• Advances in aircraft and spacecraft science
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• v.5 no.6
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• pp.653-669
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• 2018

This work has the objective to analyze multibody mechanisms of inflatable structures for manned space applications. The focus is on the evaluation of the main characteristics of MaxFlex, a new module of MSC Adams including the effect of nonlinear flexible bodies. MaxFlex integrates the nonlinear Finite Element Analysis (FEA) of Nastran-SOL400-and the Adams multibody capabilities in one unique solver, providing an improvement concerning the concept and technology based on the co-simulation among solvers. MaxFlex converts the equations of motion of the nonlinear FEA into phase-space form and discretizes them according to the multibody system integrator framework. The numerical results deal with an inflatable manned space module having rigid components and a flexible coating made of Kevlar. This paper is a preliminary assessment of the computational capabilities of the software and does not provide realistic guidelines for the actual design of the structure. The analysis leads to some recommendations related to the main issues to consider in a nonlinear simulation including both rigid and flexible components. The results underline the importance of realistic deployment times and applied forces. Also, a proper structural modeling is necessary, but can lead to excessive computational overheads.

• Structural Engineering and Mechanics
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• v.61 no.6
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• pp.721-736
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• 2017

In this paper, free vibration characteristics of functionally graded (FG) nanobeams embedded on elastic medium are investigated based on third order shear deformation (Reddy) beam theory by presenting a Navier type solution for the first time. The material properties of FG nanobeam are assumed to vary gradually along the thickness and are estimated through the power-law and Mori-Tanaka models. A two parameters elastic foundation including the linear Winkler springs along with the Pasternak shear layer is in contact with beam. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived based on third order shear deformation beam theory through Hamilton's principle and they are solved applying analytical solution. According to the numerical results, it is revealed that the proposed modeling can provide accurate frequency results of the FG nanobeams as compared to some cases in the literature. The obtained results are presented for the vibration analysis of the FG nanobeams such as the influences of foundation parameters, gradient index, nonlocal parameter and slenderness ratio in detail.

• Structural Engineering and Mechanics
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• v.64 no.6
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• pp.793-802
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• 2017

The damage of concrete due to the expansion of alkali-aggregate reaction (AAR) and thermal-chemical reactions affecting the strength of concrete is studied. The empirical equations for the variations of expansion of AAR, compressive strength and degradation of the modulus of elasticity with time, and compressive strength with degradation of the modulus of elasticity are proposed by analysing numerous experimental data. It is revealed that the expansion of AAR and compressive strength increase with time. The proposed combination of the time variations of chemical and mechanical parameters provides a satisfactory prediction of the concrete strength. Seismic analysis of the aged Koyna dam is conceded for two different long-term experimental data of concrete incorporating the proposed AAR based properties. The responses of aged Koyna dam reveal that the crest displacement of the Koyna dam significantly increases with time while the contour plots show that major principal stress at neck level reduces with time. As the modulus of elasticity decreases with ages the stress generated in the concrete structure get reduces. On the other hand with lesser value of modulus of elasticity the structure becomes more flexible and the crest displacement becomes very high that cause the seismic safety of the dam reduce.

• 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.

• Industrial Engineering and Management Systems
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• v.14 no.3
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• pp.236-247
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• 2015

This study aims to examine the effects of industrial clustering and manufacturing flexibility on innovation capability and operational performance. This study follow a survey method to collect data pertaining to the phenomena of industrial clustering, manufacturing flexibility, innovation capability, and operational performance by utilizing a single respondent design. A total of 124 Indonesian manufacturing SMEs are taken to test the proposed theoretical model by utilizing covariance-based structural equations modeling approach. It was found that both industrial clustering and manufacturing flexibility was positively associated with operational performance and innovation capability as well. In addition, innovation capability may account for the effects of industrial clustering and manufacturing flexibility on operational performance. This implies that manufacturing SMEs have to reorient their production and operation perspectives, including agglomerate with other similar or related SMEs to develop and utilize their own resources. The SMEs also need to possess some degree of manufacturing flexibility in respond to the uncertain environment and market changes. In addition, the SMEs should put a greater emphasize to use industrial cluster and manufacturing flexibility benefits to generate innovation capability to achieve high performance.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.489-497
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• 2020

