• Title/Summary/Keyword: Source factor

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Studies on the Production of Microbial Culture Medium by Using By-Product of Salt-Fermented Kanary (까나리 액젓 부산물의 미생물 배지화를 위한 연구)

  • Won, Hye-Jin;Hahm, Young-Tae;Kim, Hye-Kyung;Kim, Byung-Yong
    • Applied Biological Chemistry
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    • v.43 no.3
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    • pp.202-206
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    • 2000
  • Feasibility of microbial culture media using by-product of salt fermented kanary was investigated. Gram negative strain, Escherichia coli, and Gram positive strain, Bacillus subtilis, and bioluminescent Photobacterium Phosphoreum were incubated with kanary by-Product media (KB media). Compared with LB media, KB media had enough carbon source, but lacked nitrogen source and growth factor. When 0.5% of peptone as a nitrogen source and 0.3% of yeast extract as nitrogen and growth factor source were fortified in KB media, the cell population rate was similar to LB media. Also, when 0.5% of yeast extract was fortified to KB media, it showed the same result as in LB media. The price of KB media with fortification of 0.5% peptone and 0.3% yeast extract, and 0.5% of yeast extract is only 46 and 19% of that of LB media, respectively. These results showed that kanary by-Product could be a good and cheaper bacterial culture media if small amount of nitrogen source and growth factor were added.

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Analysis of the Factors affecting Reverberation Time in Small Room (소규모 공간에서의 잔향시간 영향요인 분석)

  • Kim, Myung-Jun;Lee, Byoung-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.492-497
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    • 2006
  • This study gives the results of the measurements and analysises of the reverberation times in a small room such as apartment houses. We measured the RT by changing measurement conditions, which were sound sources. sound source's positions, receiving point & height, sampling time and so on. The critical factor affecting reverberation time was sound source in unoccupied houses and the reverberation time differences between result of RT using impulsive and interrupted sound source was 0.3sec at 500Hz frequency. And the difference of RT due to sound sources affected the sound insulation such as apparent sound reduction index and sound level difference about 1dB at each frequency in unoccupied houses.

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The Effects of Financial Development on Foreign Direct Investment (금융 발전이 외국인직접투자에 미치는 영향에 대한 분석)

  • Jung-Whan Cho;Tae-Hwang Kim
    • Korea Trade Review
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    • v.45 no.4
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    • pp.195-205
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    • 2020
  • This study investigates the effects of financial development on the foreign direct investment (FDI) flow in host countries. Using bilateral FDI data from 34 OECD source countries to 146 host countries, we performed panel data analysis based on a gravity FDI equation. We hypothesized that the financial development would increase the volume of FDI flows. The results suggest that the well-functioning finance market of source countries as well as a better accessable financial market of host countries contribute to the increase in FDI of OECD in their partner countries. We found also that the financial development effects of source countries are larger than those of host countries. This result shows that the financial development can play a crucial role to impact the FDI inflows as push factor in source country than as a pull factor in host countries.

A Feasibility study on the Simplified Two Source Model for Relative Electron Output Factor of Irregular Block Shape (단순화 이선원 모델을 이용한 전자선 선량율 계산 알고리듬에 관한 예비적 연구)

  • 고영은;이병용;조병철;안승도;김종훈;이상욱;최은경
    • Progress in Medical Physics
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    • v.13 no.1
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    • pp.21-26
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    • 2002
  • A practical calculation algorithm which calculates the relative output factor(ROF) for irregular shaped electron field has been developed and evaluated the accuracy of the algorithm. The algorithm adapted two-source model, which assumes that the electron dose can be express as sum of the primary source component and the scattered component from the shielding block. Original two-source model has been modified in order to make the algorithm simpler and to reduce the number of parameters needed in the calculation, while the calculation error remains within clinical tolerance range. The primary source is assumed to have Gaussian distribution, while the scattered component follows the inverse square law. Depth and angular dependency of the primary and the scattered are ignored ROF can be calculated with three parameters such as, the effective source distance, the variance of primary source, and the scattering power of the block. The coefficients are obtained from the square shaped-block measurements and the algorithm is confirmed from the rectangular or irregular shaped-fields used in the clinic. The results showed less than 1.0 % difference between the calculation and measurements for most cases. None of cases which have bigger than 2.1 % have been found. By improving the algorithm for the aperture region which shows the largest error, the algorithm could be practically used in the clinic, since one can acquire the 1011 parameter's with minimum measurements(5∼6 measurements per cones) and generates accurate results within the clinically acceptable range.

