• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.26-37
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• 1994

In this study, flow of a model intake port/valve system is analyzed by using low Reynolds number $k-{\varepsilon}$ model. Discharge coefficient was obtained from computational results for the various cases of valve lifts. Discharge coefficient becomes maximum when the valve lift is 20mm, and does not increase or decrease in proportional to valve lift. Most of pressure drop and production of turbulent kinetic energy occur at the edge points of the valve and the valve seat Thus, in order to improve discharge coefficient, rounding of edge points in valve and valve seat is recommended. As valve lift is increased, the velocity of the intake jet in the valve passage decreases, and the direction of the jet is more inclined toward the valve seat.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.433-439
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• 2001

Intakes and excretions of calcium and phosphorus were determined for 8 female adolescents(aged 16.3$\pm$0.5y; body mass index 20.4$\pm$1.3kg/$m^2$; body fat 33.3$\pm$2.5%; bone mineral density of lumbar spine in L2-L4; 0.96$\pm$0.08g/$\textrm{cm}^2$) when they consumed diets basal and high in calcium for 6 days each. All subjects consumed a basal Ca diet containing 800mg, Korean RDA level of the subjects, and a high Ca diet containing 1200mg, RDA plus 2 SDs of calcium intake. The diets provided 58% of energy intake as carbohydrate, 25% as fat, and 17% as protein. Food, urine, and fecal composites were collected during the last 3 days of each feeding period. Fecal excretion of calcium was significantly greater on the high Ca than on the basal Ca diet. Hence, apparent absorption rate was significantly lowered from 40.9% on the basal Ca diet to 33.1% on the high Ca diet. There was no significant difference in calcium retention between the two diet periods but it tended to be greater on the high Ca diet. However, excretions and retention of phosphorus did not show any significant difference even though intake was significantly increased from 1,253mg on the basal Ca diet to 1,583mg on the high Ca diet. The results indicate that higher calcium intake than the Korean RDA level is recommended for adolescents to meet peak bone mineral accretion and attain a desirable level of calcium retention. (Korean J Nutrition 34(4) : 433~439, 2001)

• Journal of the Korean Dietetic Association
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• v.12 no.2
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• pp.146-156
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• 2006

The purpose of this study was to analyze characteristics of the obese children in depth and provide basic information for a comprehensive educational program for the obese children. Physical and biochemical characteristics, nutrient intake, and self-esteem, etc. of 16 obese elementary school children (OC) and 14 normal weight elementary school children (NWC) were examined. Self-esteem was measured using Likert-type scales with description. Plasma levels of total cholesterol, LDL-cholesterol, and glucose of OC were higher than those of NWC. Dietary intake with a lunch provided more energy and vitamin B1 in OC than in NWC. Physical appearance and athletic competence among self-esteem in OC were lower than in NWC. However, there was no significant difference in physical activity between OC and NWC. In OC, atherogenic index was positively related with waist circumference, obesity index and BMI while athletic competence self-esteem was negatively related with them. It is recommended that the children should receive the comprehensive educational program for improving children' dietary behavior and their self-esteem.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.904-910
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• 2013

The aim of this study was to investigate the eating behavior and nutritional status of subjects according to their purpose of exercise. A total of 214 subjects, 20 to 30 years of age, who visited fitness centers in Seoul were enrolled. Anthropometrics, exercise habits, nutritional knowledge, and eating behaviors were analyzed using a questionnaire. Nutritional status was assessed by serial 24 h recalls. The subjects were divided into two groups based on their purpose of exercise: increasing muscle (Muscle growth, n=107) or losing body weight (Weight loss, n=107). The Muscle growth group contained a higher percentage of men, whereas the Weight loss group contained a higher percentage of women. The Muscle growth group showed significantly higher scores of nutritional knowledge and eating behaviors compared to the Weight loss group. The Muscle growth group also had a significantly higher intake of energy and protein compared to the Weight loss group. In fact, the intake of energy in the Weight loss group was lower than the estimated energy requirement (EER) for both men and women subjects. The intake of protein in the Muscle growth group was twice as much as the recommended nutrient intake (RNI). The intake of calcium in both groups was less than the RNI. In conclusion, those who exercised with the aim of increasing muscle took excess dietary protein and those who exercised with the aim of weight loss had a lower energy intake than the EER.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.49-66
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• 1986

