• Journal of the Korean Home Economics Association
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• v.50 no.2
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• pp.11-23
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• 2012

This qualitative study attempts to analyze the separation experiences of wild geese families from a social exchange perspective. The participants of this study were 16 mothers who lived apart from their partners for the purpose of educating their offspring. To collect data, in-depth interviews were conducted with the mothers about the decision-making process and the separation experiences. The results showed that there was a unique educational factor in Korea that affected wild geese families' decision on family separation. Geese families had to face psychological inconvenience caused by negative eyes from society. In addition, the fathers suffered loneliness and had difficulties in doing household chores, and the mothers experienced an overload of child parenting. On the other hand, emotional relationship between the husband and wife was enhanced, and the friendly relationship between a mother and her children was built. The biggest reward from the wild geese families turned out to be the educational achievement of their children.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.405-406
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• 2005

A theoretical investigation of the solid-phase mechanochemical synthesis of nano-sized target product on the basis of dilution of the initial powdered reagent mixture by another product of an exchange reaction is presented. On the basis of the proposed 3-mode particle size distribution in mechanically activated mixture, optimal molar ratios of the components in mixture are calculated, providing the occurrence of impact-friction contacts of reagent particles and excluding aggregation of the nanosized particles of the target reaction product. Derivation of kinetic equations for mechanochemical synthesis of nanoscale particles by the final product dilution method in the systems of exchange reactions is submitted. On the basis of obtained equations the necessary times of mechanical activation for complete course of mechanochemical reactions are designed. Kinetics of solid phase mechanosynthesis of nano-TlCl by dilution of initial (2NaCl + $Tl_2SO_4$) mixture with the exchange reaction product (diluent, $zNa_2SO_4$, $z=z^*=11.25$) was studied experimentally. Some peculiar features of the reaction mechanism were found. Parameters of the kinetic curve of nano-TlCl obtained experimentally were compared with those for the model reaction KBr + TlCl + zKCl = (z + 1) KCl + TlBr ($z=z_l^*=13.5$), and for the first time the value of mass transfer coefficient in a mechanochemical reactor with mobile milling balls was evaluated. Dynamics of the size change was followed for nanoparticle reaction product as a function of mechanical activation time.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.179-185
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• 2021

The aim of this study is to examine the impact of board of directors' activity on the audit committee's effectiveness score among manufactured listed companies on Saudi Stock Exchange (Tadawul) for the period 2015-2017. The final sample of this study consists of 195 firm-year observations that represent manufactured companies listed on Saudi Stock Exchange (Tadawul) for the years 2015-2017. The data of this study in terms of board of directors' meetings, audit committee size and meetings, firm leverage, firm performance, and firm age were hand-collected from the annual reports of the considered companies. The Pooled OLS regression's result indicate that audit committee's effectiveness score is influenced by the board of directors' activity. This result gives support to the agency theory prediction. This result is also consistent with the complementary function of corporate governance mechanisms in which board of directors' activity complements the function of audit committee's effectiveness score. The result of this study should be useful for manufacturing companies, Saudi Stock Exchange, auditors, and regulators which relates to the association between board of directors' activity and audit committee's effectiveness score. This study provides a new empirical evidence on the impact of board activity on the audit committee's effectiveness score in an interesting context which is Saudi Arabia.

• Journal of electromagnetic engineering and science
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• v.16 no.4
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• pp.219-224
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• 2016

In this paper, coupled-mode theory (CMT) is used to obtain a transient solution analytically for a wireless power transfer system (WPTS) when unit energy is applied to one of two resonators. The solutions are compared with those obtained using equivalent circuit-based analysis. The time-domain CMT is accurate only when resonant coils are weakly coupled and have large quality factors, and the reason for this inaccuracy is outlined. Even though the time-domain CMT solution does not describe the WPTS behavior precisely, it is accurate enough to allow for an understanding of the mechanism of energy exchange between two resonators qualitatively. Based on the time-domain CMT solution, the critical coupling coefficient is derived and a criterion is suggested for distinguishing inductive coupling and magnetic resonance coupling of the WPTS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5803-5819
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• 2017

In this paper, we proposed a contract theory based cooperative spectrum sharing scheme with joint power and bandwidth optimization under asymmetric information, where the primary user (PU) does not know the secondary users' (SUs) private information. To improve performance, PU needs to provide incentives to stimulate nearby SUs to help forward its signal. By using contract theory, PU and SUs' negotiations are modeled as a labor market. PU and SUs act as the employer and employees, respectively. Specifically, SUs provide labor (i.e. the relay power, which can be used for forwarding PU's signal) in exchange for the reward (i.e. the spectrum access bandwidth which can be used for transmitting their own signals). PU needs to overcome a challenge how to balance the relationship between contributions and incentives for the SUs. We study the optimal contract design which consists of relay power and spectrum access bandwidth allocation. We show that the most efficient SUs will be hired by the PU to attend the cooperative communication. PU can achieve the same maximum utility as in the symmetric information scenario. Simulation results confirm that the utility of PU is significantly enhanced with our proposed cooperative spectrum sharing scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2231-2245
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• 2014

