• JSTS:Journal of Semiconductor Technology and Science
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• 제1권4호
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• pp.197-201
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• 2001

The influence of argon, oxygen, and nitrogen admixtures on the dissociation of $Cl_2$ molecules in a glow discharge low-temperature plasma under the constant pressure conditions was investigated. For $Cl_2/Ar$ and $Cl_2/O_2$mixtures, the concentration of chlorine atoms was observed to be a practically constant at argon or oxygen concentrations up to 50%. This invariability is a most pro bably explained by relative increase in rate of $Cl_2$ direct electron impact dissociation due to the changes in electrophysical parameters of plasma such as EEDF, electron drift rate and mean energy. For all the considered mixtures, the contribution of stepwise dissociation involving active species from gas additives (metastable atoms and molecules, vibrationally excited molecules) was found to be negligible.

• 한국농공학회지
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• 제44권3호
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• pp.65-72
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• 2002

Rainfall and runoff data from a forested watershed and irrigated rice paddies at the Bal-an experimental watershed were monitored and analyzed to investigate the variations of runoff characteristics with different land use. The comparisons were conducted fourteen storm events ranging 21.8∼190.2 mm of rainfall. Field data showed that direct runoff from paddies and forested watershed are not significantly different in volume. The peak discharge from forest watershed was less than that from paddies far lighter storms, but became greater fur heavier storms. The peak runoff from the forest watershed was 39 percent greater than from the paddies. The results demonstrate that paddies play an important role to reduce peak discharge from heavy storms as compared to forest.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.210-213
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• 1999

A battery is the device that transforms the chemical energy into the direct-current electrical energy directly without a mechanical process. Unit cells are connected in series to obtain the necessary voltage, while being connected in parallel to organize capacity for load current and to decrease the internal resistance for corresponding the sudden shift of the load current. The circular-current, however, could be occurred when the system is driven in parallel. As a result, the new batteries are heated by over-change and discharge, and the over charge current makes to increase the rust of the positive grid and consequently the shortened life of the new batteris would be shown. In this paper, the internal resistance of charge and discharge will be balanced, through inserting the resistance into the system by way of calculation of the changed amount of internal resistance.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.209-215
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is designed and analyzed by simulation in this paper.

• 에너지공학
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• 제2권1호
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• pp.38-44
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• 1993

Electromagnetic seawater thrusters may be classified into four general categories : internal duct dc, external field dc, internal peristaltic ac, and external peristaltic ac. Internal duct dc thrusters offer the advantages of low magnetic field leakage, simple construction, and potentially high reliability. The most efficient internal duct configuration consists of converging inlet nozzle and a straight discharge duct. Ideal efficiency calculations based on the one-dimensional Bernoulli equation show that thrusters should be designed with large cross-sectional areas and operate at low discharge velocities. In practice, this may be accomplished by using multiple thruster ducts. Conductivity enhancement, high magnetic fields, and long electrodes will also improve efficiency.

• 한국CDE학회논문집
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• 제8권3호
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• pp.167-174
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• 2003

The outsole mold of the shoes has been manufactured using electro-discharge machining by graphite electrode or using casting etc. The study is concerned with the measurement of the mold of the shoes in use, the modeling by CAD/CAM system, the generation of NC data and the machining by CNC machining center. The machining has been performed from the data type obtained from 3-dimensional measurement points of mold in use. The ball end mill and the engraving cutter is used as cutter and the cutting conditions are adjusted according to the shapes and sizes of the cutter and part in cutting. The method has proposed the possibility for higher productivity and quality on mold-manufacturing of shoes outsole.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.245-250
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• 2004

The discharge current oscillation has been measured for various hollow anode widths and its axial positions using a 1㎾-class anode layer hall thruster. As a result, there were thresholds of magnetic flux density for stable discharge. The plasma structure inside the hollow anode was numerically analyzed using the fully kinetic 2D3V Particle-in-Cell (PIC) and Direct Simulation Monte Carlo (DSMC) methods. The results reproduced both stable and unstable operation modes. In the stable operation case, which corresponds to the case with low magnetic flux, the plasma penetrated into the hollow anode deeper than the case with higher magnetic flux density case. This suggests that comparably large substantial anode area should contribute to stable operation.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.783-786
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• 2008

The main goal of this study is to understand the effects of direct-runoff of chemistry and organic fertilizers which are adsorbing to sediment from farmland and non-point source discharge characteristics which are discharged to stream with soil erosion when rainfalls. pollutographs of TSS, BOD, COD, TN, and TP were measured for 10 rainfall events at watershed. EMC (Event Mean Concentration) were calculated for each rainfall event using quality and quantity measured. The result shows that the EMC ranges of 95% confidence intervals are 50.5-203 mg/L for TSS, 0.8-14.2 mg/L for $BOD_5$, 4.2-20.7 mg/L for $COD_{Mn}$, 0.2-0.5 mg/L for TP, 2.4-4.5 mg/L for TN, 1.36-3.04 mg/L for NO3--N, 0.13-0.42 mg/L for NH4+-N and 0.82-1.77 mg/L for TKN.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.602-605
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• 2008

The anode sheath structure in the hollow anode of an anode-layer type Hall thruster was numerically computed using a fully kinetic 2D3V Particle-in-Cell and Direct Simulation Monte Carlo(PIC-DSMC) code. By treating both ions and electrons as particles, anode surface region, which is electrically non-neutral, was analyzed. In order to analyze in detail, the calculation code was parallelized using Message Passing Interface (MPI). The code successfully simulated the discharge current oscillation. In the low magnetic induction case, ion sheath appears in the anode surface because ionization is enough to maintain the plasma occurs in the anode hollow. As the magnetic induction increases, main ionization region move to outside of the anode. At the same time, anode sheath voltage decreases. In the high magnetic induction case, electron sheath appears on the anode surface periodically because the ionization occurs mainly in the discharge channel. This anode sheath condition shift can be explained using the simple sheath model.

• 한국잠사곤충학회지
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• 제32권1호
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• pp.68-72
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• 1990

견직물의 품질이 좋다는 것은 소비자의 취향과 실용성을 만족시켜주어야 한다. 고급패션용 직물 또는 이브닝드레스와 다른 독특한 제품에는 디자인과 색상이 중요한 역할을 하고 타운드레스, 스포츠ㆍ레저용품에는 수용성과 취급이 간편한 실용성이 강조된다. 이러한 두 가지 요구를 위하여 염색견뢰도를 분석한 결과는 다음과 같다. 공시 견직물들은 고급패션 제품에는 다소 부족하였고 일부 견직물은 ISA공인품질 기준에 미치지 못하였다. 특히 색상이 밝은 염색견직물과 발염날염견섬물은 물, 땀, 아이론견뢰도가 불량하여 염료선택에 주의가 필요하며, 염색후가공 등을 하여 견뢰도 개선에 관한 연구를 하고, 견섬물가공 업체는 시장동향과 소비자의 취향 및 요구를 분석하면서 기술개발을 추진한다면 세계선진 업체와 경쟁할 수 있을 것이다.