• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.101-102
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the de bias voltage of -10V showed lower discharge voltage, lower erosion rate by ion bombardment, higher optic transparency and higher crack resistance in annealing process than those samples prepared by conventional magnetron sputtering or E-beam evaporation.

• Electrical & Electronic Materials
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• 제10권8호
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• pp.807-811
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• 1997

In this paper we have investigated the removal characteristics of NOx by pulsed corona discharge with a multi-pointplane electrode where a magnetic field is applied in the discharge region. The efficiency of NOx removal was measured and analyzed as a function of pulse frequency gas flow rate NOx initial concentration magnetic flux density. In this result the highest removal efficiency of NOx was obtained at the following operating conditions; the frequency =400[Hz] gas flow =1[$\ell$/min] initial concentration= 400[ppm] and magnetic flux density=0.36[T].

• Proceedings of the KIEE Conference
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1619-1621
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• 1994

Both Facing Target Sputtering(FTS) and Cylindrical Post-Magnetron Sputtering(CPMS) systems have been degigned in order to form high density plasma and to obtain high deposition rate. However, these two systems have some different applications, and discharge characteristics of these two systems are not well known. In this paper, the discharge characteristics and plasma parameters of both FTS and CPMS systems are studied experimentally. It is found that these two system show some different discharge characteristics under magnetic fields. The plasma density and electron temperature of these two systems are in the range of $10^{10}{\sim}10^{11}[cm^{-3}]$ and $3.5{\sim}5.5[eV]$, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제15권5호
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• pp.397-405
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• 2003

Heat and fluid flow in a compressor into which liquid refrigerant is injected for the purpose of reducing discharge gas temperature in a heat pump system has been numerically studied. A mechanistic approach encompassing liquid jet breakup and droplet evaporation has been performed to investigate the effects of liquid injection on the spacial and temporal variation of the gas temperature and pressure inside the compressor cylinder. Various parameters, such as liquid injection mass, time, duration and droplet size, are considered in the present study to elucidate the flow field inside the compressor. As the injection mass is increased, discharge gas temperature is decreased, while the pressure is increased due to the added mass of the injection. For the injected liquid mass corresponding to 15% of the total vapor mass in the cylinder, the discharge gas temperature drops by 22.4 K. It is observed that the droplet size plays a major role in the evaporation rate of the droplets that determines the degree of the discharge temperature drop.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_3호
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• pp.97-106
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• 2001

To improve the water quality, particularly for sea bathers, the behaviour of wastewater from sewage outfalls in water adjacent to Swansea, UK, was studied using a mathematical model. The water quality in the sewage receiving basin was determined using factors like the outfall diffuser location(distance from land boundary), sewage treatment scheme, discharge time, and bacteria decay rate, etc. With respect to these factors, an optimal strategy for sewage discharge was then investigated to minimize bacteria levels along the bathing beaches. As water quality criteria, predicted faecal coliform levels were monitored along the coast adjacent to the outfall locations. The resultant values were compared with EC Mandatory(<2000, 95 % of 20 samples) and Guideline Standards(< 100, 80 % of 20 samples). For the advective-diffusion equation, the non linear advective terms were represented using the ULTIMATE algorithm and the third-order accurate QUICKEST scheme to avoid numerical diffusion. Details of the simulation results are then presented as an optimal policy for sewage discharge in the region.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.314-317
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• 2004

On 9/5/2003, the planet probe “HAYABUSA” as MUSES-C project was launched by The Institute of Space and Astronautical Science. “HAYABUSA” has microwave discharge ion engines and these engines are characterized by their high efficiency and specific impulse in comparison with chemical engine. A large ion engine can be used as a planet explorer, while a small ion engine can be used as attitude control of small satellite. We have been developing a high thrust density microwave discharge ion engine using “Multi-Monopole Antenna”. The performance of this engine are: ion cost of 344W/A, propellant utilization efficiency of 52% and thrust density of 0.055mN/$\textrm{cm}^2$ for Kr gas flow rate of 2.5sccm, microwave(2.45㎓) power of 32W and acceleration voltage of l.4㎸.

• The Transactions of the Korean Institute of Electrical Engineers C
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• 제49권9호
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• pp.527-532
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with dc bias voltage of -10V showed lower discharge voltage and lower erosion rate byion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardement during deposition process.

• Journal of the Korean Society of Safety
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• 제8권2호
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• pp.10-15
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• 1993

In this paper, it is studied the electrostatic discharge In Insulating oil for the purpose of the technical control of the streaming electrification resulted from the interface between an insulating liquid and a solid. The streaming current increases exponentially with flow rate and In region of lower than 50［$^{\circ}C$］but decreases at higher than the same temperature. The phenomena of electrostatic discharge appear at an interface between measuring tank and insulating oil when the seven sheets of gauzes are inserted in electrification apparatus. And those of partial or surface discharge are shown when eight sheets are inserted.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.558-562
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• 2003

In this paper, neural networks is studied to apply as a PD source classification in XLPE power cable specimen. For treeing discharge sources in the specimen, three defected models are made. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different models of discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for three PD sources.

• Korean Journal of Radiology
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• 제21권6호
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• pp.736-745
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• 2020

Objective: To identify the initial chest computed tomography (CT) findings and clinical characteristics associated with the course of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: Baseline CT scans and clinical and laboratory data of 72 patients admitted with COVID-19 pneumonia (39 men, 46.2 ± 15.9 years) were retrospectively analyzed. Baseline CT findings including lobar distribution, presence of ground glass opacities, consolidation, linear opacities, and lung severity score were evaluated. The outcome event was recovery with hospital discharge. The time from symptom onset to discharge or the end of follow-up (for those remained hospitalized) was recorded. Data were censored in events such as death or discharge without recovery. Multivariable Cox proportional hazard regression was used to explore the association between initial CT, clinical or laboratory findings, and discharge with recovery, whereby hazard ratio (HR) values < 1 indicated a lower rate of discharge at four weeks and longer time until discharge. Results: Thirty-two patients recovered and were discharged during the study period with a median length of admission of 16 days (range, 9 to 25 days), while the rest remained hospitalized at the end of this study (median, 17.5 days; range, 4 to 27 days). None died during the study period. After controlling for age, onset time, lesion characteristics, number of lung lobes affected, and bilateral involvement, the lung severity score on baseline CT (> 4 vs. ≤ 4 [reference]: adjusted HR = 0.41 [95% confidence interval, CI = 0.18-0.92], p = 0.031) and initial lymphocyte count (reduced vs. normal or elevated [reference]: adjusted HR = 0.14 [95% CI = 0.03-0.60], p = 0.008) were two significant independent factors that influenced recovery and discharge. Conclusion: Lung severity score > 4 and reduced lymphocyte count at initial evaluation were independently associated with a significantly lower rate of recovery and discharge and extended hospitalization in patients admitted for COVID-19 pneumonia.