• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.153-156
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• 2005

Nondestructive sensing of electrospun PYDF web and multi-wall carbon nanotube (MWCNT)/epoxy composites were investigated using electro-micromechanical technique. Electrospinning is a technique used to produce micron to submicron diameter polymeric fibers. Electrospun PVDF web was also evaluated for the sensing properties by micromechanical test and by measurement electrical resistance. CNT composite was especially prepared for high volume contents, 50 vol% of reinforcement. Electrical contact resistivity on humidity sensing was a good indicator for monitoring as for multifunctional applications. Work of adhesion using contact angle measurement was studied to correlate acid-base surface energy between carbon fiber and CNF composites, and will study furher for interfacial adhesion force by micromechanical test.

• Progress in Superconductivity
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• 제6권2호
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• pp.142-145
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• 2005

YBCO coated conductors have been fabricated with a newly developed oxide-precursor-based MOD process. The precursor solution was synthesized with low cost YBCO powders as starting materials and YBCO coated conductors have been deposited on IBAD substrate ($CeO_2$/IBAD-YSZ/SS). YBCO coated conductor prepared by dip coating shows transport $I_c$ of 15A/cm-w at 77 K. Microstructural and crystallographic analyses indicate that YBCO layer was grown in epitaxy with substrate and exhibited well-developed dense microstructure. Also discussed are processing and analysis of YBCO coated conductor by slot-die web coating method. It was shown that this oxide-based MOD process provides a low cost route to coated conductor with high $J_c$.

• 한국정밀공학회지
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• 제28권10호
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• pp.1153-1158
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• 2011

Roll-to-roll process is an emerging mass production method for printed and flexible electronics such as touch screen panel, RFID tag, thin film solar cell, and flexible display due to its high throughput. High precision in printing and coating is required to apply functional materials onto substrate. For such reason, every part of the roll-to-roll equipment needs to be precisely fabricated and to retain its precision under regular operation. In this article, the precision of cantilever type idler roller and a novel method to mitigate its deflection under web tension loading are discussed and the method is verified using both the numerical and the experimental works. The proposed method improves the structural rigidity of cantilever type roller whose advantages, such as low capital cost and high web path configurability, are maintained.

• 한국도서관정보학회지
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• 제34권3호
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• pp.193-210
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• 2003

공공도서관에서 웹기반 독서교육을 활성화시키자는 취지에서 웹을 통한 독서교육의 실제를 살펴보고 그 활용방안에 대해 연구하였다. 웹기반 독서교육은 사서와 이용자가 시간과 공간의 지배를 받지 않고 언제 어디서나 글감을 읽고 독서교육의 목표를 이루는 것이다. 그 방법으로는 멀티미디어의 환경인 인터넷을 통해 독서교육 홈페이지를 개설하고, 이용자가 편리한 시간에 웹상에 제시되어 있는 다양한 독서자료와 독서계획을 볼 수 있도록 안내한다. 또한 사서나 이용자들과 전자메일, 게시판, 채팅, 화상회의 등을 통해 독서에 대한 감상문과 토론, 의견 제시 등 독서교육에 대한 다양한 상호작용 활동이 이루어지도록 웹기반 독서교육 시스템의 구축과 다양한 프로그램을 개발 등을 제시하였다.

• 소성∙가공
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• 제29권5호
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• pp.282-289
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• 2020

Flexible roll forming is an advanced sheet-metal-forming process that allows the production of parts with various cross-sections. During the flexible process, material is subjected to three-dimensional deformation such as transverse bending, inhomogeneous elongations, or contraction. Because of the effects of process variables on the quality of the roll-formed products, the approaches used to investigate the roll-forming process have been largely dependent on experience and trial- and-error methods. Web-warping is one of the major shape defects encountered in flexible roll forming. In this study, an SVR model was developed to predict the web-warping during the flexible roll forming process. In the development of the SVR model, three process parameters, namely the forming-roll speed condition, leveling-roll height, and bend angle were considered as the model inputs, and the web-warping height was used as the response variable for three blank shapes; rectangular, concave, and convex shape. MATLAB software was used to train the SVR model and optimize three hyperparameters (λ, ε, and γ). To evaluate the SVR model performance, the statistical analysis was carried out based on the three indicators: the root-mean-square error, mean absolute error, and relative root-mean-square error.