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Residence s Exposure to Nitrogen Dioxide and Indoor Air Characteristics (거주지역 실내공기 특성 및 이산화질소 노출에 관한 연구)

  • 양원호;배현주;정문호
    • Journal of Environmental Health Sciences
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    • v.28 no.2
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    • pp.183-192
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    • 2002
  • Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level and so on. Although technologies exist to measure these factors directly, direct measurements of all factors are impractical in most field studies. The purpose of this study was to develop an alternative methods to estimate these factors by multiple measurements. Daily indoor and outdoor NO$_2$concentrations for 21 days in 20 houses in summer and winter, Seoul. Using a mass balance model and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor(emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the ventilation and source strength were estimated. During sampling period, geometric mean of natural ventilation was estimated to be 1.10$\pm$1.53 ACH, assuming a residential NO$_2$decay rate of 0.8 hr$^{-1}$ in summer. In winter, natural ventilation was 0.75$\pm$1.31 ACH. And mean source strengths in summer and winter were 14.8ppb/hr and 22.4ppb/hr, respectively. Although the method showed similar finding previous studies, the study did not measure ACH or the source strength of the house directly. As validation of natural ventilations, infiltrations were measured with $CO_2$tracer gas in 18 houses. Relationship between ventilation and infiltration was statistically correlated (Pearson r=0.63, p=0.02).

On-line Techniques of SHE-PWN for Current Source GTO Converter (전류형 GTO 컨버터의 SHE-PWM 실시간제어기법)

  • 최재호;팽성일;채경훈
    • The Transactions of the Korean Institute of Power Electronics
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    • v.4 no.6
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    • pp.523-530
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    • 1999
  • This paper presents the on -line techniques of SHE-PvVI\I for GTO current source converter. The look-up t table is linearized with this proposed method so that the tum-on/off periods of the GTO switches can be c computed in real-time for any modulation index. This allows the rapid and continuous regulation of the DC O output current while producing the sinusoidal AC input current waveform and unity power factor. The l linearized S}lE-PW~I technique and the high power factor control scheme are Prolxlsed and their‘ performance i is tested analytically. The validity of this proposed technique is well verified through the simulation and e experimental results.

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Studies on the Chemical Compositions and Distributions of Ambient Sumicron Aerosols (Submicron 부유분진의 화학적 조성 및 분포에 관한 연구)

  • 황인조;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.1
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    • pp.11-23
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    • 1998
  • The purpose of this study was to survey chemical distribution of inorganic elements and ions in the submicron particles, to characterize qualitatively emitting sources by factor analysis, and finally to reveal existing patterns in terms of chemical compounds by a stepwise multiple regression analysis. Total of 141 samples were collected by a cascade impactor from 1989 to1996. Fifteen chemical species (Al, Ba, Cd, K, Pb, Cu, Fe, Ni, $Cl^-, NO_3^-, SO_4^{2-}, K^+, Mg^{2+}, Ca^{2+}, and Na^+$) were characterized by AAS and IC. The study showed that average seasonal levels of submicron particulate matters $(d_p<0.43 \mum)$ were 18.7 $\mug/m^3$ in spring, 15.5 $\mug/m^3$ in summer, 15.7 $\mug/m^3$ in fall, and 24.5 $\mug/m^3$ in winter, respectively. All of the anion concentrations in the particle were highest in the winter season. By applying a factor analysis, 5 source patterns were qualitatively obtained, such as sulfate related source, nitrate related source, oil burning source, calcium related source, and coal combustion source. Finally, when applying a stepwise multiple regression analysis, the results clearly showed that $Na^+ and Ca^{2+}, K^+ and Ca^{2+}, NO_3^-$ and relative humidity, $Cl^-$ and ambient temperature, $Ca^{2+} and Cl^-, Mg^{2+} and SO_4^{2-}, Na^+ and NO_3^-, and Ca^{2+} and NO_3^-$, respectively, are negatively contributed to each other. As a result of those statistical analysis, we could suggest that some chemical compounds in the submicron particles such as$NaNO_3, MgSO_4, Ca(NO_3)_2, and CaCl_2$ may not exist on the filter as final composing products; however, other compounds may possibly exist in the form of $Mg(NO_3)_2, CaSO_4, Na_2SO_4, K_2SO_4, MgCl_2, NaCl, and KCl$. Thus, it must be necessary to identify differences between the results of above statistical analysis and of the real world by laboratory experiments.

