• Journal of Advanced Marine Engineering and Technology
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• v.34 no.7
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• pp.951-962
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• 2010

An experimental study was performed to investigate the improvement of response performance of a turbocharged diesel engine under the operating conditions of low speed and fast acceleration. In this study, the experiment for improving the low speed and acceleration performance is performed by means of injecting air into the intake manifold of compressor exit during the period of low speed and application of a fast acceleration from low speed. The effects of air injection into the intake manifold on the response performance were investigated at various applicant parameters such as air injection pressure, accelerating rate, accelerating time, engine speed and load. The experimental results show that air injection into the intake manifold at compressor exit is closely related to the improvement of turbocharger lag under low speed and accelerating conditions of a turbocharged diesel engine. During the rapid acceleration period, the air injection into the intake manifold of turbocharged diesel engine indicates the improvement of the combustion characteristics and gas pressure in the cylinder. At low speed range of the engine, the effect of air injection shows the improvement of the pressure distribution of turbocharger and combustion pressure during the period of gas exchange pressure.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.378-385
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• 1999

A reduced NaCl intake for the general population of the world has been recommended to reduce the overall blood pressure level and hence to reduce the overall incidence of cardiovascular disease. A high NaCl diet convincingly contributes to elevated arterial pressure in humans and animal models of hypertension. Among individuals there is considerable variability of blood pressure responsiveness to NaCl intake. In normotensive as well as hypertensive subjects, blood pressure can be judged to be salt sensitivity (SS) when observed to vary directly and substantially with the net intake of NaCl. The prevalence of SS in normotensive adults in the U.S. ranges from 15% to 42% and in hypertensive adults from 28% to 74%. SS is a risk factor for hypertension and may be an important marker in the identification of children for hypertension prevention programs. High NaCl intakes produce expansion of the extracellular fluid volume and thus increase blood pressure. Nonchloride salts of sodium does not expand the extracellular fluid volume and does not alter blood pressure. Blood pressure response to NaCl may be modified by other components of the diet. Low dietary intakes of potassium or calcium augment NaCl-induced increases of blood pressure. Conversely, high dietary intakes of potassium or calcium attenuate NaCl-induced hypertension. A greater intakes of potassium or calcium may prevent or delay the occurrence of hypertension. SS occurs when dietary potassium is even marginally deficient but is dose-dependently suppressed when dietary potassium is increased within its normal range. Orally administered KHCO$_3$, abundant in fruits and vegetates, but not KCl has a calcium-retaining effect which may contributed to its reversal of pressor effect of dietary NaCl. Since nutrients other than NaCl also affect blood pressure levels, a reduced NaCl intake should be only one component of a nutritional strategy to lower blood pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.105-108
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• 2005

The radiated noise from the automotive intake system should be predicted at the design stage. To this end, the precise measurement of in-duct acoustic source parameters of the intake system, i.e., the source strength and source impedance, is essential. Most of previous works on the measurement of acoustic source parameters were performed under a fixed engine speed condition. However, the requirement of vehicle manufacturer is the noise radiation pattern as a function of engine speed. In this study, the direct method was employed to measure the source parameters of engine intake system under a fixed engine speed and engine run-up condition. It was noted that the frequency spectra of source impedance hardly changes with varying the engine speed. Thus, it is reasonable to calculate the source strength under the engine run-up condition by assuming that source impedance is invariant with engine speed. Measured and conventional source models, i.e., constant pressure source, constant velocity source, and non-reflective source, were utilized to predict insertion loss and radiated sound pressure level. A reasonable prediction accuracy of radiated sound pressure level spectra from the intake system was given in the test vehicle when using the measured source characteristics which were acquired under the operating condition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.797-805
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• 2014

The purpose of this study was to investigate the drag and lift characteristics of the cavitator of a supercavitating underwater vehicle and the pressure loss due to water intake. These investigations were performed by changing the diameter, velocity, radius of curvature of the intake, and angle of attack of the cavitator. With increasing ratio of the intake diameter to the cavitator diameter ratio($d/D_1$), the drag coefficient and the pressure loss coefficient of the water intake decreased. The greater the increase in the ratio of the intake velocity-to-free stream velocity ratio(S), the smaller was the decrease in the drag coefficient and the lift coefficient. When the intake had a radius of curvature(c), the pressure loss coefficient decreased. On the contrary, the effect of the radius of curvature on the drag coefficient was imperceptible. For angles of attack (${\alpha}$) of the caviatator in the range of $0^{\circ}$ to $10^{\circ}$, the drag coefficient and the pressure loss coefficient changed slightly, whereas the lift coefficient increased linearly with increasing angle of attack.

