• Smart Structures and Systems
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• 제15권5호
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• pp.1329-1344
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• 2015

The stiffness of a structure is one of several structural signals that are useful indicators of the amount of damage that has been done to the structure. To accurately estimate the stiffness, an equation of motion containing a stiffness parameter must first be established by expansion as a linear series model, a Taylor series model, or a power series model. The model is then used in multivariate autoregressive modeling to estimate the structural stiffness and compare it to the theoretical value. Stiffness assessment for modeling purposes typically involves the use of one of three statistical model refinement approaches, one of which is the efficient Akaike information criterion (AIC) proposed in this paper. If a newly added component of the model results in a decrease in the AIC value, compared to the value obtained with the previously added component(s), it is statistically justifiable to retain this new component; otherwise, it should be removed. This model refinement process is repeated until all of the components of the model are shown to be statistically justifiable. In this study, this model refinement approach was compared with the two other commonly used refinement approaches: principal component analysis (PCA) and principal component regression (PCR) combined with the AIC. The results indicate that the proposed AIC approach produces more accurate structural stiffness estimates than the other two approaches.

• 한국경영과학회지
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• 제29권3호
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• pp.23-39
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• 2004

This paper focused on empirically testing the ESM(Electronic-Store Success Model). The model was developed by basing upon the ‘Updated D&M(DeLone and McLean) IS Success Model(2003)’ and reflecting the characteristics of marketing and e-business, and composed of the six dimensions including system quality, information quality, service quality, trust, customer loyalty and financial performance. The research model consisting of five dimensions, excluding financial performance, was proposed and empirically verified by structural equation model with respect to data from 224 customers on 69 Electronic-Stores. The results show that system quality and information quality significantly influence service quality, and that service quality also significantly influence trust and customer loyalty, and that trust has significant influence on customer loyalty.

• 디지털융복합연구
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• 제15권5호
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• pp.419-429
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• 2017

본 연구는 대학생의 불안과 우울이 스마트폰 중독에 미치는 영향에 있어서 성별의 조절효과를 검증하는데 있으며, 이를 위해 임의 표본추출한 경기지역 대학생 331명을 대상으로한 설문 결과에 대해 구조방정식모형을 설계하고 검증하였다. 연구 결과, 여학생이 남학생보다 불안, 우울, 스마트폰 중독 수준이 유의미하게 높은 것으로 나타났다. 둘째, 불안과 우울이 스마트폰 중독에 미치는 영향을 알아보기 위한 구조방정식 모형 분석 결과, 우울이 스마트폰 중독에 영향을 주는 것으로 나타났다. 셋째, 불안, 우울이 스마트폰 중독에 미치는 영향에 대해 성별이 조절효과를 갖는 것으로 나타났다. 남학생은 불안이, 여학생은 우울이 스마트폰 중독에 영향을 미쳤다. 본 연구 결과를 토대로 스마트폰 중독을 예방하고 중재하는데 있어서 성별에 따라 다른 접근이 필요함을 논의하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.971-976
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• 2006

This paper presents a design technique of steel structures subjected to static and dynamic loadings using practical nonlinear inelastic analysis software. The beam-column approach using the stability functions and the plastic hinge concept enables the software to suitably predict second-order effects and inelastic behavior of beam-columns. For dynamic analysis. the incremental from of the equation of motion is solved by the use of a step-by-step numerical integration procedure in which the assumption of constant acceleration over a small time step is employed. The accuracy of the analysis program is validated using the results of ABAQUS program and experimental tests. A user-friendly graphic interface of the software is developed to facilitate the modeling process and result interpretation of the problem. A design example of large span bridge is presented to detail the direct design process using the practical advanced analysis software.

• 한국컴퓨터정보학회논문지
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• 제26권6호
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• pp.155-166
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• 2021

본 연구에서는 공적이전소득과 사적이전소득이 노인의 삶의 만족에 영향을 미치는 데 있어 우울과 사회적 지지가 다중매개효과를 가지는가를 규명하고자 한다. 이를 위해 국민노후보장패널조사(KReLS: Korean Retirement & Income Study) 데이터 중 7차 패널자료(2017년도)를 분석에 사용하였으며, 구조방정식모형(structural equation modeling, SEM)을 활용하여 분석을 실시하였다. 분석결과, 첫째, 노인의 공적이전소득이 많을수록 우울 수준은 낮아졌으며, 사회적 지지는 높아졌고, 삶의 만족은 높아지는 것으로 분석되었다. 둘째, 노인의 공적이전소득, 사적이전소득이 삶의 만족에 영향을 미치는데 있어서 우울의 부분매개효과가 검증되었다. 셋째, 노인의 공적이전소득, 사적이전소득이 삶의 만족에 영향을 미치는데 있어서 사회적 지지의 부분매개효과가 검증되었다. 넷째, 노인의 공적이전소득과 사적이전소득이 삶의 만족에 미치는 영향에서 우울과 사회적 지지의 다중매개효과가 유의함이 검증되었다. 이러한 분석결과에 근거해, 노인의 사회적 지지망 강화를 위한 Community Care 사업의 활성화 등의 정책적 제안을 하였다.

