• Korean Journal of Community Nutrition
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• v.1 no.3
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• pp.366-375
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• 1996

The effect of carbohydrates, fat and protein consumption on the blood pressure of adolescents was investigated from the cross sectional data. The two major areas of inquiry were : 1)measuring the variation of blood pressure at various levels of macronutient intake. 2)measuring the relative importance between the factor of nutrient intake and physical growth. A total of 726 students(341 boys and 385 girls) in the first grade of middle school in Kangwha country were studied for their dietary consumption and physical growth as well as blood pressure. Multiple regression analysis was used as the analytical method to identify the relative importance between the factors. Besides the macronutrient consumption, other nutrients such as vitamin and mineral intakes were included in the regression model. The results showed a variation of blood pressure by macronutrient intake level was in consistant both in blood pressure and by gender. Systolic and diastolic blood pressure decreased with increasing protein intake for girls(p<0.05). However, it was not observed in the case of boys. The systolic blood pressure of boys showed a tendency to decrease with fat intake increase, while their diastolic blood pressure showed the opposite trend. Results of the regression analysis showed that physical growth was a more influential factor than nutrition on blood pressure for both sexes. This could imply that the dietary hypertension factors observed in adults may not be operative generally in a population with normotensive blood pressure during growth.

• Journal of Nutrition and Health
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• v.34 no.1
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• pp.62-68
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• 2001

The purpose of this study was to confirm that regular physical exercise habit and calcium intake play a role reducing the risk of cardiovascular diseae, particularly to confrim that regular exercise is important in reducing serum lipid levels. Subjects were classified into regular exercise group(more than 3 times/wk, more than 30 min per exercise) and non-regular exercise group. A convenient frequency method was used to assess the nutritional intake of subjects. Anthropometric measurement such as bodyweight and hight, and blood pressure were measured. There was no significant difference between nonexercisers and exerciser in energy intake, calcium intake and blood lipid levels. The strength of frequency of exercise may not by adequate to modify lipid profiles in premenopausal woman with normal lipid level, Although we found no significant difference in blood lipid levels, this result does not imply there are no benefits of exercise subjects. There were no signigicant correlations between age or weight with blood lipids in regular exercise group, while there were significant positive correlations between age of weight with blood lipids in non-regular exercise group. The levels of serum cholesterol, and triglyceride, blood pressure and atherogenic index increased with age in nonexercise women, Especially, atherogenic index was lower in regular exercise group. The blood pressure in nonexercise group was significantly higher than that in regular exercise group There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women, There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women. The results suggest that increased habitual physical activity and calcium intake may have desirable effects on serum lipid levels and blood pressure in premenopausal women.(Korean J Nutrition 34(1):62-68, 2001)

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.47-53
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• 1997

The importance of intake system can not be overstressed in the recent heavy duty commercial vehicle design. The basic requirements of intake system are to have less flow resistance and better air cleaning performance which have direct effects on the performance and service life of engine. In order to improve the performance of engine intake system, the flow phenomena in the intake system should be fully understood. With readily availble CFD code, the numerical analysis becomes the more reliable tools for flow optimization in recent design work. In this research, flow field in the intake system was analyzed by STAR-CD, the 3-D computational fluid dynamics code. Especially, the flow inside of air cleaner was thoroughly analyzed. Pressure distribution and velocity profile in the air cleaner and intake duct was obtained. Having the dust seperated from incoming air at the expense of less pressure drop is the ultimate goal for the research.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.25-31
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• 2012

A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.132-140
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• 2010

High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.4
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• pp.57-65
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• 1988

The study of unsteady gas exchange processes in the intake and exhaust systems of four-cylinder, four-stroke cycle internal combustion engine is described in this paper. The calculation model for the intake and exhaust systems is established and solved by the characteristic method for the equations defining these systems. A constant pressure theory is used for modeling branches of intake and exhaust manifolds. The relationship between the volumetric efficiency and the intake, exhaust pressure variation is clarified by simulation of these systems. It is found that the volumetric efficiency mainly depends on the intake pressure during the short period before the intake valves is closed, that the volumetric efficiency is influenced a little by intake chamber volume in the intake and exhaust system.

• The Korean Journal of Community Living Science
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• v.14 no.1
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• pp.107-117
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• 2003

This study was carried out to investigate the nutrients intakes, blood pressure, and correlations between these two factors in Korean rural adults(60 men, 60 women). Nutrients intakes were measured by analyzing with CAN Pro after weighing the each diets of the subjects had for 24 hours. We measured body mass index(BMI), waist to hip ratio(WHR), and fat content in the body besides blood pressure, and considered their relationship with blood pressure. This examination includes collections and analysis of serum and urine, and considers the correlations between blood pressure and serum or urinary factors. These results were as follows ; 1) The mean ages of men and women were 50.$\pm$12.6 and 46.0$\pm$12.5, respectively. The percentage of hypertensive was higher in men(43%) than in women(37%). 2) The values of WHR, body water and lean body mass were higher in men and the value of body fat was higher in women. Weight, BMI, waist or hip circumferences, and WHR were correlated with blood pressure in these subjects. 3) Though the levels of serum triglyceride, sodium, potassium and iron levels were higher in men and urinary Na was higher in women, these factors didn't showed any significant correlations with blood pressure in both sexes. 4) The values of calcium and vitamin B$_2$ intake in men and women, and of iron intake in women didn't meet the Korean recommended allowances(RDA). Animal protein and Na intakes were negatively correlated with blood pressure. These results showed that the levels of calcium and vitamin B$_2$ intake in both sexes and iron intake in women were lower than those of RDA, and weight, BMI, waist or hip circumferences and WHR were significantly correlated with blood pressure. Therefore we suggest that the farmers of this research need to increase intake of nutrients like calcium and vitamin B$_2$ and control the weight.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.6
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• pp.679-687
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• 2002

In this study, a cycle simulation using a two-zone model is carried out to investigate the effect of intake charging conditions such as oxygen concentration, temperature and pressure on NO emissions in a DI diesel engine. The model is validated against measurements in terms of cylinder pressure, torque, BSFC and NOx emissions with 2902 cc DI diesel engine. Calculated results can be summarized as follows. The oxygen concentration in the intake charge is decreased with increasing of EGR rate and equivalence ratio. As the intake oxygen concentration is reduced, the combustion pressure and the burned gas temperature decrease and, as a result, NO formation decreases. Also, the results show that as the intake pressure increases and the intake temperature decreases, NO emissions are effectively reduced.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.95-99
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• 2004

The developing Smart UAV in KARI supposes high speed flight as like a conventional plane, as well as vertical takeoff and landing as like a helicopter. Therefore, the air intake system should be designed to provide the sufficient air flow to the engine and the maximum possible total pressure recovery at the engine intake screen over a wide range of flight conditions. For this purpose, we designed the intake system using a pilot type intake model and plenum chamber In this paper, we designed the intake model and analyzed the performance of designed intake system using the general-purpose commercial CFD code, CFD-ACE+ For 3-D calculation, we generated mesh using the unstructured gird and used $\kappa-\epsilon$ turbulence model. The analysis results of the total pressure variation and the velocity distribution was illustrated in this paper. The pressure recovery and distortion coefficient at a plane coincident with the compressor inlet were calculated and streamline variation through the intake system was investigated at the worst condition as well as the standard flight condition.