• Journal of Korean Society of Transportation
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• v.34 no.3
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• pp.222-233
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• 2016

Recently, mobile phone data was applied in travel demand modeling as a new source of dynamic population movement. This study is also aimed to estimate "occupancy population" during a given period of time within a given spatial region using mobile phone data. An occupancy population was defined as the number of people residing or moving within a given time and space. In case of Seoul Metropolitan area, we divided the area into a number of administrative districts as zones for analysis and estimated the occupancy population of each zone by mobile phone data collected by SK telecom Co., a wireless telecommunication provider in Korea. For the expansion of mobile phone data, a new concept of "communication probability" was introduced and applied in the estimation of occupancy population of each zone by the hour. We compared the estimated number with the daytime population and the daytime population index referred by the Statistics Korea. The results showed that a positive correlation existed between the estimated number and the statistical number by nationwide survey. It was concluded that mobile phone data could be more cost-effective sources than a conventional survey method to estimate the pattern of population movement by the hour or by the day.

• Sleep Medicine and Psychophysiology
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• v.22 no.1
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• pp.11-19
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• 2015

Objectives: Whether daytime sleepiness is proportional to the severity of sleep apnea in obstructive sleep apnea syndrome (OSAS) is controversial. In this study we investigated how insomnia severity affects the association between daytime sleepiness and sleep apnea severity in OSAS. Methods: The present study included 235 male subjects who were diagnosed with OSAS based on clinical history and nocturnal polysomnography. Pearson's correlation analysis was conducted among sleep and mood-related self-reported data, polysomnographic data and demographic data of all subjects. Based on Pittsburgh Sleep Quality Index (PSQI), the subjects were divided into 2 groups; group A (n = 75; $PSQI{\leq}5$) and group B (n = 160; PSQI > 5). Partial correlation analysis was performed between the Epworth Sleepiness Scale (ESS) and other data in both groups. Multiple linear regression analysis was conducted to investigate the factors which affected the ESS in group A. Results: Pearson's correlation analysis showed weak or non-existent correlations between ESS and apnea severity data such as apnea-hypopnea index (AHI) (r = 0.148, p = 0.023), apnea index (AI) (r = 0.137, p = 0.036), hypopnea index (HI) (r = 0.058, p = 0.377), oxygen desaturation index (ODI) (r = 0.149, p = 0.022) and arousal total index (ATI) (r = 0.129, p = 0.048). Positive correlations between ESS and apnea severity data such as AHI ($r_p=0.313$, p = 0.008), AI ($r_p=0.339$, p = 0.004), ODI ($r_p=0.289$, p = 0.015) and ATI ($r_p=0.256$, p = 0.031) were observed only in group A. Multiple regression analysis showed that AI (t = 2.996, p = 0.004) and BAI (t = 2.721, p = 0.008) were associated with ESS in group A. Conclusion: The correlation between daytime sleepiness and sleep apnea severity was shown only in group A. This result suggests that associations between daytime sleepiness in OSAS and sleep apnea severity will become prominent when controlling for insomnia-related variables.

• Journal of the Korean association of regional geographers
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• v.13 no.5
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• pp.576-594
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• 2007

The purpose of this study is to derive policy implications in allocating day care centers for the elderly with more efficiency and/or equity by calculating and analysing the accessibility scores of individual dongs to day care centers for the elderly in Seoul using GIS spatial analysis techniques. The study finds that the spatial distribution of the centers does not respond to the distribution of the potential users very well and that dongs in Gangseo-gu and Songpa-gu at the outskirt of Seoul has the lowest level of accessibility. The findings of the study has policy implications in the management of day care centers for the elderly. First, in order to improve the accessibility of the elderly to the centers, an increase in the number and the capacity of the centers needs to be made especially in areas with lower level of services provided. Second, if policy decision is made in the way to increase the capacity of the existing centers rather than to increase the number of centers due to, for example, the budget limit, capacity expansion needs to be made in the centers with higher proximity in order for more elderly people to use the centers more frequently with easy access. Finally, this type of accessibility analysis techniques needs to be used to allocate, expand, and evaluate other types of care facilities for the elderly and social welfare facilities in order to preserve the welfare right of the users of the facility who usually have a lower mobility and to assure the necessity of the resource investment.

