• Journal of Communications and Networks
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• v.16 no.2
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• pp.227-237
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• 2014

Throughput scaling laws for two coexisting ad hoc networks with m primary users (PUs) and n secondary users (SUs) randomly distributed in an unit area have been widely studied. Early work showed that the secondary network performs as well as stand-alone networks, namely, the per-node throughput of the secondary networks is ${\Theta}(1/\sqrt{n{\log}n})$. In this paper, we show that by exploiting directional spectrum opportunities in secondary network, the throughput of secondary network can be improved. If the beamwidth of secondary transmitter (TX)'s main lobe is ${\delta}=o(1/{\log}n)$, SUs can achieve a per-node throughput of ${\Theta}(1/\sqrt{n{\log}n})$ for directional transmission and omni reception (DTOR), which is ${\Theta}({\log}n)$ times higher than the throughput with-out directional transmission. On the contrary, if ${\delta}={\omega}(1/{\log}n)$, the throughput gain of SUs is $2{\pi}/{\delta}$ for DTOR compared with the throughput without directional antennas. Similarly, we have derived the throughput for other cases of directional transmission. The connectivity is another critical metric to evaluate the performance of random ad hoc networks. The relation between the number of SUs n and the number of PUs m is assumed to be $n=m^{\beta}$. We show that with the HDP-VDP routing scheme, which is widely employed in the analysis of throughput scaling laws of ad hoc networks, the connectivity of a single SU can be guaranteed when ${\beta}$ > 1, and the connectivity of a single secondary path can be guaranteed when ${\beta}$ > 2. While circumventing routing can improve the connectivity of cognitive radio ad hoc network, we verify that the connectivity of a single SU as well as a single secondary path can be guaranteed when ${\beta}$ > 1. Thus, to achieve the connectivity of secondary networks, the density of SUs should be (asymptotically) bigger than that of PUs.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.193-202
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• 2020

This study was intended to present the magnitude of privacy infringement concerns and their relationship to consumer innovation (functional innovation, hedonistic innovation, social innovation, cognitive innovation), to identify differences among groups and to suggest implications for marketing strategies for the spread of new products. The implications of this study are as follows. First, functional innovation has shown that differences exist between groups. Analysts say that sensitive groups are buying products that can simplify their work immediately after release despite concerns over privacy violations. Second, hedonistic innovation has shown that differences exist between groups. These findings suggest that sensitive groups prefer novel products, products that give excitement and excitement about products, and products that give new enjoyment and fun that they have never known before. Third, social innovation has been shown that there is no difference between groups. These analyses show that the self-esteem of using products that others have never experienced before, and the curiosity that anyone envies, are purchased or used first. Finally, cognitive innovation showed that differences existed between groups. These analyses show that new products are purchased when they meet the functions, design, and innovation that consumers want.

• The Korean Journal of Health Service Management
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• v.11 no.2
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• pp.17-27
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• 2017

Objectives : The rapidly changing consumer-centric and customer-oriented nature of the medical environment results in significant cognitive load. We aimed to clarify the situation of emotional labor and job stress among hospital employees and seek policies and hospital management for employees' emotions. Methods : The study was conducted through a questionnaire about emotional labor and job stress among 554 individuals working in Seoul, in 9 national, public, and private hospitals. Results : The results of the emotional labor and job stress questionnaire showed statistically significant differences in surface behavior and job stress; both had higher values in employees from the private hospitals than employees from public hospitals. Conclusions : This study found that the stress of emotional labor is a serious problem in government medical institutions. In addition, these institutions need to provide internal customer satisfaction through the hospital ombudsman and harmonize work and healing programs by including plans for improvement.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.3
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• pp.61-73
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• 2020

This study is an empirical analysis of the cultural competencies of college students majoring in aviation services on their major satisfaction and professionalism. In order to focus on the cultural competencies of aviation service college students, who are rarely addressed in the preceding study and to see how cultural competencies have significant effects on their major satisfaction and professionalism, we divid them into six sub factors: willingness to participate, cognitive openness/flexibility, emotional control, patience with uncertainty, self-efficacy, and cultural empathy. And the mediated effects of major satisfaction on cultural competency and professionalism are analyzed to provide educational implications for cultural competency. Based on the results of this study, it is expected to apply to the education of aviation service-related departments, it will be a basic data to promote students' adaptation to the department and satisfaction of the department and to train global professional service personnel who can improve their post-employment work adaptability, job satisfaction, and service productivity.

• The Korean Journal of Health Service Management
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• v.14 no.1
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• pp.1-14
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• 2020

Objectives: This study examined factors influencing hospital workers' perception of patient safety culture, job boredom and job crafting in reporting of safety compliance. Methods: Structured questionnaires were used to collect data from 245 hospital workers who were full-time staff for six months or more. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and hierarchical multiple regressions with SPSS/WIN version 22.0. Results: The mean score for perception of patient safety culture was 3.16±0.32, for job boredom was 2.52±0.52, for job crafting was 3.35±0.49 and for degree of safety compliance was 2.87±0.3. The hierarchical multiple analysis revealed that hospital work environment (β=.27, p<.001), communication process (β=.27, p<.001) of subarea perception of patient safety culture and cognitive crafting (β=.15, p=.039) of subarea job crafting were predictive of patient safety compliance (R2=.47, p<.001). Conclusions: The findings indicate that perception of patient safety culture and job crafting are important factors to be considered in working to improve hospital workers' safety compliance. Therefore, education and systematic programs to improve perception of patient safety culture and job crafting should be developed.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.7.1-7.7
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• 2012

