• Structural Engineering and Mechanics
• /
• 제61권6호
• /
• pp.693-700
• /
• 2017

Concrete cover cracking due to the corrosion of steel reinforcing bars is one of the main causes of deterioration in Reinforced Concrete (RC) structures. The oxidation level of the bars causes varying levels of expansion. The rebar expansions could lead to through-thickness cracking of the concrete cover, where depending on the cracking characteristics, the service life of the structures would be affected. In this paper, the effect of geometrical and material parameters, i.e., concrete cover thickness, reinforcing bar diameter, and concrete tensile strength, on the required pressure for concrete cover cracking due to corrosion has been investigated through detailed numerical simulations. ABAQUS finite element software is employed as a modeling platform where the concrete cracking is simulated by means of eXtended Finite Element Method (XFEM). The accuracy of the numerical simulations is verified by comparing the numerical results with experimental data obtained from the literature. Using a previously proposed empirical equation and the numerical model, the time from corrosion initiation to the cover cracking is predicted and then compared to the respective experimental data. Finally, a parametric study is undertaken to determine the optimum ratio of the rebar diameter to the reinforcing bars spacing in order to avoid concrete cover delamination.

• International Journal of Human Ecology
• /
• 제16권2호
• /
• pp.63-77
• /
• 2015

The current study investigated how academic stress, academic burnout, and academic self-efficacy relate to each other; in addition, this study examined the mediating effects of academic self-efficacy on the relationship between academic stress and academic burnout of Chinese adolescents. A total of 412 students attending third-grade from two different middle schools (ninth-grade in the United States) located in Jiading District of Shanghai participated in the final analysis. By using structural equation modeling (SEM) and the maximum likelihood estimation procedures of AMOS 20.0, the latent variable measurement models were confirmed. The results and conclusions of this study are summarized as follows. A positive correlation between academic stress and academic burnout was soundly supported by this study. Meanwhile, both academic stress and academic burnout indicated negative correlations with academic self-efficacy. The modeling indicated that academic self-efficacy has a partial mediating process and a direct effect on the relationship between academic stress and academic burnout. Thus, academic stress and academic burnout were significantly weaker when academic self-efficacy was higher. In the field of education and curriculum, these results are applicable for restructuring or developing Chinese middle school curriculum utilizing useful methods for adolescents to develop their academic self-efficacy.

• Structural Engineering and Mechanics
• /
• 제19권5호
• /
• pp.477-501
• /
• 2005

In this study, a new smart beam finite element is proposed for the finite element modeling of beam-type smart structures that are equipped with bonded plate-type piezoelectric sensors and actuators. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered in the formulation. By using a variational principle, the equations of motion for the smart beam finite element are derived. The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. The proposed smart beam finite element is applied to the free vibration control adopting a constant gain feedback scheme. The electrical force vector, which is obtained in deriving an equation of motion, is the control force equivalent to that in existing literature. Validity of the proposed element is shown through comparing the analytical results of the verification examples with those of other previous researchers. With the use of smart beam finite elements, simulation of free vibration control is demonstrated by sensing the voltage of the piezoelectric sensors and by applying the voltages to the piezoelectric actuators.

• Structural Engineering and Mechanics
• /
• 제72권3호
• /
• pp.329-338
• /
• 2019

In this paper, the magnetic field influence on the wave propagation characteristics of graphene nanosheets is examined within the frame work of a two-variable plate theory. The small-scale effect is taken into consideration based on the nonlocal strain gradient theory. For more accurate analysis of graphene sheets, the proposed theory contains two scale parameters related to the nonlocal and strain gradient effects. A derivation of the differential equation is conducted, employing extended principle of Hamilton and solved my means of analytical solution. A refined trigonometric two-variable plate theory is employed in Kinematic relations. The scattering relation of wave propagation in solid bodies which captures the relation of wave number and the resultant frequency is also investigated. According to the numerical results, it is revealed that the proposed modeling can provide accurate wave dispersion results of the graphene nanosheets as compared to some cases in the literature. It is shown that the wave dispersion characteristics of graphene sheets are influenced by magnetic field, elastic foundation and nonlocal parameters. Numerical results are presented to serve as benchmarks for future analyses of graphene nanosheets.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권12호
• /
• pp.959-968
• /
• 2020

Tourist loyalty is created through good tourism service quality and the availability of tourism products. This study discussed the various attributes of tourism service quality, namely, tour agents, efficient personnel, accessible transportation, and information service quality. Whereas for tourism product availability attributes were varieties of product availability, wide selection of tour agents and tourist products, and wide variety of amenity services. As a general rule, the minimum is to have at least five times as many observations as the number of variables to be analyzed, and the more acceptable sample size would have a 10:1 ratio. A total of 424 questionnaires were returned, with 35 removed due to errors. Finally, 389 questionnaires respondents were used via accidental sampling method through the distribution of questionnaires to foreign tourists at Soekarno Hatta International Airport. In addition, AMOS 7.0 software is used to test models in confirmatory factor analysis (CFA) as well as hypothetical testing using structural equation modeling (SEM). The results showed that all hypotheses were accepted, except for the effect of tourism service quality on tourist loyalty in Indonesia. This research aims to contribute significantly to the existing knowledge of tourism, specifically from a foreign tourist perspective in Indonesia.

