• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.391-400
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• 2009

Recently, cellular communication networks are migrating from 2G to 3G. Spectrum utilization tends to be inefficient during the transition. Cognitive radio (CR) technology can be a key solution to increase spectrum efficiency by allowing secondary networks to utilize frequency resource of primary networks. However, conventional CR approaches which do not utilize the frequency reuse factor of primary networks may incur degradation of whole network performance. In this paper, we propose a mechanism that a secondary network senses pilot signals of a primary network and select optimum frequency bands. In order to maximize whole network performance, we formulate an optimization problem subject to interference constraints for a primary network and present algorithms. Simulation results compare the proposed method with the conventional method. Our proposed method shows performance gain over the conventional method if channel variation of a primary network is dynamic and the frequency reuse factor of a primary network is high.

• Journal of the Korean Society of Food Culture
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• v.35 no.2
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• pp.156-166
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• 2020

In this study, 594 questionnaires administered to men and women residing in the capital metropolitan area who work night shifts were analyzed in order to study the effect of health information cognition on healing needs in accordance with the type of food selection criteria of the night worker. The results of confirmatory factor analysis in deriving food selection type identified four categories, a safety seeking type, a food exploratory type, a habitual seeking type, and a rational type, and the cognition types on health information were classified into physical cognition and psychological cognition. The need for healing, which was the investigated factor, was found to have a high correlation between questionnaire items with high reliable consistency. The results of this study were as follows. First, the food selection types of safety seeking type and habitual food seeking type had significant positive effects on the cognitive level of physical health information, and food exploratory type and habitual seeking type had significant positive effects on the cognitive level of psychological health information. In addition, it was shown that food exploratory type and rational type had significant positive effects on healing needs. As a result of this study, it was found that the cognition level of physical and psychological information was different according to food selection type, and the higher the cognitive level, the higher the healing needs. In particular, the result that the level of psychological health information significantly affected healing needs signifies that there is a demand to develop programs and menus that satisfy various needs related to healing and recovery from fatigue. In addition, further interest and study on the health and healing of night workers are required.

• The Korea Journal of Herbology
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• v.35 no.5
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• pp.33-39
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• 2020

Objectives : Increasing evidence supports the biological and pharmacological activities of essential oils on the central nervous system such as pain, anxiety, attention, arousal, relaxation, sedation and learning and memory. The purpose of present work is to investigate the protective effect and molecular mechanism of cypress essential oil (CEO) against scopolamine (SCO)-induced cognitive impairments in C57BL/6 mice. Methods : A series of behavior tests such as Morris water maze, passive avoidance, and fear conditioning tests were conducted to monitor learning and memory functions. Immunoblotting and RT-PCR were also performed in the hippocampal tissue to determine the underlying mechanism of CEO. Results : SCO induced cognitive impairments as assessed by decreased step-through latency in passive avoidance test, relatively low freezing time in fear conditioning test, and increased time spent to find the hidden platform in Morris water maze test. Conversely, CEO inhalation significantly reversed the SCO-induced cognitive impairments in C57BL/6 mice comparable to control levels. To elucidate the molecular mechanisms of memory enhancing effect of CEO we have examined the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. CEO effectively elevated the protein as well as mRNA expression of BDNF via activation of cAMP response element binding protein (CREB). Conclusions : Our findings suggest that CEO inhalation effectively restored the SCO-impaired cognitive functions in C56BL/6 mice. This learning and memory enhancing effect of CEO was partly mediated by up-regulation of BDNF via activation of CREB.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.1
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• pp.1-15
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• 2015

