• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1459-1460
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• 2015

안경을 제작하기 위하여 안경테 혹은 렌즈의 사이즈를 측정하는 기계를 취형기라 하며, 측정된 데이터를 사용하여 렌즈를 절삭하는 기계를 옥습기라 한다. 본 논문에서는 취형기를 통해 획득한 데이터를 3D 시각화 하는 방법에 대하여 서술한다. 취형기의 탐침자에서 획득된 데이터는 1024개, 즉 데이터당 약 $0.352^{\circ}$에 해당하는 각도로 획득한 데이터로 구성되며, 각 데이터는 취형기 중심에서 경계까지의 거리와 렌즈 혹은 안경테의 높이 데이터를 포함한다. 해당 데이터는 취형기에서 얻은 원통좌표계 형식의 원시 데이터 형태에서 OpenGL에서 사용하기 좋은 3차원 데이터 형식으로 나타낼 수 있도록 재가공하여 X, Y, Z 축 기반의 3차원 직교좌표계 형식으로 변환한다. 그 후, OpenGL을 사용하여 3D로 시각화하였다. 해당 데이터를 회전할 수 있도록 하기 위하여 쿼터니언 기반의 ArcBall을 사용하여 회전 가능하게 하였으며, 3D 시각화 된 결과를 확대/축소할 수 있게 하였다. 디스플레이에서 실제와 같은 크기로 출력하기 위하여 DPI를 활용한 축척 계산법을 사용하였고, 출력결과의 더 나은 시각화를 위하여 평균보간법을 사용하였다.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1011-1017
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• 2023

In this study, the harmless crack size (a_hml) by double shot peening (DSP) using shot balls with different diameters was evaluated on carburized, quenched-tempered SCM822H steel. The minimum crack size (a_NDI) detectable by non-destructive inspection was also evaluated. The relationship between the crack size (a_25,50) that reduces the fatigue limit by 25% and 50% and a_hml was evaluated. The residual stress of DSP was greater in SP_(0.6+0.08) than SP_(0.8+0.08) and appeared deeper in the depth direction. In addition, the hardness below the surface appeared larger. The fatigue limit of DSP increased 2.07 times and 1.95 times compared to non-SP. All a_hml of the DSP specimen was determined at the depth (a). The compressive residual stress distribution affects a_hml, and the a_hml of SP_(0.6+0.08), which has a large compressive residual stress and a high fatigue limit, appeared large. a_hml of SP_(0.6+0.08) introduced deeper than the residual stress of SP_(0.8+0.08) is larger in the range of As=1.0-0.3. Since the residual stress in the thickness direction has a greater effect on a_hml than the residual stress at the surface, it is necessary to introduce it more deeply. The relation of a_hml, a_25,50, and a_NDI were evaluated in the point for safety and reliability.

• Resources Recycling
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• v.28 no.3
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• pp.26-34
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• 2019

Due to the increasing demand of rare earth magnet for various application, it is predicted that the amount of waste rare earth magnet will increase sharply. The process of waste rare earth magnet recycling is mainly consisted of leaching and separation of rare earth element contained in the magnet. However, there is no study on the breakage characteristics of the waste rare earth magnet for production of magnet powder. Therefore, in this study, effective crushing/grinding process and breakage characteristics were investigated for waste rare earth magnet. In the case of jaw crusher, the particle size of magnet was effectively reduced without rapid oxidation. In ball mill grinding test, it was found that the grinding process was not performed properly at the early stage of grinding. Moreover, waste rare earth magnet showed very low specific rate of breakage(S) and high fraction of fine particle breakage distribution(B) compared to ordinary minerals. These results can be used as a basic data for developing crushing/grinding circuit of waste rare earth magnet.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.59-70
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• 2022

This study investigates the sensitivity reflected in the accounting earnings differs according to the difference in the characteristics of accounting information such as profit and loss for the same market information. For this, market information and accounting data were analyzed for 11,462 non-financial listed companies listed on the KOSPI and KOSDAQ markets from 2012 to 2020 by using Basu's measurement of conditional conservatism and Ball and Shivakumar's measurement of conservatism. Accounting earnings sensitivity was analyzed according to the combination of information. As a result of the study, it was confirmed that both earnings and losses corporates recognize losses with delay, while losses are recognized quickly by loss corporates and delayed recognition by earnings companies. It was confirmed that more strict conservatism was applied to the losses corporates compared to the earnings corporates by delaying the recognition of earnings while the early recognition of the losses. It provides empirical data on the causality between the asymmetric timeliness and the combined effect of market information and accounting information by verifying that the losses corporates responds sensitively to market information while the earnings corporates does not react sensitively to the market information.

• Journal of Powder Materials
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• v.20 no.5
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• pp.359-365
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• 2013

In this study, we fabricated $Nd_2Fe_{14}B$ hard magnetic powders with various sizes via spray drying combined with reduction-diffusion process. Spray drying is widely used to produce nearly spherical particles that are relatively homogeneous. Thus, the precursor particles were prepared by spray drying using the aqueous solution containing Nd salts, Fe salts and boric acid with the target stoichiometric composition of $Nd_2Fe_{14}B$. The mean particle sizes of the spray-dried powders are in the range from one to seven micrometer, which are adjusted by controlling the concentrations of precursor solutions. After debinding the as-prepared precursor particles, ball milling was also conducted to control the particle sizes of Nd-Fe-B oxide powders. The resulting particles with different sizes were subjected to subsequent treatments including hydrogen reduction, Ca reduction and washing for CaO removal. The size effect of Nd-Fe-B oxide particles on the formation of $Nd_2Fe_{14}B$ phase and magnetic properties was investigated.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.361-368
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• 2013

