• Title/Summary/Keyword: Structural equations model

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Exploring the Mediating Effect of Conspicuous Consumption by Utilizing Mobile Phone Brands

  • KWON, Youngseo
    • Journal of Distribution Science
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    • v.18 no.3
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    • pp.15-24
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    • 2020
  • Purpose: The purpose of this study is to investigate the mediating effect of conspicuous brand usage between brand experience and brand loyalty in relational perspective, and to probe the difference between the positively experienced consumers and the negatives. Research design, data and methodology: Apple iPhone, Samsung Galaxy, and other brands were suggested as consideration set to be selected from 223 Amazon Mechanical Turk respondents, and they answered the structured survey of 33 questions made by Qualtrics with 5-point Likert scale. Structural Equations Model (SEM) was employed to test the hypothesized model, and RStudio and SPSS 18 were used to analyze the dataset. Results: It was confirmed that the more consumers have positive brand experience, the more they are loyal to brand. Conspicuous brand usage can be positively mediated, and consumers who experienced high conspicuous brand usage are more likely to be loyal to the brand. Conclusions: It is noteworthy to find the mediating effect of conspicuous brand usage, and the hidden mechanism between brand experience and brand loyalty. Managers can promote positive conspicuous brand usage when consumers get in touch with product and service channels. By providing impressive conspicuous brand experience, the brand loyalty of the band can be enhanced.

Effect of hydraulic and structural parameters on the wave run-up over the berm breakwaters

  • Milanian, Farzad;Niri, Mahmood Zakeri;Najafi-Jilani, Ataollah
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.3
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    • pp.282-291
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    • 2017
  • The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged Navier-Stokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

Finite element vibration analysis of nanoshell based on new cylindrical shell element

  • Soleimani, Iman;Beni, Yaghoub T.;Dehkordi, Mohsen B.
    • Structural Engineering and Mechanics
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    • v.65 no.1
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    • pp.33-41
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    • 2018
  • In this paper, using modified couple stress theory in place of classical continuum theory, and using shell model in place of beam model, vibrational behavior of nanotubes is investigated via the finite element method. Accordingly classical continuum theory is unable to correctly compute stiffness and account for size effects in micro/nanostructures, higher order continuum theories such as modified couple stress theory have taken on great appeal. In the present work the mass-stiffness matrix for cylindrical shell element is developed, and by means of size-dependent finite element formulation is extended to more precisely account for nanotube vibration. In addition to modified couple stress cylindrical shell element, the classical cylindrical shell element can also be defined by setting length scale parameter to zero in the equations. The boundary condition were assumed simply supported at both ends and it is shown that the natural frequency of nano-scale shell using the modified coupled stress theory is larger than that using the classical shell theory and the results of Ansys. The results have indicated using the modified couple stress cylindrical shell element, the rigidity of the nano-shell is greater than that in the classical continuum theory, which results in increase in natural frequencies. Besides, in addition to reducing the number of elements required, the use of this type of element also increases convergence speed and accuracy.

Aeroelastic Stability Analysis of Hingeless Rotor Blades with Composite Flexures

  • Kim, Seung-Jo;Kim, Ki-Tae;Jung, Sung-Nam
    • Journal of Mechanical Science and Technology
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    • v.16 no.4
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    • pp.512-521
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    • 2002
  • The flap-lag-torsion coupled aeroelastic behavior of a hingeless rotor blade with composite flexures in hovering flight has been investigated by using the finite element method. The quasisteady strip theory with dynamic inflow effects is used to obtain the aerodynamic loads acting on the blade. The governing differential equations of motion undergoing moderately large displacements and rotations are derived using the Hamilton's principle. The flexures used in the present model are composed of two composite plates which are rigidly attached together. The lead-lag flexure is located inboard of the flap flexure. A mixed warping model that combines the St. Versant torsion and the Vlasov torsion is developed to describe the twist behavior of the composite flexure. Numerical simulations are carried out to correlate the present results with experimental test data and also to identify the effects of structural couplings of the composite flexures on the aeroelastic stability of the blade. The prediction results agree well with other experimental data. The effects of elastic couplings such as pitch-flap, pitch-lag, and flap-lag couplings on the stability behavior of the composite blades are also investigated.

