• 한국유체기계학회 논문집
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• 제9권1호
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• pp.47-55
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• 2006

This paper presents the theoretical model to investigate the effect of Coulomb damping in the sub-structure of a foil bearing. Foil deflection is restricted by friction of bumps. Equivalent viscous damping of the bump foils is derived from the Coulomb friction. Dynamic equation of the bumps is constituted by stiffness and damping terms. This point give the difference from Heshmat's frictionless and simple compliance bump model. The fluid is modeled with the compressible Reynolds equation. A perturbation approach is used to determine the static and dynamic performance of the bearing from the coupled fluid-structural model. The analysis result shows that the static and dynamic performance is enhanced by bump friction. This analysis technique would be extended to development of a high performance bearing.

• Architectural research
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• 제23권1호
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• pp.1-10
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• 2021

Project management information systems (PMIS) have been implemented to support cooperation among the participants of construction projects. Unlike other information systems used by members from an organization with similar culture and business environment, the PMIS are members from one-off fragmented project organization with diverse professional background. Successful operation is significantly affected by the tendencies of client's side and individual awareness of participants. In this regard, it is imperative to evaluate the success of the system based on the individual characteristics of PMIS users. Thus, this study proposes a method for determining the system success by analyzing the extent of the effects of system factors such as System Quality, Information Quality, and Service Quality and individual factors such as a user's IT application ability, Extrinsic Motivation to achieve User Satisfaction, and loyalty. Accordingly, a structural equation model (SEM), an effective tool to examine of the comprehensive structure of a causal relationship, is applied for analysis because the internal awareness of individuals is established as a variable.

• Smart Structures and Systems
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• 제25권2호
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• pp.219-228
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• 2020

This work presents a modified continuum model to explore and investigate static and vibration behaviors of perforated piezoelectric NEMS structure. The perforated nanostructure is modeled as a thin perforated nanobeam element with Euler-Bernoulli kinematic assumptions. A size scale effect is considered by included a nonlocal constitutive equation of Eringen in differential form. Modifications of geometrical parameters of perforated nanobeams are presented in simplified forms. To satisfy the Maxwell's equation, the distribution of electric potential for the piezoelectric nanobeam model is assumed to be varied as a combination of a cosine and linear functions. Hamilton's principle is exploited to develop mathematical governing equations. Modified numerical finite model is adopted to solve the equation of motion and equilibrium equation. The proposed model is validated with previous respectable work. Numerical investigations are presented to illustrate effects of the number of perforated holes, perforation size, nonlocal parameter, boundary conditions, and external electric voltage on the electro-mechanical behaviors of piezoelectric nanobeams.

• 소성∙가공
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• 제13권2호
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• pp.168-173
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• 2004

Microforming can be a good application for bulk metallic glasses. It is important to simulate the deformation behaviour of the bulk metallic glasses in a supercooled liquid region for manufacturing micromachine parts. For these purposes, a correct constitutive model which can reproduce viscosity results is essential for good predicting capability. In this paper, we studied deformation behaviour of the bulk metallic glasses using the finite element method in conjunction with the fictive stress constitutive model which can describe non-Newtonian as well as Newtonian behaviour. A combination of kinetic equation which describes the mechanical response of the bulk metallic glasses at a given temperature and evolution equations fur internal variables provide the constitutive equation of the fictive stress model. The internal variables are associated with fictive stress and relation time. The model has a modular structure and can be adjusted to describe a particular type of microforming process. Implementation of the model into the MARC software has shown its versatility and good predictive capability.

• 보건교육건강증진학회지
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• 제26권2호
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• pp.49-61
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• 2009

Objectives: The purpose of the study was to test the applicability of the Theory of Planned Behavior(TPB) to Korean adult smokers in order to obtain an enhanced understanding of their smoking-cessation intention and to establish strategies for effective smoking-cessation interventions at the community clinic. Methods: The data came from a survey that was conducted on adult male smokers who visited the smoking-cessation clinic at H community clinic in Korea from January to November in 2006 (N=434). Included in the survey were questions asking core variables and salient belief variables dictated by TPB. A structural equation model was established using TPB and data were analyzed to examine the applicability of the theory to the understanding of the structure of variables leading to intention. Results: The analysis of the structural model revealed that the study model was statistically significant(p<.001), suggesting the high validity of TPB in explaining the structure of the data. Among the relationships in the model, negative behavioral beliefs were not significant(p>.05), and negative control beliefs and subjective norm were significant(p<.05) but not as highly as other variables in the model(p<.001). Conclusion: TPB was useful in understanding smoking-cessation intention of smokers who visited community clinic to stop smoking. More specific strategies for counseling and education need to be developed to enhance attitude and perceived behavioral control (self-efficacy) toward smoking-cessation intention, such as emphasizing health benefits of quitting smoking, and eliciting values and life principles that can help increase the intention to stop smoking.

