• 한국안전학회지
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• 제17권4호
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• pp.25-30
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• 2002

This paper demonstrates the effects of dust electrical resistivity on electrostatic precipitability. The effects of gas temperature, velocity and humidity on the collection efficency were considered by used of coal fly ashes from fluidized bed combustion boiler. The experiments for collection efficiency were carried out in the pilot plant. The ashes which have non-spherical geometry and high electrical resistivity were used. Electrical resistivity is an important property for the collection efficiency in the electrostatic precipitators. Fly ash resistivity as a function of temperature up $350{\circ}C$ and water concentration(up to 15%) has been experimentally investigated using the resistivity test equipment consisted of the movable electrode, dust cup, and furnace. As the resistivity of fly ash in the operating temperature($150{\circ}C$) of an electrostatic precipitator was measured higher than $1010{\Omega}{\cdot}$cm, flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash is required.

• 전기학회논문지
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• 제66권6호
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• pp.975-980
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• 2017

Overhead catenary system of electric railway has overlap sections which devide and tighten trolley wire supplying electric power to train, where current collection performances may become worse according to railway speed-up. Current collection tests conducted at 400 km/h test-bed section of Honam high-speed railway show that balanced line arrangement at overlap section is needed to secure current collection without arc generation between trolley wire and train current collection device. This paper proposes a design procedure of the overlap section to allow for tension increase and uplift of the trolley wires according to railway speed-up. By applying the proposed procedure to the overhead catenary system of Honam high-speed railway, it is suggested that the minimum span length should be 33.2 m for railway speed-up to 350 km/h and 43.7 m for speed-up to 400 km/h.

• 보존과학연구
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• 통권32호
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• pp.185-193
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• 2011

영국 국립 박물관 중의 하나인 런던의 월레스 컬렉션은 보존과 관련된 상설 전시를 하고 있는데, 유물의 제작 기법과 재료를 다룬 전시뿐 아니라, 보존에 관한 특별 주제로 전시를 하기도 한다. 월레스 컬렉션의 현재 보존관련 상설전시와 특별 전시 그리고 영국 내 다른 박물관의 예를 통해서, 보존과 일반 대중과의 관계와 교류의 변화를 살펴보고자 한다. 박물관은 기존에는 수동적 정보 전달의 역할이었지만, 현재는 보다 적극적인 교육에 초점을 맞추면서, 보존도 일반 대중의 위한 프로그램과 전시를 통해 이러한 변화에 동참하는 추세다.

• 수산해양기술연구
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• 제50권3호
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• pp.318-325
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• 2014

The main object of this study is to investigate the collection characteristics of wet-type rotating porous disk system experimentally. The experiment is carried out to analyze the pressure drop and collection efficiency for the present system with the experimental parameters such as system inlet velocity, stage number, tube diameter, inlet concentration, etc. In results, for the present system, at 5 stage and ${\upsilon}_{in}=1.8m/s$, the pressure drop becomes significantly lower as $64mmH_2O$ in comparison with that of the conventional wet type scrubber (Venturi scrubber, over $250mmH_2O$). The collection efficiencies increase with higher inlet velocity showing 92, 95.7, 98.4%, while $SO_2$ removal efficiencies decrease with increment of inlet velocity as 80, 65, 50% at ${\upsilon}_{in}=1.08$, 1.44, 1.8 m/s and tube diameter $D_t=10mm$, respectively. The present system is to be considered as an effective compact system for a simultaneous removal of particle/gas phase pollutants from marine diesel engines.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.27-35
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• 2021

NAND flash memory-based SSD needs an internal software, Flash Translation Layer(FTL) to provide traditional block device interface to the host because of its physical constraints, such as erase-before-write and large erase block. However, because useful host-side information cannot be delivered to FTL through the narrow block device interface, SSDs suffer from a variety of problems such as increasing garbage collection overhead, large tail-latency, and unpredictable I/O latency. Otherwise, the new type of SSD, open-channel SSD exposes the internal structure of SSD to the host so that underlying NAND flash memory can be managed directly by the host-level FTL. Especially, I/O data classification by using host-side information can achieve the reduction of garbage collection overhead. In this paper, we propose a new scheme to reduce garbage collection overhead of open-channel SSD by separating the journal from other file data for the journaling filesystem. Because journal has different lifespan with other file data, the Write Amplification Factor (WAF) caused by garbage collection can be reduced. The proposed scheme is implemented by modifying the host-level FTL of Linux and evaluated with both Fio and Filebench. According to the experiment results, the proposed scheme improves I/O performance by 46%~50% while reducing the WAF of open-channel SSDs by more than 33% compared to the previous one.

