• Journal of Nutrition and Health
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• v.32 no.6
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• pp.671-680
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• 1999

In order to investigate the relationship between plasma renin activity and metabolism of Ca and Na in blood pressure, the habitual dietary intakes of Na and Ca urinary excretion of Ca, Na and K, and plasma level of renin activity, aldosterone, and indices of Ca metabolism were measured in 27 untreated hypertensive women and 30 age-matched normal women on a free diet. Hypertensive subjects were classified into high renin hypertensive (HH), medium renin hypertensive(HM) and low renin showed no significant difference among normotensive, LH, MH and HM groups. It appeared that 25-(OH) Vit D3 level of HH group was significantly higher than LH group(p<0.05). There was significant difference in habitual intake of Ca between normotensive and LH groups. However, habitual intake of Na showed no significant difference among normotensive, LH, MH and HH group. Positive correlation of systolic and diastolic blood pressure with PTH(r=0.324, r=0.375) and urinary Ca(r=0.496, r=0.278) and a negative correlation of systolic blood pressure with habitual Ca intake(r=-0.371) existed(p<0.05). A relative magnitude of factors affecting hypertension was analyzed by multiple regression analysis. Overall results about relative influence of independent variables to dependent variable (systolic blood pressure) indicated that urinary Ca was the higher correlation in all subjects(p<0.0001), followed by age and aldosterone. PTH showed a significant correlation for relative influence on diastolic blood pressure in all subjects. The above results indicated that renin-aldosterone system and Ca regulating hormone had a mutual relationship in hypertension.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.632-638
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• 2000

This paper represents the characteristics of evapotranspiration rate (EVTR) and graft-taking of watermelon grafted seedlings in a graft-taking enhancement system using fluorescent lamps as artificial lighting source. Four air temperature levels of 23, 25, 27 and 29C, three humidity levels of 85, 90 and 95%R.H. and two photosynthetic photon flux (PPF) levels of 30 and 50 ${\mu}$mol m$\^$-2/ S$\^$-1/ were provided to investigate the effects of air temperature, relative humidity and light intensity on EVTR and graft-taking of grafted seedlings. EVTR of grafted seedlings increased with increasing air temperature and the passage of time after grafting. Also EVTR increased with decreasing relative humidity. As relative humidity decreased and air temperature increased, vapor pressure deficit increased and thus EVTR increased. It is required to maintain a low level vapor pressure deficit for suppressing EVTR of grafted seedlings during first 1-2 days after grafting. Therefore, less EVTR at initial stage after grafting would be adequate for smooth joining of the scion and rootstock.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.2
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• pp.35-42
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• 2003

This paper proposes a relative lifetime test method of MgO thin film. The suggested test conditions are 5$0^{\circ}C$, 400Torr, 20% over-voltage and 300KHz. The relative lifetime of MgO thin film is significantly affected by the MgO preparing conditions and Xe partial pressure. As result, the lifetime of the AC plasma display panel (PDP) is increased with an MgO thickness of 2000$\AA$ to 8000$\AA$ but is saturated over 5000$\AA$ (up to 9000 $\AA$). In addition, as Xe partial pressure increases, AC PDP lifetime increases.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.193-203
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• 2002

The results of an experimental study on Saemangeum dredged sands are presented. Undrained triaxial compression tests were performed with there different initial relative densities, namely 18, 34, and 50%, intend to evaluate undrained Behavior. All undrained triaxial compression tests were performed under static loading conditions. Undrained triaxial compression tests were exhibited complete static liquefaction, zero effective confining pressure and zero stress difference at lower confining pressures. As confining pressures were increased, the effective stress paths indicated increasing resistance to static liquefaction by showing increasing dilatant tendencies. The fines and larger particles create a particle structure with high compressibility at lower confining pressure. The effect of increasing relative density was to increase the resistance of the sand against static liquefaction by making the sand more dilatant.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.1
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• pp.97-105
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• 2004

