• Journal of Nutrition and Health
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• v.43 no.5
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• pp.513-523
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• 2010

The food and nutrient intakes on weekdays and weekends was examined with 196 high school girls residing in Seoul using the 3-day food record. Frequency for skipping breakfast was higher than that for lunch and dinner. Frequencies for skipping breakfast and lunch were significantly higher on weekends than on weekdays (p < 0.05). The daily average food, vegetable food, and animal food intakes were 1,074.8 g, 680.0 g, and 317.3 g, respectively. The total food and vegetable food intakes on weekdays were significantly higher than on weekends (p < 0.05). The daily average dietary variety score (DVS) was 20.5, and was significantly higher on weekdays (23.3) than on weekends (15.1)(p < 0.05). The daily averages of energy, protein, fat and carbohydrate intake were 1,732.9 kcal, 68 g, 56.2 g, and 240.9 g, respectively. Energy, protein, carbohydrate, phosphate, iron, sodium, potassium, thiamin, niacin, folate and vitamin C intakes were significantly higher on weekdays than on weekends (p < 0.05). Fat intake was significantly lower on weekdays than on weekends (p < 0.05). The daily average percentages of energy intake from carbohydrate, protein, and fat were 55.4%, 15.6%, and 29.0%: 56.1%, 15.8%, and 28.2% on weekdays and 54.7%, 15.3%, and 30.1% on weekends, respectively. The percentages of energy intake from carbohydrate on weekdays and weekends were below 60%, and that from fat was above 28% on weekdays and weekends. The daily averages of energy, vitamin A, riboflavin, niacin and phosphate intake were above 80% as compared with the estimated energy requirement (EER) or the recommended intake (RI). The intakes of calcium, potassium and folate were below 50% as compared with the adequate intake (AI) or (RI). The daily average mean adequacy ratio (MAR), an index of overall dietary quality, was 0.77, and significantly high school girls was worse on weekends than on weekdays.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1765-1773
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• 2012

The accuracy of load forecast is very important from the viewpoint of economical power system operation. In general, the weekdays' load demand pattern has the continuous time series characteristics. Therefore, the conventional methods expose stable performance for weekdays. In case of special days or weekends, the load demand pattern has the discontinuous time series characteristics, so forecasting error is relatively high. Especially, weekdays near the thanksgiving day and lunar new year's day have the mixed load profile characteristics of both weekdays and weekends. Therefore, it is difficult to forecast these days by using the existing algorithms. In this study, a new load forecasting method is proposed in order to enhance the accuracy of the forecast result considering the characteristics of weekdays and weekends. The proposed method was tested with these days during last decades, which shows that the suggested method considerably improves the accuracy of the load forecast results.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.10-16
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• 2014

Objectives: This pilot study assessed secondhand smoke (SHS) exposure in smoking and non-smoking nightclubs in Seoul, Korea by measuring the concentration of particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$). Methods: This comparative study was conducted in three nightclubs in Seoul. While one non-smoking nightclub was measured on weekdays and weekends, different smoking nightclubs were measured on weekdays and weekends. The concentration of $PM_{2.5}$ was observed using a real-time monitor over an average of three hours. The number of people in the clubs was also estimated. Settled dust was collected in a smoking and a non-smoking nightclub and analyzed for NNK concentration. Results: The $PM_{2.5}$ concentration in the smoking nightclubs was higher than those found in the non-smoking nightclub by 26 times on weekdays and three times on weekends. Indoor $PM_{2.5}$ concentration was correlated with the number of people in the smoking nightclubs. Relatively high $PM_{2.5}$ concentration was observed in the non-smoking nightclub on weekends. NNK concentration in the smoking nightclub was 7 times higer than in the non-smoking nightclub. Conclusion: Smoking in nightclubs caused high $PM_{2.5}$ concentration. Although the non-smoking nightclub had a lower $PM_{2.5}$ concentration, $PM_{2.5}$ concentration on weekends was higher due to the smoking room. Complete prohibition of smoking in nightclubs can protect patrons from secondhand smoke exposure.