• 농업과학연구
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• 제48권4호
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• pp.761-770
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• 2021

A study was undertaken to identify variations in the level of awareness, the information collection status, the level of acceptance, and the characteristics of information collection as it pertains to agricultural biotechnology based on information collection in the field of agricultural biotechnology. When examining subjective awareness, objective awareness, and interest in agricultural biotechnology, the results showed that the levels of all three variables were higher in cases where information exploration of agricultural biotechnology had been experienced. Among the participants who have experience in voluntarily collecting information about agricultural biotechnology, helpful information at a rate of 51.6% and harmful information at a rate of 42.0% were acquired, values much higher than the 37% and 30% corresponding rates for participants who had no experience. However, it was also found that harmful information has a significantly greater impact on perceptions of the future. The characteristics of information collection for agricultural biotechnology indicated that those with experience in voluntary information collection particularly preferred the Internet, whereas those without any experience showed little difference with regard to television and/or the internet. According to a survey of participants' interest areas in agricultural biotechnology and their level of information acquisition, "Safety of human bodies" was rated the top interest area at 36.9%, which also had the highest level of information acquisition at 30.0%. In providing and sharing information in the future, this is a direct reference to the priorities and proportions of each field.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.202.2-203
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• 2000

No Abstract, See Full Text

• 한국도서관정보학회지
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• 제15권
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• pp.79-111
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• 1988

The purpose of this study has its meaning to indicate the direction on collection and preservation of national literature which is one of the must important functions of the Central National Library. The Central National Library is, however, a representative library of our country and collect every kind of literature and to meet the requests of its users, the present situation of The Central National Library can't be performed sufficiently on these actions. According to studies of this paper, it have suggested the following five methods as a method of collecting national literature. First, the method by registering copyright endowing the number of copyright like ISBN. Second, the method a n.0, pplied by revising and su n.0, pplementing present legal deposit system. Thirdly, the method that the central one institution secure national budget collect literature of nation i.e., central intensive collection one. Fouthly , method of collecting literature by partial charge through local library networks. Fifthly, method by subject intensive collecting. As the preserving method of national literature, this research has indicated the following two ways. First, to keep the literatures forever, the method of The Central National Library keeps records as a limited volume. Second, The method of dispersing records as the local libraries. To put these methods into practice, it must be preceded that not only national helps, budget secures are needed but special committee must be organized to keep and preserve national literatures and material range also be extended and bibliographies for information data issuing must be worked out.

• 한국대기환경학회지
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• 제26권3호
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• pp.339-345
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• 2010

There have been a number of efforts to satisfy national emission regulations and reduce the amount of emitted air pollutants. There are several air pollution control devices, however, only wet scrubber is efficiently used to remove particulate matters and gaseous pollutants, even if it has minimum collection efficiency in the particle size range of $0.1{\sim}1{\mu}m$. This study aimed to improve the collection efficiency of a spray tower type scrubber by introducing an electrospray system with two-flow nozzle. We found that the collection efficiency of a spray tower type scrubber was similar to that of a conventional wet scrubber. However, installation of an electrospray system in the scrubber resulted in drastic further improvement of collection efficiency comparing to that of a conventional scrubber, which is 26%, 35.2%, and 45.1% at the liquid to gas ratio of 0.26 $L/m^3$ and 19.9%, 35.1%, and 42.5% at 0.34 $L/m^3$ for the applied voltage of -30 kV, -35 kV, and -40 kV, respectively. Therefore, we found that the introduction of an electrospray system is very effective to improve the collection efficiency of a spray tower type scrubber.

• 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.