approach to identify the role quality factor (글로벌 기업의 고객만족과 경쟁력 모델 구축: 품질요인확인을 위한 구조방정식모델 적용)

  • Kim, Gye Soo;Park, Jong Cheol
    • Journal of Korean Society for Quality Management
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    • v.43 no.1
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    • pp.43-56
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    • 2015
  • Purpose: In this research, We made the conceptual frameworks for SEM(Structural Equation Modeling) on Global quality's origin and empirical research. Developing conceptual frameworks is an important step in theory building and theory testing. This research model was developed by strong theoretical foundation which is quality and systematical model. Methods: Questionnaire was developed, and data was collected and analyzed for this study. The analysis was conducted using SEM(Structural Equation Modeling). Results: Results show that process quality and interaction quality are important drivers in customer satisfaction. Customer satisfaction is strongly impact on customer loyalty(repeated purchase). Conclusion: In turbulent business era, Global company require not only excellent quality but also create customer oriented culture and control over operation in the foreign country.

A Rate-Dependent Elastic Plastic Constitutive Equation in Finite Deformation Based on a Slip Model (슬립모델을 이용한 변형률의존 유한변형 탄소성재료의 구성방정식 개발)

  • 남용윤;김사수;이상갑
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.04a
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    • pp.181-188
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    • 1994
  • Generally, the structural material shows rate dependent behaviors, which require to constitute different strain-stress relations according to strain rates. Conventional rate- independent constitutive equations used in general purpose finite analysis programs are inadequate for dynamic finite strain problems. In this paper, a rate dependent constitutive equation for elastic-plastic material was developed. The plastic stretch rate was modeled based on slip model with dislocation velocity and density so that there is no yielding condition, and no loading conditions. Non-linear hardening rule was also introduced for finite strain. Material constants of present constitutive equation were determined by experimental data of mild steel. The constitutive equation was applied to uniaxile tension. It was appeared that the present constitutive equation well simulates rate dependent behaviors of mild steel.

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Finite Elements Analysis Application to the Structural Design of the Frame Type Furniture (골조형(骨造型) 가구구조설계(家具構造設計)에의 유한요소해석 응용)

  • Chung, Woo-Yang;Eckelman, Carl A.
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.8-15
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    • 1995
  • This analytical study was carried out to make quality and productivity up in designing the frame-type furniture with semi-rigid joint by understanding the mechanical and structural behavior of the joint and by evaluating the validity of application of the time-saving Finite Element Method to its structural analysis. Slope deflection equation for rigid joint was modified to describe the moment-rotation behavior of semi-rigid joint and the joint stiffness factor(Z) could be calculated to lessen the experimental expense. It was proved that Finite Element Analysis with imaginary elements having equivalent MOE to the semi-rigid joint could be the alternative method for the structural analysis of the frame-type furniture, comparing the internal rotation of the 2-dimensional beam-to-column model with two-pin(wooden dowel) from the finite element method with other available theoretical and experimental rotation value.

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Structural relations of late night snacking choice attributes and health promotion behaviors according to dietary style of industrial workers

  • Park, Young Il;Joo, Nami
    • Nutrition Research and Practice
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    • v.8 no.4
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    • pp.432-438
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    • 2014
  • BACKGROUND/OBJECTIVES: This research was conducted to develop a construct model regarding the dietary style, late night snacking choice attributes and health promotion behaviors of industrial workers. SUBJECTS/METHODS: The surveys were collected during the period between January and February 2013. A statistical analysis of 888 industrial workers was conducted using SPSS 12.0 for Windows and SEM (Structural Equation Model) using AMOS (Analysis of Moment Structure) 5.0 statistics package. RESULTS: The results of the correlations between all variables showed significant positive correlations (P < 0.05). Results of factors analysis on dietary styles were categorized into five factors and health promotion behaviors were categorized into four. The reliability of these findings was supported by a Cronbach's alpha coefficient of 0.6 and higher for all other factors. After obtaining the factors from processing an exploratory factor analysis and the end results supported the validity. In an attempt to study the late night snacking choice attributes in accordance to dietary styles and the health promotion behaviors of industrial workers, a structural equation model was constructed and analyzed. CONCLUSIONS: All tests proved the model satisfied the recommended levels of the goodness on fit index, and thus, the overall research model was proved to be appropriate.

A Study on Structural Analysis for Aircraft Gas Turbine Rotor Disks Using the Axisymmetric Boundary Integral Equation Method (축대칭 경계적분법에 의한 항공기 가스터빈 로터디스크 구조해석에 관한 연구)

  • Kong, Chang-Duk;Chung, Suk-Choo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.8
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    • pp.2524-2539
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    • 1996
  • A design process and an axisymmetric boundary integral equation method for precise structural analysis of the aircraft gas turbine rotor disk were developed. This axisymmetric boundary integral equation method for stress and steady-state thermal analysis was improved in solution accuracy by appling an implicit technique for Cauchy principal value evaluation, a subelement technique for weak singular integral evaluation and a double exponentical integral technoque for internal point solution near boundary surfaces. Stresses, temperatures, low cycle fatigue lifes and critical speeds for the turbine rotor disk of the thrust 1421 N class turbojet engine were analysed in a pratical calculation model problem.

Structural Relations of Learning Orientation, Self-Efficacy, Learning Transfer and Job Performance of Farmers who Participated in the Strong and Small Farms Education (강소농교육 참여 농업인의 직무성과와 학습지향성, 자기효능감, 학습전이의 구조적 관계)

  • Kim, Sa-Gyun;Yang, Suk-Joon
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.4
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    • pp.455-464
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    • 2015
  • The purposes of this study are to explain and identify the frame of structural relations of learning orientation, self-efficacy, learning transfer and job performance of farmers who participated in the strong and small farms education. This is an experimental research with the data collected from 495 farmers who have taken the farm education. Based on the collected data, the study conducted a structural equation modeling(SEM) to confirm the validity and analyze the structural relations of the suggested model. Using measured and latent variables drew from the analyses, the study set a structural equation model and tested the model by analysis of the structural equation modeling with AMOS 18.0. The results found from the empirical analysis can be summarized as follows. 1) Learning orientation and self-efficacy positively influenced job performance through learning transfer. 2) The hypothesis that learning orientation would have direct impact on job performance was not supported. 3) The strong and small farms education is useful to expand learning transfer and to enhance job performance. So, government policy support has to reinforce learning support on farmers in order to achieve high performance of learning and job management through farm educations.

The Study on Comparative Analysis of the Same Data through Regression Analysis Model and Structural Equation Model (동일 데이터의 비교분석에 관한 연구 (회귀분석모형과 구조방정식모형))

  • Choi, Chang Ho;You, Yen Yoo
    • Journal of Digital Convergence
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    • v.14 no.6
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    • pp.167-175
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    • 2016
  • This study analyzed empirically the same data through SPSS statistic(regression analysis) and AMOS program(structural equation model) used for cause and effect analysis. The result of empirical analysis was as follows. The different outcome of coefficients and p-values were deducted. Especially, in the mediated effect testing, meanwhile, SPSS statistic(regression analysis) pictured mediated effect, AMOS program(structural equation model) did not picture mediated effect on the reject zone of null hypothesis(absolute t-value and C.R.-value were nearby 1.96). Eventually, this study showed that what program used determined the outcomes of coefficients and p-values(In particular, the outcomes were differentiated further in the increasing measurement error) though using the same data.