• 대한임상검사과학회지
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• 제45권4호
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• pp.139-143
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• 2013

In 2008, according to Statistics Korea's population over the age of 20 and 26.3% of the smokers, 73.7% were non-smokers, smokers and non-smokers by smoking of 22.0% was reported. 336 people of 255 people (75.9%) is currently also showed that smoking. Hypertension, 48 people(14.30%), the boundary type of high blood pressure 193 people (57.40%) of them, especially for high blood pressure appear as a systematic management is required. 336 people targeting taxi drivers smoking and blood pressure, and the relevance of the reserch results did not show a statistically significant difference. Current smokers of 336 people surveyed 255 people (75.90%), respectively. Men over 15 years old in Korea smoking population (1990) was reported as 73.2%, Lee 2001, according etc. Korea 61.8% of the adult male smoking rate is quite high as compared to what is reported. Taxi drivers are working in very bad working conditions. The health of a taxi driver affect the safety of customers were considered.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.234-243
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• 2002

When a vehicle is operated over sort terrain, torque(or soil thrust) applied to driving wheel brings about shear displacement far soil due to compression and shear failure of soil under tire. This shear displacement give rise to slip and a additional sinkage due to slip. This additional sinkage is usually referred to as slip-sinkage. The slip-sinkage is affected by soil conditions and inflation pressure of tire. This slip-sinkage influence tractive performance on driving wheel . We conducted the experimental study far investigating the effect of slip on sinkage and tractive performance of driving wheel, such as motion resistance, thrust and drawbar pull. The experiment was carried out over three different soil conditions(soft, hard and very hard soil) far a tire with three levels of inflation pressure(120kPa, 240kPa and 360kPa). The results of this study show qualitatively slipsinkage characteristics and slip-tractive performance relationships of driving wheel with soil conditions and inflation pressure of tire.

• 한국지구과학회지
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• 제31권5호
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• pp.531-538
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• 2010

This study presents the development of an elevated subsidence inversion over a surface low pressure system, which was formed along the Changma front or Meiu-Baiu front. The results of our analysis strongly suggest that the inversion is dissimilar to those formed in anticyclonic situations but is instead similar to the onion-shaped sounding found in wake low. The present analysis indicates that the observed elevated inversion resulted from the intrusion of stratospheric air associated with tropopause folding.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.52-58
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• 1998

The spray characteristics of air-assisted fuel injection and its effects on the engine combustion was investigated in this study. The atomization characteristics of a Bosch fuel injector inserted into the air-assist adapter were measured using particle motion analysis system. Droplet size decreased with air supplied and fine spray with below $60\mu\textrm{m}$ of SMD was acquired under the conditions of air-assist pressure over 0.5bar. The lean combustion performance of a 1.8L DOHC engine equipped with air-assist adapters was tested on the dynamometer. When the assistant air pressure is 1.0bar, lean limit recorded the highest value, and CO, HC emissions were decreased at the pressure over 1.0bar.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권2호
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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.

• 대한기계학회논문집B
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• 제27권4호
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• pp.458-465
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• 2003

The main objective of the research is to develop a research code solving transient incompressible Navier-Stokes equation. In this research code, Adams-Bashforth method was applied to the convective terms of the navier stokes equation and the splitted equations were discretized spatially by finite element methods to solve the complex geometry problems easily. To reduce the divergence on the boundaries of pressure poisson equation due to the unsuitable pressure boundary conditions, multi step approximation pressure boundary conditions derived from the boundary linear momentum equations were used. Simulations of Lid Driven Flow and Flow over Cylinder were conducted to prove the accuracy by means of the comparison with results of the previous workers.

• 한국대기환경학회지
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• 제11권2호
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• pp.171-178
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• 1995

The hydrodesulfurization (HDS) of dibenzothiophene (DBT) were performed simultaneously over CoPtMo/LaY catalyst under high H$_{2}$ pressure. The structure and physical properties of this catalyst were characterized using XRD, IR and surface area analyzer. The origin of acid site was mainly Bronsted. The structures of impregnated molybdenum and platinum were deactivated by DBT to MoS$_{2}$ and PtS, respectively. The activities of the HDS and the hydrocracking increased with increasing temperature and pressure. They decreased with increasing the DBT mole ratio(DBT/n-heptane). They remained constant with increasing the H$_{2}$/H.C. mole ratio. With increasing pressure and DBT mole ratio, the products of secondary cracking increased. To perform simultaneous HDS and hydrocracking effectively, the optimum condition were 500.deg.C, 4MPa.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.217-223
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• 1995

In this paper, we investigated physical properties and electrical characteristics of the fluorocarbon that used as coolants for large power gas-insulated transformer. Volume resistivity of the fluorocarbon was .rho.=1.87*10$^{15}$ [.ohm.cm] at 1 atm, 27.deg. C. Dielectric constant was 1.86 and decreases as temperature increase. The breakdown voltage at 1 atm was higher than that of transformer oil. The breakdown voltage of fluorocarbon vapor was about 18kV when pressure in a test chamber increases over lkg/cm$^{2}$. When fluorocarbon was mixed with SF$_{6}$ gas, breakdown voltage of the mixed was higher than that of fluorocarbon. Then fluorocarbon leads to increase over 4kg/cm$^{2}$ in pressure as temperature increase. Therefore, when a gas-insulated transformer is manufactured, the design must be taken into consideration a high-pressure.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1477-1484
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• 2007

Artificial neural networks (ANNs), for a first time, were successfully developed for the prediction partial molar heat capacity of aqueous solutions at infinite dilution for various polar aromatic compounds over wide range of temperatures (303.55-623.20 K) and pressures (0.1-30.2 MPa). Two three-layered feed forward ANNs with back-propagation of error were generated using three (the heat capacity in T = 303.55 K and P = 0.1 MPa, temperature and pressure) and six parameters (four theoretical descriptors, temperature and pressure) as inputs and its output is partial molar heat capacity at infinite dilution. It was found that properly selected and trained neural networks could fairly represent dependence of the heat capacity on the molecular descriptors, temperature and pressure. Mean percentage deviations (MPD) for prediction set by the models are 4.755 and 4.642, respectively.

• 한국태양에너지학회 논문집
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• 제34권1호
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• pp.28-38
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• 2014

The effects of geometric parameters (stack position, stack length, resonator tube length) and varying input power over acoustic energy output were investigated. The acoustic laser kit (Garret 2000) was used for the construction of TA lasers. A series of sound pressure level measurements in different orientations did not differ significantly confirming that the sound wave generated could be assumed as a spherical wave. An increase in acoustic pressure was recorded with respective increase in input power, stack and resonator tube lengths owing to their relative influence over heat transfer rate and critical temperature gradient across the stack.