• Structural Engineering and Mechanics
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• v.3 no.4
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• pp.313-324
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• 1995

Flexible cantilever pipes conveying fluids with high velocity are analysed for their dynamic response and stability behaviour. The Young's modulus and mass per unit length of the pipe material have a stochastic distribution. The stochastic fields, that model the fluctuations of Young's modulus and mass density are characterized through their respective means, variances and autocorrelation functions or their equivalent power spectral density functions. The stochastic non self-adjoint partial differential equation is solved for the moments of characteristic values, by treating the point fluctuations to be stochastic perturbations. The second-order statistics of vibration frequencies and mode shapes are obtained. The critical flow velocity is first evaluated using the averaged eigenvalue equation. Through the eigenvalue equation, the statistics of vibration frequencies are transformed to yield critical flow velocity statistics. Expressions for the bounds of eigenvalues are obtained, which in turn yield the corresponding bounds for critical flow velocities.

• Structural Engineering and Mechanics
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• v.53 no.3
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• pp.481-495
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• 2015

Many hydropower stations in southwest China are located in regions of brittle rock mass with high geo-stresses. Under these conditions deep fractured zones often occur in the sidewalls of the underground caverns of a power station. The theory and methods of fracture and damage mechanics are therefore adopted to study the phenomena. First a flexibility matrix is developed to describe initial geometric imperfections of a jointed rock mass. This model takes into account the area and orientation of the fractured surfaces of multiple joint sets, as well as spacing and density of joints. Using the assumption of the equivalent strain principle, a damage constitutive model is established based on the brittle fracture criterion. In addition the theory of fracture mechanics is applied to analyze the occurrence of secondary cracks during a cavern excavation. The failure criterion, for rock bridge coalescence and the damage evolution equation, has been derived and a new sub-program integrated into the FLAC-3D software. The model has then been applied to the stability analysis of an underground cavern group of a hydropower station in Sichuan province, China. The results of this method are compared with those obtained by using a conventional elasto-plastic model and splitting depth calculated by the splitting failure criterion proposed in a previous study. The results are also compared with the depth of the relaxation and fracture zone in the surrounding rock measured by field monitoring. The distribution of the splitting zone obtained both by the proposed model and by the field monitoring measurements are consistent to the validity of the theory developed herein.

• 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.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.277-286
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• 2021

This study compares the long-term hydrological cycles of the Seolmacheon and Cheongmicheon basin by applying the structural equation model (SEM). These two basins are found different especially in their land-use pattern. Both basins have the actual evapotranspiration data measured by the eddy-covariance method as well as the rainfall and runoff data. The length of the data considered in this study is nine years from 2010 to 2018. The structure of the SEM is determined by considering the correlations among the data as well as the general knowledge on the hydrological cycle. As a result, a total of three SEMs are applied sequentially to analyze their fittings. As irony would have it, two basins are found to be similar in the application of one SEM, but different in the application of another. Especially, when considering the feedback process between precipitation and evapotranspiration, two basins are found to be very different. That is, the feedback process between precipitation and evapotranspiration is found to be significant in the Cheongmicheon basin where the portion of agricultural area (i.e., paddy) is more than 40%.

• International Journal of Quality Innovation
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• v.8 no.3
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• pp.1-10
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• 2007

A sample of Italian manufacturing companies was selected in order to verify the abilities and effects (relationships) of the management factors human resources, leadership and strategic planning on company performance. The Partial Least Squares (PLS) estimation method was used for analyzing the data collected, where the relationships between the management factors and performance were formalized by a Structural Equation Model (SEM). The analysis of the survey data showed unexpected result regarding the non significant direct relationship between Leadership and Performance. The effect of Leadership is obtained by an indirect relationship through Human Resources. The combination of Leadership and Human Resources has hence been identified as the management factors which have the highest impact on the performance of Italian industrial companies. Another interesting and unexpected result was that there was no significant impact of Strategic Planning on Performance. It seems that the leaders of Italian industrial companies have not understood that good strategic planning is a necessary condition for achieving excellence. So another improvement area is in fact Strategic Planning. This area should have the highest priority of any top management team and the focus should include how to establish a strong relationship between strategic planning and performance. No correlation between strategic planning and performance is a strong indication that something is wrong. It is not enough that Leadership is doing Strategic Planning-Leadership is also about studying and follow up on results in order to assure impacts on performance. This link seems to be missing in Italian industrial companies.