Objectives The aim of this study was to investigate the effects of Cannabis Fructus on exercise capacity and cognitive function in chronic hypoperfusion induced vascular dementia rat model. Methods Vascular dementia rat models were induced by chronic cerebral hypoperfusion through bilateral common carotid arteries occlusion (BCCAO). All rats were randomly divided into 4 groups: normal group; control group; CF I group (feeding Cannabis Fructus 100 mg/kg); CF II group (feeding Cannabis Fructus 300 mg/kg). In order to study the effects of oral administration of Cannabis Fructus on vascular dementia rat models, corner turn test, hole board test, radial arm maze test, passive avoidance test were taken and Acetylcholine (ACh) activity, Acetylcholinesterase (AChE) activity, serum of Vascular endothelial growth factor (VEGF) protein level were measured. Also histological findings of the liver, kidney, brain and the change of Tau immunoreactive neurons in hippocampus were observed. Results CF I and CF II showed significant improvement in corner turn test, hole board test, radial arm maze test, passive avoidance test, Acetylcholine (ACh) activity, Acetylcholinesterase (AChE) activity, the serum of Vascular endothelial growth factor (VEGF) protein level and the change of Tau immunoreactive neurons in hippocampus. CF I showed more significant effect than CF II in these tests. However in histological observations of the liver and kidney both CF I and CF II showed glomerular injury and hepatotoxicity. Conclusions These results suggest that Cannabis Fructus was helpful in improving exercise capacity and cognitive function on Chronic hypoperfusion induced Vascular Dementia rats. However Cannabis Fructus affects the liver and kidney, therefore suggest that this is an area for further study.

• Journal of dental hygiene science
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• v.19 no.3
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• pp.170-180
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• 2019

Background: Recently, competency-based education has been reorganized in the dental hygiene curriculum. In education, non-cognitive factors are emphasized. Grit, the non-cognitive ability to persevere to achieve an individual's long-term goals, is emerging. This study aims to identify the degree of grit and core competencies in students and to investigate the relationship between them and the factors that affect these core competencies. Methods: This study was conducted using 350 dental hygiene students who were randomly assigned a structured questionnaire to complete. The final analysis included 321 students. The survey contents evaluated grit, core competencies, and general characteristics. The difference in the degree of grit and core competencies in conjunction with the general characteristics of the subjects was analyzed using the t-test/Mann Whitney U-test and the ANOVA/Kruskal-Wallis H test. Multiple regression analysis was then conducted to determine the factors affecting the core competencies of the subjects. Results: The difference of 'grit' according to general characteristics was statistically significant in 'major satisfaction', 'relationship', 'perceived academic achievement', 'grade point average (GPA)'. The difference in 'core competency' according to general characteristics was statistically significant in 'grade', 'department selection', 'major satisfaction', 'relationship', 'perceived academic achievement', 'GPA'. Among the sub-areas of 'grit', 'perseverance of effort' showed a high correlation with 'core competency' and was statistically significant. As a result of regression analysis, 'major satisfaction', 'perceived academic achievement' and 'grit' of dental hygiene students had a statistically significant influence on 'core competency'. Meanwhile, 'GPA' was not seen to be statistically significant in 'core competency'. Conclusion: Grit, a non-cognitive factor, had a statistically significant effect on core competency, while the effects on GPA, a cognitive factor, were not statistically significant. Among the sub-factors of grit, 'perseverance of effort' had a statistically significant effect on 'problem-solving competency' and 'academic competency', which are 'core competency' sub factors.

• Archives of design research
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• v.16 no.3
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• pp.221-230
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• 2003

In product design, many designers incorporate psychological aspects to express the "fun" factor. If so, is it possible to apply the fun inducing mechanism utilized in psychology to product design and are there any problems in the application\ulcorner Psychology defines the sense of fun as the result of relief to a situation that causes a mental accumulation through the discovery of a due. The psychological extraction of fun inducing mechanism tends to lean too much to the cognitive aspect. Therefore, when dealing with product design, psychology's particular disposition is inadequate in explaining the important perceptive factor of fun. This study hypothesizes that perceptive aspect of should be induced along with the cognitive aspect in order to rationalize fun in product design. In order to understand the perception of fun, this study will introduce the amusement aspect within Kitsch products. Methods of developing a humorous form will be studied and these methods will be applicable to perceptive aspects. This paper hypothesizes that through the theoretical basis of internal characteristic of cognitive factors and external characteristic of perceptive factors, the mechanism of fun can be determined.etermined.

