• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.421-439
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• 2003

Statement of problem : It is difficult to obtain a good titanium casting body using the traditional sprue design because of high melting point of Ti, and the low fluidity and high reactivity of molten Ti. Purpose : A new sprue design for titanium casting bodies needs more trial and error. In order to decrease the number of trial and error, computer simulation(MAGMASOFT, Magmasoft Giessereitechnologie GmbH, Achen, Germany) was used to optimize sprue design in U-shaped implant superstructures. Material and method : Five kinds of sprue were examined for the design of the sprue former for titanium casting: Sprue design A(sprue length 4 mm, rectangular shape, 4 sprues), Sprue design B(sprue length 4 mm. round shape. radius 2 mm, 7 sprues), Sprue design C (sprue length 2 mm, round shape, radius 2 mm, 7 sprues). Sprue design D (sprue length 2 mm, cone shape, large radius 3mm. small radius 2mm, 7 sprues), and Sprue design E( sprue length 2 mm. one unit channel shape). Sprue design F(sprue length 2mm, one unit channel shape) was also examined for the design of the customized sprue former in the Biotan system(Schutz Dental Gmbh, Germany). The casting bodies were taken in Sprue design A, Sprue design D, Sprue design E, and Sprue design F in the Biotan casting system. The numerically predicted defects were compared with the experimental dental castings by the radiographic and sectional view observations. Results : 1. According to the result of computer simulation, turbulence during mold filling was decreased in the sequence of Sprue design F, Sprue design E, Sprue design D, Sprue design C, Sprue design B, and Sprue design A. 2. The calculated solidification time contours indicate that hot spot was moved from the casting body to the sprue button in the sequence of Sprue design A, Sprue design B, Sprue design C, Sprue design D, and Sprue design E. The filling pattern of Sprue design F was similar to that of Sprue design E. 3 The predicted filling pattern shows that less turbulence was found in the customized sprue former than in the standard sprue former. 4. According to the results of the radiographic and cross sectional observations, casting defects less than 1mm were found at the center of a casting body with Sprue design E and Sprue design F. However, larger casting defects of 4mm were found in a casting with Sprue design A. 5. The predicted casting porosity was similar to that of the real casting. Conclusion : One unit channel-type and customized sprue former can be recommended. Further research and developement of various sprue designs using computer simulation in necessary to optimize casting design, in order to reduce the formation of casting defects in implant titanuim super-structures.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.2
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• pp.33-43
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• 2024

This study comprehensively analyzes previous research comparing the similarities between 3D virtual and actual fittings, and identifies the current usage and limitations of virtual fitting programs. The findings reveal that, in most cases, 3D virtual fittings are not perfect substitutes for actual fittings. To address these limitations, this research focuses on the Hohenstein fitting test and BP-ANNs-based garment fit evaluation method, which incorporate various parameters, such as the correlation between wearers and garments, garment pressure, and ease, thus providing objective data, such as data acquired that can enhance subjective evaluations. By integrating such objective assessments, the study suggests potential improvements in virtual fitting accuracy. This research is expected to provide foundational data necessary for the development of a consumer virtual fitting systems alongside advancements in 3D virtual fitting technology.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.277-285
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• 2012

This research studied how to develop tight upper sportswear from 3D scan data considering fabric stretch property. Subjects were five Korean men of average figure in their 20's. Scanning was done for ten postures via vitus smart/pro(Techmath LTD). Analyzing from 3D scan data, more than 70% of the upper body surface showed surface change rate under 20%. It was shoulder and under arm side part that showed most noticeable body surface change when moving. A parametric model with convex surface was generated and flattened onto the plane, resulting 2D pattern. The error rate occurring in the process of 3D to 2D conversion was 0.2% for outline and 0.13% for area, respectively. Thirteen kinds of stretchable fabrics in the market were collected for this study. Stretch property was in the range of 16.0~58.2% for wale direction; 23.1~78.4% for course. Based on wear trial test, four fabrics were chosen for making the 1st experimental garment and finally one fabric was chosen for the 2nd one, which was developed applying 4 kinds of crosswise reduction rate on 2D pattern: 0, 5, 10, and 15%. Through wear trial test and garment pressure measurement, experimental garment applied with 10% pattern reduction rate was evaluated as most comfortable and considerable.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.2
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• pp.115-127
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• 2024

This study was initiated by focusing on the characteristics of 3D virtual clothing utilized by fashion brands aiming for sustainability. The purpose of this study is to analyze the characteristics of fashion brands that utilize 3D virtual imagery to mitigate environmental pollution caused by the fashion industry from the perspective of green design. The research methodology draws on green design literature and analyzes three hypothetical cases. These include experiential immersive design, design that rewards engagement, and design that delivers economic benefits that were utilized by fashion brands from 2019 to 2023. The findings and conclusions are as follow. First, the for the commercialization of virtual clothing, offline stores are reproduced in the digital world to provide an immersive shopping experience, similar to reality. These promote fashion products in a virtual space without the constraints of space and time, and creates profits and sustainable value. Second, virtual clothing promotes playfulness. Games and events utilize branded virtual worlds and characters to attract users. Rewards are given for achieving goals, and it is a practice of green marketing that uses virtual items to express products and minimize resource waste. Third, virtual clothing is affordable and can reduce the financial burden on consumers by digitally reproducing expensive products as physical brand collections at an acceptable price point. This reduces environmental pollution, saves physical resources, and increases the utilization of virtual clothing by providing a convenient way to purchase. This study is a basic study that examines the current status and characteristics of fashion brands' use of 3D virtual imagery from the perspective of green design based on literature and case analysis, and follow-up studies are expected on empirical virtual imagery activation measures through interviews or surveys with users for each case.