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Analysis of Effective Soil Thermal Conductivities and Borehole Thermal Resistances with a Line Source Method (선형열원법에 의한 지중유효열전도도와 보어홀 전열저항 해석)

  • Lee, Se-Kyoun;Woo, Joung-Son;Ro, Jeong-Geun
    • Journal of the Korean Solar Energy Society
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    • v.30 no.4
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    • pp.71-78
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    • 2010
  • Investigation of the effective soil thermal conductivity(k) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. The line source method is required by New and Renewable Energy Center of Korea Energy Management Corporation in analyzing data obtained from thermal response tests. Another important factor in designing the ground loop heat exchanger is the borehole thermal resistance($R_b$). There are two methods to evaluate $R_b$ : one is to use a line source method, and the other is to use a shape factor of the borehole. In this study, we demonstrated that the line source method produces better results than the shape factor method in evaluating $R_b$. This is because the borehole thermal resistance evaluated with the line source method characteristically reduces the temperature differences between an actual and a theoretical thermal behaviors of the borehole. Evaluation of $R_b$ requires soil volumetric heat capacity. However, the effect of the soil volumetric heat capacity on the borehole thermal resistance is very small. Therefore, it is possible to use a generally accepted average value of soil volumetric heat capacity($=2MJ/m^3{\cdot}K$) in the analysis. In this work, it is also shown that an acceptable range of the initial ignoring time should be in the range of 8~16hrs. Thus, a mean value of 12 hrs is recommended.

Utility Interactive Photovoltaic Generation System using PWM Current Source Inverter (PWM 전류형인버터를 이용한 계통연계형 태양광 발전시스템)

  • 박춘우;성낙규;이승환;강승욱;이훈구;한경희
    • Proceedings of the KIPE Conference
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    • 1996.06a
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    • pp.109-112
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    • 1996
  • In this paper, we composed utility interactive photovoltaic generation system of current source inverter, and controlled that low harmonic and high power factor are hold by supposing control and compensation method which is concerned with synchronous signal distortion and modulation delay. And we put parallel resonant circuit into dc link, so, magnitude of direct reactance was reduce by restraining direct current pulsation which had accumulation of pulsating power in alternating electrolytic condenser. Also we controlled that modulation factor is operated around maximum output of solar cell.

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The Control of Single Phase High Power Factor PWM converter using Sliding mode Observer without a source voltage sensor (슬라이딩 모드 관측기를 이용한 전원전압 센서 없는 단상 PWM 컨버터의 고역률 제어)

  • 양이우;최정수;김영석
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.1
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    • pp.46-53
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    • 2000
  • 본 논문에서는 전원전압 센서 없는 단상 PWM 컨버터의 전류제어방법을 제안한다. 제안된 방법에서 전원전압은 슬라이딩 모드 관측기에 의해 추정되며 추정된 전원전압을 이용하여 컨버터의 입력 역률을 '1'로 하고 일정한 DC링크전압을 얻을 수 있다. 제안된 방법의 특징은 전원전압의 크기와 위상의 추정이 실제전류와 추정전류의 전류오차에 의해서 얻어질 수 있다. 제안된 방법은 DSP를 이용하여 구현하고, 실험결과는 제안된 방법의 정당성을 입증한다.