• Design & Manufacturing
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• v.12 no.2
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• pp.34-39
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• 2018

The biggest topics in the automobile industry are light weightening and fuel efficiency improvement. There's a lot of research going on. It is focused on light weight materials. Light weight material is seen as the best way to reduce fuel consumption and to solve the problem of environmental pollution and resource depletion. For the light weight materials, new materials such as aluminum, magnesium, and carbon-hardening materials can be found. Research on the joining techniques of dual materials, improvement of material properties by improving the method of manufacture of existing materials, and studies on ultra-high strength steel sheets are expected to take up the most weight in lightweight materials. As the strength of the ultra-high strength steel sheets increases during forming, it is difficult to obtain dimensional precision due to the increase in elastic restoring force compared to mild or high strength steel sheets. Spring back is known to be affected by a number of factors due to poor plastic molding, and can be divided into the effects of the material spraying and the process. The study on the plasticitic variables were studied as plasticitic factors that can be controlled by a part company. Tensile testing of ultra-high strength materials was conducted to derive properties for plasticitic analysis and to analyze spring back with two factors controlling the height of the bead and blank holding force by adding tensile force and controlling the flow rate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.75-76
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• 2006

LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50{\sim}200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current dot patterned LGP, optical pattern design with $50{\mu}m$ micro-lens was applied in the present study. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different pattern conditions to the brightness distribution of BLU with micro-lens patterned LGP. Finally, negative micro-lens patterned LGP showed superior results to the one made by positive in average luminance.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.75-79
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• 2006

The upper and lower lateral cartilages provide the key to the lower cartilaginous portion of the nose. Lifting the cartilages is essential procedure for correction of unilateral cleft lip nose deformity. After correction of cleft lip nose deformity, authors used acoustic rhinometry (AR) to compare the lower nasal cavity of cleft side with non-cleft side. AR is a well known new, non-invasive diagnostic technique in which nasal geometry is assessed by means of acoustic reflection. From June 1996 to January 2004, we performed acoustic rhinometric analysis after correction of unilateral cleft lip nose deformity. This study involved 40 children of age ranged from 3 months to 8 years. Subjects were divided into the group of incomplete unilateral cleft lip nose deformity(20 subjects), and the group of complete unilateral cleft lip nose deformity(20 subjects). Results show that lower nasal cavity volume between non-cleft side and cleft side has no difference, and better results were obtained when nasal molding prong was applied at cleft side nostril. The results between incomplete type and complete type have no significant difference. In conclusion, AR is an effective method to calibrate cross sectional area and nasal cavity volume of unilateral cleft lip nose deformity, and furthermore effective in comparing the volume of cleft side with non-cleft side after unilateral cleft lip nose deformity correction with lifting the lower lateral cartilages to the upper lateral cartilages.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.345-350
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• 2016

Modern design started from having form of nature and biology and had gradually faced limit on the design subject, therefore changed to something with emotions. However, personal emotion is hard to receive sympathy from the public. Therefore the researcher have selected subject that is already receiving love from the public and tried to visualize it through metal sculpture. The subject selected for visualization is 'Counting Stars at Night' by poet Yoon Dong Ju who the Koreans love the most and the aesthetic factor was selected through prior studied literature and have made by applying metal, gemstone and coloring method. As a result the aesthetic factor could be selected understanding the emotion inside the poet 'Counting Stars at Night' by Yoon Dong Ju and have not lost objectivity in the emotions and could be able to feel the beauty of the metal sculpture with deep emotions of the 'Counting Stars at Night' by Yoon Dong Ju through completed metal sculpture. This served as a momentum for suggesting possibility of shaping the immaterial subject.

• Polymer(Korea)
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• v.35 no.1
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• pp.1-6
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• 2011

Pressurized high temperature plastic resin flows into the cavity of mold and is solidified in injection molding process. Residual stress is being developed in injection molded part because of high temperature variations and high pressure. Developed residual stress relaxes as time goes. Consequently this makes part deformed and deteriorates quality of product. A measurement method of residual stress for injection molded transparent articles has been investigated using photoelasticity. Light, a composite of electromagnetic waves, is purified into a single wave by a polarized film. When this wave passes through the specimen, birefringence is developed according to the level of residual stress in the specimen and color fringed pattern appears after the second polarized film. Residual stress in the injection molded transparent flat a part has been measured quantitatively using the color fringed pattern. Optical characteristics have been a part also predicted by computer simulation and compared with experimental results.