• Korean Journal of Community Nutrition
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• v.17 no.6
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• pp.737-751
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• 2012

The purpose of this study was to assess sodium and potassium intakes and urinary excretion of adults in Busan and to evaluate the relationship of urinary sodium/potassium excretion (UNa/UK) to the status of anthropometric, blood pressure, urine analysis, and nutrient intake of subjects. Nutrient intake by 24-h recall, 24-h UNa/UK were measured with 87 adults aged 20-59 yrs (42 men and 45 women). The mean intakes of sodium and potassium were 3915.4 mg and 3093.9 mg, respectively. The mean 24-h UNa/UK was 3457.0/1680.4 mg. UNa showed significant positive correlations with sodium intake (p < 0.001, p < 0.001), sodium/potassium ratio (p < 0.001, p < 0.01), UK (p < 0.001, p < 0.001), and UNa/UK ratio (p < 0.05, p < 0.01) in men and women and with age, BMI, systolic blood pressure (SBP) and diastolic blood pressure in women (p < 0.05, p < 0.05, p < 0.05, p < 0.05). The UK showed significant positive correlations sodium intake (p < 0.001, p < 0.001), UNa (p < 0.001, p < 0.001) in men and women and with sodium density in men (p < 0.001) and with age, intakes of protein and potassium in women (p < 0.01, p < 0.05, p < 0.05). Mean SBP was lowest in the second quartile and highest in the fourth quartile of UNa. Mean UNa in the second, third, and fourth quartiles were 2821.1 mg, 3621.3 mg, and 5456.4 mg, respectively. Mean SBP in the second, third, and fourth quartiles were 115.8 mmHg, 120.7 mmHg, and 125.9 mmHg, respectively. Based on the results, UNa was related to sodium intake, UK, and SBP. We conclude that nutritional education for the reduction of high sodium intake is needed in the general population to prevent and control adverse blood pressure levels.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.429-444
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• 1997

This study aimed at investigating correlation of nutrients intake and serum lipids in middle-aged korean male and female workers. One hundred sixty eight(male ;105, female ;63) for adult aged 30-59yr(average age male ;36.5yr, female ;44.5yr) were selected as subjects during 2 months, from April to May, 1996. Nutrients intake status was investigated by questionnaire, 24-hour recall method. Antropometric assessments, serum lipids and blood pressure of the subjects were investigated. The results as follows: 1. Nutrients intake status ; male was superior to female. Vitamin A intakes of 40-49yr group were inferior to other group but amounts of intake were above Korean RDA(recommended dietary allowances), Intakes of calcium and vitamin C of 30-39yr and over 50yr group in female were below Korean RDA. In overweights group of male and underweight group of female, most nutrients intake were increased than other groups. 2. Antropometric assessments ; female was higher than male in BMI (body mass index). All subjects increasingly with age were increased in BMI. 3. Blood components were above normal range in triglyceride in both sexes and all subjects increasingly with age were increased In level of serum lipids and blood pressure, especially in male's forty and in female's fifty were higher than other groups In serum lipids and blood pressure. In overweights group, serum lipids and blood pressure had a significantly($\alpha$=0.05) increasing tendency in both sexes. 4. Serum lipids and connected factors; atherogenic index correlated positively with triglyceride, total-chol(total cholesterol), LDL-chol(low density-lipoprotein cholesterol) and negatively with HDL-chol(high-density-lipoprotein cholesterol) significantly(P＜0.001). Systolic blood pressure correlated positively with total-chol and diastolic blood pressure correlated positively with total-chol, LDL-chol significantly(P＜0.05). 5. Serum lipids and nutrients intake status: energy correlated positively(P＜0.05) with BMI, dietary fiber correlated positively with LDL-chol(P＜0.05), calcium correlated positively with triglyceride, atherogenic index and dietary fiber correlated negatively with BMI in male significantly(P＜0.05). Triglyceride correlated positively with vitamin C and phosphorus correlated negatively with BMI in female significantly(P＜0.05). Above results, in male's forty and in female's fifty were liable to variation in terms of serum lipids and blood pressure. As increasing triglyceride, total-chol, LDL-chol and decreasing HDL-chol Increased atherogenic index that suggest increasing risk of atherosclerosis. But, this point will be considered more subdivided study.