The aim of this study was to identify influence that integrated PNF(IPNF) on sprinter and skater pattern exercise had an effect on static and dynamic balance in chronic low back pain elderly adult. The subjects of this study were 34 and they were divided into two groups: IPNF exercise group(n=17), swiss ball exercise group(n=17). They were measured static balance ability using Good Balance System (GBS) and dynamic balance ability using functional reaching test(FRT) and timed up and go (TUG) during pre and post exercise. The results of this study were significant differences in groups about pre and post static and dynamic balance tests the greater part(p<.05). There were significant differences in groups according to exercises(p<.05). The above results from this study indicated that integrated patterns of PNF have improved the static and dynamic balance ability. This study will be enough to provide the basic raw material using a integrated PNF.

• Journal of Powder Materials
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• v.20 no.6
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• pp.474-478
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• 2013

The most general photocatalyst, $TiO_2$ and $WO_3$, are acknowledged to be ineffective in range of visible light. Therefore, many efforts have been directed at improving their activity such as: band-gap narrowing with non-metal element doping and making composites with high specific surface area to effectively separate electrons and holes. In this paper, the method was introduced to prepare a photo-active catalyst to visible irradiation by making a mixture with $TiO_2$ and $WO_3$. In the $TiO_2-WO_3$ composite, $WO_3$ absorbs visible light creating excited electrons and holes while some of the excited electrons move to $TiO_2$ and the holes remain in $WO_3$. This charge separation reduces electron-hole recombination resulting in an enhancement of photocatalytic activity. Added Ag plays the role of electron acceptor, retarding the recombination rate of excited electrons and holes. In making a mixture of $TiO_2-WO_3$ composite, the mixing route affects the photocatalytic activity. The planetary ball-mill method is more effective than magnetic stirring route, owing to a more effective dispersion of aggregated powders. The volume ratio of $TiO_2(4)$ and $WO_3(6)$ shows the most effective photocatalytic activity in the range of visible light in the view point of effective separation of electrons and holes.

• Human Ecology Research
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• v.59 no.1
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• pp.83-97
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• 2021

This study developed safety clothing that is essential for adolescent to protect their bodies from accidents, pursue activities and individuality. Therefore, the developed safety clothing was first based on international standards, while changing design to emphasize creativity, activity, and functionality. Two suits of boy's clothes and a girl's suit were developed as safety clothing for sportswear, along with two pairs of girl's clothes and a pair of boy's clothes for entertainment. It was confirmed that the difference in visibility was revealed by testing under different lighting conditions. Second, the survey on adolescents indicated no significant gender difference in sportswear. Round shirt+shorts for both boys and girls were the most preferred for ball game sportswear. However, there was a significant difference by gender in the design of safety clothing for entertainment. Male students preferred jump suit=cape+pants the most, and female students preferred jump suit>cape+pants in the order (p<0.05). In the safety clothes with the highest preference for entertainment, there was no gender difference. All students preferred the jump suit at the most. Checking at each school level, it was found that both middle and high school students preferred jump suit designs, and in safety clothing, middle school students preferred high-neck shirt blouse+tight skirt, and high school students preferred jump suits. Third, 35.5% responded that they would wear it more if current safety clothing is improved. This indicated the necessity of developing various safety clothing for adolescence.

• Journal of Sport and Applied Science
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• v.5 no.2
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• pp.23-29
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• 2021

Purpose: The purpose of the study is to review the current states of new sports imported from foreign countries and to discuss strategic insights for promoting new sports which has been invented in Korea. Research design, data, and methodology: This study employed the qualitative approach, in which reviewed a related literature. First, the study selected flying disc, sports stacking, and T-ball as sample cases. This is because these new sports were recognized the prominent sports frequently played in physical education classes in Korea. Second, the study reviewed prior studies in the field of distribution and marketing in order to determine the criteria of analysis and variables that frequently examined in distribution and marketing studies. Finally, the study confirmed such terminologies as research variables including new sport name, organization name, background of the invented sports, distributional channel, promotional activities and so forth. To collect data, the study search literature via academic search engine including DBpia, KISS, RISS, ScienceDirect, SAGE Journals, SpringerLink, and Taylor & Francis. Results: It was found that all of the imported new sports organized association and its nationwide branches to deliver their sprots to local schools and recreational markets. second, they targeted schools and sought to broaden their markets to recreational communities. Conclusions: In order to promote new sport invented in Korea, associations need to be systematically organized and mission should be clearly stated. In addition, creative methods for promotion need to be developed. Future directions were discussed.

• Journal of Powder Materials
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• v.29 no.2
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• pp.118-122
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• 2022

The synthesis of porous W by freeze-casting and vacuum drying is investigated. Ball-milled WO₃ powders and tert-butyl alcohol were used as the starting materials. The tert-butyl alcohol slurry is frozen at -25℃ and dried under vacuum at -25 and -10℃. The dried bodies are hydrogen-reduced at 800℃ and sintered at 1000℃. The XRD analysis shows that WO₃ is completely reduced to W without any reaction phases. SEM observations reveal that the struts and pores aligned in the tert-butyl alcohol growth direction, and the change in the powder content and drying temperature affects the pore structure. Furthermore, the struts of the porous body fabricated under vacuum are thinner than those fabricated under atmospheric pressure. This behavior is explained by the growth mechanism of tert-butyl alcohol and rearrangement of the powders during solidification. These results suggest that the pore structure of a porous body can be controlled by the powder content, drying temperature, and pressure.