• 한국입자에어로졸학회지
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• 제19권3호
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• pp.89-100
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• 2023

In our previous study, a wire-plate type electrostatic precipitator (ESP) was developed to collect bioaerosols of 100 nm size. In the study, various flow rates (40 ~ 100 L/min) and applied voltages (3 ~ 10 kV) were tested for experiment. In this study, numerical analysis was performed for the ESP of the previous study with the same flow rates and applied voltages, but with varying the size of bioaerosols to 0.04 ~ 2.5 ㎛. Overall, the numerical analysis results well predicted the experimental data. Bioaerosols of 0.1 ~ 0.5 ㎛ showed the minimum collection efficiency for all conditions because of low charge number. The effect of the ionic wind generated by the corona discharge was calculated. However, the ionic wind did not affect much the collection efficiency. The aerosol collection in the ESP of this study was due to the electrostatic force generated by particle charge in the electric field. This numerical study on the ESP can be used for the design and optimization of higher flow rate (> 100 L/min) ESP.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.451-458
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• 1997

Signal shapes from a closed-ended coaxial HPGe detector are investigated by numerical methods. The detector used in this study has a volume of 72 ㎤ with relative efficiency of 15%. The electric field and potential distributions in the detector are determined by solving the Poisson equation at the depletion and operating bias. Hence the time dependent signal shapes induced on the electrode are obtained from the energy balance consideration and tv solving the equation of motion for the charge carriers. For various initial positions of a charge carrier pair, the collection times of induced charge vary in the range of 70 - 404 nsec.

• 한국사회복지학
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• 제63권2호
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• pp.5-29
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• 2011

본 연구는 선진복지국가 중 독일, 스웨덴, 영국의 사회보험제도의 통합사례를 분석하였다. 제도통합과 조직통합이라는 두 가지 차원으로 나누어 세 나라의 사회보험 통합을 역사적 맥락에서 분석하였다. 독일은 여전히 제도와 조직이 분리되어 있고, 사회보험의 적용 징수업무를 질병보험조합이 담당하고 있다. 영국은 제도와 조직 모두 통합되어 있고, 적용 징수업무를 국세청이 담당하고 있다. 스웨덴은 사회보험체계가 각각의 제도별로 구분되어 있지만 운영기관은 통일되어 있고, 적용 징수업무를 국세청이 담당하고 있다. 본 연구는 이러한 선진국 사회보험 통합의 역사적 발전경로에 대한 고려를 바탕으로 한국 사회보험제도가 이제까지 걸어온 과정에 비추어 2011년부터 시행되고 있는 사회보험료 징수업무 건강보험공단 이관이 적절한 선택이었는지를 평가하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1684-1689
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• 2003

Dielectric Barrier Discharges (DBD) in oxygen and air are well established for the production of large quantities of ozone and are more recently being applied to a wider range of after treatment processes for HAPs(Hazardous Air Pollutants). The potential use as a charger for particle collection are not well known. In this work, we measured charge distribution of nanometer or submicron sized particles passing through the dielectric barrier discharge reactor. The bipolar charge characteristics of particles passing DBD reactor were investigated. Fluorometric method using uranine particles and a fluorometer was employed to examine the bipolar charging characteristics of the charged particles by DBD reactor. Finally, the charge distributions of particles were determined from the electrical mobility classification using DMA.

• 한국도서관정보학회지
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• 제48권4호
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• pp.303-320
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• 2017

이 연구는 공공도서관을 건립하고 개관하는 과정에서 새롭게 구축되는 개관장서 구성의 방법론에 대하여 논하고 있다. 최근 지역자치단체 등이 공공도서관을 지속적으로 설립하고 있는 것은 매우 고무적이다. 반면, 도서관의 가장 중요한 요소인 장서구성에 대한 방법론이 정립되어 있지 않아 일선에서는 혼선의 여지가 있다, 이에 따라 이 연구에서는 최근 개관한 10개 공공도서관의 개관장서 구축 사례를 검토하여 장서개발정책 수립, 장서구성기본계획 수립, 개관장서 규모 도출, 그리고 향토자료 구축 방안 등의 측면에서 표준적인 공공도서관 개관장서 구축방안을 모색하고자 하였다.

• 한국입자에어로졸학회지
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• 제5권2호
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• pp.71-81
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• 2009

In this study, Nylon 6,6 electrospun (ES) nanofiber filter media were prepared at various spinning conditions. The ES filters tested had no intrinsic electrical charges. The ES filters were triboelectrically charged in the course of filter sample handling, and the charge was drastically decayed in a few hours. On the other hand, the corona charged melt blown filter media showed a permanent electrical charge. The electrical charge state of the ES filters was also examined by comparing collection efficiencies of ES filters for uncharged and charged aerosol particles.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.85-90
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• 2001

This work presents experimental results of filter media test by using particles from $0.02\;to\;0.6{\mu}m$ in diameter and by applying different charging states. In order to investigate the electret filter performance, the collection efficiency and the pressure drop of filter were measured. The face velocities of test filters varied from 2.4 to 20.4 cm/s. Another experiment setup for the cartridge cabin air filter was used to get an collection efficiency in submicron region. After charging level of electret filter severely decreased, the change of collection efficiency was verified. Experimental results show that the reliability of electret filters can be poor in some conditions.

• 한국정밀공학회지
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• 제14권1호
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• pp.84-89
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• 1997

Recentely, a compact and small size air-cleaning Electrostatic Precipitator(ESP) is needed to develop for air conditioning devices. From Deutsch formula for ESP efficiency, collection efficiency is affected not only the structure of collection section but also the charge rate of dust. In terms of collection area, the most useful type is a scroll type ESP. In this work, we investigated experimentally aptimum design factor of scroll type ESP by application of Taguchi method. And we developed the scroll type ESP by using optimal condition of control factor.

• 한국대기환경학회지
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• 제9권2호
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• pp.125-131
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• 1993

Electrostatic Precipitator has been widely used to get high efficiency which is required for collection of fine particles. In order to provide collection efficiency and size distribution data for a pilot electrostatic precipitator, a pilot study has been conducted on fly ash from pulverized coal burning apparatus. The aims of this study are to investigate characteristics of electric charge, to measure collection efficiency varied with the applied voltage, to get an optimum current and current density. Optimum current density was obtained to 0.7mA/$cm^2$ at the average electric field strength 2.33kV/cm in this experiment. Maximum particle collection efficiency was indicated 99.21% at the applied voltage 7kV. Finally, particle size distribution is also compared with photographic results. Both coarse and fine particles at the range of 0.5$\sim$2$\mu$m and 3$\sim$10 SEM $\mu$m were clearly removed by increasing applied voltage.

• 환경위생공학
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• 제13권3호
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• pp.93-101
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• 1998

This study was carried out to investigate and analyze the citizen's attitude for the issue of the municipal solid wastes in Miryang city. The waste generation rate was decreased by 56% compared with 1991, and 71.8% of generated wastes were treated by landfill method. 61.6% among respondents were contacted waste problem by TV and the majority of respondents felt seriousness of food-waste problem. The majority of people felt that waste discharge decreased after "volume-base charge system" and 71% of total respondents were burdened down with use of volume-base charge envelope. The greater part of citizens answered that they experienced damage due to wastes and satisfied with the collection system but they recognized the necessity of the establishment of collection system and increase of cleaners must be nessary.