• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.836-843
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• 1998

In this paper effects of resonator within intake manifold system on volumetric efficiency were investigated n the 4-cylinder and 4 stroke Diesel Engines. The effects of resonator system were analyzed on resonant speed and on volumetric efficiency for a complicated intake system with resonator was confirmed. And the optimum design method of the resonant system which had the overall high and flat characteristic of volumetric efficiecncy was proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.3
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• pp.195-203
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• 2019

Since the hypersonic intake is directly related to the overall performance of the engine, it is essential to analyze performance characteristics under various off-design conditions. In this paper, Busemann intake and conical intake with external compression were designed, and numerical simulations were performed at on/off-design conditions. Based on the results, the overall performance characteristics of two types of intake were analyzed in various Mach numbers and angle of attacks. The results showed that performance degradation of Busemann intake with truncation angle of 2 degrees was minimal. Also, the performance of Busemann intake was higher than external compression intake at various Mach numbers, however, the starting characteristics were significantly reduced with an angle of attack.

• Korean Journal of Community Nutrition
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• v.2 no.5
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• pp.701-710
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• 1997

this study was undertaken to compare the riboflavin status of rural women with different physical activity intensity and to determine factors influencing biochemical fiboflavin status. The study was carried out over three different farming seasons : planting (June), harvest(October) and interim(February) in two rural regions of Korea. One was a traditional farming region, the other a commercial farming region with heavier work intensity. Twenty women in the traditional region and eighteen women in the commercial region were involved. The intensity of physical activity was determined by a daily activity record. Body composition was assessed by bioelectrical impedence. Dietary riboflavin intake was measured by the food frequency method. Riboflavin biochemical status was assessed by erythrocyte glutathione reductase activity coefficient (EGR AC) and ruinary riboflavin excretion. The results from the EGR AC and urinary riboflavin excretion during the period showed the overall riboflavin status of the commercial farming women was significantly worse than that of the traditional farming women(EGR AC p<0.0001, urinary riboflavin excretion p<0.05). The traditional farming group had about 40% with risk of riboflavin deficiency, whereas the commercial farming group had about 70%. Overall mean nutrient intake was not significantly different between the two groups, however, overall mean percent lean body mass representing long term physical activity was significantly higher in the commercial farming group ( <0.005). It appears that the biochemical riboflavin status of traditional farming women was significantly influenced by riboflavin intake and crude nitrogen balance while the biochemical riboflavin status of the commercial farming women was significantly influenced by riboflavin intake and percent of lean body mass over the three seasons. (Korean J Community Nutrition 2(5) : 701∼710, 1997)

• Journal of Nutrition and Health
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• v.26 no.4
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• pp.414-422
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• 1993

The longitudinal changes on human milk intake of exclusively breast-fed infants(boys=15, girls=12) from 0.5 to 6 months after parturition have been studied by test-weighing method in Cheongju and Anseong area. Infant milk intake per day tended to increase during lactation. The mean intake at 0.5, 1, 2, 3, 4, 5, and 6 months were 532, 695, 734, 756, 785, 767, and 710g, respectively. The average intakes were 752 and 660g for boys and girls, respectively. The overall mean intake was 711g/day. The milk intake between boys and girls at 1, 2, 4 months, and mean value was significantly different(p<0.05). Infant milk intake had a significant positive correlation with human milk volume of lactating women, but no correlation with maternal age, weight before delivery, height, and birth weight.

• Korean Journal of Community Nutrition
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• v.6 no.1
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• pp.51-68
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• 2001

This investigation studied the relationship between Body Mass Index(BMI) and dietary intake, levels of serum lipid, lipoprotein(a) and plasminogen activator inhibitor-1(PAI-1) of 28.449 Korean adults(16.937 men, 11.542 women) from 1995 to 1999. The dietary assessment was conducted using 24-hour dietary records and food frequency questionnaires. During this five year study, the BMI normal-weight group, as a percentage of the annual test population, decreased from 68.0% to 60.2%, while the BMI overweight and obese groups collectively increased from 25.0% to 29.7%. The levels of serum total cholesterol (TC), LDL-cholesterol(LDL-C), Triacylglycerol(TG) and PAI-1 increased as the values of BMI increased, while the levels of HDL-cholesterol(HDL-C) and lipoprotein(a)(men only) appeared to decrease as values of BMI increased. The levels of daily energy intake also increased as values of BMI increased in both men and women. The obese group had significantly higher levels of carbohydrate, protein, fat(men only), and cholesterol intake than those of the normal-weight, underweight, and overweight groups. In men, BMI positively correlated with the levels of macronutrients and cholesterol intake(p＜0.001), % energy of protein, fat, and alcohol intake(p＜0.001), and the levels of serum TC, LDL-C, TG and PAI-1(p＜0.001), while BMI negatively correlated with % energy of carbohydrate intake, and the levels of Lp(a) and HDL-C(p＜0.001). In women, BMI negatively correlated with level of cholesterol(p＜0.01), fat(p＜0.001), alcohol intake(p＜0.05),% energy of fat (p＜0.001), % energy of alcohol intake and level of and HDL-C(p＜0.001). Subjects who had serum TC, LDL-C, HDL-C, and TG levels greater than the standard reference values(TC＞240mg/㎗, LDL-C＞130mg/㎗, HDL-C＞35, TG＞200mg/㎗) exhibited a higher intake of the three macronutrients, iron, calcium, meat, milk and fatty foods than those subjects who had serum lipid concentrations less-than-or-equal-to the standard reference values. Overall, there was positive correlation between the high risk factors of vascular disease variables, dietary intake, and BMI. Prevalence of hypertension and high blood sugar were increased as BMI increased, but the prevalence of hypertension is decreased as the year goes by. These findings showed that dietary intake, level of serum lipids and other vascular disease risk factors increased as BIM increased. Therefore, middle or upper class Korean adults who have high BMI should improve their eating habits. This involve reducing alcohol, animal fat, high carbohydrate foods, and overall food intake, and balancing intake in order to lower vascular disease risk factors, including obesity.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.149-157
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• 2016