The introduction of self-service technologies (SSTs) in retail stores aims to provide customers with a more satisfying shopping experience. Many retailers are increasingly turning toward the adoption of self-service technologies in providing services directly to customers. Given that previous SST research has focused mainly on the impact of the introduction of SST on customer responses, the present study explored the impact of the presence of employees in the relationship between SST and customer responses. Based on the two ground theories, motivation-based theories of behavior and social impact theory, this study tested the relationships between shopping motivations, SST use intention, and retailer attitude. Moderating effects of the presence of employees on the three relationships were also tested. Data were collected using an online survey and analyzed through structural equations modeling. Test results showed that both hedonic and utilitarian shopping motivations effect on SST use intentions, and SST use intentions effect on retailer attitude, subsequently. Although the presence of employee did not moderate the relationship between shopping motivations and SST use intentions, the employee presence moderated the relationship between SST use intentions and retailer attitude. The impact of SST use intentions on retailer attitude was higher in the high presence of employee group than in the low group.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.510-515
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• 2000

Dynamic stability of a flying structure undertaking constant and pulsating axial forces is investigated in this paper. The equations of motion of the structure, which is idealized as a free-free beam, are derived by using the hybrid variable method and the assumed mode method. The structural system includes a directional control unit to obtain the directional stability. The analysis model presented in this paper considers the nonlinear effect due to rigid body motion of the beam. Dynamic stability of the system is influenced by the nonlinear effect. In order to examine the nonlinear effect, first the unstable regions of the linear system are obtained by using the method based upon Floquet's theory, and dynamic responses of the nonlinear system in the unstable region are obtained by using direct time integration method. Dynamic stability of the nonlinear system is determined by the obtained dynamic responses.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.4
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• pp.107-116
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• 2018

The aim of this study is to delve deeper into the online brand community study. This study tests (a) the effects of online brand community on its outcomes, (b) the impact of value creation practice construct as a whole, (c) the effects of value creating practice construct on the two types of loyalty, loyalty toward the brand and the community. Participants of this study (N=353) are members of four types of online brand communities (e.g., business-to-consumer virtual product support community, firm-hosted online community, user-generated online community, peer-to-peer problem-solving community, and social media based brand community). Data were collected online using Amazon Mechanical Turk from April 10, 2016 to May 10, 2016. The data were analyzed through structural equations modeling using AMOS 20. The three community markers (e.g., consciousness of kind, rituals and traditions, and moral responsibility) and the four value creation practices (e.g., social networking, impression management, community engagement, and brand use) are proved to be significant indicators of online brand community and value creation practice constructs, respectively. Test results showed that strong and effective online brand communities generate value creation practices, and value creation practices enhance brand loyalty. The mediating effects of community loyalty between value creation practices and brand loyalty were revealed.

• Journal of Distribution Science
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• v.17 no.9
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• pp.67-81
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• 2019

Purpose - The overarching aim of this study is to empirically test the effect of ex-post control mechanisms on multi-dimensional trust and channel performance in franchise systems. Although the franchise system is a vertical marketing channel based on trust between the franchisor and the franchisees, issues related to franchisee's opportunistic behavior have persisted and thus requires research into the effective control system of franchise headquarters. Research design, data, and methodology - In this study, data was collected from 150 franchises to identify the effect of two types of franchising headquarters' control system on the multi-dimensional trust and franchise channel outcome between franchisor and franchisee. To test the hypotheses intended to achieve this aim, structural equations modeling technique is utilized. Results - The results of this research reveal that among the two formal control systems studied (output and process control), output control positively and significantly affects multidimensional trust. Additionally, among the three dimensions of trust employed in this study, only expertise has a positive and significant effect on contract compliance. Equally, only expertise and integrity have a negative and significant effect on opportunistic behavior. Conclusions - The study provides managerial and theoretical insights into understanding ex-post control mechanisms, trust, compliance and opportunistic behaviors in franchise systems.

• Wind and Structures
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• v.7 no.2
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• pp.107-130
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• 2004

This paper presents a time-domain approach for analyzing nonlinear random vibrations of long-span suspended cables under transversal wind. A consistent continuous model of the cable, fully accounting for geometrical nonlinearities inherent in cable behavior, is adopted. The effects of spatial correlation are properly included by modeling wind velocity fluctuation as a random function of time and of a single spatial variable ranging over cable span, namely as a one-variate bi-dimensional (1V-2D) random field. Within the context of a Galerkin's discretization of the equations governing cable motion, a very efficient Monte Carlo-based technique for second-order analysis of the response is proposed. This procedure starts by generating sample functions of the generalized aerodynamic loads by using the spectral decomposition of the cross-power spectral density function of wind turbulence field. Relying on the physical meaning of both the spectral properties of wind velocity fluctuation and the mode shapes of the vibrating cable, the computational efficiency is greatly enhanced by applying a truncation procedure according to which just the first few significant loading and structural modal contributions are retained.