Cognitive Radio (CR) has very promising potential to improve spectrum utilization by allowing unlicensed Secondary Users (SUs) to access the spectrum dynamically without disturbing licensed Primary Users (PUs). Mitigating interference is a fundamental problem in CR scenarios. This is particularly problematic for deploying CR in cellular networks, when users are located at the cell edge, as the inter-cell interference mitigation and frequency reuse are critical requirements for both PUs and SUs. Further cellular networks require higher cell edge performance, then SUs will meet more challenges than PUs. To solve the performance decrease for SUs at the cell edge, a novel Dynamic Spectrum Allocation (DSA) scheme based on Game Theory is proposed in this paper. Full frequency reuse can be realized as well as inter-cell interference mitigated according to SUs' sensing, measurement and interaction in this scheme. A joint power/channel allocation algorithm is proposed to improve both cell-edge user experience and network performance through distributed pricing calculation and exchange based on game theory. Analytical proof is presented and simulation results show that the proposed scheme achieves high efficiency of spectrum usage and improvement of cell edge SUs' performance.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.107-117
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• 2016

This study investigates design strategies for improving the educational quality of multimedia contents for early childhood education. It emphasizes both traditional education theory and developmental aspects in its exploration of interactive and educational qualitative multimedia contents for early children. Accordingly, for an effective early childhood education, it is necessary to experience of the playful learning for the conception of ideas and the understanding of the social life. Because this study 1) possibility of multimedia contents for early childhood education, 2) computer application method for early childhood education, 3) examines used in the designing of multimedia contents for early childhood education according to traditional education theory. Multimedia early childhood education system is possible to organize information such as test, image, sound and video based on hyperlink system. I use Microsoft's Ms-office and Asymetrix's ToolBook software that are useful for hyperlink and parameter. Multimedia contents and other pages are used by Dynamic Data Exchange(DDE). Therefore multimedia contents for early childhood education is a useful tool for students of early childhood education department, parents, and children.

• Journal of Information Science Theory and Practice
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• v.9 no.2
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• pp.83-98
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• 2021

Research collaboration is an important strategy to improve research output, and virtual academic communities (VACs) have become an important platform to collaborate on. This paper reveals the influencing factors of researchers' collaboration intention in VACs from two attributes: individual, and inter-members. On the basis of the Social Cognitive Theory, Social Exchange Theory, social network theory, and Five-Factor Model, this paper constructed a model demonstrating the influencing factors of VACs researchers' collaboration intention. A self-administered questionnaire was employed on members of four VACs in China to collect data; subsequently, 558 usable responses were analyzed using structural equation modeling. The result showed that openness, conscientiousness, reciprocity, trust, and the social network characteristic had a significant influence on the collaboration intention of researchers in VACs, while self-efficacy, agreeableness, extroversion, neuroticism, and experience had no significant effects on the collaboration intention of researchers in VACs. This model plays a positive role in promoting the research collaboration intention of Chinese VACs researchers and in guiding the construction of VAC platforms.

• Journal of Distribution Science
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• v.20 no.5
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• pp.75-84
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• 2022

Purpose: The paper employs the theory of planned behaviour, social identity theory, social presence theory, and social exchange theory to propose a model for using the social media platform Facebook in distributing information in universities. Research design, data and methodology: Data were obtained from 618 students at Hanoi University of Industry (HaUI) in Vietnam. The study used structural equation modeling in SPSS and the statistical analysis software AMOS version 24 to explore the information distribution role of Facebook. Results: Findings reveal that subjective norms and social presence play a key role in driving students to use Facebook for studying. In addition, university administrators can boost student satisfaction and academic achievement through Facebook. Interestingly, students who strongly identify with the brand name of the university have a strong connection with the university are more likely to engage in behaviors supportive toward the university. Conclusions: These findings show that Facebook had played a key information distribution role in universities. Thus, the study provides the executive board of the university and teachers can gain new understanding of why students employ Facebook for studying as well as capitalize on the platform to improve several operational metrics such as brand identification, student satisfaction, and academic achievement.

• Journal of Environmental Science International
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• v.6 no.5
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• pp.505-512
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• 1997

The Interfacial characteristics between various heavy metals and hydrous FeS were investigated. Heavy metals which have lower sulfide solubilities than FeS undergoes the lecttice exchange reaction when these metal tons contact FeS In the aqueous phase. For heavy metals which have higher suede solubilities than FeS, these metal ions adsorb on the surface of FeS. Such characteristic reactions were interpreted by the soled solution formation theory. The presence of ligand such as EDTA reduced largely metal removal efficiency due to formation of metal-ligand complex In the solution. In an attempt to elucidate the Interfacial characteristics, zeta potential of the hydrous FeS In the absence and In the presence of various metal loons were measured and analyzed.