• 한국과학교육학회지
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• 제12권3호
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• pp.35-47
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• 1992

The purpose of this study was to develop a data base system for the information on science education research and development. As a part of this study, a data base program was developed on the Macintosh SE using the 4th Dimension from ACI. The data base consisted of two files, dissertation and journal. The information on the 107 theses including the master's theses and the doctoral dissertations from the Department of Scince Education, Seoul National University and on the 640 papers on science education from the first issues to the 1991 issues of five selected science education journals was input into the data base. The selected five Journals were Journal of the Korean Association for Research in Science Education(published by the Korean Association for Research in Science Education, 148 papers), Teaching Physics(published by Korean Physical Society, 164 papers),Chemical Education(published by The Korean Chemical Society, 98 papers), The Korean Journal of Biological Education(published by The Korean Society of Biological Education, 148 papers), and Journal of Science Education(published by Science Education Center, College of Education, Seoul National University,82 papers).

• 천문학회지
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• 제49권6호
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• pp.289-293
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• 2016

We investigate the long-term spatial drift of the center and the temporal variation of the shutter delay time map of Y4KCam mounted on the CTIO 1.0 m telescope. We have collected shutter delay time maps over eight years as a part of our long-term survey program. We find that the center of the shutter delay time map can drift up to $450{\mu}m$, equivalent to ${\approx}30pixels$, on the CCD. This effect can result in a small amount of error in integration time without the proper shutter delay time correction, but it does not appear to cause any significant problems in photometric measurements. We obtain a mean shutter delay time of $69.1{\pm}0.8$ ms and find no temporal variation of the shutter delay time of Y4KCam over eight years, indicative of the mechanical stability of the shutter. We suggest that using a master shutter delay time correction frame would be sufficient to achieve high precision photometry, which does not exceed photometric errors ${\approx}1.7mmag$ across the CCD frame for exposure times longer than 1 s.

• 한국항공운항학회지
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• 제13권1호
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• pp.43-49
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• 2005

There are several ways to mold the complex material, and it is divided to vacuum pack mold, compression mold, and hand lay up for a high molecular substance as a basic material. Moreover, it can be divided to general manufacturing (Single form) and mold manufacturing(Mold form) under normal temperature for Firefly. Firefly was manufactured with hand lay up and general manufacturing that using the foam core, glass fabric, and template without mold. However, mold manufacturing that is producing the surface by semi-sandwich using thin foam core and glass fabric then reinforce the inside with spar and rib is on developing. Mold manufacturing can make easy to production, standardize the quality, and possible to mass producing. In this paper, we present the mold producing process for canard aircraft "Firefly", and the problems and solutions during producing Firefly. Moreover, it complements the defect that the problems caused by master manufacturing error when produce several masters of a large part, and make the manufacturing process to be shortened by the replacement from the supplementary plate to the foam that is installed when producing lay up mold.

• International Journal of Precision Engineering and Manufacturing
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• 제2권2호
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• pp.38-47
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• 2001

This paper decribes the development of computer-aided design of a very precise progressice die for lead frame of semiconductor chip. The approach to the system is based on knowledgr-based rules. Knowledge of fie이 experts. This system has been written in AutoLISP using AutoCAD ona personal computer and the I-DEAS drafting programming Language on the I-DEAS mater series drafting with on HP9000/715(64) workstation. Data exchange between AutoCAD and I-DEAS master series drafting is accomplished using DXF(drawing exchange format) and IGES(initial graphics exchange specification) files. This system is composed of six main modules, which are input and shape treatment, production feasibility check, strip layout, data conversion, die layout, and post processing modules. Based on Knowledge-based rules, the system considers several factors, such as V-notches, dimple, pad chamfer, spank, cavity punch, camber, coined area, cross bow, material and thickness of product, complexities of blank geometry and punch profiles, specifications of available presses, and the availability of standard parts. As forming processes and the die design system using 2D geometry recognition are integrated with the technology of process planning, die design, and CAE analysis, the standardization of die part for lead frames requiting a high precision process is possible. The die layout drawing generated by the die layout module s displayed in graphic form. The developed system makes it possible to design and manufacture lead frame of a semiconductor more efficiently.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.376-379
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• 2004

pH has been regarded as a master variable governing the heavy metal sorption on fly ash. However, the chemical constituents in the fly ash could also suggest a potential sorption site for heavy metals. So, in this study sequential extraction method is employed to evaluate the sorption behavior of fly ash for cadmium. Two different fly ashes (S-fly ash, T-fly ash) were obtained from different power plants in Korea. First, cadmium is adsorbed under four different initial pHs. And, Cd sorbed in fly ash was sequentially desorbed following the sequential extraction method suggested by Tessier. In test results, the effect of pH increase was differently exerted in two fly ash. In S-fly ash, exchangeable fraction was dominated in low initial pH, however, as increasing initial pH, the fraction bound to carbonate increased. In the T-fly ash, regardless of initial pH the fraction bound to carbonate was major part of sorption estimated. The fraction bound to Fe/Mn oxide was about 10% in T-fly ash, and 5% in S-fly ash at high pH.

