• Journal of Technologic Dentistry
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• v.45 no.3
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• pp.74-80
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• 2023

Purpose: This study aimed to evaluate the fit of the anterior and posterior teeth printed using two light-curing three-dimensional (3D) printers. Methods: Anterior and posterior single crowns were designed using dental software and were printed using 2 types of 3D printers, liquid crystal display (LCD) and digital light processing (DLP) (n=40). After the printed crown was scanned again from inside and outside, the prepared teeth were evaluated using a 3D program. To compare the root mean square (RMS) results among groups (α=0.05), the one-way analysis of variance and Tukey's test were used. Results: No statistically significant difference was found between the mean RMS values of the anterior and posterior teeth (p>0.05). However, as a result of comparing the internal, external, and tooth shapes, the DLP group showed significantly low errors in the inner and outer surfaces than LCD group (p<0.05). Conclusion: In terms of clinical acceptance standard of 100 ㎛, the fit of the anterior and posterior teeth fabricated using LCD and DLP was clinically acceptable.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.215-221
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• 2017

This paper describes a method of precise estimation for printing time and material consumption which are directly related to the 3D printing cost. Printing process and head motion of 3D printers using digital printing head, which is analyzed by its digitized steps, is rapidly simulated without slicing to calculate estimated printing results. Using this method, printing time and material usage of 3D printer were estimated quickly and precisely and compared to the real printing result. Applying compensation using the printing parameters, transferred from the 3D printer to the printing estimation system, even more accurate estimation is achieved. This method is used in the 3D Sprint software.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.305-308
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• 2016

The 3D printing technology which is called new revolution of 21C is under the spotlight recently. The technology takes effects on general manufacturing industries, as well as the prototypes, education, health care, construction. and other industries. It seems that personalized products will be produced and distributed with the introduction of 3D printers. In the case the possibility of violating intellectual property rights, we propose a system that can prevent the violation.

• 프린팅코리아
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• v.12 no.9
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• pp.66-71
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• 2013

각종 정보통신기기는 인쇄매체의 범위를 하드카피에서 전자미디어로 넓혔고, 인쇄전자는 인쇄산업을 보다 지능적으로 바꿔놓았다. 이에 그치지 않고 인쇄의 범위는 대상을 스캐닝해 입체형상으로 복원하는 3D프린팅까지 확대됐다. 인쇄의 한계, 그 끝은 어디인가? 그리고 인쇄인들은 이러한 패러다임의 변화에 어떻게 대처해야 하는가?

• Journal of Korea Technology Innovation Society
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• v.22 no.1
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• pp.119-157
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• 2019

It is important for the people in the 3D printing industry to determine which factors influence the decision-making that determine the adoption of 3D printers and the role of the factors. Through this, we intend to find ways to contribute to the development of 3D printing industry in Korea by increasing utilization of 3D printer used in domestic companies and increasing investment in related industries. 3D printers are making rapid progress according to the development of technology, the public interest, and the activation of investment. Foreign countries have made remarkable progress in equipment, materials, software, and industrial applications, but they are lower than expected in Korea. It is necessary to introduce a smooth 3D printer in order to revitalize the 3D printer industry and enlarge the base, but it is insufficient for actual introduction and field application. The independent variables that represent economic, technological, and environmental characteristics were selected through a literature survey, and a model for accepting integrated technology for convergence of societies in the 3D printing industry was proposed. This study confirms that economic factors such as output unit price, government support, and environmental factors such as 3D contents should be developed organically for the introduction of 3D printing technology and equipment. This require systematic and effective support from the government, and it is necessary to improve the economic support, related laws, and systems that can be directly experienced by the user as a user. As the domestic 3D printing industry develops with economic, technological and time investment, 3D printing industry should be the key engine of the 4th industrial revolution.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.1-8
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• 2015

Recently, a great interest in 3D printing has emerged, although many existing 3D printing technologies were first developed 2-3 decades ago. There are many mature 3D printing processes and materials; however, active research and development efforts are ongoing in this area to advance the technologies. Several companies have already started to use 3D printed parts as actual components. Many low-cost 3D printers have been released on the market, which are of particular interest to educators and hobbyists. This paper provides a brief review of 3D printing technologies and research trends. In addition, several state-of-the-art technologies and applications are introduced.

• Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.47-54
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• 2015

In recent years, 3D printers have become popular as a means of outputting geometries designed on CAD or 3D graphics systems. However, the complex user interfaces of standard 3D software can make it difficult for ordinary consumers to design their own objects. Furthermore, models designed on 3D graphics software often have geometrical problems that make them impossible to output on a 3D printer. We propose a novel AR (augmented reality) 3D modeling system with an air-spray like interface. We also propose a new data structure (octet voxel) for representing designed models in such a way that the model is guaranteed to be a complete solid. The target shape is based on a regular polyhedron, and the octet voxel representation is suitable for designing geometrical objects having the same symmetries as the base regular polyhedron. Finally, we conducted a user test and confirmed that users can intuitively design their own ornaments in a short time with a simple user interface.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.68-70
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• 2016

3D 프린터는 연속적인 계층에 특수한 재료를 출력시켜 3차원 물체를 만들어 내는 장치이다. 3D 프린팅을 위해서는 3D 모델을 생성한 후, 이를 3D 프린터에 출력할 수 있도록 G-code로 변환해야 한다. 본 논문에서는 이 변환 작업을 완전 분산 방식으로 처리할 수 있는 알고리즘을 제안한다. 이를 위해 하나의 메인 노드와 N개의 작업 노드로 구성한 시스템에서 2단계에 걸쳐 분할 정복(divide-and-conquer) 방식으로 변환하도록 하였다. 실제 구현한 시스템을 이용하여, 성능에 미치는 요소(모델의 크기 및 정밀도)에 따른 변환 시간의 단축 효과를 보였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.83-89
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• 2019

In the conventional casting and forging method, there is a disadvantage that a mold is an essential addition, and a production cost is increased when a small quantity is produced. In order to overcome this disadvantage, a metal 3D printing production method capable of directly forming a shape without a mold frame is mainly used. In particular, overseas research has been conducted on various materials, one of which is a metal printer. Similarly, domestic companies are also concentrating on the metal printer market. However, In this case of the conventional metal 3D printing method, it is difficult to meet the needs of the industry because of the high cost of materials, equipment and maintenance for product strength and production. To compensate for these weaknesses, printers have been developed that can be manufactured using sand mold, but they are not accessible to the printer company and are expensive to machine. Therefore, it is necessary to supply three-dimensional casting printers capable of metal molding by producing molds instead of conventional metal 3D printing methods. In this study, we intend to reduce the unit price by replacing the printing method used in the sand casting printer with the FDM method. In addition, Ag paste is used to design the output conditions and enable ceramic printing.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.242-253
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• 2020

Purpose: The aim of this study was to compare the accuracy of dies fabricated using 3D printing system to conventional method and to evaluate overall volumetric changes by arranging the superimposed surfaces. Materials and Methods: A mandibular right first molar from a dental model was prepared, scanned and fabricated with composites of polyetherketoneketone (PEKK). Master dies were classified into 4 groups. For the conventional method, the impression was taken with polyvinylsiloxane and the impression was poured with Type IV dental stone. For the 3D printing, the standard die was scanned and converted into models using three different 3D printers. Each of four methods was used to make 10 specimens. Scanned files were superimposed with the standard die by using 3D surface matching software. For statistical analysis, Kruskal-Wallis test and Mann-Whitney U test were done (P < 0.05). Results: Compared to the standard model, the volumetric changes of dies fabricated by each method were significantly different except the models fabricated by conventional method and 3D printer of Stereolithography (P < 0.05). The conventional dies showed the lowest volumetric change than 3D printed dies (P < 0.05). 3D printed dies fabricated by Stereolithography showed the lowest volumetric change among the different 3D printers (P < 0.05). Conclusion: The conventional dies were more accurate than 3D printed dies, though 3D printed dies were within clinically acceptable range. Thus, 3D printed dies can be used for fabricating restorations.