• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.110-114
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• 2000

This paper shows the possibility of performing the friction stir welding and the development of optimizing tools for FSW with 2mm thick plate of aluminum alloys using milling machine. This research can be reported on achieving above 90% of the tensile strength in 1050 aluminum alloys friction stir welded in the room temperature. This welding process is very simple and does not require filler metal eliminates straightening of the workpiece. It is currently attracting interest from different industries working with aluminum alloys.

• Journal of Korean Library and Information Science Society
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• v.25
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• pp.441-474
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• 1996

Up to recently, information service have emphasized mainly on efficiencies of information collection, storage, process. But, now, many people take interest in criteria and evaluation on quality of information itself and its services because of growth of electronic materials and development of telecommunication. Especially, since the greater part of infomation is made gradually digital format, quality of information service regards as of great importance. This study attempts to investigate the quality problem in information services and its a n.0, pplication. Also, to su n.0, pport high quality, it is needed criteria of information services to evaluate and measure. To understand quality of information services, This articles deal with concept of quality on information related sector, quality management, the reason of importance of information quality, quality work of information services. There is little method to measure and evaluate quality of internet services. So it is necessary to study on internet quality, user's selection on its quality, and development on high quality site.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.8
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• pp.9-15
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• 2013

With low carbon and green growth as the policy indicator, Korea has been concentrating on a variety of researches and technical development as well as recommending the LED lighting facility as part of Green Energy policy to cope with the environment and energy crisis. While the interest on LED has been increasing, the development of LED is still in its early stage and researches on diverse aspects of LED are not sufficiently implemented. Thus, this paper aimed to get the data that would help the expansion of LED lighting by comparing and analyzing the awareness and knowledge level of the public and experts on LED lighting.

• Journal of Multimedia Information System
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• v.1 no.1
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• pp.23-43
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• 2014

With the rapidity of the development on electronic technology, various mobile devices are produced to make human life more convenient. The user is always in constant search of middle with ease of deployment. Therefore, the development of infrastructure and application with ubiquitous nature gets a growing keen interest. Recently, the number of pervasive network services is expanding into ubiquitous computing environment. To get desired services, user presents personal details about this identity, location and private information. The information transmitted and the services provided in pervasive computing environments (PCEs) are exposed to eavesdropping and various attacks. Therefore, the need to protect this environment from illegal accesses has become extremely urgent. In this paper, we propose an anonymous authentication and access control scheme to secure the interaction between mobile users and services in PCEs. The proposed scheme integrates a biometric authentication in PKI model. The proposed authentication aims to secure access remote in PCE for guaranteeing reliability and availability. Our authentication concept can offer pervasive network service users convenience and security.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.446-450
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• 2004

The amount of electric energy used in a vehicle will be increased continuously. The increment of electric power demand causes interest on new higher power system such as 42V Power Net. Furthermore, the necessity for development of energy storage device is highlighted recently. Bidirectional nm Converter is one of the important parts in 42V power system. Therefore, this paper proposes bidirectional Cascade Buck-Boost DC/DC Converter which can satisfies required specifications in 42V power system The operation principle is described along with simple control method, and experimental results on a 500W prototype are provided.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.23-38
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• 1999

This study addresses the reference spent fuel and its characteristics for developing a geological repository concept. As a disposal capacity of the reference repository system to be developed, spent fuel inventories were projected based on the basis of the Nuclear Energy Plan of the Long-term National Power Program. The reference spent fuel encompassing a variability in characteristics of all existing and future spent fuels of interest was defined. Key parameters in the reference fuel screening processes were the nuclear and mechanical design parameters and the burnup histories for existing spent fuels as of 1996 and for future spent fuels with the more extended burnup the initial enrichment and its expected turnup. The selected reference fuel was characterized in terms of initial enrichment, bumup, dimension, gross weight and age. Also the isotopic composition and the radiological properties are quantitatively identified. This information provided in this study could be used as input for repository system development and performance assessment and applied in fuel material balance evaluation for the various types of back-end fuel cycle studies.

• English Language & Literature Teaching
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• v.15 no.3
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• pp.129-150
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• 2009

This paper attempts to examine the effect of children's English stories on the development of Korean EFL primary school learners' listening and speaking competences and their motivation to learn English. This paper also discusses factors of English children's stories that make EFL learners' language learning efficient. Participants were 120 primary school students who attend one of the elementary schools in Chungnam province. They were randomly chosen and divided into two groups: experimental and control groups. In order to collect data, students' listening and speaking proficiency pre- and post-tests and the pre- and post-questionnaires regarding the participants' motivation to learn English were administered. The data were analyzed by ANOVA. The results indicate that the application of English children's stories to EFL learning settings can be an efficient way to improve EFL learners' listening and speaking competences and motivation to learn their target language. The findings of this study suggest that English children's stories provide language learners with interest, meaningful and authentic contexts and enjoyment. The pedagogical suggestion and implications are provided for EFL educators and teachers.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1563-1567
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• 2005

The Home network system means that information appliances, Home PCs, etc., using wired or wireless network method enable to control and share with peripheral devices such as internet, shared data, a scanner and a printer, and it is networking solution, which intelligent communication will be possible as the system which can do a remote control such as TV Set, refrigerators, air conditioners, DVD players, digital camcorders based on external network using an internet, a potable information terminal and a mobile phone whenever, wherever and freely. In this study, the home network interface solution is used one of the wired network standards, PLC (Power-Line Communication) technology, so we can construct of intelligent home network's home controller without re-build a network at home. On keeping with current waves of thought, we will focus on a home controller development with great interest which is enabled to do an effective managed control, applying intelligent home network technology which can be new paradigm like a cyber apartment.

• KDI Journal of Economic Policy
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• v.27 no.2
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• pp.155-203
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• 2005

This paper intends to provide information about whichgroups should receive particular attention from policies aimed at raising participation and employment. A detailed portrait of the diversity of non-employment is presented with description of the extent the under-represented groups stayed in situations of labor inactivity. Also, once in employment, how these groups move from one sector to another is a main interest in the analysis. Using longitudinal data (1998-2002) constructed from 'the economically active population survey', I followed individuals over a five-year period and analyzed how frequently inactive persons enter the labor market and how they change industries and statuses.

• Research in Mathematical Education
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• v.12 no.2
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• pp.151-165
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• 2008

Asian mathematics curricula and textbooks are being recognized in the United States as at least partial explanation for the higher mathematics achievement of students in Asian countries compared to students in the United States. As a result there is considerable interest among many educators in the United States in curricula from Singapore and curricula from Japan. In addition, researchers and educators at one university in the American heartland have been using the English translations of a Korean primary mathematics curriculum for professional development and assessment with groups of Missouri teachers for the purpose of enhancing teachers' understanding of the fundamentals of mathematics, and in hopes of raising student achievement scores. A professional development initiative begun seven years ago and revived this year will entail a rigorous assessment which will be reported in 2009. Results of assessment of the earlier initiatives are reported here.