• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.344-347
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• 2011

In this paper, we propose the power control problem for cognitive radio networks (CRNs) that maximizes the total utility of the secondary users (SUs). We use the interference temperature constraints to protect the primary users (PUs). The utility functions of SUs can be any increasing functions. We formulate the power control problem as monotonic optimization that can be solved in centralization to achieve the global optimum.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.463-473
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• 2016

The purpose of this study was to investigate the relations between the cognitive functions, health conditions, activities of daily living, depression and sleep states among the elderly at care facilities. The subjects include 204 elderly people aged 65. The data collected were analyzed using descriptive statistics, the t-test, ANOVA, Pearson correlation, and hierarchical multiple regression. The findings show that the cognitive functions of the elderly at care facilities are related to their engagement in regular exercise, duration of residency, grade of care, lack of physical freedom, listening ability, state of teeth, urinary incontinence, activities of daily living, and state of sleep. Their cognitive functions had positive correlations with activities of daily living and negative correlations with state of sleep. Their cognitive impairment was significantly influenced by their engagement in regular exercise, duration of residency, grade of care, listening ability, ADL, IAD dependency, and sleep disorder. In short, the cognitive functions of the elderly at care facilities are highly related to their health conditions as perceived and felt by them. It is thus required to develop, apply, and consistently assess and manage cognitive rehabilitation training programs to provide interventions for the factors that influence their cognitive impairment.

• 재활복지
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• v.21 no.2
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• pp.247-259
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• 2017

We investigated the improvement of cognitive functions, activity of daily living (ADL), and quality of life (QoL) after hemorrhagic stroke and identified associated factors. For this research, twenty-five patients with a hemorrhagic stroke were enrolled. We measured cognitive function, activity of daily living (ADL), and quality of life (QoL) from 7 days to 12 months after onset of stroke. Then we analyzed the correlation between cognitive function and other risk factors. According to results, cognitive functions improved during 12 months with statistically significant differences. Other functions were similar to cognitive functions. Improvement of cognitive functions were correlated with age, the type of hemorrhagic stroke and Glasgow coma scale at 7 days after stroke. Overall, cognitive function in patients with hemorrhagic stroke recovered from acute to 12 months after onset of stroke. And, improvement of cognitive function at this phase were associated with age, the type of hemorrhagic stroke and GCS score at 7 days. These results would provide us an information to plan cognitive rehabilitation in patients with hemorrhagic stroke.

• Korean Journal of Adult Nursing
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• v.19 no.1
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• pp.78-88
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• 2007

Purpose: The purpose of this study was to find out the degree of cognitive function among the elderly and to confirm its correlated factors. Methods: The subjects consisted of 392 elderly people over the age 65 who were living in Busan. Data were collected by the interview method, using a structured questionnaire and the K-MMSE scale. Results: The average points of the elderly's cognitive functions measured by K-MMSE were 23.76(${\pm}4.02$). With the cut-off point for cognitive impairment set as 24 points below using K-MMSE scale, 38.8% of the subjects have cognitive impairments. Among the variables related to cognitive functions, literacy showed the highest correlation with cognitive function(${\beta}=.330$, t=7.249, p<.001), followed in order by educational level, age, depression level, attendance of elderly's college, and religious activity. The total explanatory power of these variables is 36%. Conclusion: In order to prevent cognitive impairment among the elderly, elderly people have to maintain social relationships continuously, and expand the social network by participating in the related programs. Some efforts to prevent the occurrence of depression and to stimulate patients' brain activity need to be recommended.

• Korean Journal of Adult Nursing
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• v.13 no.3
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• pp.451-462
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• 2001

This study was conducted to examine and compare the characteristics in the cognitive functions of peritoneal dialysis, hemodialysis and normal kidney function groups as basic data for effectively educating dialysis patients. The data were collected from May 10 to October 30. 2000, collected from each of 20 patients with peritoneal dialysis, hemodialysis and normal Kidney function and who registered for the dialysis room at a general hospital affiliated to a university in Seoul and sampled by age and educational level through personal interviews with the researchers of this study. As a measuring tool, MMSE developed by Folstein et al.(1975) to measure cognitive function disorder was used, slightly revised for hemodialysis patients. Collected data were processed into frequency, percentage, mean, and standard deviation by the use of SAS. The results of this study are as follows : 1. With a maximum of 30 points for cognitive function, the mean of the peritoneal dialysis patients was $27.06{\pm}2.06$, while that of the hemodialysis patients was $27.25{\pm}2.76$; that of the normal Kidney function patients was $27.85{\pm}2.00$, indicating no significant difference among those three groups. 2. As for the subjects who scored 23 points, the turning point of confirming the cognitive disorder, the percentage was 5% in the case of the peritoneal dialysis, 10% in the case of the hemodialysis and 5% in the case of the normal Kidney function group. 3. Differences between the peritoneal dialysis and hemodialysis patients by gender, occupation, spouse, diabetes, hypertension, the period of dialysis, number of hospitalizations, and the use of erythropoietin were not significant in the scoring of cognitive function. 4. There was no significant correlation between the level of Hb, Hct, albumin, aluminium, PTH, BUN, Cr, dialysis adequacy and the cognitive function. Considering such results, it is clear that there is no significant difference in the cognitive functions of the sampled subjects. Therefore, the nurse in the dialysis room should continually carry out assessment and intervention against elements degrading the effect of patients' education to improve self- care.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.2
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• pp.211-221
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• 2010

