• ETRI Journal
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• v.34 no.2
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• pp.276-279
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• 2012

In this letter, a modified 802.11-based opportunistic spectrum access is proposed for single-channel cognitive radio networks where primary users operate on a slot-by-slot basis. In our opportunistic spectrum access, control frames are used to reduce the slot-boundary impact and achieve channel reservation to improve throughput of secondary users. An absorbing Markov chain model is used to analyze the throughput of secondary users. Simulation results show that the analysis accurately predicts the saturation throughput.

• ETRI Journal
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• v.44 no.6
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• pp.966-976
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• 2022

Optical wireless communication, or free space optics, is a promising solution for backhauls in sixth-generation mobile systems. However, the susceptibility of optical links to weather conditions has led to FSO links being furnished with radio frequency (RF) backups. These Hybrid FSO/RF systems provide enhanced link availability but lead to RF resource wastage. Cognitive radio technology, in contrast, is well known for its optimal use of RF resources and may be combined with an FSO link to create a Cognitive Hybrid FSO/RF system. This work uses such a system to analyze a configuration for a mobile backhaul in sixth-generation mobile systems. This configuration can seamlessly coexist with established large scale RF cellular networks. The performance of this configuration is analyzed with respect to outage probability and average bit error by considering the impact of optical channel turbulence, misalignment loss, RF interference, and noise. Mathematical closed-form expressions are verified by simulations.

• Asia pacific journal of information systems
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• v.28 no.1
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• pp.61-74
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• 2018

Meeting, Incentive travel, Convention, Exhibition (MICE) industries recently introduced new information systems, such as the exhibition guide system (EGS), to keep pace with Smart MICE and maximize the effect of exhibition performance. We investigate how persuasive EGS can affect the EGS acceptance of attendees via cognitive and affective response. We analyzed data from 442 EGS users at an exhibition. We found that information accuracy, information relevance, and source credibility were predictors of cognitive response. Source credibility had a significant effect on affective response. Furthermore, cognitive response was found to be a positive predictor of affective response and EGS acceptance. We also found affective response is a predictor of EGS acceptance. The theoretical and practical implications of the study were presented based on the results.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.505-512
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• 2013

PURPOSE: The purpose of this study applied computerized cognitive therapy and proprioception exercise to stroke patients and analyzed improvement in their changes in Electrocephalogram(EEG). METHODS: The subjects were 30 patients who were diagnosed with stroke and they were randomly selected to a proprioceptive training group(n=15), a cognitive training group(n=15). The experiment was performed for three times per week for 6 weeks and EEG was measured before and after the experiment. RESULT: Before and after the experiment in each group of experiments, the ${\alpha}$-and ${\beta}$-wave study showed significant changes but, there was no significant difference in the change between groups before and after the experiment. CONCLUSION: From the above results, the cognitive training and the proprioception training have a positive impact in stroke patients EEG changes, but it is difficult to suggest a better therapeutic interventions. However, as compared with that the cognitive training that directly involved in the cognitive and brain activation, the proprioception training have changes on brain activation. Therefore, of Clinical therapeutic interventions, the proprioception training can be presented effectively to the changes in brain activation in stroke patients.

• 한국벤처창업학회:학술대회논문집
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• 2024.04a
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• pp.103-110
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• 2024

This study aimed to confirm the positive impact of individual entrepreneurial orientation on entrepreneurial intentions and to investigate whether cognitive competency and social awareness of entrepreneurs serve as mediating variables in the relationship between individual entrepreneurial orientation and entrepreneurial intentions. The results of this study are as follows: Individual entrepreneurial orientation positively influenced entrepreneurial intentions, cognitive competency, and social awareness of entrepreneurs. Moreover, it was found that higher levels of cognitive competency and social awareness led to higher entrepreneurial intentions. Additionally, it was demonstrated that cognitive competency and social awareness of entrepreneurs had parallel mediating effects in the relationship between individual entrepreneurial orientation and entrepreneurial intentions. Based on these findings, this study provides theoretical foundations for research on the relationship between individual entrepreneurial orientation and entrepreneurial intentions, which have been relatively underexplored. Furthermore, by identifying cognitive competency and social awareness as mediating variables, this study opens avenues for academic expansion. Finally, the findings of this study can serve as practical groundwork related to individual entrepreneurial orientation.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.11-23
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• 2023