• 한국보육지원학회지
• /
• 제12권2호
• /
• pp.73-88
• /
• 2016

The present study was designed to examine the structural relationship between mothers' perceptions of their relationships with their parents and husbands (as the predictors of parenting self-efficacy), mothers' parenting self-efficacy (PSE), and parenting behaviors among contemporary Korean mothers. A sample of 95 Korean mothers of pre-school,1st, 2nd, and 3rd grade elementary school children in Seoul, South Korea were recruited. Mothers were asked to respond to a survey that captured mothers' perceptions of their relationships with their parents and husbands, PSE, and their parenting behaviors. Structural equation modeling(SEM) was applied to analyze the hypothesized model. The results indicate that mothers who perceive their relationships with their own parents as positive were more likely to have higher PSE. In addition, mothers who reported higher PSE levels were less likely to be inconsistent in their parenting behaviors and more likely to be responsive in their parenting behaviors. The results of this study underscore the importance of PSE as a psychological resource that enables contemporary Korean mothers to parent in positive ways. Furthermore, these findings emphasize the importance of mothers' perceptions of their social relationships as a factor that contributes to higher PSE.

• The Journal of Asian Finance, Economics and Business
• /
• 제5권3호
• /
• pp.133-142
• /
• 2018

The purpose of this study was to examine the effect of two-dimensional factor of motivators and hygiene on civil servants' job satisfaction using the partial least square structural equation modeling (PLS-SEM) as a technique employed to analyze the measurement and structural models. Exploratory study was deployed to evaluate the relationship among variables. By using multistage stratified sampling, statistical data was collected from a survey of 441 public municipal civil servants who have employed in various levels (municipal government, districts and communes) in Vietnam. The findings provided evidence that hygiene factors (relationship with leader, salary, relationship with coworker and working environment) directly impact on civil servants' job satisfaction. Meanwhile, only career development factor from motivators significantly influenced on public employee's job satisfaction. Based on the empirical results, the hygiene factors of job satisfaction are more dominated that the motivators one. This finding suggests that municipal governments should focus policies on improving the hygiene factors which lead to higher job satisfaction on civil servants. Gaining a thorough understanding of the determinants of job satisfaction toward municipal public servants will enable policy makers to grasp the factors that results in retaining employees. Finally, the policy makers can use this knowledge to promote civil servants' job satisfaction.

• 유통과학연구
• /
• 제10권10호
• /
• pp.11-16
• /
• 2012

Purpose - This study focused on consumer perceptions of service quality in organic food shops, the innovativeness of organic products, and which SERVQUAL sub-dimensions increase purchase intentions. Another purpose of this study was to explore the relationship between consumer perceptions of organic food shops, their direct interest in organic food, and their purchase intentions. Research design, data, and methodology - We tested our hypothesized model within a structural equation modeling (SEM) framework, utilizing path-analysis implementation. The AMOS 18.0 software was used, and we found that it fit very well with the observed data. Results - The results of the full model (structural and measurement models) indicated the following fit indices: χ²=39.492, degree of freedom=25, provability level=0.033, RMR=0.047, GFI=0.948, AGFI=0.906, NNFI=0.958, CFI=0.984, and RMSEA=0.060. The effects of service quality on purchase intention, service quality on innovativeness, and innovativeness on purchase intention we resignificant. We also examined the statistical significance of the mediation effects using the Sobeltest and found further evidence to support service quality and purchase intention through innovation. Conclusions - These results suggest that, if organic food shops want to achieve a greater level of competitiveness, they must try to raise the quality of their service and actively promote the innovativeness of organic food.

• 복식
• /
• 제65권7호
• /
• pp.118-128
• /
• 2015

The purpose of this study was to identify the relationship of interpersonal relations disposition, appearance concern, appearance management behavior of men through a structural study method. Three hypotheses were established to verify the relationships among interpersonal relations disposition, appearance concern and appearance management behavior. The questionnaires were administered in the city of Daegu to 201 males in their 20s to 50s. The SPSS 20.0 package was utilized for data analysis, which included frequency analysis, factor analysis, correlation analysis and Cronbach's ${\alpha}$. Also, Amos 21.0 program was utilized for a confirmative factor analysis( CFA) and a structural equation modeling(SEM) analysis. The results of this study are as follows; First, interpersonal relations disposition showed a positive influence on appearance concern. Second, appearance concern had a positive influence on appearance management behavior. Third, the interpersonal relations disposition showed a positive influence on appearance management behavior. In conclusion, interpersonal relations disposition, appearance concern, appearance management behavior of men are found to have a correlation.

• The Journal of Asian Finance, Economics and Business
• /
• 제4권3호
• /
• pp.75-83
• /
• 2017

This paper examines key determinants and the effect of country-of-origin on customer's purchase intention of functional food and dietary supplement product in Vietnam. Exploratory study was identified to evaluate personal and social factors on customer's buying behavior. Twenty-eight reflective constructs were adapted from literature and designed by using a seven-point Likert scale to facilitate measurement. By using non-probability convenience sampling, data was collected from a survey of 242 Vietnamese who have experienced in buying functional and supplement food. This paper employed partial least square structural equation modeling (PLS-SEM) as a technique employed to analyze the measurement and structural models. The findings provide evidence that social prestige customer perceives and their positive attitude toward functional food which are main factors influencing on consumers' purchase intention. Customer's perceived prestige plays an important role in decision-making process to purchase. The higher social prestige taken up in consumers' mind, the higher consumers' purchase intention is. Moreover, the more positive attitude customer holds toward functional food, the higher consumers' purchase intention. The research results provide useful information in current understanding of what antecedents determine factors influencing customer's intention to purchase functional food and lead to managerial implications for business strategies.