• 한국도서관정보학회지
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• 제31권1호
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• pp.1-21
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• 2000

This study intends to analyze the general printed encyclopedia published and circulated in Korea. The main purpose it is to offer extensive information helping users or librarians to select superior encyclopedia. 4 printed encyclopedia published and circulated in Korea since 1993 are selected for this purpose And they are analyzed on the basis of 6 evaluation standards (purpose & scope, authority, accessibility, clarity & readability, format and special features & cost). Especially, 4 printed encyclopedia among the best American encyclopedia having long history were also co-analyzed to certificate the validity of the evaluative standards.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.3-6
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• 2004

In this paper, we studied on permissible current of unperfected earthing for cross-bond system. The factors of unperfected earth were jacket damage, cross-bonding mistake, arrestor damage, effect of other circuit but we only studied permissible current of arrestor or jacket damage. In the result, we earned that permissible current of normal 154[[kV]] CV $1C{\times}400SQMM$ cable is 760[A] but current of unperfected earthing cable is 76[A], unperfected earthing confirmed that accident of underground cable could occur. So, we could confirmed that Earthing resistance of unperfected earthing need to limit.

• 한국환경과학회지
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• 제16권4호
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• pp.441-447
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• 2007

This study was carried out to investigate the effect of electrochemical (EC) disinfection of artificial wastewater contaminated by Escherichia coli culture. Circulated batch type electrochemical disinfection system using three plates electrodes was used. Also, the several factors (pH, ORP, DO, temperature, current, conductivity) were measured in order to investigate the fundamental design factor in the EC disinfection system. It was demonstrated that the EC process was highly effective for wastewater disinfection. At the constant voltage, the disinfection efficiency was increased according to time. The disinfection efficiency and current increased as the increase of voltage. The variation of conductivity was a little related to the variation of CFU (colony forming units). The differences in disinfection efficiency according to the ice pack and the variation of electrodes were not occurred. The EC disinfection efficiency and current increased according to the increase of circulating flow rate.

• 전력전자학회논문지
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• 제7권6호
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• pp.596-603
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• 2002

본 논문에서는 영상고조파 주입법을 사용하여 3상 다이오드 정류기의 입력전류를 개선하는 새로운 방식의 고조파 저감기술을 제안한다. 3고조파 주입을 근간으로 하는 본 방식은 다이오드 정류기의 상측과 하측의 전류를 독립적으로 제어하기 위하여 두 대의 단상 반파 인버터와 두 대의 단상 변압기로 구성되어져 있다. 이렇게 만들어진 영상전류는 zigzag 변압기에 의해서 다이오드 정류기의 상측과 하측으로 주입이 되어진다. 이 결과 3상 다이오드 정류기의 입력전류는 순수한 정현파 전류가 된다. 본 방식의 타당성을 1.5kVA 시작품의 실험을 통하여 입증하였다.

• 대한예방한의학회지
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• 제4권2호
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• pp.193-204
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• 2000

In this study, advanced model for quality control of oriental medicine and methods for practice was suggested through literature inspection, analysis of foreign system such as China and Japan, survey analysis on the current system, quality analysis of randomly selected oriental medicine samples, and intensive discussions among oriental medicine specialists 1. The quality of oriental medicine should be consistently controlled by Ministry of Health and Welfare form its cultivation or import to its circulation process to final consumer 2. All oriental medicines should be circulated as standardized goods which should be marked by lot numbers. The packing material and Packing size should be liberalized. The qualify should be differentialized though free competition among makers. 3. Realistic standards for pesticide, heavy metal and decolorant should be established though long-term monitoring process according to each oriental medicine's origin, therapeutic part, cultivation area, harvesting time, and cultivation method. 4. Ministry of Health and Welfare should educate oriental medicine's quality control personnel regularly or on demand, and establish specialist pool. Ministry of Health and Welfare should also establish oriental medicine information system to provide informations about quality of domestic or foreign oriental medicinal raw materials. 5. The government should provide information about foreign of oriental medicine market to importers. Quality of imported oriental medicine should be inspected before its customs clearance, and all imported oriental medicine should be circulated by standardized oriental medicine makers. 6. Oriental medicine's pharmacopoeia should be Published to provide quality standard of oriental medicine and improve it.