The purpose of this study was to investigate nutrition intake of high school girls related to food habit, physical status, family environmental factor. The survey of 216 high school girls, aged 15 to 17 years old in Seoul area was conducted from April, 21 to 30, 1986. Food habit and family environmental factor were researched by means of questionnaires and nutrition intake was surveyed. by recording the kinds, amounts and ingredients of foods taken by the girls for two days, and height and weight were also measured during the period. The findings are summarized as follows: 1. Mean value of height and weight of the girls were 157.6cm and 50.9kg. 2. Number of family members per household was 5.2. Mean value of father's age was 47.1 and mean value of mother's age was 43.6. 44.9% of the girls had fathers who graduated the college, 41.6% of the girls had mothers who graduated the high school and 29.2% of the girls had mothers who had the job. 3. Breakfast missing rate was high, most of the reason for breakfast missing was 'have no time to eat' and time for breakfast was short. 64.4% of the girls had meal irregularly. 4. Mean daily intake of all nutrients except vitamin A and riboflavin was higher than Recommended Dietary Allowances. Mean caloric intake was 89.8% of R.D.A.. Breakfast intake of energy and most of nutrients was less than snack. Mean meal balance score was 47.9 and mean food diversity score was 13.4. 5. Mother's education level was related to intake of protein and calcium and height. Breakfast and lunch missing and number of snack intake were related with nutrition intake.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.11-20
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• 2022

Research articles were reviewed to validate the estimated energy requirements (EERs) equations developed by the Institute of Medicine of the National Academies (IOM). These equations are based on total energy expenditure (TEE) measured by the doubly labeled water (DLW) method. We subsequently aimed to provide the basis for the suitability to apply the IOM equations as EER equations for Koreans, and develop relevant equations for EER in the Dietary Reference Intake for Koreans (KDRI). Additionally, besides the EER(IOM) equations, other equations were examined for EER estimation. Research papers demonstrating the validation of the EER(IOM) equations based on TEE(DLW) were searched through PubMed (up to September 2019). Of the 637 potentially relevant articles identified, duplicates and unsuitable titles and abstracts were excluded. Furthermore, papers with irrelevant subject and inappropriate study design were also excluded. Finally, 11 papers were included in the review. Among the reviewed papers, 8 papers validated the application of the EER(IOM) equations for EER based on TEE(DLW). These included 3 studies for children (USA 1, Korea 2), 1 for adolescents (Portugal), 2 for adults (Korean), and 2 for the elderly (Korea, USA). EER(IOM) equations were found to be generally acceptable for determining EER by using the DLW method, except for Korean boys at 9-11 yrs (overestimated) and female athletes at 19-24 yrs (underestimated). Additionally, 5 papers include the validation of other EER equations, beside EER(IOM) for EER based on TEE(DLW). In Japanese dietary reference intake and recommended dietary allowance, EER equations are acceptable for determining EER based on TEE(DLW). The EER(IOM) equations is generally acceptable for determining EER using the DLW method in Koreans as well as several populations, although certain defined groups were found to be unfit for the estimation. Additionally, the concept of healthy body mass index of Koreans and physical activity levels need to be considered, thereby providing the basis for developing relevant equations of EER in KDRI.

• Journal of Nutrition and Health
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• v.27 no.8
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• pp.794-804
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• 1994

This study was conducted to investigate the relationship between lactational capacity and intakes of energy and energy-yielding nutrients. Food consumption, intakes of carbohydrate, protein, fat and energy and quantity and proximate composition of milk of 11 lactating Korean mothers were determined at 1, 2 and 3 months postpartum longitudinally. Food consumption was estimated using a 24-hour recall method ; intakes of energy and energy-yielding nutrients were calculated according to the Food Composition Table. Daily milk production was estimated using a 72-hour test-weighing method ; protein, fat, lactose and energy concentrations were analyzed. Average intakes of energy and protein were 1974$\pm$386㎉/day and 67.0$\pm$12.3㎉/day, these were 73% and 74% of the Korean Recommended Allowances, respectively. Average milk yield was 720.1$\pm$123.3ml/day containing energy 59.6$\pm$9.5㎉/dl, protein 1.1$\pm$0.1g/dl, fat 2.7$\pm$0.8g/dl, and lactose 6.3$\pm$0.3g/dl. No relationship existed between the intakes of carbohydrate, protein, fat and energy and the quantity and proximate composition of the milk. However, the intakes of energy, carbohydrate and vegetable protein were inversely related to the concentrations of energy and lactose in the milk. This result indicates that lactational capacity may be affected by the other factors excluding intakes of energy and energy-yielding nutrients and a high intake of energy may not guarantee optimal lactational capacity.