The Vapor-liquid equilibrium data for the binary system of 2-methyl-2-propanol-2-butanone are measured at subatmospheric pressure of 100, 200, 300, 400, 500, 600, 700 and 760 torr. This study shows that the relations between logarithmic values of relative valatility(log ${\alpha}$)and liquid phase composition(${\chi}$) in the above binary systems are expressed as a linear function. When the linear relationships of between logarithmic values of relative volatilities and liquid phase compositions in the binary systems of various pressure intersect at a point, this empirical equation can be applied to the systems of this kind. From these relations the vapor-liquid equilibrium data are estimated and compared with the measured values to be in a good agreement with in accuracy ${\pm}0.0021$ for the various pressure.

• Geomechanics and Engineering
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• v.12 no.4
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• pp.689-705
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• 2017

The present study deals with the Pressure-settlement behavior of square and rectangular skirted footing resting on sand and subjected to a vertical load through a laboratory experimental study. A series of load tests were conducted in the model test tank to evaluate the improvement in pressure-settlement behavior and bearing capacity of square and rectangular model footings with and without structural skirt. The footing of width 5 cm and 6 cm and length/width ratio of 1 and 2 was used. The relative density of sand was maintained at 30%, 50%, 70%, and 87% respectively. The depth of skirt was varied from 0.25 B to 1.0 B. All the tests were carried out using a strain controlled loading frame of 50 kN capacity. The strain rate for all test was kept 0.24 mm/min. The results of present study reveal that, the use of structural skirt improves the bearing capacity of footing significantly. The improvement in bearing capacity was observed almost linearly proportional to the depth of skirt. The improvement in bearing capacity of skirted footings over footing without skirt was observed in the range of 33.3% to 68.5%, 68.9% to 127% and 146.7% to 262% for a skirt depth of 0.25 B, 0.50 B and 1.0 B respectively. The skirted footings were found more effective for sand at relative density of 30% and 50% than at relative density of 70% and 87%. The bearing capacity was found to increase linearly with footing width for footings with and without skirts. This observation was found to be consistent for footings with different skirt depths and for relative density of sand i.e., 30%, 50%, 70%, and 87%. The obtained results from the study for footing with and without skirts were comparable with available solutions from literature.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1458-1465
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• 2010

A lot of dredging and reclaming projects are recently under way in Korea for the efficient use of limiting land space. Saemanguem area is special case of reclaiming by dredged soil. In case of a confined disposal of dredged soils by a pump dredger, generally coarse grained soils are separated from fines with dropping at the near part of the pump dredger. This kind of seperation of fine contents could be a factor of liquefaction by earthquake. In Korea, recently, earthquakes with magnitude of 3.0 or higher are distinctively increasing in 1990. In this study, cyclic shear characterics of Saemanguem Dredged sand depending on fine content were analyzed. A series of undrained cyclic triaxial test with cyclic stress ratio ($\sigma_d/{2\sigma_{{\upsilon}c}}'$) were performed on both isotropic consolidated specimen and sand with fine contents of 0%, 5%, 15%, 30%, 40% under the effective vertical stress of 100kPa and 50% and 60%, 70% of relative density for fine content of 0%, respectively. In the test results, cyclic shear strength increased by increasing of cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) with increasing the relative density at the same number of cyclic under the effective confining pressure of 100kPa. It is almost highest the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10% at fine content of 15% between Cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) value at cyclic number five and fine content. Number of cyclic is 30 under the effective vertical stress of 100kPa, 70% of relative density for fine content of 15%. when the cyclic stress ratio at each relative density was compared at cyclic number five, the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10%, and the pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value were compared; under the relative density of 70% and the effective confining pressure of 100kPa. The pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value showed a similar trend to the double amplitude (DA) 5% line.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3950-3960
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• 2014