• 아태비즈니스연구
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• 제3권1호
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• pp.10-16
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• 2012

India is having a high growth rate of Mobile subscribers which has opened up a new marketing channel of communication with customers. There is a need to study the factors affecting Mobile user's attitude towards Mobile marketing and the relationship between these factors. To study the mobile users attitude towards mobile marketing 489 mobile users opinion is taken on 12 statements for a period of 5 months. Using factor analysis method these 12 statements are grouped into 5 groups they are Mobile advertisement, Mobile Usability, Mobile Promotions, Mobiles shopping and Mobile Marketing. Confirmatory Factor Analysis (CFA) was performed to confirm the findings. SPSS Statistics 17.0 is used to conduct factor analysis and the validity of the model. Once the model was validated, SPSS Amos 18.0 was used to fit a model based on Structure Equation Model to analyze the factors affecting Mobile user's attitude and the relationship between these factors. The present study revealed that Mobile Advertisement and Mobile Sales Promotion are having positive effect on Mobile Marketing where as Mobile Shopping and Mobile Phone Usability is having negative effect on Mobile Marketing. The impact of indicators like Mobile Phone user's permission and personalization of Mobile Phone communication on Mobile Marketing are also discussed in this article.

• 경영과학
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• 제33권2호
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• pp.65-74
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• 2016

The present study applies the TAM (Technology Acceptance Model) to investigate the factors that affect the intention to use the mobile payment services. For this purpose five potential variables (perceived usefulness, perceived convenience, ubiquity, innovativeness, and safety risk) that are expected to affect the intention to use the mobile payment services were selected. An online survey was administered, and 339 questionnaires were analyzed. Structure Equation Model (SEM) Analysis revealed that TAM variables (perceived usefulness and perceived convenience) partially influenced the attitude. The perceived usefulness predicted the attitude while perceived convenience did not predict the attitude toward the mobile payment service. Personal characteristics variable (innovativeness) and mobile nature variables (ubiquity, and security risk) were identified as the predictors of the attitude toward the mobile payment service. While innovativeness and ubiquity affected the attitude positively, security risk affected the attitude negatively. Finally, the analysis substantiated the influence of attitude toward the mobile payment services on the intention to use the services. On the basis of findings, managerial implications and suggestions for further studies were discussed.

• 대한간호학회지
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• 제40권3호
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• pp.389-399
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• 2010

Purpose: The aim of this study was to construct a structural equation model that would further explain the mental health status of Korean immigrants living in Canada. Methods: Survey using a structured questionnaire was conducted with 386 people in Canada (Vancouver and Toronto). Six instruments were used in this model. The analysis of data was done with both SPSS 14.0 for descriptive statistics and AMOS 5.0 for covariance structure analysis. Results: Based on the constructed model, physical health status, immigrant life stress, self esteem, and quality of life were found to have significant direct effect on mental health. In addition, factors such as physical health status, immigrant life stress, quality of life, English proficiency, family cohesion and social support were found to indirectly affect mental health. The final modified model yielded Chi-square=34.79 (p<.001), df=13, $x^2$/df=2.68, GFI=0.98, AGFI=0.94, NFI=0.95, PNFI=0.44, PGFI=0.35, RMSE=0.07 and exhibited good fit indices. Conclusion: This structural equation model is a comprehensive theoretical model that explains the related factors and their relationship with mental health in Korean immigrants. Findings of this study can contribute to the designing of an appropriate prevention strategy to further improve the mental health of immigrants in Canada.

• 디지털융복합연구
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• 제7권2호
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• pp.71-81
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• 2009

This paper studied the impact of Internet addiction on school life adaptation of high school students. We searched the literature on Internet addiction for such research and analyzed the impact that Internet addiction has on school life fitness. The SPSS statistics program was used for Internet addiction factor analysis and the analysis was carried out through the structure equation model. The family relation, individual relation, school relation and friend relation factor were deduced to Internet addiction as a result. It was revealed that the individual relation factor among Internet addiction factors had an influence on school life fitness. It is expected that this research will prove helpful in providing preventative education for Internet addiction

• 산업기술연구
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• 제27권B호
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• pp.29-36
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• 2007

A comparative study of airborne salinity and sea wind was done for a coastal area, Sokcho city, of East Sea in Kangwon province, Korea. In this study, a relationship between the formation of airborne salinity and wind velocity was investigated, and then the airborne salinity was simulated and forecasted by the obtained wind-salinity characteristics. It is founded that most airborne salinity is brought by sea winds with the occurrence of velocity, higher than and equal to 4m/s, while the occurrence of lower wind velocities (ie., lower than 4m/s) in sea wind and the occurrence of inland wind give diluted effects on the airborne transfer. By using these characteristics and a proposed linear equation model, the salinity in Sokcho city is successfully simulated and forecasted. It is expected that the linear equation model may be useful for durability design of concrete structures under the conditions of chloride attack, induced by the airborne salinity.