• Journal of the Korean Society of Food Culture
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• v.10 no.2
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• pp.119-123
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• 1995

This study was carried out to obtain the information concerning nutritional status, including factors of food habits of 293 men working at industry in Ulsan area. The subjects of this study were composed of 152 clerical workers and 141 physical workers. The results of this study can be summarized as follows: Average age of this subjects was 34.7 years (ranging from 21 to 52), the mean height and weight were 171.5 cm and 66.9 kg, corresponding to the BMI of 22.7. The mean food habit score was 4.4 (ranging from 0 to 9.5) and the mean nutrition knowledge score was 4.9 (ranging from 0 to 10.0) which showed significant correlations with food habit score. Dietary intake data showed the average daily intake of energy, protein, calcium and iron were higher than Korean recommended dietary allowances (RDA), vitamin A, $B_1,\;B_2$, niacin, ascorbic acid were lower than RDA. Among the various influential factors, nutrition knowledge, drinking, smoking and prevalence symptoms of subjects correlated with food habits significantly.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1455-1463
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• 2006

Effects of different levels of molasses in a concentrate supplement on milk yield of cows grazing Setaria grass pastures were investigated. Thirty Friesian cows, 6-7 years old with mean pre-experimental body weight of $428{\pm}6.5$ kg, in early stage of lactation were randomly allotted to five dietary treatments in a completely randomized design experiment that lasted for 126 days. Experimental dietary treatments were forage alone and forage/concentrate mixtures with molasses included at 0, 5, 10 or 15% levels designated as $T_1$, $T_2$, $T_3$, $T_4$ and $T_5$, respectively. The parameters studied were voluntary dry matter (DM) intake, average daily live weight change (LWC), milk yield, body condition score (BCS) and apparent nutrient digestibility coefficients. The DM and energy contents of Setaria grass were low compared to the concentrate diets. Fibre fractions-NDF, ADF, ADL, hemicellulose and cellulose; and gross energy were higher in concentrate mixtures than in the forage. Total DM intake (forage+concentrate mixtures) was significantly higher (p<0.001) in cows on the concentrate mixtures. LWC was not significantly different (p>0.05) between the cows. Average milk yields were significantly different (p<0.05) between cows. Fat corrected milk (FCM) was similar among cows in the treatments. BCS was better (p<0.001) in cows on concentrate mixtures. Digestibilities of DM, CP, NDF, ADF, ADL, OM, and energy were significantly higher (p<0.001) in cows on $T_2$, $T_3$, $T_4$ and $T_5$ than in those on $T_1$. There were no significant differences in the digestibility of DM, CP, NDF, ADF and ADL (p>0.001) in cows on concentrate mixtures. This study therefore demonstrated that lactating dairy cows in Fiji need a level of readily fermented energy source such as molasses in their diets; however, a level above 10% is not nutritionally suitable for lactating dairy cows. Based on data on production parameters-milk yield, fat corrected milk, body condition score and apparent nutrient digestibility coefficients-molasses levels that range between 5-10% are recommended, however, 10% is the best and therefore recommended for inclusion in the concentrate mixture of lactating dairy cows on a basal diet of Setaria sphacelata in Fiji.

• Journal of Nutrition and Health
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• v.46 no.5
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• pp.461-469
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• 2013

This study was conducted in order to investigate body awareness and dietary life according to gender. Subjects of the study were 120 men and 127 women aged 20 to 30 years, who exercise regularly at a fitness center in Seoul. The subjects were asked to fill out a questionnaire on body awareness, reason for regular exercise, dietary behaviors, and nutrition knowledge. The percentage of overweight and obesity was 69.2% in men, and 25.2% in women. The percentage of subjects who considered themselves as overweight was 38.3% in men and 59.8% in women. Intake of protein in men was higher than the recommended nutrient intake (RNI). Intake of energy in women was lower than the estimated energy requirement (EER). Men who considered themselves as overweight showed lower energy intake than men who considered their body weight as under and normal, whereas no difference in energy intake was observed between women who considered themselves as overweight and women who considered their body weight as under and normal.