• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.904-914
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• 2004

The fiber reinforced composite material is widely used in the multi-industrial field because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage proceeding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material can be applied in the field such as defence industry and aerospace industry. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding of composite vessel subjected to internal pressure, the standard interpretation model is developed by using the ANSYS with AutoLISP and ANSYS APDL languages, general commercial software, which is verified as useful characteristic of the solution. Among the modules of the system, both the process planning module for carrying out the process planning of filament wound composite pressure vessel and the autofrettage process module for obtaining higher residual stress will minimize trial and error and reduce the period for developing new products. The system can serve as a valuable system for experts and as a dependable training aid for beginners.

• Transactions of Materials Processing
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• v.27 no.4
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• pp.201-210
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• 2018

An airbag is an essential automotive component used in all kinds of vehicles such as an internal combustion engine and an electric motor vehicle and is used to minimize the damage of an occupant in the event of an accident. Airbag-related parts are being monopolized by a small number of foreign companies around the world. In this situation, it is necessary to develop and research the airbag-related part molding technology for expansion of the domestic airbag-related market and corporate export. As a part of this research, we have developed a mold for airbag inflator cap. The development consists of three steps which are the design of components, analysis of the design and verification of it. In the case of the design, the transfer type mold was designed for the multi-cylindrical shaped feature. Analysis was then conducted on the design. By examining the results of analysis, changing features and numbers of punches and dies were added in the analysis and repeatedly analyzed. After the addition, proper dimensions from the analysis were achieved, and prototypes were practically produced and verified. In the case of prototype verification, Pressurizing Burst Test was conducted on the existing products and the prototype. By comparing the results of the test, the possibility of replacing the existing product of the airbag inflator cap is presented in this paper.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.131-153
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• 2010

The fusion of learning, information, and technology presents dynamic challenges for all librarians, educators and students in 21st century libraries and schools. At the heart of this fusion is the growth of a pervasive, integrated information environment characterized by vast quantities of digital content, open choice, collaborative and participatory digital spaces, and the transition of the web environments from consumption of information to creation of information. This environment heralds important opportunities for librarians and teachers to rethink, re-imagine and recreate a dynamic approaches to information literacy instruction. Drawing on an extensive body of research undertaken through the Center for International Scholarship in School Libraries (CISSL), and published research on both information literacy and constructivist learning, this paper provides a critical examination of the current status of information literacy: its multiple conceptualizations, competing models, viewpoints, and its operationalizations in educational and library environments. The paper will challenge information literacy practices which center on simplistic, reductionist approaches to information literacy development, and the separation of information process and knowledge content. In particular it will address apparent contradictions in espoused conceptions of information literacy which revolve around "knowledge": knowledge construction, critical thinking, problem solving and the development of knowledgeable people; and information literacy practices which revolve around "information": a predominant focus on skills of access and evaluation of resources and with less attention given to engaging with found information to develop deep knowledge and understanding. The paper will present a series of challenges for moving forward with information literacy agendas in libraries and schools.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.14-17
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• 1999

The wrinkling behavior of a thin sheet with perfect geometry is a kind of compressive instability. The compressive instability is influenced by many factors such as stress state mechanical properties of the sheet material geometry of the body contact conditions and plastic anisotropy. The analysis of compressive instability in plastically deforming body is difficult considering all the factors because the effects of the factors are very complex and the instability behavior may show wide variation for small deviation of the factors. In this study the bifurcation theory is introduced for the finite element analysis of puckering initiation and growth of a thin sheet with perfect geometry. All the above mentioned analysis and the post-bifurcation behavior is analyzed by introducing the branching scheme proposed by Riks. The finite element formulation is based on the incremental deformation theory and elastic-plastic material modeling. in order to investigate the effect of plastic anisotropy on the compressive instability a square plate that is subjected to compression in one direction and tension in the other direction is analyzed by the above-mentionedfinite element analysis. The critical stress ratios above which the buckling does not take place are found for various plastic anisotropic modeling method and discussed. Finally the effect of plastic anisotropy on the puckering behavior in the spherical cup deep drawing process is investigated.