• Journal of Korean Public Health Nursing
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• v.23 no.1
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• pp.61-68
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• 2009

Purpose: This study was conducted to examine the effects of walking exercise training on body composition and physical fitness in middle aged women. Method: The subjects were randomly assigned into an obese walking exercise training group (n=21), a non-obese walking exercise training group (n=9), or a control group (n=10). The women in the treatment groups were then subjected to brisk walking at 50~70% of maximum heart rate twice a week for 12 weeks. The results were then analyzed by repeated measures ANOVA using SPSS 12.0 for windows. Results: Body weight, BMI, % body fat, and WC were not significantly improved in the obese walking exercise training group and the non-obese walking exercise training group. However, muscular flexibility and muscular endurance were significantly improved in each of these groups (p<.05). Conclusion: These results indicate that 12 weeks of walking exercise training enhanced physical fitness. However, the treatment in this study did not improve the body composition of middle aged women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7078-7088
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• 2015

This study examined effects of health behaviors and sleep related factor on cognitive function in the elderly hypertensive patients. Data were collected through a face to face interview survey with structured questionnaire form 140 elderly with hypertension ($age{\geq}65years$) from February 5 to May 1, 2013. Research instruments included Pittsburgh Sleep Quality Index(PSQI), Epworth Sleepiness Scale(ESS) and Korean version the Mini-Mental State Examination(MMSE-K). Cognitive function was negatively related to degradation in quality of sleep(r=-.29, p<.001). Sleep duration were negatively related to body mass index(r=-.18, p=.032) and degradation in quality of sleep(r=-.59, p<.001). Sleep duration was positively related to daytime sleepiness(r=.22, p=.008). Hierarchical multiple regression showed that age, education levels and living arrangement were associated with cognitive function(F=8.56, p<.001, Adjusted $R^2=.14$). After controlling for demographic characteristics and health behaviors, degradation in quality of sleep(${\beta}=-.27$, p=.008) was identified as significant predictors of cognitive function. This final model explained 17.0% of the cognitive function in the elderly hypertensive patients(F=4.09, p<.001). Therefore, as a strategy improving cognitive function of the elderly with hypertension, therapeutic intervention should be developed to improve quality of sleep considering age, education levels and living arrangement.

• Journal of Food Hygiene and Safety
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• v.24 no.1
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• pp.69-77
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• 2009

This study was performed to investigate the effect of dried powder of chestnut on lipid metabolism, anti-thrombotic effect in rats. Thirty 5-week-old male Sprague Dawley (SD) rats were randomly allocated into five groups and used for experiment. We examined the lipid metabolism and antithrombotic capacity of SD rats administered for 5 weeks with 0.16 g/kg, 0.5 g/kg chestnut flesh powder and 0.16 g/kg, 0.5 g/kg chestnut inner shell and flesh powder mixture, respectively. Food intake, body weight gain and food efficiency ratio were also checked. The levels of serum triglyceride and tree fatty acid were not statistically significant between the all experimental groups. However, the antithrombotic capacity and total lipid levels of the treatment groups were significantly lower than those of the negative control group. These results suggest that the supplementation of chestnut on diet lower the total lipid level in SD rats.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.21-27
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• 2012

This research was carried out as a survey on the contents of lead, cadmium, and arsenic in processed foods (milk, vegetable oil, and margarine) in Korea. The limits of quantification (LOQs) were Pb 0.3 ${\mu}g/kg$, Cd 0.15 ${\mu}g/kg$, and As 0.45 ${\mu}g/kg$ for milk and Pb 0.61 ${\mu}g/kg$, Cd 0.31 ${\mu}g/kg$, and As 0.91 ${\mu}g/kg$ for vegetable oil and margarine. The recoveries were 92.6-98.0% for Pb, 91.2-98.9% for Cd, and 97.9-104.7% for As. The average levels of Pb were 2.395 ${\mu}g/kg$ for milk, and 7.656 ${\mu}g/kg$ for vegetable oil. The average levels of Cd were 0.483 ${\mu}g/kg$ for milk, and 0.380 ${\mu}g/kg$ for vegetable oil, and levels of As were 0.781 ${\mu}g/kg$ for milk, and 1.241 ${\mu}g/kg$ for vegetable oil. The results of this study showed that Pb, Cd, and As contents in the whole samples were less than the maximum residual levels in the processed foods that were specified by the Codex standard.