Purpose : The purpose of this study is to find out the effects of combined exercise including walking and yoga on cognitive functions in the elderly women. Methods : Sixteen elderly women aged above 65 are invited in this study. Each subject participated in exercise three times a week for eight weeks from July 14th to September 13th in 2008. The changes between pre and post exercise are analyzed by Wilcoxon sign rank test and repeated ANOVA test with SPSS (ver 17.0) package program. Results : After exercise, In the below 23 points group, only interference STROOP test (p<.05) among sub items of Cognition Scale for Older Adults (CSOA) is improved significantly. In the above 24 points group, words memory (p<.05), delayed recall (p<.05), and picture naming (p<.05) among sub items of CSOA are improved significantly. But it is no different to the change patterns among two groups. Conclusion : These results show that combined exercise including walking and yoga is helpful to improve cognitive functions. And we find that exercise is helpful in the above 24 points elderly women more than in the below 23 points.

• Physical Therapy Korea
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• v.22 no.2
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• pp.11-20
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• 2015

The purpose of this study was to evaluate the effect of dual-task training with cognitive effort on the walking and balance functions of chronic stroke patients. The study included 14 chronic stroke patients, who were randomly divided into the experimental group (EG) and control group (CG), each with 7 patients. The EG performed the dual-task training with cognitive effort 3 times a week, 30 minutes for 4 weeks, where as the CG performed single-task training three times a week, for 30 minutes for 4 weeks. Outcome assessments were made with 10 m walk test, timed up and go test, 6 minutes walk test, and Berg balance scale. In within-group comparison, subjects from the EG showed significant differences in all variables (p<.05), while subjects from the CG showed only significant differences in 6 minutes walk test, and Berg balance scale (p<.05). Further, there was significant difference in the improvement rate of 10 m walk test. The findings suggest that the dual-task with cognitive effort may be beneficial for improving walking and balance functions of patients with chronic stroke.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.278-290
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• 2009

The purpose of this study is to investigate the relationship between learning skills and cognitive functions on elementary school students. In this study CAS and Learning Skills Test(LST) were administered with 3 to 6 grade, 60 students from 5 elementary schools. The data were analyzed according to Pearson's correlation and Stepwise Multiple Regression Analysis. The results are as follows. Firstly, girls and older students showed significantly higher ability than boys and younger students on the learning skills. And girls significantly outperformed boys on the planning function and attention function and on the simultaneous cognitive function was the other way round. Secondly, learning skills were explained 41% by two variables that the planning function and the successive function which are sub factors of the cognitive function. And then, planning and successive processing effected to self-management, attention and planning to test-taking skills, successive processing and attention to class-participation skills, and successive processing to information processing.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.11
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• pp.67-74
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• 2018

With the rapid increase in the elderly population, numerous problems arise related to the decreased cognitive function such as the declines of reaction time and concentration which are both resulting from ageing. Recently, ICT-based smart home and other residential services are being developed as a means of complementing human cognitive functions, but the elderly, who are in most cases digital-illiterate, find it hard to utilize these tools actively and if so it usually takes longer time and endeavor for the elderly to be familiarized with ICT devices. In this context, this study suggests a configuration of the holographic system in houses that complement the cognitive function of the elderly with the consideration of the interaction with the vision which is a critical function in the cognitive process. The method of this study consists of a literature review on topics including the characteristics of the cognitive function among the elderly, holographic technology and residential services; a configuration of residential services for different space types, depending on the aspects of the cognitive function among the elderly; and finally a suggestion of a holographic system configuration and application depending on various scenarios.

• Journal of Korean Academy of Nursing
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• v.51 no.3
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• pp.294-304
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• 2021

Purpose: This study aimed to investigate objectively measured physical activity (PA) in institutionalized older adults with mild cognitive impairment (MCI) and to elucidate the influence of autonomic nervous function, salivary cortisol, and PA on cognitive functions based on neurovisceral integration model. Methods: Overall cognitive function was evaluated using the mini-mental state examination (MMSE) and executive function was evaluated using semantic verbal fluency test and clock drawing test. Actigraph for PA, HRV and sAA for autonomous function, and the geriatric depression scale for depression were used. Saliva specimens were collected in the morning for sAA and cortisol. Results: Ninety-eight older adults from four regional geriatric hospitals participated in the study. They took 4,499 steps per day on average. They spent 753.93 minutes and 23.12 minutes on average in sedentary and moderate-to-vigorous activity, respectively. In the multiple regression analysis, lower salivary cortisol level (β = - .33, p = .041) and greater step counts (β = .37, p = .029) significantly improved MMSE score. Greater step count (β = .27, p = .016) also exerted a significant influence on verbal fluency, and greater sAA (β= .35, p = .026) was significantly associated with a better clock drawing test result. Conclusion: Salivary cortisol, sAA and physical activity were significantly associated with cognitive functions. To prevent older adults from developing dementia, strategies are needed to increase their overall PA amount by decreasing sedentary time and to decrease salivary cortisol for cognitive function, and to maintain their sympathetic nervous activity for executive function.