• Journal of Power System Engineering
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• v.14 no.1
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• pp.65-70
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• 2010

Magnetic levitation system is nonlinear and inherently unstable, so it is difficult to control. Analog control circuit was widly used as the controller of magnetic levitation system, but digital controller is now substituted for analog controller according to development of digital electronics. In this study, Atmel AVR series, ATmega 128 which is a kind of $\mu$-processor for digital controller is used because the chip is cheap and popular. We designed and made ATmega 128 one-board controller and aimed to verify validity through the experiance of levitation response.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.267-267
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• 2010

The continuous change in the electronic band structure of metal-adsorbed bilayer graphene was calculated as a function of metal coverage using first-principles calculations. Instead of modifying the unit cell size as a function of metal coverage, the distance between the metal atoms and bilayer graphene in the same $2{\times}2$ unit unit cell was controlled to change the total charges transferred from the metal atoms to bilayer graphene. The validity of the theoretical method was confirmed by reproducing the continuous change in the electronic band structure of K-adsorbed epitaxial bilayer graphene, as shown by Ohta et al. [Science 313, 951 (2006)]. In addition, the changes in the electronic band structures of undoped, n-type, and p-type bilayer graphene were studied schematically as a function of metal coverage using the theoretical method.

• Research in Mathematical Education
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• v.16 no.4
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• pp.245-263
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• 2012

The Korean mathematical curriculum has been changed three times during the resent five years. It led to changes in textbook system. In the 2007 revised mathematics curriculum, workbook was developed focusing on student's self-oriented learning, effective practice in differentiated classroom, and mathematics problem solving considering individual difference. This paper examines the characteristics of the tasks and the way the tasks are organized in the textbooks and the workbook in accordance with the 2007 revised mathematics curriculum; comparing with the function section before and after the amendment. Researchers examine whether the textbook and workbook were accomplished the purpose with "cognitive expectation", "level of cognitive demand", "and "response types". Researchers revised framework of [Son, J. W. & Senk, S. (2010). How reform curricula in the USA and Korea present multiplication and division of fraction. Educ. Stud. Math 74(2), 117-142] to make them suitable for the function section at the seventh grade.

• Communications of Mathematical Education
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• v.24 no.2
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• pp.365-384
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• 2010

This paper is an analysis study where we surveyed how well pre-service teachers understand the mathematical concepts taught in elementary school. We analyzed the results focusing on the following: First, what are the pre-service teachers' understandings of the equal sign and variables? Secondly, how exact are their understandings of other elementary school mathematical concepts? The survey was done on the students in Teachers College of Jeju National University. We hope that the results of this study will help the improvement of mathematical education for elementary pre-service teachers.

• The Pure and Applied Mathematics
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• v.23 no.3
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• pp.237-246
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• 2016

Ebadian et al. proved the Hyers-Ulam stability of bimultipliers and Jordan bimultipliers in C*-ternary algebras by using the fixed point method. Under the conditions in the main theorems for bimultipliers, we can show that the related mappings must be zero. Moreover, there are some mathematical errors in the statements and the proofs of the results. In this paper, we correct the statements and the proofs of the results, and prove the corrected theorems by using the direct method.

• Journal of the Korean Society of Earth Science Education
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• v.3 no.3
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• pp.209-218
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• 2010

In this study, we investigate the effects of instruction using science magic program on the scientific attitude and scientific inquiry ability in elementary students. For this study, it was chosen two classes of the forth grades J elementary school in Seoul. Instruction using science magic program was applied to the experimental group for 8 weeks during the school hours. The results of this study were as follows : 1. Science tasks applied science magic had influence on elementary learners' scientific attitude in positive way. 2. Science tasks applied science magic had valuable significance to observation, classification, data intepretation ability. However it had no valuable significance to scientific integrated inquiry.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1217-1220
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• 2010

본 연구는 초등학생들의 안전의식이 사고유형 위험인식에 미치는 영향에 대한 관련성을 알아보고자 시도하였다. 2009년 6월 25일부터 7월 15일까지 J도 소재 J시 K시 4개교에 재학하는 초등학생 378명에 대하여 실시하였다. 통계처리는 SPSS WIN 12.0 Version 프로그램을 사용하였으며, 통계적 유의성은 p<.05로 설정하였다. 안전실태의 특성의 변수들과 안전의식, 사고유형 위험인식 간의 상관관계는 안전의식은 외상사고 위험인식(r=.179, p<.01)과 환경사고 위험인식(r=.104, p<.05)에 양의 상관관계를 보였다. 사고유형 위험인식 전체에 대해서 살펴보면 1년 내 안전 교육($\beta$=.139, t=2.654, p<.01)과 교통안전의식($\beta$=.172, t=2.714, p<.01)이 사고유형 위험인식에 유의한 영향을 주는 것으로 나타났다.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1018-1020
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• 2010

현대 사회에서 고객으로 대표되는 사용자와 이를 목표로 이익을 추구하는 공급자간의 관계가 복잡해지고 신규 고객의 확보 및 기존 고객과의 관계 유지는 기업 생존에 중요한 요건으로 부각되고 있는 실정이다. 이를 위해 본 논문에서는 보편화되고 일상화된 모바일 기반의 기기를 이용하여 고객과의 원격 통신 및 관리 기능이 접목된 고객 관리와 서비스 제공 기능을 확장한 고객관계관리 시스템을 설계하였다. 따라서 모바일의 특징을 기반으로 고객관계관리 시스템에서 사용자 인터페이스를 제공하고 세분화된 고객 관리를 그룹화하며 다양한 고객가치산출 및 분석 등의 기능을 제공하는 고객관계관리 시스템을 설계하였다. 또한 고객의 DB를 통해 서비스 요청 및 관리를 제공하는 부가적 기능을 통합적으로 운영할 수 있는 시스템을 구성하였다.

• Laser Solutions
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• v.13 no.1
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• pp.6-10
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• 2010

Crystallization of 100 nm thick amorphous silicon (a-Si) films on glass substrates was carried out by using a double laser irradiation method. Depending on a-Si deposition method or glass types, the quality of crystallized silicon film varies significantly. For a-Si films deposited with high concentration of impurities, large grains or high crystallinity can not be achieved. Crystallization with different a-Si deposition methods confirmed that for the polycrystallization of a-Si films on glass substrates, controlling the impurity density during substrate preparation is critical.

• Convergence Security Journal
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• v.10 no.4
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• pp.77-82
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• 2010

Cloud computing is defined as numerous concepts by research institutions and scholars. However, due to the present business trend in the IT sector, emphasizing on cost and efficiency, cloud computing has been defined as a form of computing which can provide extendable mass storage components in the virtual environment. As a result, security issues have been arising due to the variety of cloud computing services provided by the industries. This paper aims to analyze the weaknesses such as security techniques and inquiries, and personal information protection required for various cloud computing services.