Effects of viscoelastic memory on the buffeting response of tall buildings

  • Palmeri, A.;Ricciardelli, F.;Muscolino, G.;De Luca, A.
    • Wind and Structures
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    • v.7 no.2
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    • pp.89-106
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    • 2004
  • The response of tall buildings to gust buffeting is usually evaluated assuming that the structural damping is of a viscous nature. In addition, when dampers are incorporated in the design to mitigate the response, their effect is allowed for increasing the building modal damping ratios by a quantity corresponding to the additional energy dissipation arising from the presence of the devices. Even though straightforward, this procedure has some degree of inaccuracy due to the existence of a memory effect, associated with the damping mechanism, which is neglected by a viscous model. In this paper a more realistic viscoelastic model is used to evaluate the response to gust buffeting of tall buildings provided with energy dissipation devices. Both cases of viscous and hysteretic inherent damping are considered, while for the dampers a generic viscoelastic behaviour is assumed. The Laguerre Polynomial Approximation is used to write the equations of motion and find the frequency response functions. The procedure is applied to a 25-story building to quantify the memory effects, and the inaccuracy arising when the latter is neglected.

The Roles of Health Consciousness and Service Quality toward Customer Purchase Decision

  • TRAN, Tung Anh;PHAM, Ngan Thi;PHAM, Kien Van;NGUYEN, Linh Cam Tran
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.345-351
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    • 2020
  • The study investigates how marketing mix factors are mediated by health consciousness and service quality in creating fresh fruit buying decisions of customers in Vietnam. This study employs samples of customers in Vietnam via the survey questionnaire. The authors have used a total of 256 responses that acquired the valid criteria. The compound of data analysis comprises reliability test, validity test, exploratory factor analysis, group analysis and multiple regression analysis to structure the hypothesized model. Respectively, the structural equation model (SEM) is applied to conduct the multiple multivariate equations. By the assumption of causal-effect relationship between independent variables such as marketing mixed factors, and mediator as health consciousness and service quality, which potentially impact on purchase decision; the SEM method is deployed. The results reveal that consumers have paid no attention to the marketing mix factors, but they care much about service quality and health consciousness. Thus, health consciousness and service quality are effective mediators. These findings are new and contribute to the consumer behavior and retail marketing literature. The findings of this study can provide assistance to managers in the given field to understand more easily the consumer behavior about fresh fruits, then improve their own performance.

The modal characteristics of non-uniform multi-span continuous beam bridges

  • Shi, Lu-Ning;Yan, Wei-Ming;He, Hao-Xiang
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.997-1017
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    • 2014
  • According to the structure characteristics of the non-uniform beam bridge, a practical model for calculating the vibration equation of the non-uniform beam bridge is given and the application scope of the model includes not only the beam bridge structure but also the non-uniform beam with added masses and elastic supports. Based on the Bernoulli-Euler beam theory, extending the application of the modal perturbation method and establishment of a semi-analytical method for solving the vibration equation of the non-uniform beam with added masses and elastic supports based is able to be made. In the modal subspace of the uniform beam with the elastic supports, the variable coefficient differential equation that describes the dynamic behavior of the non-uniform beam is converted to nonlinear algebraic equations. Extending the application of the modal perturbation method is suitable for solving the vibration equation of the simply supported and continuous non-uniform beam with its arbitrary added masses and elastic supports. The examples, that are analyzed, demonstrate the high precision and fast convergence speed of the method. Further study of the timesaving method for the dynamic characteristics of symmetrical beam and the symmetry of mode shape should be developed. Eventually, the effects of elastic supports and added masses on dynamic characteristics of the three-span non-uniform beam bridge are reported.

