• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.289-294
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• 1984

The energy expended while playing tennis was determined from the players heart rate and from the amount of oxygen they consumed. This study was made using eight healthy but unathletic male college students. Expired air was collected for 2 minute periods during each game by the Douglas bag method. Samples were collected when serving and receiving. The air collected was measured using a wet test gas meter. The amount of air collected was expressed in STPD. Oxygen consumption was determined by measuring the oxygen content of the expired air with a Orzat gas analyzer. The energy expended during the tennis games was calculated indirectly. The caloric coefficient of oxygen was multiplied by the volume of oxygen consumed. The caloric coefficient of oxygen varied from 4.6 to 5.1 kcal/liter of oxygen. In this study the value of 5 kcal/liter of oxygen was used in the calculations. The accuracy of the measurements of energy expended was tested using regression analysis of the measured volume of oxygen. The mean values of heart rate, oxygen consumed and energy expended did not vary when the activity of serving and receiving was compared. The mean value of oxygen consumed during play was $1.4329{\pm}282ml/min$ or $21.6{\pm}4.0ml/kg/min$. The energy expended was $7.15{\pm}1.46kcal/min$ or $6.45{\pm}1.23kcal/kg/min$. The values were equivalent to 5.5 mets. When the levels of oxygen consumed were estimated using the formulas, they were found to be higher than the measured levels. The estimated amounts, however, were within 25% of the measured amounts.

• 토지주택연구
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• 제11권3호
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• pp.69-74
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• 2020

Since the design Standard for Energy Conservation in Building was implemented in 2008 for the first time, building elements such as window and door should satisfy the minimum criteria to apply for a building. Though its regulation does not cover the whole building yet, recent demand to reduce energy consumption in building sector grows rapidly year by year and also draws a lot of interest to ensure the whole building level. For example, a Zero energy building, one of low-energy buildings, requires a customized solution to resolve the air leakage issue to meet the standards in achieving the high level of air tightness. In this study, six non-residential buildings were tested by fan pressurization method to observe the air tightness of whole building to suggest the construction guideline for air tightness of low-energy building. Five out of six tested buildings showed 0.27 to 1.16 h^-1 of number of air changes except one community center. These buildings were carefully constructed not only for building planning but also for parts where there was a concern of air leakage, thereby securing high levels of air-tightness. The construction skills were developed as a checklist to manage and supervise the construction site. It is our suggestion to use this checklist at construction sites for ZEB with the high level of air-tightness.

• Journal of Nutrition and Health
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• 제39권5호
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• pp.451-459
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• 2006

The purpose of our study was to evaluate an association between milk consumption and bone mineral density (BMD) of female college students in Korea. The dietary data of 1,410 Korean college students living in the vicinity of Seoul area were collected through the Food Frequency Questionnaire. The mean age, height, weight and 8MI of the subjects were 20.4 years, 162.1 cm, 52.7 kg, and $20.0\;kg/m^2$ respectively. The mean intakes of energy, protein, and phosphorus were 2,398.7 kcal, 95.2 g, and 1,302.9 mg respectively, which were above their EER or Recommended Intake (RI), but the mean intake of calcium was 657.8 mg which was below its RI, and 44.0% of the subjects did not meet Estimated Average Requirement (EAR) of calcium. The daily milk consumption was 131.1 g, and the total consumption of milk and dairy product was 228.7 g. Forty five percent of the subjects consumed $50{\sim}200\;g$ of milk or dairy products. After the analysis of their dietary intakes, the subjects were divided into quintiles of total consumption of milk and dairy product, which were considered as major source of dietary calcium. Ninety two subjects from the upper quintile (UQ) and 85 subjects from the lower quintile (LQ) were selected and their bone mineral densities (BMD) of lumbar spine (L1-L4) and the femur were examined by the dual energy X-ray absorptiometry. The BMD $(g/cm^2)$of L1, L2, L3, and average of femur were 1.065, 1.150, 1.187, and 0.988 for the UQ subjects, which were significantly higher than those of the LQ subjects, 1.010, 1.090, 1.146, and 0.942 respectively. Moreover, the T-scores of the UQ were significantly higher than those of the LQ. The prevalence rates of osteopenia classified according to WHO's criterion were 12.0% in the UQ. and 20.0% in the LQ group which showed non significant. Blood levels of calcium, and phosphorus of UQ and LQ group were both within the normal range, and were not significantly different. Our results showed that UQ group presented the better status of bone mineral density and bone health. Therfore our results suggest that continuous consumption of more than one and a half cups of milk per day, which corresponds to the least amount of UQ group's consumption, would affect positively on the bone health of Korean adults.