Objectives: Modafinil is a waking drug prescribed to narcolepsy patients, but its usage among healthy individuals is increasing to enhance their alertness or to mitigate fatigue. This study was conducted to investigate practical use and toxic effects on neuro-immune interaction of modafinil. Methods: This study reviewed the significance of psychoactive drugs, and discussed the benefits and risks of the application of modafinil, which seems to be ideal as an anti-psychotic or anti-fatigue agent. Results: Modafinil is known to have less or no adverse effects than those found in traditional psychostimulants such as amphetamine, methylphenidate or cocaine. It can be applied as an anti-psychotic or anti-fatigue agent. However, the waking mechanism of modafinil is yet to be fully revealed. Recent studies reported that modafinil may be subject to abuse and addiction. In addition prolonged sleeplessness induces stress responses and impairs immune function. Conclusions: Modafinil can be used by anyone, who wishes to work late, stay awake, enhance their cognitive reactions, or brighten their moods. Users may already be under a great level of stress, i.e. cancer patients or soldiers in a battle field. A psychoneuroimmunological approach is thus needed to investigate the multi-functional effects of modafinil.

• Journal of The Korean Association of Information Education
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• v.18 no.4
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• pp.529-540
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• 2014

We propose an efficient information science teaching-learning method to improve information-scientific creativity of mathematically and scientifically gifted students. The students are able to improve their creative problem solving and team-work abilities through team project work to resolve a variety of application problem in real world. In the pursuit of this purpose, we designed a new two-stage information science learning method consisted of the standard stage and the application stage, and a new systemic project process. Moreover, we applied small-scale cooperation learning strategies and a multi-dimensional assessment system. The analysis on our proposed model shows that there is a remarkable achievement of educational objectives on cognitive capability, social and affective ability of information science creativity.

• Korean Journal of Childcare and Education
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• v.15 no.6
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• pp.21-40
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• 2019

Objective: The purpose of this study is to find the tendencies and differences of mother's child-rearing anxiety before and after their children enter into elementary school, to analyze the factors influencing child-rearing anxiety at each time, and thereby to seek a support plan at the time of transition. Methods: The subjects of this study were 181 mothers who participated in two surveys which were conducted before and after their child entered into elementary school. Results: Firstly, mother's child-rearing anxiety before and after their children's entrance into elementary school was at a middle level, but increased significantly when they experienced their children's transition to elementary school. Secondly, mother's child-rearing anxiety, before their children's entrance into elementary school, was influenced by private education, the collection of educational information, cognitive ability, whether or not to develop a work status change plan, and birth order sequentially. Thirdly, child-rearing anxiety after their children's entrance into elementary school was significantly influenced by child-rearing anxiety before their children's entrance into elementary school and the mother's employment. Conclusion/Implications: This study is meaningful in the point that it suggested the necessity for the cooperation between multiple systems, such as systematic and stepwise parenting education, the importance of offering information to educational institutions and local governments, and for work- family support policy to prioritize children in order to support children's successful transition into elementary school.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1073-1083
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• 2015

As an empirical study focused on how transactive memory concept influence the four processes of knowledge growth, this study aimed at explaining the function of transactive memory in the dynamic process of knowledge growth. To verify the research model, this study carried out a path analysis of 130 team memebers and as a result, part of the team transactive memory measurements does affect the knowledge growth. Consequentially, transactive memory especially based on team level, is relevant with knowledge growth. According to team level, this study targeted at the team members, and by adopting the team transactive memory concept in Cognitive Psycology, theoretically explained and analysed how to approach personal knowledge in internal organizations. To accelerate the knowledge process, the work should be modified collaboratively by trusting the team members' duty relations more than specialized knowledge. Furthermore, managers had better assign team members the work where they can make the most of their personal knowledge, and this study presented that the whole team performance could be improved by doing that.

• Journal of The Korean Association For Science Education
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• v.35 no.3
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• pp.499-508
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• 2015

The purposes of this study are to investigate elementary students' perception of science classroom through an analysis of students' answer to an open-ended question and to suggest a framework for the analysis of science classroom culture, as the first step to develop an analysis tool for qualitative exploration of science classroom culture. We analyzed 571 responses and developed an analysis framework with six categories (i.e. major factors; power structure of a classroom community; focused domains of the science classroom; student concerns; atmosphere of science classroom; participation form). The details of the six categories can be summarized as follows: (1) major factors were revealed to be practical work, fun, teacher, community and others; (2) the power structure of classroom community was in the order of peer students, teacher, and individual student himself/herself; (3) the focused domains of the science classroom perceived by students were more about affective and behavioral domains than cognitive one; (4) major student concerns were teachers' teaching, having practical work, and the understanding of and the sharing of knowledge and opinions (5) science classroom atmosphere was noisy and pranky but fun and interesting; (6) the students participation forms were to be total participation or voluntary participation or cooperative practice. Through this study, not only suggesting the framework, but we could also get implications for the cultural aspects of science classroom based on the results of data analysis in this study.