• 유통과학연구
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• 제14권11호
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• pp.129-138
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• 2016

Purpose - The ICT(information and communications technologies) development is affecting consumer behaviors on selecting channel or distribution system. This study aims to advance our knowledge about the factors influencing omni-channel behaviors. This study considers the positive brand experience as the moderating variable into the relationship between omini-channel use intention and consumer brand relation. Also, the effect of positive brand experience on consumer-brand relation is researched. Research design, data, and methodology - This study conducted an empirical test with the subject as customers who purchase goods or service through on-off cross channel simultaneously. The research model is developed from prior literatures about influencing variables on channel selection. The structure of this study is designed to identify causal relationships between the variables. 268 survey data from the questionnaire survey which is conducted to target customers who use online and offline channels, is used for empirical analysis. This study validates generality with descriptive statistics and data reliability with Cronbach's alpha value. The exploratory factor analysis is used for value purification. Then, the confirmatory factor analysis is conducted for structural equation modeling. Finally, the execute structural equation modeling is analyzed to confirm the hypotheses Results - First, the two causal influences between perceived performance risk and the propensity of omni-channel and between price consciousness and the propensity of omni-channel are verified through the empirical test. Second, the result identifies that the propensity of omni-channel is influenced on consumer-brand relationship. Third, the AMOS analysis proves that the moderating variable, positive brand experience, has significant positive impact on consumer-brand relationship. This significant relationship is highly supported by the regression analysis between brand experience and propensity of omni-channel because it results that positive brand experience has positive impact on the propensity of omni-channel. All hypotheses are verified to be true. Conclusions - Based on the empirical result, this study confirms that perceived performance risk and price consciousness are the important factors influencing propensity of omni-channel. According to the additional analysis, the moderating variable and positive brand experience plays important role between the propensity of omni-channel and consumer-brand relationship. Furthermore, positive brand experience influences more on consumer-brand relationship than non-positive brand experience.

• 성인간호학회지
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• 제28권4호
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• pp.415-423
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• 2016

Purpose: This study was designed to identify the structural relationships among psychosocial variables related to sick role behavioral compliance among patients undergoing hemodialysis. Methods: The subjects were 476 patients from seven major hospitals and twelve dialysis centers located in D and P cities. Data were collected using self-report questionnaires. Data analysis was done by using SPSS/WIN 18.0 and AMOS 18.0 programs for structural equation modeling, to estimate the hypothesized model. Results: This findings support that a modified path model is efficient and appropriate to explain sick role behavioral compliance among hemodialysis patients. These factors account for 80.1% of the variance of sick-role behavioral compliance among hemodialysis patients. The variables having direct effect on sick role behavioral compliance were knowledge related to hemodialysis, social support, attitude, self-efficacy and intention. Conclusion: The modified model explains the integration process of psychosocial and behavior variables for sick-role behavioral compliance among patients undergoing hemodialysis.

• 아동학회지
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• 제33권1호
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• pp.81-92
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• 2012

The main purpose of this study was to analysis of the structural relationship between early adolescents' social relationships, self esteem, life satisfaction, and school adjustment. Data harvested from the Korean Youth Panel Survey 2010 was analyzed by means of Structural Equation Modeling (SEM). The results indicate that the model is appropriate in terms of goodness of fit and significant path based on the validation procedure. According to the model, the social relationships have some degree of influence upon self esteem which then goes on to have a subsequent effect on life satisfaction; which in turn have a further influence on school adjustment. Social relationships also have a direct influence on life satisfaction, school adjustment, and self esteem has a direct influence on school adjustment. The paper concludes with an outline of the implications of the present study for future studies on this subject.

• Structural Engineering and Mechanics
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• 제66권3호
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• pp.329-341
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• 2018

This paper considers the smooth receding contact problem between a homogeneous half-plane and a composite laminate composed of an inhomogeneously coated elastic layer. The inhomogeneity of the elastic modulus of the coating is approximated by an exponential function along the thickness dimension. The three-component structure is pressed together by either a concentrated force or uniform pressures applied at the top surface of the composite laminate. Both semianalytical and finite element analysis are performed to solve for the extent of contact and the contact pressure. In the semianalytical formulation, Fourier integral transformation of governing equations and boundary conditions leads to a singular integral equation of Cauchy-type, which can be numerically integrated by Gauss-Chebyshev quadrature to a desired degree of accuracy. In the finite element modeling, the functionally graded coating is divided into homogeneous sublayers and the shear modulus of each sublayer is assigned at its lower boundary following the predefined exponential variation. In postprocessing, the stresses of any node belonging to sublayer interfaces are averaged over its surrounding elements. The results obtained from the semianalytical analysis are successfully validated against literature results and those of the finite element modeling. Extensive parametric studies suggest the practicability of optimizing the receding contact peak stress and the extent of contact in multilayered structures by the introduction of functionally graded coatings.

• 가정과삶의질연구
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• 제30권2호
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• pp.75-86
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• 2012

The purpose of this study was to investigate the structural relationships school-aged children and related variables. For this study, the respondents were 704 children in elementary schools in the areas of Gyeongsan-Si and Daegu-Si. The questionnaires and psychological tests used in this study surveyed the following concepts: suicide ideation, social support, self-esteem and the scale of depression. The collected data were analyzed with AMOS 19.0, a statistical program for structural equation modeling, to estimate the hypothesized structural equation model. The results were as follows: First, self-esteem, - and depression as perceived by children were found to affect their suicide ideation directly. Second, parental support and teacher support as perceived by children were found to affect children's depression directly. Third, parental support, teacher support, and the support of friend's as perceived by children were found to affect-children's self-esteem directly. Last, parental support and, teacher's support did not show direct effect on children's suicide ideation, though these factors had an indirect effect on suicide ideation through the children's self-esteem and depression. Finally, teacher's support did not direct effectly children's suicide ideation, whereas it had an having indirect effect on suicide ideation through the children's self-esteem.