• Polymer(Korea)
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• v.38 no.5
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• pp.645-649
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• 2014

The causes of residual stress in an injection molded part are high temperature variation and shear stress during molding process. Chemical cracking test is one of the methods of measuring residual stress and cracks are developed according to the degree of residual stress. In this study, the relationship between chemical cracking and exerted stress have been investigated. Deformation jig was designed and used to give a stress through deformation in a specimen. Specimens were molded by a hot press using polycarbonate (PC) and annealed to remove residual stresses in the specimens. Specimens were fixed in the deformation jig and immersed into the solvent to create cracks in the specimens. Solvents were prepared by using tetrahydrofuran and methyl alcohol. As stress accordance with the deformation in the specimen increased, the frequency and density of cracks in the specimen also increased. The results of this study can be used for the measurement of residual stress quantitatively in an injection molded PC product using a chemical cracking method.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.265-271
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• 2020

This study aims to help the creative idea of nail art design and the expansion of artistic realm by presenting nail art applied with dot, line, and plane, which are the basic elements of the sculpture that make up the space for visual expression of nail art. The research method considered the concepts and characteristics of the molding elements through professional books, prior research, and Internet website. Along with various expression techniques, the characteristics of dot, line, and plane were applied to nail art and expressed as visual messages, and a total of six works were produced according to each characteristic. This research aims to find a new perspective on nail art expression by reinterpreting the characteristics of dot, line, and plane, which are formative elements, in an artistic approach, and to contribute to enhancing the infinite possibilities of nail art design by utilizing them.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.165-172
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• 2016

Since the advent of digital games with hardware development a key component of the game characters are changed to retard the rate at which types of users based on their favorite theory of human proportion. Many popular to gamers in the game according to the change in the retard rate in a unique image of the character. Studies on the head and body proportion are thought that up to now been insufficient. The purpose of this study is to examine a fundamental human proportion that has importance as a molding factor in the game character development, it investigated the characteristics of the game character, and classifying the retard rate of the game character, through the research method of analyzing the results, into the retard rate look for and investigate studying the effect on future game images. Five types of game characters that make up the analysis were analyzed with a unique image, and the more specialized users prefer retard rate, the figurative exaggeration to retard rate than the actual main body. Utilizing a bit exaggerated the difficulties of the character looks relatively small proportion character in the graphic wallpaper increased visibility. The proportion of a game character through the study is considered as a very important factor as the game image in the game development.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.349-355
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• 2020

The Fourth Industrial Revolution has emerged, and technologies of various industries are being converged, compounded, or clouded computing, mobile, or big data. The emergence of a variety of skills and new jobs to match them is bringing the public out of the education and occupation of traditional metal crafts. In this change, craft education should find and study the education method suitable for the present times, and apply it to the educational field to raise public interest and revival. To this end, we will investigate the cases of education in other industries where new materials or technologies have been introduced, and use them in education of traditional metal craft techniques. In addition, we will investigate various cases and features of 3D printing technology and use it for education in craft techniques that have limited time, space and resources.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3589-3592
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• 2012

Carbon composite bipolar plates with various carbon black contents were prepared by a compression molding method. The electrical conductivity and electrochemical stability of the bipolar plates have been evaluated. It is found that the electrical conductivity increases with increasing carbon black contents up to 15 wt %. When the carbon black contents are greater than 15 wt %, the electrical conductivity decreases because of a poor compatibility between epoxy resin and carbon black, and a weakening of compaction in the carbon composite bipolar plate. Based on the results, it could be concluded that there are optimum carbon black contents when preparing the carbon composite bipolar plate. Corrosion tests show that the carbon composite bipolar plate with 15 wt % carbon black exhibits better electrochemical stability than a graphite bipolar plate under a highly acidic condition. When the optimized carbon composite bipolar plate is applied to vanadium redox flow cells, the performance of flow cells with the carbon composite bipolar plate is comparable to that of flow cells with the graphite bipolar plate.