• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.2
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• pp.1-8
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• 2009

Present studies of these experiments was conducted to using water, over a range of cross-flow velocities from 42 to 136 m/s, with injection frequencies from 35.7 to 166.2 Hz. In cross-flow field, main parameters of liquid jet for secondary breakup were cross-flow drag rather than pressure pulse frequency. As oscillation of the periodic pressure, liquid jet was moved up and down. Also, a bulk of liquid jet puff was detected at upper field of liquid surface. Because of pressure pulsation frequency, an inclination of SMD for the structured layer was evanescent. Cross-sectional characteristics of SMD at downstream area were non-structured distributions. The tendency of volume flux value for various frequency of pressure pulse was same distribution. And volume flux was decreased when the frequency of pressure pulse increasing.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2377-2386
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• 2021

To model the atmospheric dispersion of radionuclides released from nuclear accident is very important for nuclear emergency. But the uncertainty of model parameters, such as source term and meteorological data, may significantly affect the prediction accuracy. Data assimilation (DA) is usually used to improve the model prediction with the measurements. The paper proposed a parameter bias transformation method combined with Lagrangian puff model to perform DA. The method uses the transformation of coordinates to approximate the effect of parameters bias. The uncertainty of four model parameters is considered in the paper: release rate, wind speed, wind direction and plume height. And particle swarm optimization is used for searching the optimal parameters. Twin experiment and Kincaid experiment are used to evaluate the performance of the proposed method. The results show that the proposed method can effectively increase the reliability of model prediction and estimate the parameters. It has the advantage of clear concept and simple calculation. It will be useful for improving the result of atmospheric dispersion model at the early stage of nuclear emergency.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.563-576
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• 1998

To study the influences of the emission sources during lune 13∼15 1997 in Seoul, MESOPVFF II model has been used. The MESOPVFF II model includes terrain effects, chemical transformation and removal processes. Data of 20 surface meteorological stations and the upper air station on mid-west area in Korea were used as a DWM (Diagnostic Wind Model) input data. This model is likely to be applicable because the predicted SO2 concentration was well matched with measured 502 concentration in Seoul and Kyonggido. In generally air pollutants in Seoul have major influence on the other cities but the result of modeling appeared also air pollutants of the other cities influence on Seoul. Finally, in the case of calculating the air quality by diffusion model, the influences of air pollutants emitted in metropolitan area as well as the emission rate in modeling area should be considered.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.57-64
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• 2000

The sensitivity analysis of two short-term models (ISCST3, INPUFF2.5) is performed to improve the model accuracy. It appears that the sensitivities on the changes of wind speed, stack height and stack inner diameter in the near distance from source, stability and mixing height in the remote distance form source, are significant. Also the gas exit velocity, stack inner diameter, gas temperature and air temperature which affect the plume rise have some effects on the concentration values of each model within the downwind distance where final plume rise is determined. And in modeling for the atmospheric dispersion of point pollutant source INPUFF2.5 can calculate amount, trajectory of puff and concentration versus time at each receptors. So, it is compatible to analyze distribution of point pollutants concentration at modeling area.

• Journal of the Korean Society of Costume
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• v.12
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• pp.68-86
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• 1988

This paper is described about applied method of personal computer for clothes-patterns. The personal Computer (Fijitsu FM-$16{\beta}$) and X-Y Plotter (GRAPHTEC GP-9101 R) were used in this study. It is studied to draft of sleeve designs automartically in this paper. The Basic Language is used and the programs were main program and subroutine programs. The results are as follows; 1) The Y's system of sleeve sloper is selected in this study. 2) The co-ordinate points were indicated relative location of all necessary in drafting of sleeve designs. 3) In the variations of sleeve sloper, Puff sleeve and Raglan sleeve were selected. Programs for drafting of them were developed. 4) About the drafting of Raglan curve, it is gotten adequate curve using sprine function. 5) Clothes-Pattern are making very correctly and quickly by using computer.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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• pp.170-176
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• 1995

Effect of circumference, net weight, and moisture content on the physicochemical propesties of cigarette were investigated. At the same net weight of cigarette, the pressure drop(E.P.D) of cigarette was increased as the circumference was decreased. Loseend and firmness were improved by reduction of circumference. In this condition, tar, nicotine, and carbon monoxide deliveries were decreased, and the puff count was significantly increased. When the moisture content of the cigarette were decreased, firmness and loseend were increased. Also in this condition nicotine and carbon monoxide tend to be increased. Key words : cigarette design, circumference, net weight.

• Journal of the Korean Home Economics Association
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• v.20 no.1
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• pp.47-55
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• 1982

1. Pasts containing 10, 12.5, 15, 17.5 and 20g of butter respectively with identical contents of flor(16.25g) and egg(50g) were prepared. 2. For the five batter samples described above, following tests were conducted. a) Hardness and adhesiveness determination by texturometry b) Light microscopic observation d) Sensory Test 3. Significant differences of hardness, adhesiveness, and viscosity among the five samples were not recognized; but 1% significant difference in volumns were recognized. The best swelling was observed for the 17.5g butter sample; those of 15g and 12.5g butter samples were identical, while those of 10g and 20g showed the lowest swelling. Generally, stirring at 60~7$0^{\circ}C$ gave the best homogenity The degree of emulsification influenced the swelling. Not only large but also small amount of butter gave undestirable swelling. Sensory test for the 15g butter sample also gave best result.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.64-69
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• 1997

Deliveries of tar, nicotine, CO and $CO_2 in main stream smoke decreased as the potassium salt content of reconstituted tobacco leaves increased. The peak temperatures of the central region of a burning cone during a puff was in the range 940$^{\circ}C$∼430$^{\circ}C$ by IR thermal video system. The exogenous Potassium salt contents influenced the reduction of carbon-monoxide delivery through a decrease in the Peak temperature of the burning cone. Consequently, the amount of CO formed in the combustion Process was reduced by potassium salt. Moreover, the temperature of the burning cone was lowered, and the CO formed from carbonaceous reduction was decreased.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.107-114
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• 2009

In this study, we investigated the existence of melamine and cyanuric acid in cigarette smoke because leaf tobacco contains lots of nitrogen compounds and they are capable of pyrolytic synthesis while smoking. The extraction and derivatization conditions of two compounds were performed according to the procedure of U.S. Food and Drug Administration(FDA). Ky3R4F as reference cigarette was smoked on ISO condition(Puff volumne : 35 ml, duration : 60 sec, Interval : 2 sec). Compared with the results Ky3R4F and standard solution, retention time of two compounds was not corresponded. As a result, we concluded that melamine and cyanuric acid were not existed in cigarette smoke.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2876-2882
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• 2015

The object of this study is to identify changes in air pollution in the maximum ground level concentration and the surrounding area when air pollution control facilities are improved in the thermal power plants. The effects of improved facilities are analyzed by comparing air quality after applying improved air pollution control facilities. For prediction of air quality, the change of wind field can be represented with movement of Puff and CALPUFF Model, air pollution diffusion models which can implement abnormal conditions. Major air pollutants of thermal power plants such as $SO_2$, $NO_2$, and $PM_{10}$ are selected as prediction items. That results show that improvement of air pollution control facilities is significantly effective in reduction of air pollution of $SO_2$ and $NO_2$ in the maximum ground level concentration and areas around of thermal power plants. In the case of $PM_{10}$, it is found that the effect of reduction in pollution is high in the maximum ground level concentration, but the effect of reduction in air pollution is somewhat low in the area around of the thermal power plant.