• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2128-2147
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• 2021

Cognitive radio systems are being implemented recently to tackle spectrum underutilization problems and aid efficient data traffic. Spectrum sensing is the crucial step in cognitive applications in which cognitive user detects the presence of primary user (PU) in a particular channel thereby switching to another channel for continuous transmission. In cognitive radio systems, the capacity to precisely identify the primary user's signal is essential to secondary user so as to use idle licensed spectrum. Based on the inherent capability, a new spectrum sensing technique is proposed in this paper to identify all types of primary user signals in a cognitive radio condition. Hence, a spectrum sensing algorithm using improved convolutional neural network and long short-term memory (CNN-LSTM) is presented. The principle used in our approach is simulated annealing that discovers reasonable number of neurons for each layer of a completely associated deep neural network to tackle the streamlining issue. The probability of detection is considered as the determining parameter to find the efficiency of the proposed algorithm. Experiments are carried under different signal to noise ratio to indicate better performance of the proposed algorithm. The PU signal will have an associated modulation format and hence identifying the presence of a modulation format itself establishes the presence of PU signal.

• Asia-Pacific Journal of Business
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• v.14 no.2
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• pp.17-31
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• 2023

Purpose - The purpose of this study is to verify the effects of attributes of personal media content and influencers on the cognitive and emotional trust of platform users. In addition, the structural relationships among cognitive trust, emotional trust, viewing commitment, and purchase intention were examined. Design/methodology/approach - For the empirical analysis of the study, a survey was conducted on 192 consumers who have recently experienced using personal media content. The Confirmatory Factor Analysis (CFA) and the Structure Equation Model (SEM) were hired in order to analyze the survey data. Findings - Findings of this study are 1) informativeness and expertise had a significant effect on cognitive and emotional trust. However, entertainment had no significant effect on both cognitive and emotional trust; 2) interactivity had a significant effect on emotional trust, but not on cognitive trust; 3) cognitive and emotional trust had a positive effect on the viewing commitment of the content; 4)content users' viewing commitment had a positive effect on their intention to purchase recommended products. Research implications or Originality - The theoretical and practical implications were discussed through the above empirical research results, and the limitations of the study and the direction of follow-up studies were presented.

• The Korean Journal of Franchise Management
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• v.7 no.2
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• pp.15-25
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• 2016

Purpose - This study examined the effect of perceived corporate social responsibility (CSR) on cognitive trust, emotional trust, and loyalty among using Korean food buffet franchises. The result of this study is expected to provide practical implication to industry practitioners in expanding their understanding of the CSR effect in the marketing perspective. Research design, data, and methodology - The data was collected from a panel of online research companies who are over 20 years old and dined in at Korean style buffet franchise outlets more than five times. A total of 370 samples were used after eliminating outliers and missing data. the data were analyzed SEM with SPSS and AMOS. Result - The result of this study showed that: 1) social CSR activities have an effect only on emotional trust; 2) food-related CSR activities influence both cognitive trust and emotional trust; and 3) both cognitive trust and emotional trust have a significant impact on customer loyalty in Korean style buffet franchises. However, it is important to note that this study found no significant causal impact from environmental CSR activities. Furthermore, this study found that food-related CSR activities have the greater influence on the cognitive trust, and cognitive trust is more influential on the customer loyalty than the emotional trust. Conclusions - Based on the findings, this study provides practical implications to industry practitioners. First, that CSR has a significant impact on customer trust suggests that Korean style buffet franchises should focus on CSR activities to improve customer trust. Second, that food-related CSR activities have the greater influence on the cognitive trust implies that industry practitioners should reinforce food-related CSR activities as a marketing tool to enhance emotional trust and the overall credibility of their franchise. Third, we need to find CSR measures at the social level that can secure emotional trust so that customer loyalty can be formed. Fourth, Korean food buffet franchise food service companies should concentrate their efforts on CSR activities at food and social level among the three dimensions suggested by researchers in order to form customer loyalty. For next study, perceived concept of CSR on individual customer should be examined.