This paper presents the traffic speed limit of heavy vehicles at each wind velocity region, which is based on their accident risk analysis under cross-wind. The variables for the accident risk analysis are overall height, overall length, intake weight, and friction coefficient of the road surface. It was confirmed from analysis results that the risk of overturning increased with higher overall height and length, and the risk of sliding decreased with higher intake weight. The risk of sliding was largest at the friction coefficient of 0.1, and the risk of overturning was lagest at friction coefficient more than 0.25. Finally, traffic speed limit was proposed by using the accident risk analysis.

• International Journal of Human Ecology
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• v.4 no.2
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• pp.101-106
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• 2003

The relationship between fat intake and breast cancer has been debated for a long period of time. Animal, ecological, and case-control studies have supported that dietary fat increases breast cancer risk. However, cohort studies have not support any strong association between dietary fat intake and breast cancer risk. It has not been clear whether fat per se or some specific type of fat is responsible for the increased risk. Recently, a few cohort studies have found some positive association between specific types of fat intake, but not overall fat intake and breast cancer risk. In this review, the findings from previous studies will be summarized with advantages and disadvantages of different types of study design and recent findings will be introduced.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.16-21
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• 2005

The performance of reciprocating internal combustion engine is a strong function of the air intake system configuration. In order to improve engine power, it is essential to optimize the air induction system. In this study, a numerical investigation has been carried out for the three-dimensional flow and pressure characteristics in air intake system of a large-sized commercial bus. CFD simulations using STAR-CD were also perform ed to evaluate effects of intake duct geometry and structure variation inside air cleaner on the negative pressure distribution of overall intake system. Studies for improving the back pressure distribution have been proposed and quantitatively examined based on intensive case studies.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.644-649
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• 2015

BACKGROUND/OBJECTIVES: Targeting consumers who consume lunches at their worksite cafeterias would be a valuable approach to reduce sodium intake in South Korea. To assess the relationships between socio-demographic factors, consumer satisfaction, attitudes, barriers and the frequency of sodium-reduced meal intake. SUBJECTS/METHODS: We implemented a cross-sectional research, analyzing data from 738 consumers aged 18 years or older (327 males and 411 females) at 17 worksite cafeterias in South Korea. We used the ordinary least squares regression analysis to determine the factors related to overall satisfaction with sodium-reduced meal. General linear models with LSD tests were employed to examine the variables that differed by the frequency of sodium-reduced meal intake. RESULTS: Most subjects always or usually consumed the sodium-reduced meal (49%), followed by sometimes (34%) and rarely or never (18%). Diverse menus, taste and belief in the helpfulness of the sodium-reduced meal significantly increased overall satisfaction with the sodium-reduced diet (P < 0.05). We found importance of needs in the following order: 1) 'menu diversity' (4.01 points), 2) 'active promotion' (3.97 points), 3) 'display of nutrition labels in a visible location' (3.96 points), 4) 'improvement of taste' (3.88 points), and 5) 'education of sodium-reduction self-care behaviors' (3.82 points). CONCLUSION: Dietitians could lead consumers to choose sodium-reduced meals by improving their taste and providing diverse menus for the sodium-reduced meals at worksite cafeterias.

• Journal of Nutrition and Health
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• v.37 no.2
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• pp.143-152
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• 2004

A dietary survey was conducted using 24-hour recall method in 80 male elementary school children, 83 high school students, 87 adults and 98 elderly people over 65 years of age to discuss food and nutrient intakes among different age groups. In observing food intake by age groups, the percentage of plant foods to total food intake was significantly higher in the elderly than other groups and that of animal foods was the highest in the children. The children consumed significantly higher amounts of milk and dairy products. Carbohydrate energy percent in the elderly people was 68.0%, significantly higher than other age groups. All age groups consumed Ca below Korean RDA and especially, 65.1% of the adolescents and 68.4% of the elderly consumed below 75% of RDA. Nutrient adequacy ratio (NAR) of most nutrients was lowest in the elderly. Mean adequacy ratio (MAR), an index of overall dietary quality, was 0.94 for the children, 0.84 for the adolescents, 0.84 for the adults, and 0.73 for the elderly. The above results suggest that food and nutrient intakes have been differently affected with advancing age, and overall dietary quality of the elderly people is lower than that of other age groups. (Korean J Nutrition 37(2): 143-152, 2004)