• Korean Journal of Health Education and Promotion
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• v.31 no.3
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• pp.73-81
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• 2014

Objectives: This study examined how adolescents' cognitive stress relates to suicidal thought, thereby offering basic data about social and institutional ways to reduce adolescent suicide. Methods: In this study, data from an online survey on adolescents' health conducted by Korea Center for Disease Control(2013, 9th) was used after altering it to fit the purpose of the study. The data was analysed using the complex sampling method and structural equation model(SEM). Results: Whilst adolescents' cognitive stress had positive effects on suicidal thought, problem drinking and cognitive depression, it had a negative effect on physical activity. The structural equation model from cognitive stress, problem drinking, cognitive depression, physical activity influenced suicidal thought. Problem drinking on the other hand had an influence on cognitive depression. Conclusion: These findings suggest that future intervention programs for prevention of adolescents' suicidal thought should also address problem drinking, cognitive depression, and cognitive stress.

• Journal of Korean Society for Quality Management
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• v.37 no.3
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• pp.10-17
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• 2009

This study developed a new model for evaluating effects about the success of six sigma activities. This model consists of four constructs such as success of six sigma, employee's success experience, customer satisfaction, and business performance. Structural Equation Modeling (SEM) is used to analyze causality among the four constructs. Hypothesis were tested through a field study conducted for one hundred and thirty-one project leaders, who were asked to evaluate their experiences of six sigma projects. The results indicate that six hypothesis are statistically significant. As a result, the success of six sigma doesn't influence the customer satisfaction directly, but it influences customer satisfaction indirectly through employee's success experience. We find out that control for employee's success experience is important as well as success of six sigma in business innovation. Otherwise business performance is influenced directly by success of six sigma, that is business performance isn't influenced directly by employee's success experience but influenced indirectly through customer satisfaction. This study found that the change management raising employee's success experience is important in Six Sigma.

• IE interfaces
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• v.16 no.spc
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• pp.116-122
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• 2003

We analyze how much employees' work abilities and overall satisfaction on the job or corporate influence on the productivity and customer satisfaction in the service industry, which is characterized by simultaneity, heterogeneity, intangibility and etc. Employees always encounter customers in process of the service. So, the employees' attitudes and behaviors have direct influences on the service quality or satisfaction which customers perceive. Also, employees' satisfaction or work abilities can lead to increase or decrease the productivity. To grasp and demonstrate the cause and effect relationship, we firstly measure the degrees of employee satisfaction organized by 11 factors through survey, and also measure employees' overall satisfaction, organizational commitment and productivity. Secondly, we define service value as the employee's objective measure index and collect it with the data related to customer satisfaction. Based on the collected data, thirdly we define how the relationship among the employee satisfaction, the productivity, the service value and the customer satisfaction are affected by the employees' work abilities and overall satisfaction with SEM(Structural Equation Model). And finally, we classify employees according to their abilities and the degrees of satisfaction respectively and suggest important strategies to manage them effectively.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.162-170
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• 2005

The effective development of event product for a successful event is first started with figuring out the participation motive of event. Second, what level of expectation before participating event for participant will have. Third, what level of satisfaction and safety satisfaction based on figured out motive and expectation will participant have. Fourth, what level of revisit based on satisfaction will have. The study is needed for these low items. Therefore, this investigation started as an exploratory study for a successful event to analysis the relationship among expectation satisfaction, safety satisfaction and revisit. The results indicated that participated motive is positively influenced on expectation. The expectation is positively influenced on safety satisfaction. The satisfaction is positively influenced on revisit. Finally, the safety satisfaction is positively influenced on revisit. The unique characteristics of this study is considered a safety satisfaction as m event safety and as an important factor when terror becomes often these days.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.141-148
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• 2019

This research proposes a model of SERVQUAL scale calibration and uses the SERVPERF model to study the relationship between quality of ATM service and customer satisfaction. The research uses the combination of qualitative and quantitative methodology with the Cronbach's alpha reliability analysis, Exploratory Factor Analysis (EFA) method; Confirmation Factor Analysis (CFA) and Structural Equation Modeling (SEM) through SPSS and AMOS 20.0 data analysis software. The survey was conducted with 800 questionnaires with the convenient sampling method. The number of remaining sample for analysis was 779 responses of individual customers using ATM card services of Bank for Foreign Trade of Vietnam (Vietcombank) Vinh Long. The results show that the satisfaction of customers using ATM cards of Vietcombank Vinh Long is influenced by 4 factors with the order of importance as follows: (1) Price; (2) Network; (3) Reliability; (4) Empathy. Thereby, the author suggests some managerial implications to Vietcombank Vinh Long management to enhance the ATM service quality, then improve customer satisfaction. This research still has some limitations: (1) The study does not investigate other influencing factors, (2) The convenient sampling method has not been generalized well, (3) The research is only conducted for Vietcombank.