• Korean Journal of Health Education and Promotion
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• v.33 no.1
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• pp.23-32
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• 2016

Objectives: The aim of this study was to examine the effects of home-based cognitive physico-occupational therapy(HBCPOT) on cognitive function, depression, and quality of life in dementia patients, using a cognitive impairment model. Methods: The data was analysed for Mini-Mental State Examination-Korean version (MMSE-KC) for assessing cognitive function, Quality of life-Alzheimer's Disease (QOL-AD) and Geriatric Depression Scale (GDS) in 31 dementia patients who received home-based cognitive physico-occupational therapy for one hour once a week for 12 weeks by a trained occupational therapist at the Dementia Prevention and Management Center of Y-city during 20111-2013. Results: Among these 31 patients, 18(58.1%) were female, and 25(80.6%) had Alzheimer's Disease. After HBCPOT, the mean scores of MMSE-KC and QOL-AD were significantly improved, but GDS score was not significantly decreased. Conclusions: It was suggested that HBCPOT was effective in improving cognitive function and quality of life.

• Korean Journal of Adult Nursing
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• v.28 no.6
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• pp.691-700
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• 2016

Purpose: The aim of this study was to evaluate the effects of a computerized cognitive training on older adults affected by mild cognitive impairment (MCI) in terms of cognitive function, depression, self-esteem, and activities of daily living (ADL). Methods: This study used a non-equivalent control group non-synchronized design. A total of 53 older adults who reside in long-term care facilities were recruited, 26 subjects for an experimental group and 27 subjects for a control group. A computerized cognitive training was performed for 20~40 minutes/day, three days/week for ten weeks. Data were analyzed using SPSS/WIN 21.0 with $x^2$ test, Fisher's exact test, and t-test. Results: Scores of MMSE (t=3.30, p=.002), depression (t=-2.15, p=.036), and self-esteem (t=2.76, p=.008) were significantly better in the experimental group than the control group. However, the difference in ADL (t=-1.01, p=.316) was not significant between the two groups. Conclusion: These findings suggest that the computerized cognitive training can be used as an effective nursing intervention to improve cognitive function and self-esteem and lower depression among older adults with MCI.

• Journal of Preventive Medicine and Public Health
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• v.52 no.5
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• pp.333-343
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• 2019

Objectives: This study aimed to evaluate the association between dental implants and cognitive function in community-dwelling older adults. Methods: Data were collected from the baseline survey (2016-2017) of the Korean Frailty and Aging Cohort Study. The study sample comprised 1115 community-dwelling people aged 70 years to 84 years who had 0-19 natural teeth. Dental implants and natural teeth were identified by panoramic radiography, while the cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The association between dental implants and cognitive function was analyzed by multiple linear regression. Sensitivity analysis was performed to test for potential bias. Results: The mean number of natural teeth in the study population was 9.50 (standard deviation [SD], 6.42), and the mean MMSE-KC score was 24.93 (SD, 3.55). In the simple univariate analysis, tooth replacement, age, sex, smoking status, alcohol consumption, body mass index, osteoporosis, number of natural teeth, periodontitis, chewing discomfort, tooth-brushing frequency, education level, monthly household income, participation in economic activity, living alone, and marital status had a significant impact on the association. After adjusting for confounders, the association between dental implants and cognitive function remained significant (B, 0.85; standard error, 0.40; p<0.05). Age, body mass index, periodontitis, tooth-brushing frequency, and education level were also significantly associated with cognitive function. The results of the sensitivity analyses were consistent with those of the primary analysis. Conclusions: Dental implants were associated with cognitive function in older adults living in the community. Dental implants as tooth replacements may play a role in preserving cognitive function.