• 식품보건융합연구
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• 제5권3호
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• pp.7-20
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• 2019

The use of caffeine as a psychoactive stimulant in tea has been observed to have serious negative effects in humans' systems such as respiratory, nervous, cardiovascular, renal and skeletal systems. This study was carried out to assess the levels of caffeine in 10 different tea brands available in local market in Dutse, Jigawa State, Nigeria. Quantitative analysis of caffeine was performed by a simple and fast UV-Vis spectrophotometric methods using different solvents for extraction. The caffeine content in all the tea samples analyzed in this study were below the maximum allowable limits set by the USFDA. Tea have been associated with adverse health effects and the claims made by manufacturers about the benefits of tea do not highlight risks associated with excessive consumption of a combination of the ingredients contained in tea. Long term effects of tea consumption of children and young people have not been adequately studied. Therefore, it is recommended that further research be carried out on the adverse effects of energy drinks on children. Research is also needed to be done on the effects of the combination of ingredients on health and excessive consumption of those ingredients to children and adolescents. People need to be educated and given proper awareness on the health risks associated with caffeine containing beverages.

• 산경연구논집
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• 제13권7호
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• pp.37-45
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• 2022

Purpose: Leisure time is an intrinsic part of the work-life balance that enables people to rejuvenate their energy and provides a platform to maintain their health while sustaining their productivity levels. The purpose of this study is to investigate the effects of changes in leisure consumption culture on the modern economy through various research materials. Research design, data and methodology: To have completeness in published systematic reviews and meta-analyses, the use of the standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist is essential and the present research selected this research design. Results: This research figured out that individuals who spend most of their leisure time watching TV have been shown to experience lesser satisfaction in their job designation and less happiness overall and also found that Leukocyte Telomere Length is influenced by the type of leisure an individual engages in. Conclusions: Overall, this research points out that the income effect may provide an inverse relationship between work time and labor in that high income from labor makes an individual less inclined to work to make the same money they made before the increased benefits. It is a narrative that may need further research in finding the principles that govern leisure in the labor force.

• 대한영양사협회학술지
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• 제16권4호
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• pp.369-377
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• 2010

This study was conducted to investigate the effects of food consumption monitoring based on a digital photography method using a mobile phone on food consumption and weight reduction. Eighteen female college students (>30% body fat) participated in the weight control program using a mobile-phone for 4 wks. The energy intake was reduced significantly after 3 wks compared to baseline (P<0.05, baseline: 1,453.0 kcal, 3rd wk: 1,171.1 kcal, 4th wk: 1,130.8 kcal). The subjects lost 2.8 kg of body weight, 1.4% of % body fat, and 1.1 $kg/m^2$ of body mass index (BMI) after 4 wks. There were also significant differences in blood pressure (P<0.001) and serum cholesterol (total cholesterol: P<0.05, LDL-cholesterol: P<0.01) before and after the self-regulated diet program. In this study, the digital photography method using a mobile-phone influenced weight control through trained consumption monitoring, which helps individuals reduce discrepancies between perceived and actual consumption levels. Therefore, effective monitoring by taking food pictures using a mobile-phone can lead individuals to rely more heavily on easy-to-monitor visual cues.

• Journal of Community Nutrition
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• 제7권1호
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• pp.29-35
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• 2005