• 공학교육연구
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• 제5권1호
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• pp.3-18
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• 2002

최근에 인터넷과 웹의 이용이 보편화됨에 따라 이를 교육에도 활용하고자 하는 많은 노력이 전 세계적으로 교육자들에 의해 이루어지고 있다. 웹 기반 강의의 장점은 언제 어디서나 저렴한 비용으로 교육받을 수 있다는 것이다. 웹을 이용하여 자바 프로그래밍을 배우고자 하는 수요도 늘어나고 있다. 이에 따라 자바 프로그래밍을 웹 기반 강의로 가르치기 위한 교안이 많이 개발되어 사용되고 있다. 이러한 교안들은 프로그래밍 기법과 관련된 내용이 부족하고 흔히 실습 환경과 분리되어 있다. 본 논문은 이러한 문제를 해결하기 위한 교안 개발 방법과 개발 사례를 제시한다. 또한 교안의 학습자들에 의한 교안 평가 결과를 보고한다.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.107-114
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• 2006

Material selection is one of the important activities in design and manufacturing. A selected material at the conceptual design stage affects functionality of the designed part as well as manufacturability and cost of the final product. Unfortunately there are not many accessible material databases that can be used for design. In this research, a web-based material database was constructed. In order to assist designers to compare different materials, two-dimensional and three-dimensional graphs were provided via the web browser Using these graphical tools, multi-dimensional comparison was available in more intuitive manner. As a case study, this system was applied for material selection of an automotive engine pulley.

• 소성∙가공
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• 제12권6호
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• pp.550-557
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• 2003

In this study, a web-based system was developed by utilizing finite element method and virtual system designed using Virtual Reality Modeling Language (VRML). The simulation program for axi-symetric sheet forming is developed using finite flement method. The developed system consists of two modules, client module and server module. The client module was developed by using Active-X control. The input data for FEM calculation is transferred to the server module by using communication protocol. Then sever module performs several successive processes: input data generation, forming simulation, conversion of results to VRML format. After that, the results from the simulation can be visualized on the web browser in client computer. Besides, client module offers the capability to control and navigate on virtual forming machine and calculated result. By using this system simulation result can be investigated more realistically in virtual environment including forming machine.

• Journal of information and communication convergence engineering
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• 제1권2호
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• pp.88-92
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• 2003

Most document consists of primary content and supporting material, such as footnotes, detailed explanations, and illustrations, and the related supporting materials are linked as hypertext on web document. However, the content of hypertext links is appeared in the new windows on present web browser. Then the user will leave the primary material, may lose the entire context, and must have some difficulties to return to the primary context when the interest disappears. Using the technique for fluid links, we can solve these problems easily. If the mouse is putted on the link, the related material is presented in between lines or at margin maintaining the context of primary material. In this paper, we introduce the various browsing techniques using fluid links, analyze the forms and the features, and then we propose the way to implement in Java.

• Educational Technology International
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• 제9권2호
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• pp.123-142
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• 2008

The purpose of this study was to examine how computer conferencing might facilitate collaborative learning for students to engage in meaningful discussion. The participants in this study consisted of the instructor and the students in a graduate level course. Different sources of evidence were used to triangulate the data: in-depth interviews, content analysis of transcripts of discussion, and other archival data including course syllabus, presentation materials, and lecture notes. Participants perceived web-based learning as collaborative process, providing opportunities to share the idea, respect and evaluate different perspectives, and co-construct new insights. Analysis of the data revealed several challenges related collaboration in a web-based learning environment: absence of a sense of community, technical problems, adaptability to different types of learner, and managing the discussion. The data also indicated that a variety of strategies were used to facilitate learning: building a sense of community, technical support, developing instructional methodologies, class size, and design of the content.