• Journal of dental hygiene science
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• v.22 no.2
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• pp.67-74
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• 2022

Background: Depression and cognitive function have a positive effect on the improvement of quality of life and extension of lifespan in the elderly. In addition, it appears as a major factor influencing oral health status. Therefore, this study looked at the relationship between the Geriatric Oral Health Assessment Index (GOHAI), depression, and cognitive function in the elderly using the Korea Longitudinal Study of Aging. Methods: In this study, 4,535 elderly people aged 65 years and over were targeted using the 7th data of the 2018 Korea Longitudinal Study of Aging. A t-test and ANOVA analysis were performed to compare GOHAI, depression, and cognitive function by group. In addition, hierarchical multiple linear regression was performed to understand the effect of the elderly's perceived depression scale and cognitive ability on GOHAI. Results: As a result of adding the depression scale and cognitive function variables to Model 2, the explanatory power was 22%. Educational level, marital status, private health insurance subscription, average monthly allowance, subjective health status, use of dentures, smoking status, economic activity, depression scale, and cognitive function were found to have significant influence (p<0.05). In addition, when controlled and viewed with all factors, depression and cognitive function were found to have an effect on oral health-related quality of life. Conclusion: The findings indicate that depression and cognitive function are associated with oral health-related quality of life in the Korean elderly. As the age increases, the quality of life declines due to depression and cognitive function problems, in addition to oral discomfort, eating disorders, and physical discomfort.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.890-910
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• 2014

This paper investigates the spectrum hole utilization of cooperative schemes for the two-way relaying model in order to improve the utilization efficiency of limited spectrum holes in cognitive radio networks with imperfect spectrum sensing. We propose two specific bidirectional secondary data transmission (BSDT) schemes with two-step and three-step two-way relaying models, i.e., two-BSDT and three-BSDT schemes, where the spectrum sensing and the secondary data transmission are jointly designed. In the proposed cooperative schemes, the best two-way relay channel between two secondary users is selected from a group of secondary users serving as cognitive relays and assists the bi-directional communication between the two secondary users without a direct link. The closed-form asymptotic expressions for outage probabilities of the two schemes are derived with a primary user protection constraint over Rayleigh fading channels. Based on the derived outage probabilities, the spectrum hole utilization is calculated to evaluate the percentage of spectrum holes used by the two secondary users for their successful information exchange without channel outage. Numerical results show that the spectrum hole utilization depends on the spectrum sensing overhead and the channel gain from a primary user to secondary users. Additionally, we compare the spectrum hole utilization of the two schemes as the varying of secondary signal to noise ratio, the number of cognitive relays, and symmetric and asymmetric channels.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.401-408
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• 2015

This study was done to examine the relation of cognitive function, depression and anxiety in elderly people above 65 years of age, and to identify factors influencing anxiety. The data were collected from June 1 to August 30 2014. Data were collected by questionnaire from 363 elderly people. The instruments for this study were MMSE-DS, depression, anxiety. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and multiple linear regression with the SPSS/WIN 18.0 program. According to results, the significant factors influencing anxiety were sleeping time(${\beta}=-.249$, p<.001), depression(${\beta}=.218$, p<.001), cognitive function(${\beta}=-.209$, p<.001), occupation(${\beta}=-.133$, p=.006). The study reveals that it is necessary to develop a convergent program that maintain adequate sleep, prevents of cognitive impairment and decreases depression.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6B
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• pp.483-488
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• 2012

With the fast growing data traffic, the performance of the convergent overlay network environment under the cognitive networking environment is crucial for the implementation of the efficient network structure. In order to achieve high capacity and reliable link quality in wireless communication of the overlay convergent networks with the cognitive networking based on the advanced capability of the mobile terminal, a Distributed Wireless Communication System (DWCS) can provide the capability of ambient-aware dual cell system's operation. This paper has considered virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The considered system constructs DVC by using cognitive ability of finding useful virtual signals. Also, for multi-user high-rate data transmission, the DWCS system exploits Space-Time Trellis Codes. The effects of changing environments on the system performance has been investigated thereafter.