• 한국재료학회지
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• 제24권7호
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• pp.344-350
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• 2014

Metal films (i.e., Ti, Al and SUH310S) were prepared in a magnetron sputtering apparatus, and their cross-sectional structures were investigated using scanning electron microscopy. The apparatus used consisted of a cylindrical metal target which was electrically grounded, and two anode rings attached to the top and to the bottom of the target. A wire was placed along the center-line of the cylindrical target to provide a substrate. When the electrical potential of the substrate was varied, the metal-film formation rate depended on both the discharge voltage and the electrical potential of the substrate. As we made the magnetic field stronger, the plasma which appeared near the target collected on the plasma wall surface and thereby decreased the bias current. The bias current on the conducting wire was different from that for cation collection. The bias current decreased because the collection of cations decreased when we increased the magnetic-coil current. When the substrate was electrically isolated, the films deposited showed a slightly coarse columnar structure with thin voids between adjacent columns. In contrast, in the case of the grounded substrate, the deposited film did not show any clear columns but instead, showed a densely-packed granular structure. No peeling region was observed between the film and substrate, indicating good adhesion.

• 식물분류학회지
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• 제34권1호
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• pp.37-41
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• 2004

T. Nakai는 1911년 Flora Koreana vol. II에 러시아 식물분류학자인 V. L. Komarov의 1897년 북한 채집 표본을 120여점 인용하였다. Nakai가 언급한 북한의 지명은 약 65개로서 Komarov의 채집지명의 상당 부분에 해당된다. Nakai가 언급한 지명은 러시아발음에 근간을 두고 로마자로 표기하였는데 최근 혹은 과거 지도에서 정확한 채집지명을 확인하기가 매우 어렵다. 본 연구는 Flora Koreana II에 기재된 채집지명을 과거 발표된 러시아와 일본 번역서인 만주식물지와 표본레이블 등의 자료를 근간으로 Nakai가 언급한 원명과, 한자 지명, 현재 지명의 로마자표기, 위도와 경도, 출처의 페이지 등을 도표로 제시하여 정리하였다.

• 품질경영학회지
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• 제39권3호
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• pp.422-431
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• 2011

The number of mobile telecommunication service subscribers has been over 50 millions as of the end of Nov. 2010. And the number of used mobile phones has been growing continuously caused by shortened life cycle of products and competing between service providers, which is about 21 millions for only one year, 2010 in Korea. However, the quality level of reverse logistics network for used mobile phones is very low and statistics show that the collection ratio of them has not been over 40%. The current low collection ratio can be one of the significant causes of environment destruction due to the cumulated growth. Accordingly new practical alternative recovery systems are required in addition to the current one with EPR(Extended Producers Responsibility). In this paper, suggested are alternative policies to improve the quality level of reverse logistics network for used mobile phones effectively. ENR(Extended Network service providers Responsibility) is representative of them.

• 정보관리학회지
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• 제30권2호
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• pp.83-99
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• 2013

본 연구는 경기지역의 상호대차데이터를 분석하여 상호대차 장서의 지역 간 네트워크를 분석하여 보고자 하였다. 경기지역 공공도서관의 지역 간 상호대차 장서의 네트워크를 분석하여 장서의 이동이 어떻게 이루어지는가 파악함으로써 실무기반 데이터의 활용 방안을 모색해보았다. 이를 통하여 효율적 상호대차를 위하여 지역을 권역별로 나누어 상호대차를 실시한다면 더욱 원할한 상호대차가 이루어질 수 있음을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제22권4호
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• pp.25-32
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• 2017

Recently, the use of NAND flash memory is being increased as a secondary device to displace conventional magnetic disk. NAND flash memory, as one among non-volatile memories, has many advantages such as low power, high reliability, low access latency, and so on. However, NAND flash memory has disadvantages such as erase-before-write, unbalanced operation speed, and limited P/E cycles, unlike conventional magnetic disk. To solve these problems, NAND flash memory mainly adopted FTL (Flash Translation Layer). In particular, garbage collection technique in FTL tried to improve the system lifetime. However, previous garbage collection techniques have a sensitive property of the system lifetime according to write pattern. To solve this problem, we propose BSGC (Balanced Selection-based Garbage Collection) technique. BSGC efficiently selects a victim block using all intervals from the past information to the current information. In this work, SFL (Search First linked List), as the proposed block allocation policy, prolongs the system lifetime additionally. In our experiments, SFL and BSGC prolonged the system lifetime about 12.85% on average and reduced page migrations about 22.12% on average. Moreover, SFL and BSGC reduced the average response time of 16.88% on average.

