• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1316-1332
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• 2012

Formation flying is an important technology that enables high cost-effective organization of outer space aircrafts. The ad-hoc wireless network based on direct-sequence ultra-wideband (DS-UWB) techniques is seen as an effective means of establishing wireless communication links between aircrafts. In this paper, based on the theory of matched filter and error bits correction, a hybrid detection algorithm is proposed for realizing multiuser detection (MUD) when the DS-UWB technique is used in the ad-hoc wireless network. The matched filter is used to generate a candidate code set which may contain several error bits. The error bits are then recognized and corrected by an novel error-bit corrector, which consists of two steps: code mapping and clustering. In the former step, based on the modified optimum MUD decision function, a novel mapping function is presented that maps the output candidate codes into a feature space for differentiating the right and wrong codes. In the latter step, the codes are clustered into the right and wrong sets by using the K-means clustering approach. Additionally, in order to prevent some right codes being wrongly classified, a sign judgment method is proposed that reduces the bit error rate (BER) of the system. Compared with the traditional detection approaches, e.g., matched filter, minimum mean square error (MMSE) and decorrelation receiver (DEC), the proposed algorithm can considerably improve the BER performance of the system because of its high probability of recognizing wrong codes. Simulation results show that the proposed algorithm can almost achieve the BER performance of the optimum MUD (OMD). Furthermore, compared with OMD, the proposed algorithm has lower computational complexity, and its BER performance is less sensitive to the number of users.

• Research in Community and Public Health Nursing
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• v.27 no.1
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• pp.1-8
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• 2016

Purpose: The purpose of this study was to examine the depression and cognitive function of community-dwelling older adults. Methods: 243 aged over 65 in Won-Ju in South Korea participated in this study. Data were collected from April to June 2013 through interviews. This study utilized the Geriatric Depression Scale Short Form, the Korean version of MMSE-DS (MMSE for Dementia Screening), and infirmity testing for basic health status. Descriptive statistics, ${\chi}^2$, t-test, ANOVA, $Scheff{\acute{e}}^{\prime}s$ test, and Pearson's correlation coefficient were used. Results: 75.3% of the participants belonged to the depression group, and the prevalence of cognitive impairment was 17.3%. There were significant differences in depression and cognitive function according to gender, educational level, type of insurance, subjective health, frailty, and whether to be a client of home care service. The level of depression was significantly higher and the level of cognitive functions was significantly lower in older adults in home care services than in community-dwelling older adults. Conclusion: This study is meaningful in that it included older adults in home care services to provide information to develop effective prevention programs for improving cognitive functions. The results of this study can be used to develop future community prevention and intervention.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.187-196
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• 2003

We consider the use of error control coding in direct sequence-code-division multiple access (OS-COMA) systems that employ multiuser detection (MUO) and space diversity. The relative performance gain between Reed-Solomon (RS) code and convolutional code (CC) is well known in [1] for the single user, additive white Gaussian noise (AWGN) channel. In this case, RS codes outperform CC's at high signal-to-noise ratios. We find that this is not the case for the multiuser interference channel mentioned above. For useful error rates, we find that soft-decision CC's to be uniformly better than RS codes when used with DS-COMA modulation in multiuser space-time channels. In our development, we use the Gaussian approximation on the interference to determine performance error bounds for systems with low number of users. Then, we check their accuracy in error rate estimation via system's simulation. These performance bounds will in turn allow us to consider a large number of users where we can estimate the gain in user-capacity due to channel coding. Lastly, the use of turbo codes is considered where it is shown that they offer a coding gain of 2.5 dB relative to soft-decision CC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.311-316
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• 2002

In this paper, an adaptive beamforming algorithm, based on the Minimum Mean Squared Error (MMSE) criterion, is devised fer adaptive antenna applied to an MC-CDMA system. A new method for updating the weight vector is derived. Computer simulations show that proposed algorithm is capable of rejecting co-channel interference that affects the MC-CDMA system. Thus, the BER performance of the MC-CDMA system is improved compared with that of the MC-CDMA system without using adaptive antenna and that of the DS-CDMA system with adaptive antenna in multi-path Ricean fading channel.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.313-322
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• 2016

Purpose: This study was conducted to examine the relationship among cognitive function, nutrition screening initiative (NSI) score, and food intake status. Methods: A total of 409 subjects aged over 60 years were recruited from the Yongin dementia prevention and control center. Mini Mental State Examination Dementia Screening (MMSE-DS) method was used to assess the cognitive function of the subjects. Information on health related behaviors and food intake was collected by face to face interview using a structured questionnaire. The questionnaires included the NSI DETERMINE checklist, food intake sheets by 24 hr recall method and by semi-quantified food frequency questionnaire. Results: Subjects were divided into low cognitive or normal groups according to the MMSE-DS result. The prevalence of low cognitive function in the subjects was 25.7%. The low cognitive group exercised less and had higher nutritional health risk than the normal group. The low cognitive group had lower consumption of polyunsaturated fatty acid and higher tendency of thiamin, riboflavin, and iron deficiency. The low cognitive group had less frequency of eating mackerel, pepper, tangerine, and watermelon and higher frequency of eating white rice and cookies than the normal group. Conclusion: The results of this study imply that the cognitive function of elderly is related to exercise behavior, nutritional health risk, and food and nutrient intake status.

