• The Journal of Information Systems
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• 제30권4호
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• pp.43-69
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• 2021

Purpose Although companies occupied the network market take the advantageous position first and can be successful in securing users over a certain size, it is important to satisfy the customers' demand and prevent the outflow of users toward a new alternative SNS. What is more, there are frequent changes in the flow of users toward new SNSs. Despite these dynamic market circumstances, there is a lack of research to explain the switching behaviors of SNS users. Design/methodology/approach The objective of this study is to explain and verify a specified migration theory(Push-Pull-Mooring model) focused on SNS fatigue in the psychological point of view, as well as reviewing previous studies on functional and technical characteristics of SNSs themselves. Moreover, this study tried to highlight factors affecting users actual SNS switch rather than their switching intention. Findings According to the statistical analysis, the most influenced pull factor to switch SNS was the alternative attractiveness. On the other hand, undesired relationship burden, service innovation and important mooring factors to prevent users' SNS switch. This study has a significant contribution to the theory, which analyzed users' actual SNS switch, and examined SNS users' psychological factors(SNS fatigue), reviewing the characteristics of existing services. To secure more users and to keep them, companies providing social network service need to develop differentiated strategies by analyzing psychological characteristics of various users.

• Coupled systems mechanics
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• 제12권4호
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• pp.391-407
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• 2023

This paper presents a static study of a rectangular functional graded material (FGM) plate, simply supported on its four edges, adopting a refined higher order theory that looks for, only,four unknowns,without taking into account any corrective factor of the deformation energy with the satisfaction of the zero shear stress conditions on the upper and lower faces of the plate. We will have determined the contribution of these stresses in the transverse deflection of the plate, as well as their effects on the axial stress within the interfaces between the layers(to avoid any problem of imperfections such as delamination) and on the top and bottom edges of the plate in order to take into account the fatigue phenomenon when choosing the distribution law of the properties used during the design of the plate. A numerical statement, in percentage, of the contribution of the shear effect is made in order to show the reliability of the adopted theory. We will also have demonstrated the need to add the shear effect when the aspect ratio is small or large. Code routines are programmed to obtain numerical results illustrating the validity of the model proposed in the theory compared to those available in the literature.

• Journal of Korea Trade
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• 제27권4호
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• pp.61-76
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• 2023

Purpose - Along with emerging international entrepreneurship, there is a need for exploring the influencing mechanism of dual network embeddedness of the host country on international entrepreneurial performance. Drawing on network embeddedness theory and organizational improvisational theory, the present study constructs a theoretical model regarding the logic relationships between the dual network embeddedness of the host country, organizational improvisational capability, and international entrepreneurial performance. Design/methodology - Using a questionnaire survey, our study conducted data in two ways. The final research sample comprised 129 international new ventures. To test the hypotheses, a three-step mediation test method was conducted. Findings - Our empirical results suggested that both host-country social network embeddedness and industrial network embeddedness significantly affected the international entrepreneurial performance. Organizational improvisational capability significantly affected the international entrepreneurial performance. Third, organizational improvisational capability partially played mediating role in the relationship between the dual network embeddedness of the host country and international entrepreneurial performance. Originality/value - This study mainly concentrates on the two important types of host-country networks, host-country social network embeddedness and industrial network embeddedness, that may help international new ventures access the strategic resources necessary to support performance. Thus, it extends the existing network embeddedness theory and improvisational theory to encompass international entrepreneurship.

• Journal of the Korean Society of Food Culture
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• 제24권4호
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• pp.440-450
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• 2009

The purposes of study were to survey the status of nutrition education in school and investigate the perception of nutrition teacher candidates concerning the direction and ideal method for nutrition education. A questionnaire was distributed to 554 nutrition teacher candidates from August to October, 2006. A total of 468 usable data were collected (84.5% response rate). The statistical data analysis was completed by using SPSS for Windows (ver. 10.0) for descriptive analysis, ANOVA and $X^2$-test. About 52% of respondents had nutrition education teaching experience. Half of the respondents indicated that the necessity for nutrition education stemmed from their own need for such education. The main problem in students' dietary life was 'the increasing intake of processed foods, instant foods and fast foods (4.23 out of Likert 5 point scale)' and the major nutritional problem was 'high calorie intake with low essential nutrients (3.96 out of Likert 5 point scale)'. Over half the respondents (53.4%) recommended that nutrition education be oriented towards behavioral change rather than knowledge delivery. Social learning theory was preferred mostly as an theory apt to nutrition education (60.3%) and the most effective means of education was referred to organizing the regular class for nutrition education (50.5%). The 'playing such as songs or game' was reported as both effective and realizable method in nutrition education.

• Educational Technology International
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• 제15권2호
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• pp.89-115
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• 2014

This research aims to develop an elementary school English e-learning system based on the 'Self-determination theory (SDT)', which is widely applied to traditional face-to-face foreign language classes. The study also attempts to verify whether SDT-a traditional motivational theory that has been applied to face-to-face classes- is effective in an e-Learning environment with students who use this newly developed system. For the purposes of this project, the following three actions were carried out. First, a motivational strategy based on SDT was deduced. In SDT, the needs for autonomy, competence, and relatedness were introduced as basic psychological needs, and assumed that these three needs provided the natural motivation for learning, growth, and development. Second, an e-Learning system was created based on the deduced motivational strategy. Third, the system was implemented in 115 private tuition academies, and education was provided to 1,400 users for one year across the country. Afterwards, by surveying users, correlation between the role of the three psychological needs in learning English, and also the correlation between each need and motivation were investigated. Research results showed that traditional motivational theories used in face-to-face classes so far were effective in an e-Learning environment.