• 한국환경과학회지
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• 제10권5호
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• pp.351-358
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• 2001

The main purpose of this study was to investigate the characteristics of cylindrical electrostatic precipitator with centrifugal effect in viewpoints of pressure drip and collection efficiency, experimentally. The experiment was carried out for the analysis of current-voltage, pressure drop and collection efficiency with various experimental parameters such as the applied voltage, inlet velocity, inlet size and inlet type(upper and bottom), etc. In the results, the pressure drops were estimated as 27~54, $34~63mmH_2O$ for inlet size $15mm{\tiems}30mm$ and $30mm{\tiems}60mm$, respectively. The collection effeciencies were shown over 90% with the small inlet size($15mm{\tiems}30mm$) for the applied voltage 40kV, inlet velocity(15~21m/s), and 51~89% with the large inlet size ($30mm{\tiems}60mm$). Moreover, in the applied voltage 0kV and inlet size $15mm{\tiems}30mm$, the collection efficiency induced by centrifugal force was represented as about 35% with inlet velocity 15 - 21m/s.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.83-91
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• 2011

Even if smoke, fumes, mist or dust particles are removed by electrostatic precipitators (ESPs), the occurrence of ozone, which is harmful to human body, has to be severely restricted in the indoor environments of hospitals, offices, and workshops. Therefore, the two-stage ESP generating positive corona at the ionizer is typically used because it creates less ozone than the two-stage ESP generating negative corona at the ionizer. In order to predict the collection performance and the optimal design of the two-stage ESP applied to positive high-voltage, particle concentration is experimentally investigated in this paper. In addition, particle motion within the collector section is also numerically analyzed. The positive corona discharge current of the ionizer is found to be affected by the applied voltage in the collector section but less so by the particle concentration. Particle concentration shows a minimum near the high voltage electrode of the collector section. The minimum value of the collection efficiency is almost proportional to gas velocity. When the collector length decreases, the minimum value of the collection efficiency increases. Charged particles entering the collector region are linearly deflected towards the grounded plate by an electric field. From the above experimental and numerical results, two empirical equations on the concentration ratio and the collection efficiency are derived, and are in good agreement with the experimental data.

• 한국도서관정보학회지
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• 제43권3호
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• pp.457-479
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• 2012

본 연구에서는 현재 국내 공공도서관 자료선정업무의 현황을 자료구입비 규모, 자료선정정책과 자료선정기준, 자료선정 담당 인력과 자료선정위원회, 자료선정방법과 자료선정도구 등의 카테고리로 나누어 살펴 본 다음 사서들의 자료선정업무에 대한 인식을 조사하였다. 이러한 현황을 바탕으로 효율적인 자료선정이 이루어질 수 있는 방안을 자료선정정책, 자료선정인력, 자료선정방법의 세 가지 측면으로 나누어 논의하였다. 자료선정업무현황 분석을 위한 데이터 수집은 국내 공립공공도서관 315개관을 대상으로 한 설문조사를 통하여 이루어졌다.

• 한국문헌정보학회지
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• 제54권2호
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• pp.53-77
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• 2020

본 연구는 외국의 국가대표도서관 구술 컬렉션의 현황을 분석하여 한국의 국가대표도서관에서 구술 컬렉션을 구축할 때, 고려해야 할 핵심 요소를 도출하고자 수행되었다. 미의회도서관과 영국국립도서관, 호주국립도서관에서는 구술자료를 국가적으로 전승시켜야 할 국가지식유산으로 간주하여 일찍부터 관련 센터나 부서를 설치하고 모든 역량을 집중시켜 구술 컬렉션을 대표적인 컬렉션 중의 하나로 수집, 활용, 보존하고 있다. 이들 국가대표도서관의 구술 컬렉션 분석을 바탕으로 현재 구술 컬렉션이 전무한 국립중앙도서관이 국가대표도서관으로서 구술 컬렉션을 처음 시작할 때 고려해야 할 핵심 요소를 법령, 조직, 수집 정책, 서비스, 컬렉션, 교육 및 협업, 기금 및 후원을 중심으로 제시하였다.

• 설비공학논문집
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• 제20권2호
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• pp.144-153
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• 2008

A numerical analysis has been carried out to examine the flow characteristics and the collection efficiency for fine particles in a cyclone using Computational Fluid Dynamics (CFD) technique. The cyclone with the cylinder diameter of 60 mm has been considered for the investigation of the particle collection in a relatively smaller cyclone with somewhat higher inlet air velocities. Fundamental air flow patterns for different inlet velocities have been calculated and then the motions of particles of different sizes have been obtained. The calculated collection efficiencies for fine particles are compared with the experimental results, which shows a good agreement. The current result can be used for the design of cyclones with high collection efficiency.