In this study, the drag forces on a submerged square cylinder were analyzed using a three dimensional hydrodynamic model. The numerical results were compared with the experimental results to check the reliability of the numerical simulations, and the characteristics of the drag forces with the relative depths were analyzed by analyzing the pressure acting on the cylinder surface, which are normally difficult to measure experimentally. The numerical results showed that the drag forces acting on a submerged square cylinder originate mainly from the pressure forces, and component of the shear forces decreased with increasing relative depth. The pressure coefficient distributions showed that in the case of a low relative depth, a relatively high pressure was formed in the front of a cylinder, and a relatively low pressure was formed in the rear, which gives a high drag coefficient. In a high relative depth, the pressure in the front decreased and pressure in the rear increased, which is a similar phenomenon to that normally observed in two dimensional square cylinder flow. The effect of the static pressure was analyzed and the surface elevation difference between the front and rear zone of a cylinder has a limited effect on the drag forces. Finally, the numerical results showed that the drag forces acting on a submerged square are dominated by the dynamic pressure formed by three dimensional flow and the distribution of local surface elevation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.299-311
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• 2020

This paper analyzes the distribution of water vapor pressure and relative humidity in complex terrains by collecting weather observation data at 6 locations in the valley in Jungdae-ri, Ganjeon-myeon, Gurye-gun, Jeolla South Province and 14 locations in Akyang-myeon, Hadong-gun, Gyeongsang South Province, which form a single drainage basin in rural and mountainous regions. Previously estimated water vapor pressure used in the early warning system for agrometeorological hazard and actual water vapor pressure arrived at using the temperature and humidity that were measured at the highest density (1.5 m above ground) at every hour in the valley of Jungdae-ri between 19 December 2014 and 23 November 2015 and in the valley of Akyang between 15 August 2012 and 18 August 2013 were compared. The altitude-specific gradient of the observed water vapor pressure varied with different hours of the day and the difference in water vapor pressure between high and low altitudes increased in the night. The hourly variations in the water vapor pressure in the weather stations of the valley of Akyang with various topographic and ground conditions were caused by factors other than altitude. From the observed data of the study area, a coefficient that adj usts the variation in the water vapor pressure according to the specific difference in altitude and estimates it closer to the actual measured level was derived. Relative humidity was simulated as water vapor pressure estimated against the saturated water vapor pressure, thus, confirming that errors were further reduced using the derived coefficient than with the previous method that was used in the early warning system.

• Journal of Korean Academy of Nursing
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• v.30 no.6
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• pp.1479-1487
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• 2000

This study was conducted to draw out prevalence and the risk factors of diabetes mellitus and impaired fasting glucose for adults,(age 30-69). The subjects were 2096 adults, who had regular health examinations between January and December of 1999 at K Hospital in Seoul. The data was analyzed using chi-square test, unpaired t-test and logistic regression. Diabetes Mellitus and impaired fasting glucose were diagnosed by ADA (American Diabetes Association, 1997) criteria. The results were as follows: 1. Mens' prevalence of Diabetes Mellitus was 7.9% and womens' prevalence of Diabetes Mellitus was 3.8%. Mens' prevalence of impaired fasting glucose was 10.4% and womens' prevalence of impaired fasting glucose was 6.5%. Prevalences of Diabetes Mellitus and impaired fasting glucose increased with age. 2. Prevalence of Diabetes Mellitus and impaired fasting glucose of obese subjects (relative body weight>=162) was higher than that of overweight subjects (110<=relative body weight<=119) in men and women. 3. The diagnoses of Diabetes Mellitus and impaired fasting glucose increased with systolic blood pressure and triglyceride. 4. Significant factors associated with diabetes in the logistic regression best gut model were age, relative body weight, systolic blood pressure, triglyceride in men, and systolic blood pressure in women. In conclusion, as age, weight, systolic blood pressure and triglyceride get higher, Diabetes Mellitus and impaired fasting glucose prevalence also increases, porportionally.