• Journal of Information Science Theory and Practice
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• v.3 no.4
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• pp.6-18
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• 2015

There has been an explosion of new research and writing about all aspects of the information disciplines. Nevertheless, both academics and practitioners often find it difficult to engage in successful writing strategies. Indeed, writing is hard work, and doing it in a way that leads to publication is an even harder task. Since reading is essential to good writing, the challenges of learning to write are obvious. In this essay, I am drawing on many years of experience in writing and publishing, as well as considerable reading of writers’ memoirs, advice books on writing, literary studies, and other perspectives on the experience of writing in order to offer a set of approaches that can be pursued over a lifetime of scholarship and practice. Writing is a craft or art to be learned, and learning demands paying attention to the audience, having clear objectives, being an avid reader, and possessing the ability to accept and learn from criticism. While information professionals and scholars incessantly write for each other, there are large segments of the public and other disciplines who they ignore. Fortunately, the tools and resources for improving one’s writing are both broad and deep; discipline and realistic strategies are all that are required to improve one’s writing and, ultimately, to achieve success in publishing.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.146-154
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• 1996

In this work, rapid prototyping and three-dimensional finite element analysis are simultaneously applied to the die design of metal forming processes. Rapid prototyping is a new prototyping technology which produces three-dimensional part models directly from CAD data and has been extensively applied to various manufacturing processes. There are many types of rapid prototyping systems due to their building principles and materials. In this work, Stereolithography Apparatus(SLA), which is the most widely used rapidprototyping system, is introduced to manufacture the die set. For general preparation of STL file, which is the standard input file of rapid prototyping system, mesh data which are used in describing the die surface in finite element analysis are translated so that rapid prototyping and finite element analysis are dffectively connected. A die set for spider forging and a clover punch for deep drawing section are manufactured effciently using SLA prototypes, and metal forming experiments are carried out using them. Comparing the result of experiments with that of analyses, the processes can be predicted and designed successfully.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.177-185
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• 2001

This study shows the process design and forming analysis of permalloy shielding can that support the automobile multi-display parts to indicate the accurate information of car. This study is particularly important, since the strain and thickness of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite thickness of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite sensitively. The objective functions are strain and thickness deviation. The punch radius, die radius and blank holding force are considered as design parameters. Orthogonal array (OA) table and characteristics are applied to neural network (NN) as train data. After training, the optimal and robust condition of design parameters is selected. This study shows the correlation between the design methodology of NN and the statistical design of experiments (DOE) approach.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.93-97
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• 1997

Since the modified membrane element has the same external appearance as the ordinary membrane element, it is not able to apply the thickness variation of sheet metal in the blank holder to the contact treatment and the equally distributed blank holding force should be inevitably imposed on sheet metal along the periphery regardless of the contact status. But sheet metal does not contact with the blank holder at the periphery, nor the blank holding force is distributed uniformly along the boundary. To impose the blank holding force properly, the scheme is improved so that the blank holding force at each node imposed on sheet metal is dependent on the calculated thickness derivation and a state of equilibrium with the total blank holding force. The validity of the improved scheme is demonstrated with the simulation of cylindrical and rectangular cup deep drawing.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.4
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• pp.187-192
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• 2011

Effect of austenitizing temperatures on the impact value of the AISI 4140 steel after repetition of spheroidization and cold deep drawing treatment has been studied. Sufficient dissolution of carbide was shown after austenitizing at the high temperature of $950^{\circ}C$. Accordingly, the impact value was remarkably increased by tempering of this high temperature austenitized steel at the tempering temperature ranges between $570^{\circ}C$ and $630^{\circ}C$. On the other hand, remarkable decrease in the impact values and elongations were shown by tempering the low temperature-austenitized ($870^{\circ}C$) steel due to the coarsening of undissolved-carbide existed at the austenitizing temperature.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.1
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• pp.13-22
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• 2014

The purpose of this study is to figure out the differences in children's 'sense of place' followed by their development stages and to suggest a positive space design of school suited by their development. Haeng-Hyeon Elementary school was selected as the target area. The research methods of this study were based on drawing the cognitive map and a questionnaire survey. Through the cognitive map, children's development stages were determined. Also, through an awareness assessment, the places where the children had deep recognition were extracted. The questionnaires were based on knowing the places where children create their 'sense of place' and its reasons. The sense of place development factors are comprehended as physical factor, behavioral factor and psychological factor based on Relph(1976). The results were organized into a guide which has to be considered when designing an elementary school, sorted by adequate space responding to children's development stages.