• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.89-95
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• 2020

Purpose : This study aims to evaluate the correlation of cognitive function, activities of daily living (ADL), and driving performance in stroke hemiplegic patients residing in Korea. Methods : Subjects of the study were 18 stroke hemiplegic patients admitted to hospitals situated in Seoul. A clock drawing test (CDT), a modified Barthel index (MBI), and a virtual reality driving simulator (Eca faros-driving simulator) were used to examine their cognitive function, their ADL ability, and their driving skills, respectively. Results : Driving skills of stroke hemiplegic patients were shown to be associated with the CDT evaluation tool (r=-.777) (p<.001), but they were found to have any correlation with MBI (r=-.022) (p>.05). Additionally, an individual's CDT showed that the driving simulator evaluation result (pass/fail) could be discriminated with a sensitivity of 100.0 %, a specificity of 40.0 %, and an accuracy of 66.7 %. The result confirmed that the CDT is a useful evaluation tool for screening driving ability in people with stroke. But the MBI did not show any significant results (sensitivity of 62.5 %, specificity of 40.0 %, and predicted the results of the simulator with 50.0 % of accuracy) (p>.05). Conclusion : This study shows that cognitive function influences the driving performance in people with stroke. Driving skills of stroke hemiplegic patients are seen to be highly related to CDT. In the field of driving rehabilitation, these findings could be useful for evaluating driving skills relating to CDT. Furthermore, the study results will set a guideline for domestic occupational therapists to use the evaluation tool for assessing driving abilities in people with stroke.

• Journal of Internet Computing and Services
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• v.12 no.1
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• pp.1-10
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• 2011

The spectrum sensing is one of the fundamental functions to realize the cognitive radios. One of problems in the spectrum sensing is that the performance of spectrum sensing can be degraded due to fading and shadowing. In order to overcome the problem, cooperative spectrum sensing method is proposed, which uses a distributed detection model and can increase sensing performance. However, the performance of cooperative spectrum sensing can be still affected by the interference factors such as obstacle and malicious user. Especially, most of cooperative spectrum sensing methods only considered the stationary primary user. In the ubiquitous environment, however the mobile primary users should be considered. In order to overcome the aforementioned problem, in this paper we propose a robust spectrum detection method based on localization where we estimate the location of the mobile primary user, and then based on the location and transmission range of primary user we detect interference users if there are, and then the local sensing reporting from detected interference users are excluded in the decision fusion process. Through simulation, it is shown that the sensing performance of the proposed scheme is more accurate than that of conventional other schemes

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.333-339
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• 2019

The purpose of this study is to clarify the effect of magnesium water on the cognitive function, concentration and performance of bowling players. The total number of subjects in this study was 42, and changes in blood magnesium concentration, cognitive ability, concentration and performance were identified during the four-week experiment period. Data distribution was analyzed using SPSS18.0 with Normality test and Repeated measure two way ANOVA. Studies show that the concentration of magnesium in the blood of bowling players has changed with the intake of magnesium drinks, and that the concentration of magnesium in the blood has a proportional relationship with the cognitive function, concentration and performance.

• The Korean Journal of Coaching Psychology
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• v.7 no.3
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• pp.197-225
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• 2023

In this study, the impact of Competitive Anxiety on Cognitive Appraisal and Performance Confidence among Amateur baseball players was investigated, as well as the mediating role of Cognitive Appraisal in this relationship. Furthermore, the moderating effect of Character Strengths related to positive psychology on the relationship between Competitive Anxiety and Cognitive Appraisal was explored, dividing these Character Strengths into six virtues. To conduct this research, an online survey was administered to 201 Amateur baseball players aged 19 and above. The result of this study are as follows. First, it was found that the association between Performance Confidence and Competitive Anxiety is mediated by Cognitive Appraisal. Second, Character Strengths showed a moderating effect in the relationship between Cognitive Appraisal and Competitive Anxiety. Thirdly, statistical significance was shown for the moderated mediation effects. Specifically, it was established that values like Transcendence and Justice would considerably moderate the relationship. Notably, the degree to which Cognitive Appraisal declines as a result of Competitive Anxiety was found to be mitigated by Transcendence and Justice Character Strengths. In conclusion, based on the results of this study, implications, limitations were discussed.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.95-101
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• 2009

Cognitive Radios are encouraging solutions to improve the utilization of the radio spectrum In this paper, we propose channel allocation model for cognitive radio and analyse the performance of the model with Petri Nets. We design the model with an assumption that only partial information about current channel allocation information is known to CR users. The model is designed to communicate efficiently avoiding interference with primary and CR users and contains channel reobtaining process of CR users. The dropping rate and throughput of CR users under the various channel utilization of primary users are given as performance index.