This study aims to investigate the relationship between service recovery justice, residual emotions, and customer behavior. It empirically verifies that low justice in service recovery affects residual emotions and, in turn, has an impact on customers' negative behaviors. Furthermore, this research distinguishes customer-brand relationship quality into emotional relationship quality and cognitive relationship quality and seeks to validate that the type of relationship quality may influence the extent to which the justice of recovery processes affects residual emotions. Data was collected through surveys, and hypotheses were tested using structural equation modeling. The research findings indicate that among the dimensions of service recovery justice, procedural justice and interactional justice significantly influence residual emotions. Moreover, residual emotions have a significant impact on both the intention to revisit and the intention to engage in negative word-of-mouth. In addition, the impact of distributive justice and procedural justice on residual emotions was found to be higher for cognitive relationship quality than emotional relationship quality, and the impact of interactional justice on residual emotions was found to be higher for emotional relationship quality than cognitive relationship quality.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.3
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• pp.259-268
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• 2019

This study examines the color image of uniform of airline cabin crew according to the demographic characteristics of the customer and demonstrates how it affects the cognitive image of airlines. Adjective adjectives were derived for uniform color images of all eight airlines in Korea and analyzed the image of airline brand color. Based on the analysis of color images, the difference in perception according to the demographic characteristics of passengers was analyzed. When the colors of airline uniforms are mainly blue, sky blue, white and ivory, they have a lot of trust, neat and elegant images. Uniforms with primary colors such as red, orange and green beans are found to have a lot of cheerful, developmental and enterprising images. In addition, the empirical analysis of the impact of the customer's cognitive perception and favoritism on the uniform color image of the airline crew showed that the more positive the airline's positive perception of the uniform color image, the more positive the cognitive image is. In other words, the empirical analysis revealed that the airline's uniform color image, its cognitive image of the airline, and its popularity have significant positive relationships.

• Journal of the Korean Home Economics Association
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• v.43 no.4 s.206
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• pp.161-172
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• 2005

The present study investigation the effect of a project approach program on children's cognitive styles. It examined closely the characteristics and processes of the project approach program to determine its impact on children's individual cognitive styles such as divergent thinking, field independence, and reflection. The subjects were 384-year-old children. Eighteen children were assigned to the experimental group and twenty to the control group. Pretest-treatment-posttest design was adopted for this study. Collected data were analyzed with SPSS Win 10.0 and processed statistically using average, standard deviation, and ANCOVA. For the children's divergent thinking, the children with the project approach program showed significant difference in fluency and flexibility, but no difference in originality and elaboration, compared to the children in the control group. Children with the project approach program showed more field independence than those in the control group. Children with the project approach program showed no difference in reflection. These results showed that the project approach pro!3ram partly influenced the children's cognitive styles.

• Korean Journal of Health Education and Promotion
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• v.15 no.2
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• pp.185-198
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• 1998

This study was designed to investigate the content of health behavior and to examine factors determining health behavior of nursing students(n=159) in relation to sociodemographic and cognitive variables. Cognitive variables were categorized into saliency of health, susceptibility to illness, and health locus of control. Data analysis prodecure included factor analysis and stepwise multivariate regressions using health behavior as dependent variables. Analysis showed; 1. As a whole, nursing students showed a tendency of lack in positive health behavior, especially in diet-related health behavior. 2. Multiple regression analysis revealed that the factors such as grade, saliency of health, and birth place were to be independently and significantly associated with health behavior: Upper grade students, high level of saliency, urban-born students tend to take health behavior positively. 3. The most influential factor among them was grade, but cognitive inspite of stereotype, poorly impact on health behavior with the exception health. We can guess the effect of education indirectively from these findindgs, but longitudinal studies need to consider the direct effect of education. The results also indicate that the respondents should be encouraged to take health behavior positively. The studies including more other cognitive variables would be conducted for the nursing students in relation to health behavior.

• ETRI Journal
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• v.38 no.2
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• pp.291-301
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• 2016

In this paper, we study an optimized block-diagonal zero-forcing (BD-ZF) precoder in a two-tiered cognitive network consisting of a macro cell (MC) and a small cell (SC). By exploiting multiuser multiple-input and multiple-output Vandermonde-subspace frequency-division multiplexing (VFDM) transmission, a cognitive SC can coexist with an MC. We first devise a cross-tier precoder based on the idea of VFDM to cancel the interference from the SC to the MC. Then, we propose an optimized BD-ZF intra-tier precoder (ITP) to suppress multiuser interference and maximize the throughput in the SC. In the case where the dimension of a provided null space is larger than that required by the BD-ZF ITP, the optimized BD-ZF ITP can collect all limited channel gain by optimizing rotating and selecting matrices. Otherwise, the optimized BD-ZF ITP is validated to be equivalent to the conventional BD-ZF ITP in terms of throughput. Numerical results are presented to demonstrate the throughput improvement of the proposed optimized BD-ZF ITP and to discover the impact of imperfect channel state information.