• 한국정밀공학회지
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• 제17권2호
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• pp.89-96
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• 2000

This paper describes the characteristic of die finishing to obtain smooth surface using electro-chemical grinding after cutting process. Electro-chemical grinding is possible under lower load and tool wear comparing with those in the mechanical grinding. Conventionally, if the metal bonding material of the grinding wheel is directly t contacted with workpiece, the current is circulated without electrolytic phenomena. Sometimes, electrical discharge is occurred between tool and workpiece. To cope with this problem, the metal-resin bonded pellet was used in this study. This pellet is composed of optimal volume of metal and resin powders and its characteristics are changable with the each volume of powders. Finally, high efficient die finishing is realized using metal resin bonded pellet in electro-chemical grinding.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.141-144
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• 2015

The superconducting fault current limiter (SFCL) is an electric power device that limits the fault current immediately in a power grid. Korea Electric Power Corporation (KEPCO) has been developing a 154 kV, 2 kA SFCL since 2011 to protect power grids from increasing fault current and improve the stability and quality of electric power. This SFCL adopts 2G YBCO wires and operates at 71 K and 5 bars. In this paper, a cooling system for the 154 kV SFCL and its cooling test results are reported. This cooling system uses a Stirling-type cooler to make sub-cooled liquid nitrogen ($LN_2$), which cools the superconductor modules of the SFCL. The $LN_2$ is circulated between the cooler and the cryostat that contains superconductor modules. The $LN_2$ also plays the role of a high voltage insulator between the modules and the cryostat, so the pressure was maintained at 5 bars for high insulation performance. After installation in a test site, the cooling characteristics of the system were tested. In this operation test, some important data were measured such as temperature distribution in $LN_2$, pressure change, performance of the heat exchanger, and cooling capacity of the total system. Consequently, the results indicate that the cooling system operates well as designed.

• 한국비블리아학회지
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• 제4권1호
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• pp.103-127
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• 1980

Due to the rapid growth of publications, librarians have been facing the problems caused by the shortage of stack as well as the quality deterioration of library collections. This naturally disappointed the user communities and the present library activities are weak and inadequate. It seems to the author that one of the desirable actions in remedying this problems is to weed library collections properly and regulraly. The purpose of this study is to establish weeding criteria in library collections, particulary in the fields of polictical science, economics and law In order to establish weeding criteria, shelf-time period which is the length of time that a book remains on the shelf between the last two users of a volume, was measured by examining the book cards or date-due slips of circulating books and collections which remained in the stack. The results of this study are as follows: (1) In the fields of political science economics and law, the shelf-time periods of general materials in Korean for circulation was measured. (2) This study shows shelf-time periods that vary in different subject fields. (3) Combining the shelf-time periods of books in active circulation and the total collection including books which have never been circulated, the size of library holdings which may satisfy a certain percentage of the current circulation can be estimated.

• 한국초전도ㆍ저온공학회논문지
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• 제14권1호
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• pp.25-29
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• 2012

The novel type of cable under consideration is cooled by gaseous Helium at elevated pressure. Helium is known for having poor electric breakdown strength; therefore the dielectric capabilities of this type of cable must be tested under conditions similar to the envisaged operation. In order to study the dielectric performance we have designed and built a novel high pressure cryostat rated at 2.17 MPa which has been used for testing model cables of lengths of up to 1 m. The cryostat is an open system where the gas is not re-circulated. This allows maintaining a high purity of the gas. The target temperature range is between 40 K and 70 K. This substantially increases the critical current density of the HTS compared to 77 K, which is the typical temperature of cables cooled by liquid nitrogen. The cryostat presented allows for adjusting the temperature and keeping it constant for the time necessary to run a complete dielectric characterization test. We give a detailed description of the cryostat. Measurements of partial discharge inception voltages as well as the temperature distribution along the model cables as a function of time are presented.

• 한국비블리아학회지
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• 제30권4호
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• pp.255-274
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• 2019

본 연구에서는 법학 분야의 효율적인 장서구성을 위해 S 대학 법학도서관의 2018년 1년 동안의 대출데이터를 분석하고 소장단행본이 실제로 교육과 연구에 이용되고 있는지를 분석하였다. 먼저 S 대학 도서관리 시스템인 Alma 시스템으로부터 1년 동안 대출된 단행본에 대하여 주제별, 언어별, 출판 연도별로 분석하여 이용자의 패턴을 분석하였다. 이어서 실제로 S 대학 강의계획서에 나타난 단행본을 법학도서관이 얼마나 많이 소장하고 있는지를 분석하였으며 S 대학 연구자들이 연구한 논문에 인용된 단행본을 도서관에서 얼마나 소장하고 있는지를 분석하였다. 이런 연구결과는 법학전문도서관으로서의 장서구성의 기준을 수립하는 기초 자료로 활용해 볼 수 있을 것으로 판단된다.