• The Journal of Internal Korean Medicine
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• v.38 no.5
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• pp.628-640
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• 2017

Purpose: To describe the effectiveness of traditional Korean medicine (TKM) on the patients with secondary dementia (case 1: Rt. MCA infarction; case 2: traumatic subacute subdural hemorrhage and traumatic intracranial hemorrhage; case 3: delayed encephalopathy after carbon monoxide poisoning). Methods: We used a complete TKM treatment. The acupoints used were as follows: acupoints frequently used in hemiparesis (GV20, GV24, ST4, LI11, LI14, ST36, GB34, SP9, and LR3), and we used herbal medicine (補腎益腦湯加味, Boshiniknoe-tang-gami). The efficacy was evaluated using the Mini-Mental State Examination for Dementia Screening (MMSE-DS) and the Modified Barthel Index (MBI). Results: After treatment, the total MMSE-DS score was increased from 14 to 24 (case 1), 14 to 19 (case 2), and 0 to 17 (case 3). The total K-MBI was increased from 30 to 44 (case 1), 82 to 86 (case 2), and 30 to 86 (case 3) Conclusions: We suggest that TKM could positively influence cognition and improve activity of daily living (ADL). This study has limitations, so further studies are needed.

• The Journal of Korean society of community based occupational therapy
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• v.5 no.2
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• pp.11-21
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• 2015

Objective : We tried to know the effect on the ability of work performance, cognitive, balance, depression, ability of daily living, the quality of life, and time usage after applying the group cognitive therapy that based on lifestyle redesign to dementia elderly. Methods : We performanced the group cognitive therapy that based on lifestyle redesign to 15 dementia elderly for 12weeks by total 5 steps. We evaluated the ability of work performance(COPM), cognitive(MMSE-DS), balance(BBS), depression(GDS-K), ability of daily living(MBI), the quality of life(GQOL-D), and time usage(OQ) of before and after the programme. Results : There was a significant difference of the ability of work performance, balance, the quality of life, and locomotive area of time usage after applying the group cognitive therapy that based on lifestyle redesign to dementia elderly. Conclusion : The group cognitive therapy that based on lifestyle redesign programme is effective for satisfaction of work performance and improvement of the quality of life and balance ability. The programme is also effective for locomotive area of time usage. We found out the effect of the programme in variety of the life of dementia elderly.

• 한국노년학
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• v.37 no.4
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• pp.909-924
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• 2017

The purpose of this study was to identify the impact of chewing ability on cognitive function of older people in Korea and the mediation effect of physical function and depression using the nationwide data from "Survey of the Living Conditions and Welfare Needs of Korean Older Persons in 2014", in Korea. This study was conducted on a total of 10,451 respondents in the "Survey of the Living Conditions and Welfare Needs of Korean Older Persons in 2014" and the data collection period was from June 11, to September 4, 2014. Chewing ability was used in the scale on level of daily life inconvenience in chewing ability (meat or hardness). Cognitive function was measured using MMSE-DS, physical function using K-IADL, and depression using SGDS-K. The data were analyzed using the SPSS 24.0 program and Process Macro. Total effects of chewing ability on cognitive function were not significant(p>.05). Direct effects of chewing ability on cognitive function were not significant(p>.05). There were the dual mediation effect(p<.05) of physical function and depression, a complete mediating effect by physical function(p<.05) or depression(p<.05) in the impact of chewing ability on cognitive function of older people in Korea. These results indicate that physical function and depression effect directly and indirectly in the impact of chewing ability on cognitive function of older people. In conclusion, it is suggested that to prevent the decline of cognitive function in older people, it is necessary to consider not only nursing strategies for strengthening chewing ability and physical function, but also nursing interventions for relieving or preventing depression in older people.

• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.389-400
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• 2019

In this study we compared the cognitive function (Mini-Mental State Examination for Dementia Screening: MMSE-DS) and nutrient intake of elderly women with dementia in a long-term care facility (EW-LCF) and a day-time care facility (EW-DCF). This survey was conducted from July 2015 to May 2017 on 73 elderly women with dementia (47 women in LCF and 26 women in DCF) in the city of Incheon. The data obtained from interviews with the subjects and caregivers were analyzed using the SPSS 20.0. The total score of the MMSE-DS and intakes of most nutrients in the EW-LCF were significantly lower compared to the EW-DCF (p<0.05). The nutrient adequacy ratios (NAR) of protein, vitamin A, C, $B_6$, $B_{12}$, thiamin, riboflavin, niacin, folic acid, calcium and phosphorus in the EW-LCF were significantly lower compared to the EW-DCF (p<0.05). However, the indexes of nutritional quality (INQ) of vitamin C, $B_6$, thiamine, niacin, calcium, magnesium, and iron in the EW-LCF were significantly higher compared to the EW-DCF (p<0.05). As a result, the subjects showed an unbalanced and insufficient nutrition intake status regardless of the type of care facility. Most nutrient intakes of the EW-LCF with lower cognitive function were very significantly lower compared to the EW-DCF (p<0.001). Therefore, it is necessary to assess the cognitive function and nutritional status regularly at care facilities for the elderly women suffering with dementia and to provide specialized individual nutritional management.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.210-216
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• 2019

The purpose of this study is to investigate the effect of the multimodal cognitive intervention focusing on instrumental daily life on the cognitive function, depression and quality of life of the elderly with high-risk of dementia. This study was conducted on 24 elderly people with high-risk of dementia who participated in cognitive rehabilitation program from March to June, 2018 in Chungbuk A region. The intervention was applied to cognitive training and creative activities related to instrumental daily life. MMSE-DS, Subjective Memory Complaints Questionnaire, Short Geriatric Depression Scale-Korean version and Geriatric quality of life - Dementia were performed before and after the intervention. We confirmed that the subjects showed significant improvement in Subjective Memory Complaints and Quality of Life, but showed no significant changes in cognitive function and depression after the intervention program. Through this study, it was confirmed that this program which can affect the real life of the elderly can be usefully applied in the community. In the future, it will be necessary to develop a program that utilizes more diverse instrumental activities of daily living.