Nonlinear dynamic analysis of spiral stiffened functionally graded cylindrical shells with damping and nonlinear elastic foundation under axial compression

  • Foroutan, Kamran;Shaterzadeh, Alireza;Ahmadi, Habib
    • Structural Engineering and Mechanics
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    • v.66 no.3
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    • pp.295-303
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    • 2018
  • The semi-analytical method to study the nonlinear dynamic behavior of simply supported spiral stiffened functionally graded (FG) cylindrical shells subjected to an axial compression is presented. The FG shell is surrounded by damping and linear/nonlinear elastic foundation. The proposed linear model is based on the two-parameter elastic foundation (Winkler and Pasternak). A three-parameter elastic foundation with hardening/softening cubic nonlinearity is used for nonlinear model. The material properties of the shell and stiffeners are assumed to be FG. Based on the classical plate theory of shells and von $K{\acute{a}}rm{\acute{a}}n$ nonlinear equations, smeared stiffeners technique and Galerkin method, this paper solves the nonlinear vibration problem. The fourth order Runge-Kutta method is used to find the nonlinear dynamic responses. Results are given to consider effects of spiral stiffeners with various angles, elastic foundation and damping coefficients on the nonlinear dynamic response of spiral stiffened simply supported FG cylindrical shells.

Reliability analysis-based conjugate map of beams reinforced by ZnO nanoparticles using sinusoidal shear deformation theory

  • Keshtegar, Behrooz;Kolahchi, Reza
    • Steel and Composite Structures
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    • v.28 no.2
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    • pp.195-207
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    • 2018
  • First-order reliability method (FORM) is enhanced based on the search direction using relaxed conjugate reliability (RCR) approach for the embedded nanocomposite beam under buckling failure mode. The RCR method is formulated using discrete conjugate map with a limited scalar factor. A dynamical relaxed factor is proposed to control instability of proposed RCR, which is adjusted using sufficient descent condition. The characteristic of equivalent materials for nanocomposite beam are obtained by micro-electro-mechanical model. The probabilistic model of nanocomposite beam is simulated using the sinusoidal shear deformation theory (SSDT). The beam is subjected to external applied voltage in thickness direction and the surrounding elastic medium is modeled by Pasternak foundation. The governing equations are derived in terms of energy method and Hamilton's principal. Using exact solution, the implicit buckling limit state function of nanocomposite beam is proposed, which is involved various random variables including thickness of beam, length of beam, spring constant of foundation, shear constant of foundation, applied voltage, and volume fraction of ZnO nanoparticles in polymer. The robustness, accuracy and efficiency of proposed RCR method are evaluated for this engineering structural reliability problem. The results demonstrate that proposed RCR method is more accurate and robust than the excising reliability methods-based FORM. The volume fraction of ZnO nanoparticles and the applied voltage are the sensitive variables on the reliable levels of the nanocomposite beams.

Thermo-electro-elastic nonlinear stability analysis of viscoelastic double-piezo nanoplates under magnetic field

  • Ebrahimi, Farzad;Hosseini, S. Hamed S.;Selvamani, Rajendran
    • Structural Engineering and Mechanics
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    • v.73 no.5
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    • pp.565-584
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    • 2020
  • The nonlinear thermo-electro-elastic buckling behavior of viscoelastic nanoplates under magnetic field is investigated based on nonlocal elasticity theory. Employing nonlinear strain-displacement relations, the geometrical nonlinearity is modeled while governing equations are derived through Hamilton's principle and they are solved applying semi-analytical generalized differential quadrature (GDQ) method. Eringen's nonlocal elasticity theory considers the effect of small size, which enables the present model to become effective in the analysis and design of nano-sensors and nano actuators. Based on Kelvin-Voigt model, the influence of the viscoelastic coefficient is also discussed. It is demonstrated that the GDQ method has high precision and computational efficiency in the buckling analysis of viscoelastic nanoplates. The good agreement between the results of this article and those available in literature validated the presented approach. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as electric voltage, small scale effects, elastomeric medium, magnetic field, temperature effects, the viscidity and aspect ratio of the nanoplate on its nonlinear buckling characteristics. It is explicitly shown that the thermo-electro-elastic nonlinear buckling behavior of viscoelastic nanoplates is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of viscoelastic nanoplates as fundamental elements in nanoelectromechanical systems.