• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.7-12
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• 2008

• Proceedings of the Korea Technology Innovation Society Conference
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• 2013.10a
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• pp.472-482
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• 2013

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1539-1542
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• 2009

최근 모바일 단말 기술과 정보통신 기술의 급격한 발달로 국내외 이동통신사들은 새로운 킬러 콘텐츠로 주목받고 있는 모바일 3D 게임을 앞 다투어 제작 및 서비스하고 있다. 모바일 3D 게임의 경우, 용량 증가로 인한 데이터 통신비 부담을 줄이기 위하여 PC 다운로드 S/W을 통한 다운로드 방법이 제공되면서 불법 복제 우려에 대한 관심이 높아지고 있다. 현재 불법 복제 방지와 관련하여 GVM/GNEX 인증 모듈이 적용되고 있으나, 모바일 3D 콘텐츠에 대한 저작권 보호 기술 및 워터마킹 기술을 적용함으로써 콘텐츠 접근제어 및 불법배포 추적을 동시에 달성할 수 있다. 따라서 본 논문에서는 모바일 3D 콘텐츠의 저작권 보호를 위하여 익명 Buyer-Seller 워터마킹 프로토콜 상에서 3D 콘텐츠 내의 공간영역 및 암호화 영역 내에 다중 워터마크를 삽입하는 방법을 제안한다. 성능평가를 위한 비가시성 및 강인성 실험을 통하여 본 제안 기법의 콘텐츠 접근제어가 가능하며 비가시성, 강인성 면에서 우수함을 확인하였다.

• Conservation Science in Museum
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• v.29
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• pp.99-110
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• 2023

The stone fragments that are missing from the stone cultural heritage have limited use beyond being directly fitted to identify their original position, as they are relatively heavy and bulky, and there is the further risk of secondary physical damage during manual work. Therefore, in this study, morphological relationships between the missing parts and the stone fragments were identified through digital restoration, and a three-dimensional (3D) printed replica was created for use at the exhibition for Stone Buddhas in Four Directions in Hwajeon-ri, Yesan, where 72 stone fragments had been excavated together. First, for the digital restoration, stone fragments of similar shapes were selected after the coordinates of the 3D scanning model were aligned in virtual space. In addition, the stone fragments were printed using a 3D printer to check whether they were physically related to the missing parts. Thus, the original positions of a total of nine stone fragments were identified. To utilize these research results in the exhibition, a 1:1 replica of the Stone Buddhas in Four Directions was produced using 3D printing technology, and the nine stone fragments were also restored to their original positions. The digital technology used in this study is of great importance in that it not only made up for the limitations of the direct manual method but also suggested the possibility of expanding its application to the fields of documentation, restoration, and replication of similar cultural heritage.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.246-253
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• 2022

Flabby tissue is not rare for denture wearers. Mucostatic impression technique is necessary due to compromised retention and stability of denture resulting from distortion of mobile flabby tissue. In this report, individual tray was fabricated by model-scanning and 3D printing treatment denture. And then, mucostatic impression for flabby tissue was obtained by using individual tray modified with window technique. Definitive denture was fabricated based on information of treatment denture including incisal pontic arrangement, jaw relationship and occlusion.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.303-303
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• 2004

3차원 실물복제기(RODS)는 3차원 스캐닝, SFFS 및 네트워크 등의 복합기능이 내장된 장치로서 제품개발 및 사무자동화등 다양한 분야에 적용 가능한 장비이다. 또한, 기존의 각각 독립된 시스템인 3D스캐너와 SFFS를 하나의 시스템으로 구성함으로서 제작시간과 업무 효율을 높일 수 있는 차세대 시스템의 일종이다. 실물복제기는 산업용과 오피스용으로 구분되어 질 수 있으며, 본 연구에서 개발하고자 하는 다종 재료용 하이브리드형 SFFS는 다품종 소량생산 환경에 적합한 제품의 제작 방식으로서 기능성 부품을 직접 제작/검증 할 수 있다.(중략)

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.508-514
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• 2021

In this report, Replicated denture was fabricated by 3d printing after scanning the existing denture. It was used as an individual tray in closed-mouth technique. It reduced laboratory process and clinical time. Also it helped in facial evaluation and tooth arrangement. Compared to open-mouth technique, the number of visits was reduced, and the patient's adaptability to new denture was enhanced by utilized various information of the existing denture, including vertical dimension.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.212.2-212.2
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• 2005

• Journal of Conservation Science
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• v.31 no.2
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• pp.147-157
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• 2015

TExhibiting replicas of major artifacts is becoming common recently to raise their value and help the public to understand them. In Korea, more attention is paid only to appearance in creating replicas of artifacts. It is required to study reproduction technology minimizing damages to originals and applicable to massive artifacts like sculptures in the situation that replicas and artifact reproduction is increasing. To make a replica of the Stone Lion Statue excavated from Woljeong Bridge, a measured drawing and a cross section are produced based on art historical surveys using 3D scans. A non-contact reproduction method is selected. The strength of the non-contact reproduction method is that the output is detailed. Athough the non-contact method has known to be applicable only to small scale artifacts and require reprocess, it is discovered to be applicable to detailed statues like this lion statue. Therefore, this study may contribute to complement the historic authenticity of the statue as well as to raise its academic value. It also can be utilized as research material of similar artifacts'replicas and restoration.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.183-190
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• 2006

Digital 3D Real Object Duplication System (RODS) consists of 3D Scanner and Solid Freeform Fabrication System (SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and an industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. In case of industrial type SFFS, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Dual-Laser Sintering (SDLS) process and 3-axis Dynamic Focusing Scanner for scanning large area instead of the existing f lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, and scan spacing. Now, this study is in progress to evaluate the effect of experimental parameters on the sintering process.