• Journal of Korea Game Society
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• v.12 no.2
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• pp.15-29
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• 2012

In order to predict satisfaction and performance of sensible healthcare game using motion recognition sensor, this study analyzed the effects of flow, presence and social cognitive factor and then, it attempted to verify structural relationships thereof. Self-efficacy, being a social cognitive factor, was found to affect the level of functional satisfaction of health game but it showed no direct effect to intention of using game. Flow experience was also observed to be a meaningful predictor for the level of functional and entertainment satisfaction in the direction hypothesized. It is also shown that presence exerts a direct effect on functional satisfaction. Finally, it is discovered that functional satisfaction has meaningful influence on entertainment satisfaction as well as future intention to use. The results verifies that even in sensible healthcare game, user experience and social cognitive factor have significant effects on satisfaction and performance of a serious game.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.91-103
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• 2021

Purpose : This study aimed to evaluate the effects of a cognitive enhancement brain yoga program on short-term memory and serum brain-derived neurotrophic factor (BDNF) levels according to the cognitive state in men aged 20-29 years. Methods : Thirty healthy volunteers aged 20-29 years were divided into four groups: brain yoga group, yoga group, combined exercise group, and control group. Seven people were assigned randomly per group. A single-session intervention was conducted over 50 min and consisted of three parts: warm-up, main exercise (brain yoga, yoga, combined exercise, or non-exercise), and cool-down. Serum BDNF levels were measured using enzyme-linked immunosorbent assay, and short-term memory was evaluated using the forward number span test before and after the intervention. Results : BDNF levels significantly increased within the brain yoga group after the intervention (from 28874.37±5185.57 to 34074.80±7321.12, p=.003), whereas there were no significant differences pre-and post-intervention in the other groups. The inter-group comparison showed a significant interaction between the brain yoga group and the combined exercise group (p=.036) but no significant interaction between any of the other groups. Forward number span scores were significantly increased in the brain yoga group (from 9.43±9.83 to 23±7.92, p=.012) and theyoga group after the intervention (from 13.43±9.41 to 24.14±8.45, p=.011), whereas there were no significant changes after the intervention in any other groups. Conclusion : Our findings showed that a single-session, 50-minute brain yoga exercise improved short-term memory and increased serum BDNF levels in healthy men aged 20-29 years and that yoga improved only short-term memory in healthy men of this age group.

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.596-611
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• 2004

Based on conceptual change theory, cognitive conflict is known as an important factor for conceptual change even though there are still questions about its positive and negative effects on science learning. However there are little research which propose types of meaningful(constructive) cognitive conflict in learning science. The purpose of this study is to find out how are the anxiety types of cognitive conflict to which high school students respond in the action-reaction task, and to reveal what's the characteristic of the explanatory hypothesis according to the anxiety types. The result of this study indicated that first, the characteristics of the anxiety types of the cognitive conflict were classified as eight types. Especially the students who belong to the types of conviction of logical misconception and reasonable modification suggested explanatory hypothesis close to physical nature. On the other hand, the students who showed other types of anxiety except the two types of anxiety suggested temporary supported hypothesis or simple explanatory hypothesis based on students' observation and intuition. Finally we discussed the importance and the implication of the types of anxiety in applying the cognitive conflict strategy to science instruction.

• Journal of Information Management
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• v.30 no.1
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• pp.48-67
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• 1999

In an advanced computer and information network technologies, users are rapidly approaching environment in which information will be created, delivered, managed and stored, using vastly different methods to traditional pap r based systems. Information seeking behavior contains not only physical access, but also cognitive process in which reading, viewing, analyzing, reasoning etc. The most Important factor determining the usability of electronic documents is cognitive process. But, currently Navigation tools for using electronic documents depend on physical searching without considering cognitive process. Therefore, this study examined feasibility of using overal cognitive process in developing navigation tools. Six cognitive process style have been analyzed to find common skill of information seeking process. Also this study suggests skills that needs to introduce to functions of navigation tool, such as searching, filtering, visualization, traversal, content structure.