• Journal of the Korean Dietetic Association
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• v.12 no.3
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• pp.277-288
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• 2006

The purpose of this study was to assess the energy expenditure and investigate the relationship between related variables of 57 dieticians in Youngdong-area. The average daily number of steps was found to be 9358.0$\pm$2714.3 steps/day on weekdays and 7862.9$\pm$2504.9 steps/day during weekends. Hourly step rates on weekdays and weekends came to 570.6$\pm$249.8 steps/hr and 564.0$\pm$224.8 steps/hr, respectively. Activity coefficient of subjects was higher on weekdays (1.56) than weekends (1.51, p<0.05). Resting energy expenditure estimated by the Harris-Benedict formula, WHO/NAO/FAO formula as well as formulas based on body surface area and DRIs (Dietary Reference Intake for Koreans) were calculated to be 1333.7$\pm$89.5kcal/day, 1351.0$\pm$123.3kcal/day, 1388.5$\pm$100.3kcal/day and 1295.9$\pm$90.8kcal/day, respectively. Using these resting energy expenditures and the activity coefficients, daily energy expenditures were calculated to be from 2039.7kcal/day to 2183.5kcal/day on weekdays and from 2016.1kcal/day to 2159.2kcal/day on weekends. Meanwhile energy intakes of subjects on weekdays and weekends were 1594.7$\pm$698.3kcal and 2152.9$\pm$768.0kcal, respectively. The activity coefficient (1.49) of dieticians who managed less than 500 meals per day was significantly lower than that of dieticians who served more than 500 meals per day. Dieticians of schools located in rural areas had higher activity coefficient (1.59) than those of schools located in urban or island settings. These results suggest that work analysis and development of management strategies are necessary to improve dieticians' productivity.

• Journal of Family Resource Management and Policy Review
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• v.24 no.4
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• pp.21-37
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• 2020

This study focuses on the leisure activities of young, single-person households. Data collection involved selecting and interviewing eight cases. The results are as follows: 1. The leisure activities of young, single people are divided between weekdays and weekends. 2. Important factors affecting these leisure activities are time, money, and cognition. 3. Respondents maintain their work-life balance by focusing on weekdays and weekends, they work and study intensively on weekdays and spend their time and money on leisure and rest on weekends. 4. Young people want a chance to meet and share their experiences with others. This point must be central to planning the Healthy Family Support Center program.

• Journal of Family Resource Management and Policy Review
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• v.21 no.3
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• pp.77-95
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• 2017

The purpose of this study is to examine the factors related to leisure time to understand middle-aged one-person households. Data are from the recent survey of lifetime use in 2014 by Statistics Korea(N=1,138). Middle-aged one-person households aged 40-59 years were categorized into four groups by marital status (unmarried/married/widowed/divorced). Major results were found as follows: First, the total leisure time per day was 238 min in the middle-aged one-person households. The majority of the total leisure time was spent on 'fellowship & leisure activities'(204 min on weekdays, 283 min on weekends). Especially, time spent on real-time TV watching hours was the longest, as long as 89 min on weekday and 150 min on weekends. Second, gender differences were significant in terms of leisure time use in the middle-aged one-person households. Females spent less time on leisure than their male counterparts on both weekdays and weekends. In addition, gender differences related to marital status were significant. Third, on weekdays, the determinants of leisure time use among the middle-aged one-person households were health and type of employment for 'participation & volunteer activities', and gender, age, marital status, and type of employment variables for 'fellowship & leisure activities.' On weekends, time spent on 'participation & volunteer activities' were influenced by marital status, residential area, and type of employment, while time spent on 'fellowship & leisure activities' were significantly related to gender, type of employment, type of job, holiday system, and income.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.1-11
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• 2022