• Korean Journal of Community Nutrition
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• v.10 no.4
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• pp.493-500
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• 2005

There is some evidence that soy isoflavone has beneficial effects on the concentration of blood lipids. In this study, we investigated habitual isoflavone intake levels and the relation among dietary isoflavone intake, blood pressure, and blood lipids of adult men (n = 149) and women (n = 205). Anthropometric measurements including blood pressure, dietary in-take assessment using 24-hour recall method, and biochemical assessment using blood were conducted. The average age, height, weight, and BMI were 54.7 years, 168.5 cm, 67.3 kg, and 24.5 $kg/m^2$ for men and 53.9 years, 153.8 cm, 59.2 kg, and 25.0 $kg/m^2$ for women, respectively. The mean daily intakes of total food and energy were 1219.1 g and 1740.9 kcal for men and 1071.3 g and 1432.6 kcal for women, respectively. The mean daily isoflavones (daidzein + genistein) intake of men and women were 20.0 mg and 14.2 mg, respectively. Blood pressure of the subjects was 128.3/75.5 mmHg for men and 124.1/73.7 mmHg for women. Serum lipids of men and women were 180.2 and 184.9 mg/dL for total cholesterol, 160.8 and 137.6 mg/dL for triglyceride, 41.5 and 44.7 mg/dL for HDL-cholesterol, 106.6 and 112.7 mg/dL for LDL-cholesterol, and 3.5 and 3.3 for atherogenic index, respectively. Serum triglyceride and atherogenic index of men were significantly higher than those of women. In men, isoflavone intake and the level of total serum cholesterol were negatively (p < 0.05) correlated, after adjusted age. In women, there were significant correlations between isoflavone intake and blood pressure (systolic and diastolic), after adjusted age (p < 0.05). Based on these results, we concluded that higher isoflavone intake seemed to be related to a better lipid profile in men and lower blood pressure in women. But more epidemiological studies and controlled clinical trials would help to confirm the optimal amount required for the prevention and treatment of cardiovascular disease.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.649-656
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• 2004

Hypersonic wind tunnel test of the rectangular variable geometry intake is performed. For realization of a Precooled turbojet engine, development of a hypersonic ramjet engine is planned. To investigate performance of the intake of the hypersonic ramjet engine, wind tunnel test is done with freestream Mach number of 5.1. The total pressure recovery was 18 % with 12.9 % of ramp bleed. Several reasons for low total pressure recovery are shown. Supersonic internal compression is not enough. Then, the throat Mach number is high (M2.61) and total pressure losses at the terminal shock is large. Supersonic flow at the throat and position of the terminal shock is sensitive to a difference of the second ramp's throat height and the third ramp's throat height. Flow separations at the second ramp's trailing edge and the third ramp's leading edge are seen those could result in the trigger of unstart. The seal mechanism between the ramps and the sidewalls is important.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.17-21
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• 1968

Total body oxygen uptake was measured in rats following hemorrhage (16 rats) and blood transfusion (7 rats) under light Nembutal anesthesia. Arterial blood Pressure measured on the tail artery decreased or increased following hemorrhage or transfusion. No direct relationship was observed between arterial blood pressure alteration and oxygen intake variation. Hematocrit ratio which changed after hemorrhage or transfusion showed a direct relationship with oxygen intake. Decrease in hematocrit ratio resulted in a decrease in oxygen intake of rats. The correlation coefficient between decrement of hematocrit ratio and decrement of oxygen intake was r=.56. The correlation coefficient between increment of hematocrit ratio and increment of oxygen intake was r=.86. Thus it was concluded that alteration in oxygen intake was limited by the systemic oxygen transport capacity of blood.

• Journal of Nutrition and Health
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• v.31 no.1
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• pp.72-79
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• 1998

This study was intended to figure out the difference of the blood lipids, insulin and nutrients intake by fat distribution among the obese young male in Korean. Twenty-eight male college students participated in this study, whose to find out body fat distributions were classified on the basis of Waist /hip ratio (WHR) into three groups-upper body type (UBTM), intermediate body type(IBTM) and lower body type (LBTM). To conduct this study, anthropometric measurements , blood pressure, serum lipids and insulin levels, and daily nutrients intake were analized . The results are as follows : The three body type groups showed significant differences each other in waist circumference(p<0.05), WTR(p<0.001) and body fat percentage (p<0.05). Also they showed significant difference each other in the daily construction in the daily energy intake. But they did not show significant differences in the blood pressure, serum lipids and insulin levels. From the above results, we could concluded that the body fat distribution in obese the young men could affect nutrients intake pattern.