• Journal of The Korean Association of Information Education
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• v.19 no.2
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• pp.167-174
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• 2015

A recent increase of interests on the influence of 3D printing and low prices of 3D printers makes a high possibility of 3D printer adoption as a educational equipment in public education settings. The Ministry of Science, ICT and Future Planning and Ministry of Trade, Industry and Energy proposed '3D printing industry development strategies', and had pilot schools to include understanding of 3D printing concepts and practices in the primary, secondary and high schools' curriculum. However, even if 3D printers were provided in educational settings, the research on educational content and methods to properly react to this change is very limited. Therefore, this study reviewed various 3D modeling software because a modeling skill is a prerequisite skill to use 3D printers, and proposed a creative design spiral based teaching content that can be incorporated in elementary school contexts.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.11
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• pp.54-63
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• 1997

The 1-D finite-element mehtod is applied for designing double-clad otpical fibers with dispersion-compensation capability. design parameters allowing only a $LP_{01}$ single mode are treated and macro-bending loss are taken into consideration. Design parameters are extracted to have the compensation ratio $(L_{SMF}/L_{DCF})$ of 6.2 for core structure with step-index profile, and of 5.2 for core with triangular-index profile.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.35-39
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• 2008

프로그레시브금형에 있어서 스트립 레이아웃설계는 제품 양산을 결정하는 중요 요인이다. 본 논문에서는 자동차에 사용되는 브라켓의 스트립 레이아웃설계를 하였다. 3D모델링이 아닌 자동화 모듈인 씨마트론 다이 디자인을 활용하여 3D로 스트립 레이아웃설계를 하였다. 광폭 2열 2개 뽑기의 내측캐리어를 단 배열로 블랭크 레이아웃을 최적화하였다. 사용된 3D CAD/CAM 소프트웨어는 Cimatron Die Design이며 10개 공정으로 스트립 레이아웃설계를 완성하였다.

• Journal of Korea Multimedia Society
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• v.9 no.8
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• pp.1010-1019
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• 2006

CAD system is a very important technology in designing the products which we are using today. This CAD technology has been enlarging its area into 3D CAD systems with the development of computer graphics technologies. In particular, such advances have been realized in special area such as the CAD system for designing shoes. However, because it is difficult to design a 3D CAD system, most CAD developments except for major CAD software companies usually have employed the AutoCAD which realizes 3D concepts. Also, many shoes' designers have been skilled with 2D shoe CAD systems and then they can make high achievements. Therefore, we design a new shoe CAD system with advantages of 2D CAD system and 3D CAD system. We also implement the scheme to transfer the data between 2D CAD system and 3D CAD system and also grading technologies to get patterns of various shoes size from a basic shoe's design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.6
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• pp.761-768
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• 1999

This paper is studied to find the optimum condition of double-inlet Sirocco fan installed in an indoor PAC for low noise operation by the Taguchi method. The goal of this study is to obtain the best combination of each control factor which results in a desired flowrate of Sirocco fan with minimum variability. In this study, the parameter design of the Taguchi method is adopted for robust design by the dynamic characteristic analysis using orthogonal arrays and S/N ratios. The flowrate measurements are conducted by using a multiple-nozzle-type fan tester according to the orthogonal array L9($3^4$). The results of this study can be summarized as follows ; (i) The optimum condition of control factor is a set of where A is an inner to outer diameter ratio($D_1/D_2$), B is a width to outer diameter ratio($L/D_2$), C is a blade attachment angle(${\theta}$) and D is a number of blade(Z), (ii) The flowrate under the optimum condition satisfies the equation $y=0.0384{\cdot}M$ where M is a signal factor, namely number of revolution. The flowrate performance improves about 7.3% more largely as compared with the current condition, which results in about 35RPM reduction of number of revolution for the target flowrate $18.5m^3/min$, and (iii) The sensitivity analysis shows that the major factors in contribution to flowrate performance are A, B, and D ; the percentage contributions of each control factor are 44.01%(Z), 26.77%($D_1/D_2$) and 20.42%($L/D_2$).

• The KIPS Transactions:PartA
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• v.14A no.7
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• pp.391-398
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• 2007

In this paper, we design a future mobile camera standard interface based on the MIPI CSI-2 and D-PHY specification. The proposed CSI-2 have the efficient multi-lane management layer, which the independent buffer on the each lane are merged into single buffer. This scheme can flexibly manage data on multi lanes though the number of supported lanes are mismatched in a camera processor transmitter and a host processor. The proposed CSI-2 & D-PHY are verified under test bench. We make an experiment on CSI-2 & D-PHY with FPGA type test-bed and implement them onto a mobile handset. The proposed CSI-2 & D-PHY module are used as both the bridge type and the future camera processor IP for SoC.