Purpose : Obesity is a major public health burden in developed countries and a well-known risk factor for cardiovascular disease. Short sleep duration is associated with obesity, as well as diabetes, heart disease and death. In modern society, habitual sleep restrictions seem unavoidable due to social obligations and work schedules along with a tendency toward decreased sleep time. Therefore, the purpose of this study is to examine the effect of differences in sleep time between weekdays and weekends on body mass index (BMI). Methods : This study involved 4,234 Korean adults aged 20 to 64 years based on data obtained from the 7th national health and nutrition examination survey (2016). All subjects were classified into the weekend catch-up sleep group (weekend CUS group). and the non catch-up sleep group (non-CUS group). Results : The longer the average sleep time, the lower was the BMI, and the larger the difference in sleep time between weekdays and weekends, the lower was the BMI. Compared with those with an average sleep time of 8 hours or more, obesity was 1.6-fold higher when the average sleep time was less than 6 hours, and 1.2-fold higher in the case of sleep time of 7 hours or more and less than 8 hours. When the difference in sleep time between weekdays and weekends was 0 or less, more than 0 hours but less than 1 hour, and more than 1 hour and less than 2 hours, the risk of obesity was 1.2-fold, 1.1-fold and 1.1-fold higher, respectively, compared with the risk associated with a sleep time difference of 2 hours or greater between weekdays and weekends. However, the difference was not statistically significant. Conclusion : Short sleep duration is positively associated with obesity. In addition, weekend catch-up sleep affects BMI.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.482-488
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• 2013

Load forecasting is essential to the economical and the stable power system operations. In general, the forecasting days can be classified into weekdays, weekends, special days and special light-load periods in short-term load forecast. Special light-load periods are the consecutive holidays such as Lunar New Years holidays, Korean Thanksgiving holidays and summer special light-load period. For the weekdays and the weekends forecast, the conventional methods based on the statistics are mainly used and show excellent results for the most part. The forecast algorithms for special days yield good results also but its forecast error is relatively high than the results of the weekdays and the weekends forecast methods. For summer special light-load period, none of the previous studies have been performed ever before so if the conventional methods are applied to this period, forecasting errors of the conventional methods are considerably high. Therefore, short-term load forecast for summer special light-load period have mainly relied on the experience of power system operation experts. In this study, the trends of load profiles during summer special light-load period are classified into three patterns and new forecast algorithms for each pattern are suggested. The proposed method was tested with the last ten years' summer special light-load periods. The simulation results show the excellent average forecast error near 2%.

• Journal of the Korean Society of Food Culture
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• v.26 no.6
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• pp.692-697
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• 2011

Restaurant managers seeking to maximize revenue should look carefully at how long their tables are occupied and how much the average diner spends. This study examined the effect of the customer's party size on restaurant revenue. The dining periods were divided into 2 types (lunch vs. dinner/weekdays vs. weekends), which were combined to show the average spending per minute (SPM), to determine if the dining periods have measurable effects on the dining duration and average bill. The results show that the dining duration for dinner was much longer than that for lunch and there was no significant difference in dining duration between weekdays and weekends. On the other hand, customers in larger parties at lunch time had a higher SPM than those in smaller parties. A larger customer party size was associated with a longer dining duration for dinner and on weekdays. During all operating periods (lunch, dinner, weekdays, weekends), the party size had a significantly positive effect on the mean spending per minute. For restaurant managers, these findings suggest opportunities to increase revenue and adopt revenue management strategies.

• Human Ecology Research
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• v.54 no.5
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• pp.541-550
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• 2016

This study explored a typology (or time allocation), investigated personal and work characteristic differences among time allocation types, and identified determinants of time allocation types of married working women with a preschool child. The data source for this research was the 2014 Time Use Survey conducted by Statistics Korea. We analyzed 368 time diaries (184 for weekdays and 184 for weekends) using frequency, mean, cluster analysis, chisquare, analysis of variance (ANOVA), Duncan's test, and multinomial logistic analysis. The results of this research are as follows. Time allocation of married working women with a preschool child was classified into three different types of 'work-centered,' 'work-family balanced,' and 'family-centered.' The work-centered type accounted for 14.7% of total respondents, and compared with other types, this type of people spent more time working, and less time doing house-work, caring for family, and having leisure. The work-family balanced type represents more than half of the total, and spend more time working on weekdays and house-working, having leisure on weekends. The family-centered type represents 28.8%, and spends most of the time doing house-work and caring for family on both weekdays and weekends. Occupation, employment status, monthly income, and weekly hours of work were different for each type. Occupation, employment status, perception of lack of time, health condition, and weekly hours of work were identified as determinants for each type.