• 한국도서관정보학회지
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• 제45권3호
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• pp.489-511
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• 2014

본 연구에서 부산대표도서관 건립 기본계획 연구의 일부로 수행된 건립타당성 분석 중 경제적 타당성 분석에 대한 기초적인 작업을 수행하였다. 이를 위해 비용편익 분석과 순현재가치, 내부수익률의 방법을 활용하였다. 조건부가상가치법(CVM)을 활용하여 편익분석을 실시하였으며 부산대표도서관 건립부지를 중심지 또는 외곽지로 할 때의 값을 조사하여 비교분석하였다. 분석 결과, 중심지에 건립할 경우 부산대표도서관은 충분한 경제적 타당성을 갖는 것으로 나타났으며 외곽지에 건립할 경우 그렇지 않음을 확인하였다.

• ETRI Journal
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• 제32권5호
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• pp.713-721
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• 2010

E-textile technology has earned a great deal of interest in many fields; however, existing wearable network protocols are not optimized for use with conductive yarn. In this paper, some of the basic properties of conductive textiles and requirements on wearable personal area networks (PANs) are reviewed. Then, we present a wearable personal network (WPN), which is a four-layered wearable PAN using bus topology. We have designed the WPN to be a lightweight protocol to work with a variety of microcontrollers. The profile layer is provided to make the application development process easy. The data link layer exchanges frames in a master-slave manner in either the reliable or best-effort mode. The lower part of the data link layer and the physical layer of WPN are made of a fabric serial-bus interface which is capable of measuring bus signal properties and adapting to medium variation. After a formal verification of operation and performances of WPN, we implemented WPN communication modules (WCMs) on small flexible printed circuit boards. In order to demonstrate the behavior of our WPN on a textile, we designed a WPN tutorial shirt prototype using implemented WCMs and conductive yarn.

• 한국기술사회:학술대회논문집
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• 한국기술사회 1987년도 제17회 한일기술사 합동 심포지움
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• pp.65-71
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• 1987

All Korean professional engineer′s great joy Is to welcome the Japanese professional engineers and relevant guests to the 1987 Japan-Korea Professional Engineers Joint Convention organized by the Korean Professional Engineers Association. As there exists an effort of blood, sweat and tear behind a succeeded theatrical stage, so an exquisite devotion with drawing up a master plan, investigation, supervision and etc by engineering firms is soaked through every part of huge construction projects and large unit factory buildings. It is over 14 years that the Engineering Service Promotion Law has been enacted by the Ministry of Science and Technology. In the meantime, the domestic engineering (engineering service) have reached a remarkable higher level while the number of engineering firms participating in overseas market has gradually been increasing. From a small scale of under water investigation to a large scale planning of atomic reactor or petrochemical plant, engineering service business can be said "The Software of Total Industry." Engineering service is what is called a higher business which offers specialized engineering know-how and experience. Engineering service compaines offer Its specialized knowledge and experience to government, industry and commerce. Whether the task is to modernize plant equipment, to design a building or to manage construction, an engineering company will develop and implement the most appropriate and cost effective solution. Clients use the engineering service of firm knowing that the engineer′s professional judgement is not influenced or biased by other commercial affiliations. While benefiting from the diverse experience that professional engineers can apply to a specific problem, government and industry also reduce the need for permanent in-house engineering staff. Engineering firms may be specialized or multi-disciplinary.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.632-634
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• 2005

Korea takes part in overseas business by use of accumulated advanced technology through construction of the worlds first 765kV double circuit transmission system designed with pure local technology. 'Development Study on the Power System Network Analysis in Myanmar' was received in the year 2001 and was completed in the year 2002. The following project,'Feasibility Study and Basic Designs for the 500kV Transmission System in Myanmar' has been in progress since January, 2004. With regards to this project the master plan for the Myanmar long term power system was submitted in January 2005, and now the basic designs for the 500kV transmission system construction are in progress. Technical data for the design of the transmission line is calculated using a very complex numerical formula that is almost impossible to be completed by hand. So the transmission technical calculation system was developed to calculate and support Myanmar technical data for the design of transmission line with respect to factors such as wind prossure load, tower design data conductor design data and insulator design data on the basis of weather conditions for the Myamar transmission line design area of the Myanmar 500kV trans- mission line construction basic design.

• 기본간호학회지
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• 제23권1호
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• pp.21-31
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• 2016

Purpose: This study is a qualitative research to identify new nurses' adaptation experience to sleep changes. Method: Grounded theory methodology was utilized. Participants were 10 new nurses from one university hospital. The information was collected and analyzed using the grounded theory of Corbin and Strauss'(2008). Results: Through constant comparative analysis, central phenomenon was identified as 'Shaky daily life due to the sleep change'. A core category emerged as 'In the shaky daily life, go grab my position', Causal conditions were 'Heaviness in shift work', 'Not released after getting off work', and 'Body and mind are exhausted'. Context were 'An environment that does not tolerate mistakes' and 'Clogged breathing due to worries'. Intervening factors were 'Support of colleagues', 'Recovery volition in restoration of altered relationships due to sleep'. Action/Interaction Strategies were 'To strive for a good sleep', 'Require a reasonable duty schedule' and 'Find a breakthrough'. Consequences were 'Become the master of shaky daily life' and 'Accepting the life of a nurse'. Conclusion: New nurses experience sleep patterns changes from the hospital shift system. but throughout the process of adaptation, came to accept sleep disorder as part of the life of a nurse.