• Structural Engineering and Mechanics
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• 제48권4호
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• pp.547-567
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• 2013

Nonlinear behavior of functionally graded material (FGM) plates under thermal loads is investigated here using an efficient sinusoidal shear deformation theory. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the sinusoidal distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Unlike the conventional sinusoidal shear deformation theory, the proposed efficient sinusoidal shear deformation theory contains only four unknowns. The material is graded in the thickness direction and a simple power law based on the rule of mixture is used to estimate the effective material properties. The neutral surface position for such FGM plates is determined and the sinusoidal shear deformation theory based on exact neutral surface position is employed here. There is no stretching-bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. The non-linear strain-displacement relations are also taken into consideration. The thermal loads are assumed as uniform, linear and non-linear temperature rises across the thickness direction. Closed-form solutions are presented to calculate the critical buckling temperature, which are useful for engineers in design. Numerical results are presented for the present efficient sinusoidal shear deformation theory, demonstrating its importance and accuracy in comparison to other theories.

• Geomechanics and Engineering
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• 제34권3호
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• pp.233-250
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• 2023

This paper investigates the flexural analysis of isotropic, transversely isotropic, and laminated composite plates using a new higher-order normal and shear deformation theory. In the present theory, only five unknown functions are involved compared to six or more unknowns used in the other similar theories. The developed theory does not need a shear correction factor. It can satisfy the zero traction boundary conditions on the top and the bottom surfaces of the plate as well as account for sufficient distribution of the transverse shear strains. The thickness stretching effect is considered in the computation. A simply supported was considered on all edges of the plate. The plate is subjected to uniform and sinusoidal distributed load in the static analysis. Laminated composite, isotropic, and transversely isotropic plates are considered. The governing equations are obtained utilizing the virtual work principle. The differential equations are solved via Navier's procedure. The results obtained from the developed theory are compared with other higher-order theories considered in the previous studies and 3D elasticity solutions. The results showed that the proposed theory accurately and effectively predicts the bidirectional bending responses of laminated composite plates. Several parametric studies are presented to illustrate the various parameters influencing the static response of the laminated composite plates.

• Journal of Korean Medical classics
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• 제26권1호
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• pp.131-150
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• 2013

Subject : The Imminent Labor Pulse(臨産 離經脈, extra-meridian pulse approaching labor) is one of many practical clinical knowledges, unique to Traditional Korean(Eastern) Medicine. Objective : This research explores the origin and change of perception on the subject throughout history, with objective to sort out practical knowledge applicable in the clinic of today. Also, it draws clinical meaning of pulse diagnosis according to the physiological theories, and suggests directions for future clinical researches. Method : First, the Imminent Labor Pulse was examined based on major publications such as the "Nanjing", "Maijing" and theories of major doctors. Second, this previous study was examined through clinical observation research. Third, further research was carried out on pulse theory according to the Traditional Medical theories. Fourth, their clinical practicality and points of further research were sorted out. These points need to be examined through additional clinical research. Conclusion : The following conclusions could be drawn from study of the Imminent Labor Pulse. From the Imminent Labor Pulse which indicated the beginning of the first period of labor in the "Maijing", it developed into trying to grasp the beginning of the second period of labor which is the actual time of labor, through "Zhubingyuanhoulun" and "Shizaizhifang". By Xueji, another pulse that could be felt on the middle finger of the mother had been discovered. The middle finger is where the Pericardium Meridian flows. The child's connection to the uterus becomes disconnected on the first period, but that with the Pericardium meridian which provides blood meridian to the Taichongmai of the child continues throughout labor until the umbilicus chord is cut. Therefore, this middle finger pulse could serve as showing the heart condition of the mother and child during labor. The time of its appearance and disappearance, and their correlation with the child's heartbeat need to be clinically examined.

• Journal of the Korean Society of Marine Environment & Safety
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• 제12권2호
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• pp.145-150
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• 2006

This paper proposes an analysis to image of Inchon port using fuzzy theory. After analysis, positive opinion is mean membership function 0.73 and positive membership function 0.27, negative opinion is mean membership function 0.69, negative membership function 0.31 about Inchon port development. therefore, for port development need to accomodation of each opinion positive opinion is maximum decrease from 20 age to 30 age. and negative opinion is maximum increase from 10 age to 20 age. According to the results, port development need to high positive image as leisure and development of waterfront and low negative image as integrated port management and strategy of considered environment port.

• Journal of the Architectural Institute of Korea Structure & Construction
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• 제34권9호
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• pp.3-10
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• 2018

While computer environments have been dramatically developed in recent years, as the building structures become larger, the structural analysis models are also becoming more complex. So there is still a need to model one shear wall with one finite element. From the viewpoint of the concept of FEA, if one shear wall is modeled by one finite element, the result of analysis is not likely accurate. Shear wall may be modelled with various finite elements. Among them, considering the displacement compatibility condition with the beam element connected to the shear wall, plane stress element with in-plane rotational stiffness is preferred. Therefore, in order to analyze one shear wall with one finite element accurately, it is necessary to evaluate finite elements developed for the shear wall analysis and to develop various plane stress elements with rotational stiffness continuously. According to the above mentioned need, in this study, the theory about a plane stress element using hierarchical interpolation equation is reviewed and stiffness matrix is derived. And then, a computer program using this theory is developed. Developed computer program is used for numerical experiments to evaluate the analysis results using commercial programs such as SAP2000, ETABS, PERFORM-3D and MIDAS. Finally, the deflection equation of a cantilever beam with narrow rectangular section and bent by an end load P is derived according to the elasticity theory, and it is used to for comparison with theoretical solution.