• Journal of Labour Economics
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• v.39 no.3
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• pp.33-73
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• 2016

We examine the relationship between individual's personality trait and wage performance using administrative data collected by Korea Employment Information Service. We use Aptitude Test Battery and Five Factor Personality Inventory for individual's cognitive and noncognitive skill respectively. The results show that there are robust relationships between wages and conscientiousness, extraversion. The relationships between personality traits vary across gender. Additionally, this results imply that the return to schooling is higher for those with higher cognitive ability in early labor market.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.241-247
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• 2015

Cognitive radio has been attracting increased attention as an effective approach to improving spectrum efficiency. One component of cognitive radio, spectrum sensing, has an important relationship with the performance of cognitive radio. In this paper, after a summary and analysis of the existing spectrum-sensing algorithms, we report that the existing eigenvalue-based semi-blind detection algorithm and blind detection algorithm have not made full use of the eigenvalues of the received signals. Applying multi-antenna systems to cognitive users, we design a variety of spectrum-sensing algorithms based on the joint distribution of the eigenvalues of the received signal. Simulation results validate that the proposed algorithms in this paper are able to detect whether the signal of the primary user exists or not with high probability of detection in an environment with a low signal-to-noise ratio. Compared with traditional algorithms, the new algorithms have the advantages of high detection performance and strong robustness

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.3
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• pp.249-257
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• 2013

Recently, data traffic is significantly increased by high rate data service. As a result, radio spectrum is considered one of the most scarce and valuable resources for wireless communications. For the solution of this problem, cognitive radio(CR) has been proposed as an efficient means to opportunistic spectrum sharing between primary (licensed) users and cognitive radio users. In this paper, user selection scheme in CR networks is proposed for additional consideration of secondary system. The proposed user selection scheme mitigates interference to primary user by using orthogonal channel vectors while improves performance of secondary system. Simulation results show that the proposed scheme achieves 1.62bps/Hz higher average throughput of whole system than one of the existing scheme.

• Journal of Biomedical Engineering Research
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• v.26 no.1
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• pp.1-7
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• 2005

This study aimed to investigate the hypothesis that administration of the air with 30% oxygen compared with normal air (21% oxygen) enhances cognitive functioning through increased activation in the brain. Seventeen college students (right­handed, average age of 24.3) were selected as subjects for this study. An oxygen supply equipment that provides 21% and 30% oxygen at a constant rate of 8L/min was developed. In order to measure the performance level of visuospatial and verbal cognition, two psychological tests were developed. The experiment consisted of two runs, one for cognition task with normal air (21% oxygen) and the other for cognition task with hyperoxic air (30% oxygen). Visuospatial and verbal tasks were presented while brain images were scanned by a 3T fMRI system using the single-shot EPI method. The results showed that there was an improvement in performance and also increased activation in several brain areas in the higher oxygen condition. These results suggest that while performing cognitive tasks, high concentrations of oxygen administration make oxygen administration sufficient, thus making neural network activate more, and the ability to perform cognitive tasks increase.

• PNF and Movement
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• v.10 no.4
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• pp.1-7
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• 2012

Purpose : The purpose of this study was to evaluate the relationship between physical performance, such as gait and postural control, and cognition on as assessed by clinical tools in individuals with chronic hemiparetic stroke. Methods : Twenty-six patients who had hemiparetic stroke participated in this study, and were evaluated four common clinical measurements, including the Berg balance scale (BBS), 10 meter walk test (10MWT), 6 minute walking test (6MWT), and Montreal cognitive assessment (MoCA). Multiple regression analysis was used BBS score, 10MWT, and 6MWT as the dependent variables; MoCA score, post-stroke duration, age, and affected side as independent variables. Results : In the regression equation of the BBS score, the correlation coefficient (r) was 0.875, the coefficient of determination (R2) was 0.786, and the MoCA score was the most important variable for determining the BBS score. In the regression equation for the 10MWT, ther was 0.888, the R2 was 0.999, and the MoCA score was the most important variable for determining 10MWT. Finally, the r was 0.777, the R2 was 0.998, and the MoCA score was the most important variable for determining 6MWT in the regression equation of the 6MWT. Conclusion : The results show that cognitive abilities affect gait proficiencies in individuals with chronic hemiparetic stroke. Therefore, these results suggest that cognitive tests are necessary for examining and evaluating the abilities of postural control and gait performance for chronic stroke patients in research and clinical environments.