It has been suggested that dietary fat increases the risk of breast cancer by elevating serum estrogen concentrations. However, studies on a relationship between fat intake and breast cancer risk have shown contradictory results, possibly because the levels of fat intake in study populations were too high to observe differences. Also, the effect of other dietary factors may present. The present study was performed to investigate the relationship between diet and estrogen metabolism in premenopausal women whose usual fat intake is relatively low compared to their western counterparts. Twenty lacto-ovo vegetarians (LOV) and twenty omnivores participated in the study. Three day food records including a Saturday or a Sunday were used to estimate nutrient intake. Serum lipids, estradiol, sex-hormone binding globulin, and urinary estradiol were measured. Study results showed $24.8\%$ and $20.9\%$ of energy intake were provided from fat in omnivorous and LOV subjects, respectively. Serum and urinary levels of estradiol were two times higher in omnivores. Fat intake was not related to either serum estradiol nor urinary estradiol when the Spearman correlation coefficient analysis was performed. Carbohydrate, total dietary fiber and soluble dietary fiber intakes were negatively related to serum estradiol concentration. Legumes, vegetables and fruit consumption showed significantly negative relationships with both serum and urinary estradiol concentrations. These results indicate lower estrogen availability may be associated with plant food­based diets in premenopausal women whose usual diets contain less than $25\%$ of energy as fat.

• Journal of Communications and Networks
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• 제12권2호
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• pp.130-139
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• 2010

Environmental issues and the need to reduce energy consumption for lowering operating costs have pushed power efficiency to become one of the major issues of current research in the field of wireless networks. This paper addresses a number of multiple input multiple output (MIMO) precoding and scheduling techniques across the PHY and MAC layers that can operate under a reduced link budget and collectively improve the transmit power efficiency of a base station, while maintaining the same levels of service. Different MIMO transmission and precoding schemes proposed for LTE, achieving varying degrees of multiuser diversity in both the time, frequency as well as the space domain, are examined. Several fairness-aware resource allocation algorithms are applied to the considered MIMO schemes and a detailed analysis of the tradeoffs between power efficiency and quality of service is presented. This paper explicitly examines the performance of a system serving real-time, VoIP traffic under different traffic loading conditions and transmit power levels. It is demonstrated that by use of efficient scheduling and resource allocation techniques significant savings in terms of consumed energy can be achieved, without compromising QoS.

• 한국식품영양학회지
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• 제29권4호
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• pp.547-556
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• 2016

The purpose of this study was to investigate the relationship between frequency of coffee consumption, metabolic biomarkers, and nutrition intake in adult participants in the combined 2007~2009 Korean National Health and Nutrition Examination Survey (KNHANES). Subjects (2,095 males and 3,297 females) were classified according to sex and frequency of coffee consumption (${\leq}1$ time/month, ${\geq}2$ times/month and ${\leq}6$ times/week, 1 time/day, 2 times/day, 3 times/day) using food frequency questionnaires. Nutrition intake was analyzed using 24 h recall data. The 3 times/day coffee consumption group had a significantly higher age, and frequency of smokers and drinkers compared to the ${\leq}1$ time/month coffee consumption group in both male and female participants. Males in the 3 times/day coffee consumption group had a significantly lower HDL-cholesterol level, but females had a higher waist circumference compared with the ${\leq}1$ time/month coffee consumption group. Males in the 3 times/day coffee consumption group had a significantly lower nutrient density of fiber, vitamin B2, vitamin C, calcium and phosphorus compared with the ${\leq}1$ time/month coffee intake group. Females in the 3 times/day coffee consumption group had a significantly higher nutrient density of fat and niacin, but lower nutrient density of carbohydrate, calcium, phosphorus, and iron compared with the ${\leq}1$ time/month coffee intake group. In males, the frequency of coffee consumption was not associated with the levels of metabolic biomarkers. In females, the frequency of coffee consumption was positively associated with diastolic blood pressure after adjustments for multiple confounding factors, including age, BMI, smoking status, alcohol consumption, physical activity and energy intake. Coffee consumption was associated with decreased diastolic blood pressure in females. These findings suggest the importance of an awareness of the association between coffee consumption and metabolic risk.

• 한국수소및신에너지학회논문집
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• 제35권2호
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• pp.175-184
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• 2024

This study focuses on investigating the importance of managing greenhouse gas emissions from global energy consumption, specifically examining domestic targets for clean hydrogen production. Using life cycle assessment, we evaluated reductions in global warming potential and assessed the carbon neutrality contribution of the domestic hydrogen sector. Transitioning from brown or grey hydrogen to blue or green hydrogen can significantly reduce emissions, potentially lowering CO₂ equivalent levels by 2030 and 2050. These research findings underscore the effectiveness of clean hydrogen as an energy management strategy and offer valuable insights for technology development.